Uptake of liposomes into bacterial cells
- Authors: Oidu, Benjamin
- Date: 2013
- Subjects: Liposomes , Drug carriers (Pharmacy)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10165 , http://hdl.handle.net/10948/d1021010
- Description: Liposomes are small phospholipid vesicles that have been widely investigated as drug carriers for the delivery of therapeutic agents. A variety of liposome formulations are presently under clinical trial exploration, while others have already been approved for clinical use. The aim of this study was to optimize liposome uptake into bacterial cells. Both gram-positive and gram-negative bacteria were used in the study as well as Candida albicans.Response surface methodology (RSM) using a central composite design (CCD) model was used to optimize liposomal formulations of carboxyfluorescien (CF) for each of the three microbes, and also the three microbes in combination namely; Staphylococcus aureus (Sa), Escherichia coli (Ec) and Candida albicans (Ca). Percentage of CF encapsulated and CF increase in Uptake were investigated with respect to two independent variables that were, cholesterol (CHOL) and stearylamine (SA) content. Design Expert 8 was used for the purpose of finding the combination of independent variables that would yield an optimal formulation for each microbe and the three microbes in combination. The model selected by the software managed to reasonably correlate the predicted models to the experimental data. Encapsulation of carboxyfluorescien (CF) into a liposome formulation enhanced its uptake by Staphylococcus aureus and Escherichia coli as well as Candida albicans. This was evident in the increase in CF uptake when the uptake rate of free CF was compared with that of liposomal CF.
- Full Text:
- Date Issued: 2013
- Authors: Oidu, Benjamin
- Date: 2013
- Subjects: Liposomes , Drug carriers (Pharmacy)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10165 , http://hdl.handle.net/10948/d1021010
- Description: Liposomes are small phospholipid vesicles that have been widely investigated as drug carriers for the delivery of therapeutic agents. A variety of liposome formulations are presently under clinical trial exploration, while others have already been approved for clinical use. The aim of this study was to optimize liposome uptake into bacterial cells. Both gram-positive and gram-negative bacteria were used in the study as well as Candida albicans.Response surface methodology (RSM) using a central composite design (CCD) model was used to optimize liposomal formulations of carboxyfluorescien (CF) for each of the three microbes, and also the three microbes in combination namely; Staphylococcus aureus (Sa), Escherichia coli (Ec) and Candida albicans (Ca). Percentage of CF encapsulated and CF increase in Uptake were investigated with respect to two independent variables that were, cholesterol (CHOL) and stearylamine (SA) content. Design Expert 8 was used for the purpose of finding the combination of independent variables that would yield an optimal formulation for each microbe and the three microbes in combination. The model selected by the software managed to reasonably correlate the predicted models to the experimental data. Encapsulation of carboxyfluorescien (CF) into a liposome formulation enhanced its uptake by Staphylococcus aureus and Escherichia coli as well as Candida albicans. This was evident in the increase in CF uptake when the uptake rate of free CF was compared with that of liposomal CF.
- Full Text:
- Date Issued: 2013
Treatment and care of children and adolescents diagnosed with Attention deficit/Hyperactivity disorder
- Authors: Snyman, Sanmari
- Date: 2008
- Subjects: Attention-deficit disorder in adolescence , Hyperactive children -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10144 , http://hdl.handle.net/10948/871 , Attention-deficit disorder in adolescence , Hyperactive children -- South Africa -- Port Elizabeth
- Description: Background: In recent years the incidence of Attention Deficit/Hyperactivity Disorder (ADHD) has increased. Objectives: The primary aim of the study was to determine the treatment of children and adolescents diagnosed with ADHD in South Africa and more specifically the Eastern Cape. Methods: The study consisted of two parts, a retrospective drug utilisation study and a questionnaire survey. The drug utilisation study was conducted on chronic medication records of a private sector medical scheme administrator and contained records from 1994 to 2006. A total of 42 250 records representing 8 274 patients and 4 001 families, were analysed. The questionnaire survey was conducted in the Eastern Cape. The questionnaires were distributed by responsible pharmacists to parents of children receiving medication for the treatment of ADHD from his/her pharmacy. Fifty one completed questionnaires were analysed. Results: The average age of patients in the drug utilisation study were 14.28 (SD = 5.50) years. Males represented 77.37 percent of patients. Ritalin® 10 mg was the most frequently prescribed methylphenidate-containing product, followed by Ritalin® LA 20 mg. The two most frequently prescribed active ingredients apart from methylphenidate were fluticasone and budesonide. The two most common comorbid conditions were allergic rhinitis and asthma. The average age of patients in the questionnaire survey was 10.26 (SD = 2.51) years. Males represented 73.58 percent of patients. A third of patients had relatives previously diagnosed with ADHD. Ritalin® 10 mg was the most frequently prescribed methylphenidate-containing product. Conclusion: ADHD is a complex life-long disorder. It does not only affect the child diagnosed with the disorder, but also has effects on the family, schooling system and peer relationship. Therefore, more studies regarding the incidence and treatment of ADHD need to be conducted in South Africa.
- Full Text:
- Date Issued: 2008
- Authors: Snyman, Sanmari
- Date: 2008
- Subjects: Attention-deficit disorder in adolescence , Hyperactive children -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10144 , http://hdl.handle.net/10948/871 , Attention-deficit disorder in adolescence , Hyperactive children -- South Africa -- Port Elizabeth
- Description: Background: In recent years the incidence of Attention Deficit/Hyperactivity Disorder (ADHD) has increased. Objectives: The primary aim of the study was to determine the treatment of children and adolescents diagnosed with ADHD in South Africa and more specifically the Eastern Cape. Methods: The study consisted of two parts, a retrospective drug utilisation study and a questionnaire survey. The drug utilisation study was conducted on chronic medication records of a private sector medical scheme administrator and contained records from 1994 to 2006. A total of 42 250 records representing 8 274 patients and 4 001 families, were analysed. The questionnaire survey was conducted in the Eastern Cape. The questionnaires were distributed by responsible pharmacists to parents of children receiving medication for the treatment of ADHD from his/her pharmacy. Fifty one completed questionnaires were analysed. Results: The average age of patients in the drug utilisation study were 14.28 (SD = 5.50) years. Males represented 77.37 percent of patients. Ritalin® 10 mg was the most frequently prescribed methylphenidate-containing product, followed by Ritalin® LA 20 mg. The two most frequently prescribed active ingredients apart from methylphenidate were fluticasone and budesonide. The two most common comorbid conditions were allergic rhinitis and asthma. The average age of patients in the questionnaire survey was 10.26 (SD = 2.51) years. Males represented 73.58 percent of patients. A third of patients had relatives previously diagnosed with ADHD. Ritalin® 10 mg was the most frequently prescribed methylphenidate-containing product. Conclusion: ADHD is a complex life-long disorder. It does not only affect the child diagnosed with the disorder, but also has effects on the family, schooling system and peer relationship. Therefore, more studies regarding the incidence and treatment of ADHD need to be conducted in South Africa.
- Full Text:
- Date Issued: 2008
Knowledge, attitudes and experiences of dieticians in relation to tuberculosis at the workplace
- Authors: Oxland, Ingrid Oxley
- Date: 2016
- Subjects: Tuberculosis -- South Africa -- Etiology Disease management -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/12972 , vital:27140
- Description: Tuberculosis (TB) is acknowledged as an epidemic in South Africa. Health care professionals (HCPs), including dieticians, are at an increased risk for TB-infection compared to the general population. Implementation of the World Health Organization (WHO) TB infection control measures can protect HCPs from contracting TB; however, many studies have shown poor adherence to guidelines by HCPs. The aim of the study was to determine dieticians’ knowledge, attitudes and experiences in relation to TB at the workplace. A descriptive quantitative, cross-sectional research design was employed. Convenience sampling was applied. The online survey was conducted between August 2014 and March 2015. Data analysis included descriptive and inferential statistics. Ethical principles were adhered to. The sample consisted of 102 registered dieticians in South Africa. Good knowledge was displayed as two-thirds of dieticians correctly identified the National TB Management Guidelines and the main signs and symptoms of TB. However, a critical knowledge gap regarding TB transmission was identified, as only 42% of dieticians knew that TB could spread by talking. Favourable attitudes towards TB and infection control measures were present, except towards inadequate staffing levels and being worried about TB. The respondents reported that the fear of contracting TB affected patient interaction. Poor adherence to infection control measures was found. Only 45% of dieticians reported having a written TB infection control plan at their workplace, and only 23% were trained on TB infection control measures. Coughing patients were not always triaged and education material was not always available for TB patients. The availability of N-95 respirators was reported by 76% of dieticians. Training on TB infection control measures could influence dieticians’ adherence to infection control measures, ultimately protecting them from contracting TB at the workplace.
- Full Text:
- Date Issued: 2016
- Authors: Oxland, Ingrid Oxley
- Date: 2016
- Subjects: Tuberculosis -- South Africa -- Etiology Disease management -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/12972 , vital:27140
- Description: Tuberculosis (TB) is acknowledged as an epidemic in South Africa. Health care professionals (HCPs), including dieticians, are at an increased risk for TB-infection compared to the general population. Implementation of the World Health Organization (WHO) TB infection control measures can protect HCPs from contracting TB; however, many studies have shown poor adherence to guidelines by HCPs. The aim of the study was to determine dieticians’ knowledge, attitudes and experiences in relation to TB at the workplace. A descriptive quantitative, cross-sectional research design was employed. Convenience sampling was applied. The online survey was conducted between August 2014 and March 2015. Data analysis included descriptive and inferential statistics. Ethical principles were adhered to. The sample consisted of 102 registered dieticians in South Africa. Good knowledge was displayed as two-thirds of dieticians correctly identified the National TB Management Guidelines and the main signs and symptoms of TB. However, a critical knowledge gap regarding TB transmission was identified, as only 42% of dieticians knew that TB could spread by talking. Favourable attitudes towards TB and infection control measures were present, except towards inadequate staffing levels and being worried about TB. The respondents reported that the fear of contracting TB affected patient interaction. Poor adherence to infection control measures was found. Only 45% of dieticians reported having a written TB infection control plan at their workplace, and only 23% were trained on TB infection control measures. Coughing patients were not always triaged and education material was not always available for TB patients. The availability of N-95 respirators was reported by 76% of dieticians. Training on TB infection control measures could influence dieticians’ adherence to infection control measures, ultimately protecting them from contracting TB at the workplace.
- Full Text:
- Date Issued: 2016
The medicinal chemistry of cyclo(D-Phe-2Cl-Pro) and cyclo(Phe-4F-Pro)
- Authors: Ndung'u, Susan Wanjiru
- Date: 2011
- Subjects: Peptide drugs , Cyclic peptides , Pharmaceutical chemistry , Peptides -- Synthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/7083 , vital:21223
- Description: Although peptides and proteins are considered as lead compounds for the discovery and development of new therapeutic agents, poor metabolic and physical properties have limited their optimisation as drug candidates (Adessi & Soto, 2002). Research by medicinal chemists however, generated the discovery of structural similarities between some peptides and diketopiperazines and the common occurrence of such compounds in natural products. This discovery initiated the synthesis of diketopiperazines from amino acids in an attempt to bypass the previously mentioned limitations of using peptides as drug candidates (Dinsmore & Beshore, 2002). Diketopiperazines (DKPs) are the simplest form of cyclic dipeptides, and a class of unexplored bioactive peptides that have great potential for the future. The compounds are relatively simple to synthesise and are prevalent in nature (Prasad, 1995). The DKP backbone is rigid and therefore poses conformational constraint on the compounds. This rigidity allows for simple conformational analysis of the compounds and also gives insight into the conformational requirements for interaction with the targets involved in their biological activity. The reduced conformational freedom also increases the receptor specificity and thus the compounds are proposed to have less unfavourable effects (Anteunis, 1978). The aim of the study was to synthesise compounds that would exhibit metabolic stability, receptor specificity and enhanced lipophilicity which would increase the bioavailability of the compounds. This was to be achieved by the introduction of fluorine and chlorine elements into the DKPs. The structure of the DKPs would be altered which in turn would improve the physicochemical properties and the biological activity of the compounds (Naumann, 1999). Cyclo(D-Phe-2Cl-Pro) and cyclo(Phe-4F-Pro) were synthesised using the method of Milne et al. (1992) and by boiling the linear counterparts under reflux in sec-butanol-toluene. The structures of the synthesised DKPs were elucidated using mass spectrometry, nuclear magnetic resonance spectroscopy, infrared spectroscopy and molecular modeling. Qualitative analysis and evaluation of the physicochemical properties of the DKPs were performed using high-performance liquid chromatography, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry and x-ray powder diffraction. The study aimed to determine the biological activity of cyclo(D-Phe-2Cl-Pro) and cyclo(Phe-4F-Pro) with respect to their anticancer, antimicrobial, haematological and antidiabetic effects. The anticancer results obtained indicated that the percentage inhibition produced by both DKPs were lower than those proposed by Graz et al. (2000) for proline-containing DKPs where, a greater than 50% inhibition was observed for cyclo(Phe-Pro). Antimicrobial studies revealed that both DKPs demonstrated marginal effects on Gram-positive and Gram-negative organisms but showed significant effects against C. albicans. The haematological studies revealed that cyclo(D-Phe-2Cl-Pro) at a screening concentration of 12.5 mM, significantly decreased the levels of D-dimer (P < 0.0001). The antidiabetics studies showed limited activity of the DKPs in inhibiting the activity of α-glucosidase and α-amylase enzymes.
- Full Text:
- Date Issued: 2011
- Authors: Ndung'u, Susan Wanjiru
- Date: 2011
- Subjects: Peptide drugs , Cyclic peptides , Pharmaceutical chemistry , Peptides -- Synthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/7083 , vital:21223
- Description: Although peptides and proteins are considered as lead compounds for the discovery and development of new therapeutic agents, poor metabolic and physical properties have limited their optimisation as drug candidates (Adessi & Soto, 2002). Research by medicinal chemists however, generated the discovery of structural similarities between some peptides and diketopiperazines and the common occurrence of such compounds in natural products. This discovery initiated the synthesis of diketopiperazines from amino acids in an attempt to bypass the previously mentioned limitations of using peptides as drug candidates (Dinsmore & Beshore, 2002). Diketopiperazines (DKPs) are the simplest form of cyclic dipeptides, and a class of unexplored bioactive peptides that have great potential for the future. The compounds are relatively simple to synthesise and are prevalent in nature (Prasad, 1995). The DKP backbone is rigid and therefore poses conformational constraint on the compounds. This rigidity allows for simple conformational analysis of the compounds and also gives insight into the conformational requirements for interaction with the targets involved in their biological activity. The reduced conformational freedom also increases the receptor specificity and thus the compounds are proposed to have less unfavourable effects (Anteunis, 1978). The aim of the study was to synthesise compounds that would exhibit metabolic stability, receptor specificity and enhanced lipophilicity which would increase the bioavailability of the compounds. This was to be achieved by the introduction of fluorine and chlorine elements into the DKPs. The structure of the DKPs would be altered which in turn would improve the physicochemical properties and the biological activity of the compounds (Naumann, 1999). Cyclo(D-Phe-2Cl-Pro) and cyclo(Phe-4F-Pro) were synthesised using the method of Milne et al. (1992) and by boiling the linear counterparts under reflux in sec-butanol-toluene. The structures of the synthesised DKPs were elucidated using mass spectrometry, nuclear magnetic resonance spectroscopy, infrared spectroscopy and molecular modeling. Qualitative analysis and evaluation of the physicochemical properties of the DKPs were performed using high-performance liquid chromatography, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry and x-ray powder diffraction. The study aimed to determine the biological activity of cyclo(D-Phe-2Cl-Pro) and cyclo(Phe-4F-Pro) with respect to their anticancer, antimicrobial, haematological and antidiabetic effects. The anticancer results obtained indicated that the percentage inhibition produced by both DKPs were lower than those proposed by Graz et al. (2000) for proline-containing DKPs where, a greater than 50% inhibition was observed for cyclo(Phe-Pro). Antimicrobial studies revealed that both DKPs demonstrated marginal effects on Gram-positive and Gram-negative organisms but showed significant effects against C. albicans. The haematological studies revealed that cyclo(D-Phe-2Cl-Pro) at a screening concentration of 12.5 mM, significantly decreased the levels of D-dimer (P < 0.0001). The antidiabetics studies showed limited activity of the DKPs in inhibiting the activity of α-glucosidase and α-amylase enzymes.
- Full Text:
- Date Issued: 2011
A stunting profile of children under the age of five visiting Bhisho hospital clinic, part of the umbrella project: a profile of stunting in children under the age of five in food insecure villages in Mqanduli, Ngqushwa and Bhisho hospital, Eastern Cape, South Africa
- Authors: Beyleveld, Janine
- Date: 2020
- Subjects: Children -- growth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/50201 , vital:42066
- Description: Introduction and Background: Stunting is the most prevalent form of childhood malnutrition where about 149 million children under the age of five can be classified as stunted globally. South Africa has one of the highest stunting rates in the world at 27%, causing devastating effects on economic productivity as well as on an individual’s nutritional status. The presence of stunted growth in children is a strong indicator of chronic undernutrition and highlights injustices experienced within communities. Aims and Objectives: The aim of this study is to develop a stunning profile of children under the age of five, visiting BhishoHospital’s gateway clinic in the Eastern Cape, South Africa. The objectives were to determine the prevalence of stunting of the children visiting Bhisho Hospital’s clinic and to identify the drivers of stunting in the area. Methodology: A quantitative study with a descriptive, cross-sectional design was used. The study population included all children under the age of five visiting Bhisho Hospital’s clinic. Data was collected by means of an interview-administered questionnaire. Results: The prevalence of stunting in the area was 47.5%. A significant association was found between the participants' main form of sanitation and stunting category in the group of infants younger than six months (p = 0.007) and the group older than six months(p = 0.040). Discussion: The prevalence of stunting in the area was far higher than the national average of 27%, although the majority of the sample had a normal weight. The use of non-flush toilets was found to be a risk factor for childhood stunting. Recommendation: Financial and political investment in child health needs to be placed as a top priority in South Africa to reduce stunting rates.
- Full Text:
- Date Issued: 2020
- Authors: Beyleveld, Janine
- Date: 2020
- Subjects: Children -- growth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/50201 , vital:42066
- Description: Introduction and Background: Stunting is the most prevalent form of childhood malnutrition where about 149 million children under the age of five can be classified as stunted globally. South Africa has one of the highest stunting rates in the world at 27%, causing devastating effects on economic productivity as well as on an individual’s nutritional status. The presence of stunted growth in children is a strong indicator of chronic undernutrition and highlights injustices experienced within communities. Aims and Objectives: The aim of this study is to develop a stunning profile of children under the age of five, visiting BhishoHospital’s gateway clinic in the Eastern Cape, South Africa. The objectives were to determine the prevalence of stunting of the children visiting Bhisho Hospital’s clinic and to identify the drivers of stunting in the area. Methodology: A quantitative study with a descriptive, cross-sectional design was used. The study population included all children under the age of five visiting Bhisho Hospital’s clinic. Data was collected by means of an interview-administered questionnaire. Results: The prevalence of stunting in the area was 47.5%. A significant association was found between the participants' main form of sanitation and stunting category in the group of infants younger than six months (p = 0.007) and the group older than six months(p = 0.040). Discussion: The prevalence of stunting in the area was far higher than the national average of 27%, although the majority of the sample had a normal weight. The use of non-flush toilets was found to be a risk factor for childhood stunting. Recommendation: Financial and political investment in child health needs to be placed as a top priority in South Africa to reduce stunting rates.
- Full Text:
- Date Issued: 2020
In vitro drug-herb interaction potential of African medicinal plant products used by Type II diabetics
- Authors: Fang, Yuan Yuan
- Date: 2011
- Subjects: Materia medica, Vegetable -- South Africa , Drugs -- Therapeutic use , Drug-herb interactions -- South Africa , Non-insulin-dependent diabetes -- South Africa , Non-insulin-dependent diabetes -- Treatment -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10317 , http://hdl.handle.net/10948/1341 , Materia medica, Vegetable -- South Africa , Drugs -- Therapeutic use , Drug-herb interactions -- South Africa , Non-insulin-dependent diabetes -- South Africa , Non-insulin-dependent diabetes -- Treatment -- South Africa
- Description: In Africa, use of medicinal plants for the treatment of diabetes is very common. However, efficacy on co-administering of medicinal plants with therapeutic drugs hasn't been fully determined, especially for African medicinal plants. The current study focused on assessing the in vitro modulation effects of three popular African medicinal plants, namely: Aloe ferox, Sutherlandia frutescens and Prunus africana (including five commercial preparations containing these medicinal plants) on two of the most important anti-diabetic drug metabolising enzymes, Cytochrome P450 (CYP450) 2C9 and CYP3A4 and a key drug efflux transporter, P-glycoprotein (P-gp). Vivid® microsome-based screening kits were used to assess inhibitory potency of plants preparations on CYP2C9 and CYP3A4 enzymes activities. The study showed that P. africana was a more potent inhibitor of CYP2C9 and CYP3A4 activity than the corresponding positive controls Ginkgo biloba and St. John's wort, which are known to cause clinically significant drug-herb interactions. S. frutescens leaf extract demonstrated potent to moderate inhibition on both the tested CYP activities, while its commercial products (Promune® and Probetix®) possessed moderate to mild inhibitory effects on the activities of both CYPs. Potent inhibitory effect on CYP2C9 and CYP3A4 was seen with Aloe Ferox®. Prosit® and Aloes powder® showed potent to moderate inhibition on CYP2C9 activity and moderate to mild inhibition on CYP3A4 activity. In addition to CYP450 activity, the present study also investigated the effects of the selected medicinal plant products on the activity of the main drug efflux protein, P-gp. A screening assay was specifically developed to assess the potential for herbal remedies to interact with P-gp mediated drug absorption. The assay is based on the principle of the reversal of drug resistance in modified Caco-2 cells specifically altered to express high iv efflux protein activity. These cells display a multidrug resistance phenotype and the addition of a plant extract containing a P-gp inhibitor or substrate will inhibit or compete with any cytotoxic drug and consequently reverse the drug resistance. The suitability of the assay was confirmed using a known P-gp inhibitor. The study observed that the anti-proliferation effect of vinblastine was significantly enhanced in vinblastine-resistant Caco-2 cells, which have high P-gp expression, when they were exposed to the selected African herbal preparations. This observation indicates that the studied plant preparations may alter P-gp functionality and therefore lead to interference with the absorption of co-administered drugs. The outcomes of this study provide useful information on whether there are any potential drug-herb interactions between the commonly used African medicinal plants and oral anti-diabetic drugs, at the level of CYP and P-gp drug metabolism and could contribute to better therapeutic management of Type II diabetics. However these predicted interactions will need to be verified in a clinical setting.
- Full Text:
- Date Issued: 2011
- Authors: Fang, Yuan Yuan
- Date: 2011
- Subjects: Materia medica, Vegetable -- South Africa , Drugs -- Therapeutic use , Drug-herb interactions -- South Africa , Non-insulin-dependent diabetes -- South Africa , Non-insulin-dependent diabetes -- Treatment -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10317 , http://hdl.handle.net/10948/1341 , Materia medica, Vegetable -- South Africa , Drugs -- Therapeutic use , Drug-herb interactions -- South Africa , Non-insulin-dependent diabetes -- South Africa , Non-insulin-dependent diabetes -- Treatment -- South Africa
- Description: In Africa, use of medicinal plants for the treatment of diabetes is very common. However, efficacy on co-administering of medicinal plants with therapeutic drugs hasn't been fully determined, especially for African medicinal plants. The current study focused on assessing the in vitro modulation effects of three popular African medicinal plants, namely: Aloe ferox, Sutherlandia frutescens and Prunus africana (including five commercial preparations containing these medicinal plants) on two of the most important anti-diabetic drug metabolising enzymes, Cytochrome P450 (CYP450) 2C9 and CYP3A4 and a key drug efflux transporter, P-glycoprotein (P-gp). Vivid® microsome-based screening kits were used to assess inhibitory potency of plants preparations on CYP2C9 and CYP3A4 enzymes activities. The study showed that P. africana was a more potent inhibitor of CYP2C9 and CYP3A4 activity than the corresponding positive controls Ginkgo biloba and St. John's wort, which are known to cause clinically significant drug-herb interactions. S. frutescens leaf extract demonstrated potent to moderate inhibition on both the tested CYP activities, while its commercial products (Promune® and Probetix®) possessed moderate to mild inhibitory effects on the activities of both CYPs. Potent inhibitory effect on CYP2C9 and CYP3A4 was seen with Aloe Ferox®. Prosit® and Aloes powder® showed potent to moderate inhibition on CYP2C9 activity and moderate to mild inhibition on CYP3A4 activity. In addition to CYP450 activity, the present study also investigated the effects of the selected medicinal plant products on the activity of the main drug efflux protein, P-gp. A screening assay was specifically developed to assess the potential for herbal remedies to interact with P-gp mediated drug absorption. The assay is based on the principle of the reversal of drug resistance in modified Caco-2 cells specifically altered to express high iv efflux protein activity. These cells display a multidrug resistance phenotype and the addition of a plant extract containing a P-gp inhibitor or substrate will inhibit or compete with any cytotoxic drug and consequently reverse the drug resistance. The suitability of the assay was confirmed using a known P-gp inhibitor. The study observed that the anti-proliferation effect of vinblastine was significantly enhanced in vinblastine-resistant Caco-2 cells, which have high P-gp expression, when they were exposed to the selected African herbal preparations. This observation indicates that the studied plant preparations may alter P-gp functionality and therefore lead to interference with the absorption of co-administered drugs. The outcomes of this study provide useful information on whether there are any potential drug-herb interactions between the commonly used African medicinal plants and oral anti-diabetic drugs, at the level of CYP and P-gp drug metabolism and could contribute to better therapeutic management of Type II diabetics. However these predicted interactions will need to be verified in a clinical setting.
- Full Text:
- Date Issued: 2011
Older people’s perspectives on the effectiveness of eye movement integration (emi) therapy as treatment intervention for their trauma symptoms
- Authors: Visagie, Andrea
- Date: 2020
- Subjects: Post-traumatic stress disorder in old age
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/46389 , vital:39601
- Description: Many research studies propose that we have an ageing population with an increased number of people living past the age of 85 years. Ageing is accompanied by a gradual decline in physical, mental and sensory abilities. Older people may have experienced trauma throughout their lives, and very often, their symptoms of trauma are regarded as part of the ageing process rather than actual symptoms of trauma. In addition, older people often do not seek help throughout their lives for various reasons. While there is research available about older people and trauma, little is known about Eye Movement Integration(EMI)therapy as a treatment intervention in treating symptoms of trauma in older persons. The purpose of this research was an explorative and descriptive study of older people’s responses to EMI therapy as a treatment intervention for their symptoms of trauma. More specifically, the study was designed to determine how older people process their symptoms through EMI therapy and whether they view it as valuable. This qualitative study used an exploratory-descriptive research design with a non-probability, purposive sampling method. The EMI therapy sessions were offered to older adults in the Knysna area who presented with symptoms of trauma. From this group, only those who were able and willing to engage in therapeutic interviews formed part of the research. As part of the study, they consented to the use of their inventories from the EMI sessions as a qualitative document analysis and taking part in qualitative interviews to explore their views on the usefulness of EMI therapy to deal with their trauma. The findings emphasise that older people are not familiar with EMI. However, they view their experience of it in a positive light and regard it as a useful treatment intervention for treating their symptoms. Moreover, EMI seems to be a brief and cost-effective trauma intervention with practical benefits for older adults. The results from this study can assist social work professionals, specifically those working with older people, to address and improve the overall health and emotional wellbeing of older people. Data verification methods ensured the validity of this study
- Full Text:
- Date Issued: 2020
- Authors: Visagie, Andrea
- Date: 2020
- Subjects: Post-traumatic stress disorder in old age
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/46389 , vital:39601
- Description: Many research studies propose that we have an ageing population with an increased number of people living past the age of 85 years. Ageing is accompanied by a gradual decline in physical, mental and sensory abilities. Older people may have experienced trauma throughout their lives, and very often, their symptoms of trauma are regarded as part of the ageing process rather than actual symptoms of trauma. In addition, older people often do not seek help throughout their lives for various reasons. While there is research available about older people and trauma, little is known about Eye Movement Integration(EMI)therapy as a treatment intervention in treating symptoms of trauma in older persons. The purpose of this research was an explorative and descriptive study of older people’s responses to EMI therapy as a treatment intervention for their symptoms of trauma. More specifically, the study was designed to determine how older people process their symptoms through EMI therapy and whether they view it as valuable. This qualitative study used an exploratory-descriptive research design with a non-probability, purposive sampling method. The EMI therapy sessions were offered to older adults in the Knysna area who presented with symptoms of trauma. From this group, only those who were able and willing to engage in therapeutic interviews formed part of the research. As part of the study, they consented to the use of their inventories from the EMI sessions as a qualitative document analysis and taking part in qualitative interviews to explore their views on the usefulness of EMI therapy to deal with their trauma. The findings emphasise that older people are not familiar with EMI. However, they view their experience of it in a positive light and regard it as a useful treatment intervention for treating their symptoms. Moreover, EMI seems to be a brief and cost-effective trauma intervention with practical benefits for older adults. The results from this study can assist social work professionals, specifically those working with older people, to address and improve the overall health and emotional wellbeing of older people. Data verification methods ensured the validity of this study
- Full Text:
- Date Issued: 2020
Development of antibiotic loaded liposomal hydrocolloid dressings for application in wound healing
- Authors: Ntsalu, Vuyiseka
- Date: 2017
- Subjects: Wound healing -- South Africa Liposomes Hydrocolloid surgical dressings -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13957 , vital:27361
- Description: Wound healing, as a normal biological process in the human body, is achieved through four precise and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. However, many factors can interfere with one or more of these phases, thus causing improper or impaired wound healing. Maintaining a moist wound environment is crucial in facilitating the wound-healing process. The beneficial effects of a moist versus a dry wound environment include re-epithelization, tissue granulation, and repair. The use of hydrocolloid occlusive dressings in maintaining a moist wound environment has proven to be a useful adjunct in facilitating wound healing. Although hydrocolloid dressings have been widely used clinically in wound management, bacterial resistance, poor solubility and sustained drug release remain to be a problem for many of the drugs used in wound therapy. In chronic wound management, where patients normally undergo long treatments and frequent dressing changes, a system that delivers drugs into a wound site in a controlled fashion can improve patient compliance and therapeutic outcomes. Liposomes are small phospholipid vesicles that have been widely investigated as drug carriers for the delivery of therapeutic agents. They are spherical lipid vesicles consisting of phospholipid bilayers that improve the efficacy of the drugs by fusing with biological membranes, and eventually releasing their entrapped content into the cells or bacteria. The aim of this study therefore, is to develop a new bacitracin-based controlled release hydrocolloid dressing, with good absorptive properties for improving the efficacy of antibiotics in wound healing. HPLC (high-pressure liquid chromatography) assay of bacitracin was performed for quantification of the drug. Liposomes were prepared using thin film hydration and extrusion methods. Liposomes were also characterized based on their ideal particle size and encapsulation efficiency, and then incorporated into the different ratios of chitosan/gelatin hydrocolloid films. The films were prepared with increase in gelatin concentration and were evaluated for folding endurance, tensile strength, water absorption capacity, morphology, drug release kinetics, antimicrobial activity and stability. The morphology of these films was found to be very smooth and homogeneous proving a good compatibility between the two polymers. With increase in gelatin concentration, folding endurance, water absorption capacity, tensile strength, drug release kinetics and antimicrobial activity were increased. The antibacterial activity against various bacterial species was improved in the bacitracin loaded hydrocolloid films as compared to the blank films. Based on the findings above, it can be concluded that chitosan/gelatin films at 1:3 proportion is a successful wound dressing for wound management with improved wound healing properties than other formulations. This formulation is a potential candidate for the development of alternative pharmaceutical dosage forms, for the treatment of bacterial infected wounds, based on the activity of the eco-friendly chitosan matrix added to the bacitracin activity. In this work, chitosan also demonstrated a great potential as a dressing for advanced wound therapy and confirmed its good biocompatibility and potential to provide, in combination with liposomes, sustained drug release which is highly beneficial for wound treatment. The addition of gelatin improved the water affinity of the films and facilitated water mediated cross-linking process.
- Full Text:
- Date Issued: 2017
- Authors: Ntsalu, Vuyiseka
- Date: 2017
- Subjects: Wound healing -- South Africa Liposomes Hydrocolloid surgical dressings -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13957 , vital:27361
- Description: Wound healing, as a normal biological process in the human body, is achieved through four precise and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. However, many factors can interfere with one or more of these phases, thus causing improper or impaired wound healing. Maintaining a moist wound environment is crucial in facilitating the wound-healing process. The beneficial effects of a moist versus a dry wound environment include re-epithelization, tissue granulation, and repair. The use of hydrocolloid occlusive dressings in maintaining a moist wound environment has proven to be a useful adjunct in facilitating wound healing. Although hydrocolloid dressings have been widely used clinically in wound management, bacterial resistance, poor solubility and sustained drug release remain to be a problem for many of the drugs used in wound therapy. In chronic wound management, where patients normally undergo long treatments and frequent dressing changes, a system that delivers drugs into a wound site in a controlled fashion can improve patient compliance and therapeutic outcomes. Liposomes are small phospholipid vesicles that have been widely investigated as drug carriers for the delivery of therapeutic agents. They are spherical lipid vesicles consisting of phospholipid bilayers that improve the efficacy of the drugs by fusing with biological membranes, and eventually releasing their entrapped content into the cells or bacteria. The aim of this study therefore, is to develop a new bacitracin-based controlled release hydrocolloid dressing, with good absorptive properties for improving the efficacy of antibiotics in wound healing. HPLC (high-pressure liquid chromatography) assay of bacitracin was performed for quantification of the drug. Liposomes were prepared using thin film hydration and extrusion methods. Liposomes were also characterized based on their ideal particle size and encapsulation efficiency, and then incorporated into the different ratios of chitosan/gelatin hydrocolloid films. The films were prepared with increase in gelatin concentration and were evaluated for folding endurance, tensile strength, water absorption capacity, morphology, drug release kinetics, antimicrobial activity and stability. The morphology of these films was found to be very smooth and homogeneous proving a good compatibility between the two polymers. With increase in gelatin concentration, folding endurance, water absorption capacity, tensile strength, drug release kinetics and antimicrobial activity were increased. The antibacterial activity against various bacterial species was improved in the bacitracin loaded hydrocolloid films as compared to the blank films. Based on the findings above, it can be concluded that chitosan/gelatin films at 1:3 proportion is a successful wound dressing for wound management with improved wound healing properties than other formulations. This formulation is a potential candidate for the development of alternative pharmaceutical dosage forms, for the treatment of bacterial infected wounds, based on the activity of the eco-friendly chitosan matrix added to the bacitracin activity. In this work, chitosan also demonstrated a great potential as a dressing for advanced wound therapy and confirmed its good biocompatibility and potential to provide, in combination with liposomes, sustained drug release which is highly beneficial for wound treatment. The addition of gelatin improved the water affinity of the films and facilitated water mediated cross-linking process.
- Full Text:
- Date Issued: 2017
Development of an antiretroviral solid dosage form using multivariate analysis
- Authors: Nqabeni, Luxolo
- Date: 2007
- Subjects: Analysis of variance , Experimental design , Multivariate analysis , Antiretroviral agents -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10145 , http://hdl.handle.net/10948/705 , Analysis of variance , Experimental design , Multivariate analysis , Antiretroviral agents -- South Africa
- Description: The aim of pharmaceutical development is to design a quality product and the manufacturing process to deliver the product in a reproducible manner. The development of a new and generic formulation is based on a large number of experiments. Statistics provides many tools for studying the conditions of formulations and processes and enables us to optimize the same while being able to minimize our experimentation. The purpose of this study was to apply experimental design methodology (DOE) and multivariate analysis to the development and optimization of tablet formulations containing 150 mg lamivudine manufactured by direct compression.
- Full Text:
- Date Issued: 2007
- Authors: Nqabeni, Luxolo
- Date: 2007
- Subjects: Analysis of variance , Experimental design , Multivariate analysis , Antiretroviral agents -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10145 , http://hdl.handle.net/10948/705 , Analysis of variance , Experimental design , Multivariate analysis , Antiretroviral agents -- South Africa
- Description: The aim of pharmaceutical development is to design a quality product and the manufacturing process to deliver the product in a reproducible manner. The development of a new and generic formulation is based on a large number of experiments. Statistics provides many tools for studying the conditions of formulations and processes and enables us to optimize the same while being able to minimize our experimentation. The purpose of this study was to apply experimental design methodology (DOE) and multivariate analysis to the development and optimization of tablet formulations containing 150 mg lamivudine manufactured by direct compression.
- Full Text:
- Date Issued: 2007
The medicinal chemistry of cyclo(Phe-4CI-Pro) and Cyclo(D-Phe-4CI-Pro)
- Authors: Milne, Marnus
- Date: 2012
- Subjects: Cyclic peptides , Pharmaceutical chemistry , Peptide drugs
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10157 , http://hdl.handle.net/10948/d1011848 , Cyclic peptides , Pharmaceutical chemistry , Peptide drugs
- Description: Cyclic dipeptides have limited conformational freedom due to their diketopiperazine backbone and their small size. They are relatively simple to synthesise, making them ideal subjects for investigation into their biological effects. Cyclic dipeptides have also been known for their multitude of biological activities, including antimicrobial, anticancer and haematological properties. In this study the cyclic dipeptides, cyclo(Phe-4Cl-Pro) and cyclo(D-Phe-4Cl-Pro), were synthesised from their corresponding linear precursors using a modified phenol-induced cyclisation procedure. The phenol induced cyclisation procedure resulted in good yields and purity of the cyclic dipeptides. Quantitative analysis and evaluation of the physiochemical properties of the cyclic dipeptides was achieved using high-performance liquid chromatography, scanning electron microscopy, thermal analysis and X-ray powder diffraction. Structural elucidation of the cyclic dipeptides was done by means of infrared spectroscopy, mass spectroscopy, nuclear magnetic resonance spectroscopy and molecular modelling. The study‟s aim was to determine the biological activity of cyclo(Phe-4Cl-Pro) and cyclo(D-Phe-4Cl-Pro) with respect to their anticancer, antimicrobial, haematological and ant-diabetic studies. Anticancer studies revealed that cyclo(Phe-4Cl-Pro) and cyclo(D-Phe-4Cl-Pro) inhibited the growth of HeLa (cervical cancer), HT-29 (colon cancer) and MCF-7 (breast cancer) cancer cell lines. Both cyclic dipeptides also inhibited the growth of certain selected Gram-positive, Gram-negative and fungal microorganisms in the antimicrobial study. Although the inhibition of growth in the anticancer and antimicrobial studies was statistically significant, the clinical relevance is questionable, since the inhibition produced by both cyclic dipeptides was very limited compared to other pre-existing anticancer and antimicrobial agents. Both cyclic dipeptides caused a significant shortening of the APTT and PT clotting times and an increase in the fibrin and D-Dimer formation. Cyclo(D-Phe-4Cl-Pro) at a screening concentration of 12.5 mM and 3.125 mM, showed significant anti-platelet activity. Both cyclic dipeptides failed to produce any inhibition of the α-Glucosidase enzyme and very limited inhibition of the α-Amylase enzyme.
- Full Text:
- Date Issued: 2012
- Authors: Milne, Marnus
- Date: 2012
- Subjects: Cyclic peptides , Pharmaceutical chemistry , Peptide drugs
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10157 , http://hdl.handle.net/10948/d1011848 , Cyclic peptides , Pharmaceutical chemistry , Peptide drugs
- Description: Cyclic dipeptides have limited conformational freedom due to their diketopiperazine backbone and their small size. They are relatively simple to synthesise, making them ideal subjects for investigation into their biological effects. Cyclic dipeptides have also been known for their multitude of biological activities, including antimicrobial, anticancer and haematological properties. In this study the cyclic dipeptides, cyclo(Phe-4Cl-Pro) and cyclo(D-Phe-4Cl-Pro), were synthesised from their corresponding linear precursors using a modified phenol-induced cyclisation procedure. The phenol induced cyclisation procedure resulted in good yields and purity of the cyclic dipeptides. Quantitative analysis and evaluation of the physiochemical properties of the cyclic dipeptides was achieved using high-performance liquid chromatography, scanning electron microscopy, thermal analysis and X-ray powder diffraction. Structural elucidation of the cyclic dipeptides was done by means of infrared spectroscopy, mass spectroscopy, nuclear magnetic resonance spectroscopy and molecular modelling. The study‟s aim was to determine the biological activity of cyclo(Phe-4Cl-Pro) and cyclo(D-Phe-4Cl-Pro) with respect to their anticancer, antimicrobial, haematological and ant-diabetic studies. Anticancer studies revealed that cyclo(Phe-4Cl-Pro) and cyclo(D-Phe-4Cl-Pro) inhibited the growth of HeLa (cervical cancer), HT-29 (colon cancer) and MCF-7 (breast cancer) cancer cell lines. Both cyclic dipeptides also inhibited the growth of certain selected Gram-positive, Gram-negative and fungal microorganisms in the antimicrobial study. Although the inhibition of growth in the anticancer and antimicrobial studies was statistically significant, the clinical relevance is questionable, since the inhibition produced by both cyclic dipeptides was very limited compared to other pre-existing anticancer and antimicrobial agents. Both cyclic dipeptides caused a significant shortening of the APTT and PT clotting times and an increase in the fibrin and D-Dimer formation. Cyclo(D-Phe-4Cl-Pro) at a screening concentration of 12.5 mM and 3.125 mM, showed significant anti-platelet activity. Both cyclic dipeptides failed to produce any inhibition of the α-Glucosidase enzyme and very limited inhibition of the α-Amylase enzyme.
- Full Text:
- Date Issued: 2012
Development and characterisation of miconazole nitrate loaded solid lipid nanoparticles for incorporation into a vaginal mucoadhesive system
- Authors: Gwimo, Wimana Alexis
- Date: 2019
- Subjects: Vaginitis , Vagina -- Diseases Sexually transmitted diseases -- Diagnosis Sexually transmitted diseases -- Treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39632 , vital:35335
- Description: Vulvovaginal candidiasis (VVC) is the second most common cause of vaginitis, affecting 75% of women of sexual maturity. The prescribed first line treatment involves the use of locally-acting imidazole creams. These conventional dosage forms possess limitations, such as leakage, messiness and low residence time at the site of application; all which promote poor patient adherence to pharmacotherapy. Poor adherence is then attributed to increased incidence of VVC reoccurrence and the emergence of Candida strains. It was, therefore, speculated that through the use of novel drug delivery systems (NDDS), the pharmacokinetic and antimicrobial characteristics of a model antifungal drug (miconazole nitrate [MNZ]) could be improved. Primary aim: To develop, optimise and characterise a mucoadhesive hydrogel incorporated with MNZ loaded solid lipid nanoparticles (MNZ-SLNs) for the intended treatment of VVC. This study was conducted in three phases, viz. pre-formulation studies, development, optimisation and characterisation of MNZ-SLNs, and the development and characterisation of MNZ-SLN-loaded thermoresponsive hydrogel. An alternative method for the quantification of MNZ was developed through the use of an octyl stationary phase. The method was deemed suitable for its intended use with a linear equation of y = 811214x + 67958 and a respective limit of quantitation (LoQ) and detection of 0.015 mg/ml and 0.052 mg/ml. Differential scanning calorimetry (DSC) studies suggested that cholesterol showed great promise of facilitating high drug entrapment efficiency (EE). MNZ-SLNs were prepared by means of a novel melt- emulsification sonication and low temperature solidification method and optimised statistically by a 13-run-two-factor central composite rotatable design (CCRD). The predicted optimisation parameters were 4% m/v lipid concentration and 260.94 sonication time. Optimal MNZ-SLN formulations were prepared and characterised by means of photon correlation spectroscopy (PCS), transmission electron microscopy (TEM) and centrifugation. PCS revealed uniform particles with a narrow polydispersity index (PDI) and a mean hydrodynamic diameter (z-avg.) of 73.03 nm and zeta potential (ZP) of 38.43 mV. Percent EE was calculated via an indirect method as 75.24%. Furthermore, the MNZ -SLNs were incorporated into a mucoadhesive thermo-responsive hydrogel with a sol-gel transition temperature of 33.33 ± 2.82 °C. In vitro drug release testing (IVDRT) was undertaken with the aid of a Franz diffusion vertical cell (FDVC) apparatus. A % cumulative drug release of 27.94% and 15.87% was obtained for MNZ- SLNs and MNZ-SLN hydrogels, respectively, after eight hours. The resultant data was fitted into various kinetic models with the aid of DDSolverTM (Microsoft Excel® add-ins, 2016) to evaluate which model attained the highest correlation co-efficient (r2). Both formulations attained high r2 of 0.9941 and 0.9945, respectively, with the Korsmeyer- Peppas mathematical model. A high diffusional exponent (n) of >1 was observed, suggesting a super case II drug release mechanism. Finally, a modified Kirby-Bauer disc diffusion assay was used for ascertaining Candida albicans susceptibility to the developed formulations. Controls in the form of unloaded preparations and a commercially available cream were used. MNZ-SLNs and MNZ-hydrogel demonstrated superior antifungal activity to the commercially available cream. These results indicate that the developed MNZ-SLNloaded hydrogel formulation with localised thermo-responsive effect may be a promising carrier for intravaginal delivery of MNZ in the treatment of VVC.
- Full Text:
- Date Issued: 2019
- Authors: Gwimo, Wimana Alexis
- Date: 2019
- Subjects: Vaginitis , Vagina -- Diseases Sexually transmitted diseases -- Diagnosis Sexually transmitted diseases -- Treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39632 , vital:35335
- Description: Vulvovaginal candidiasis (VVC) is the second most common cause of vaginitis, affecting 75% of women of sexual maturity. The prescribed first line treatment involves the use of locally-acting imidazole creams. These conventional dosage forms possess limitations, such as leakage, messiness and low residence time at the site of application; all which promote poor patient adherence to pharmacotherapy. Poor adherence is then attributed to increased incidence of VVC reoccurrence and the emergence of Candida strains. It was, therefore, speculated that through the use of novel drug delivery systems (NDDS), the pharmacokinetic and antimicrobial characteristics of a model antifungal drug (miconazole nitrate [MNZ]) could be improved. Primary aim: To develop, optimise and characterise a mucoadhesive hydrogel incorporated with MNZ loaded solid lipid nanoparticles (MNZ-SLNs) for the intended treatment of VVC. This study was conducted in three phases, viz. pre-formulation studies, development, optimisation and characterisation of MNZ-SLNs, and the development and characterisation of MNZ-SLN-loaded thermoresponsive hydrogel. An alternative method for the quantification of MNZ was developed through the use of an octyl stationary phase. The method was deemed suitable for its intended use with a linear equation of y = 811214x + 67958 and a respective limit of quantitation (LoQ) and detection of 0.015 mg/ml and 0.052 mg/ml. Differential scanning calorimetry (DSC) studies suggested that cholesterol showed great promise of facilitating high drug entrapment efficiency (EE). MNZ-SLNs were prepared by means of a novel melt- emulsification sonication and low temperature solidification method and optimised statistically by a 13-run-two-factor central composite rotatable design (CCRD). The predicted optimisation parameters were 4% m/v lipid concentration and 260.94 sonication time. Optimal MNZ-SLN formulations were prepared and characterised by means of photon correlation spectroscopy (PCS), transmission electron microscopy (TEM) and centrifugation. PCS revealed uniform particles with a narrow polydispersity index (PDI) and a mean hydrodynamic diameter (z-avg.) of 73.03 nm and zeta potential (ZP) of 38.43 mV. Percent EE was calculated via an indirect method as 75.24%. Furthermore, the MNZ -SLNs were incorporated into a mucoadhesive thermo-responsive hydrogel with a sol-gel transition temperature of 33.33 ± 2.82 °C. In vitro drug release testing (IVDRT) was undertaken with the aid of a Franz diffusion vertical cell (FDVC) apparatus. A % cumulative drug release of 27.94% and 15.87% was obtained for MNZ- SLNs and MNZ-SLN hydrogels, respectively, after eight hours. The resultant data was fitted into various kinetic models with the aid of DDSolverTM (Microsoft Excel® add-ins, 2016) to evaluate which model attained the highest correlation co-efficient (r2). Both formulations attained high r2 of 0.9941 and 0.9945, respectively, with the Korsmeyer- Peppas mathematical model. A high diffusional exponent (n) of >1 was observed, suggesting a super case II drug release mechanism. Finally, a modified Kirby-Bauer disc diffusion assay was used for ascertaining Candida albicans susceptibility to the developed formulations. Controls in the form of unloaded preparations and a commercially available cream were used. MNZ-SLNs and MNZ-hydrogel demonstrated superior antifungal activity to the commercially available cream. These results indicate that the developed MNZ-SLNloaded hydrogel formulation with localised thermo-responsive effect may be a promising carrier for intravaginal delivery of MNZ in the treatment of VVC.
- Full Text:
- Date Issued: 2019
An investigation into the introduction of process analytical technology, using near infrared analysis, to selected pharmaceutical processes
- Authors: Naicker, Krishnaveni
- Date: 2007
- Subjects: Near infrared spectroscopy , Pharmaceutical chemistry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10153 , http://hdl.handle.net/10948/577 , http://hdl.handle.net/10948/d1011710 , Near infrared spectroscopy , Pharmaceutical chemistry
- Description: Introduction: Process analytical technologies are systems for the analysis and control of manufacturing processes to assure acceptable end-product quality. This is achieved by timely measurements of critical parameters and performance attributes of raw material and in-process material and processes. The introduction of process analytical technology using near infrared analysis was investigated in three areas, namely incoming raw material analysis, blend uniformity analysis and moisture determination in the fluid bed dryer. Methodology: Incoming raw material identification - The FOSS XDS rapid content analyzer was used for the development of a NIR method for the identification and material qualification of starch maize and lactose monohydrate. Blend uniformity analysis – The SP15 Laboratory Blender fitted with near infrared probe was utilized for the study. Two types of blend experiments were designed to monitor the distribution of magnesium stearate (lubricant) in the blend, namely, a powder blend utilizing lactose monohydrate and a granule blend utilizing Ridaq® granule. Software methods were developed to monitor the standard deviation of the absorbance at the wavelengths that were specific for lactose monohydrate, Ridaq® granule and magnesium stearate. To confirm the prediction of end-point using near infrared, results were verified using an atomic absorption method for magnesium stearate. The blends were sampled at the selected time intervals corresponding to three states of the blend, namely, before end-point, at end-point and after end-point using a sampling plan. An additional six blends were conducted for the granule blend and sampled when the standard deviation had reached a value below 3 x 10-6 at the magnesium stearate wavelength at four consecutive data points (standard deviation value extrapolated from blends carried out to predetermined time intervals). Moisture determination in the fluid bed dryer – Moisture values for two products (Product A and Product B) were retrospectively collected from past production batches. A process capability study was conducted on the moisture values to determine if the current process was in a state of control. Results and Discussion: Incoming raw material identification – The algorithms used for the spectral library were able to distinguish between the raw materials selected. The spectral library positively identified the starch maize and lactose monohydrate samples that were not present in the library. The negative challenge with pregelatinised starch and tablettose demonstrated that the spectral library was able to differentiate between closely related compounds. Blend uniformity analysis – Blends sampled at the predetermined time intervals demonstrated a homogeneous state when the standard deviation of the absorbance was low and a non-homogeneous state when the standard deviation of the absorbance was high, thus near infrared prediction on the state of the blend was confirmed by the standard analytical methods. The series of Ridaq® granule and magnesium stearate blends sampled when the standard deviation was below 3 x 10-6 were homogeneous with the exception of one blend that was marginally out of specification. Blend durations were significantly lower than the standard blend durations used in the facility and ranged from 112 to 198 seconds. Moisture determination in the fluid bed dryer – From the process capability study of the two products it was noted that Product A is stable but can still be optimized while Product B is at a desirable state. The statistical evaluation of the moisture values for Product A and Product B demonstrated that the use of the product temperature to monitor the moisture gave consistent results. The current process is stable and capable of producing repeatable results although near infrared provides a means for continuously monitoring the product moisture and allows one to take action to prevent over-drying or under-drying. Conclusion: From the investigations conducted, it can be seen that there is definitely a niche for process analytical technology at this pharmaceutical company. The implementation is a gradual process of change, which may take time, probably several years (Heinze & Hansen 2005).
- Full Text:
- Date Issued: 2007
- Authors: Naicker, Krishnaveni
- Date: 2007
- Subjects: Near infrared spectroscopy , Pharmaceutical chemistry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10153 , http://hdl.handle.net/10948/577 , http://hdl.handle.net/10948/d1011710 , Near infrared spectroscopy , Pharmaceutical chemistry
- Description: Introduction: Process analytical technologies are systems for the analysis and control of manufacturing processes to assure acceptable end-product quality. This is achieved by timely measurements of critical parameters and performance attributes of raw material and in-process material and processes. The introduction of process analytical technology using near infrared analysis was investigated in three areas, namely incoming raw material analysis, blend uniformity analysis and moisture determination in the fluid bed dryer. Methodology: Incoming raw material identification - The FOSS XDS rapid content analyzer was used for the development of a NIR method for the identification and material qualification of starch maize and lactose monohydrate. Blend uniformity analysis – The SP15 Laboratory Blender fitted with near infrared probe was utilized for the study. Two types of blend experiments were designed to monitor the distribution of magnesium stearate (lubricant) in the blend, namely, a powder blend utilizing lactose monohydrate and a granule blend utilizing Ridaq® granule. Software methods were developed to monitor the standard deviation of the absorbance at the wavelengths that were specific for lactose monohydrate, Ridaq® granule and magnesium stearate. To confirm the prediction of end-point using near infrared, results were verified using an atomic absorption method for magnesium stearate. The blends were sampled at the selected time intervals corresponding to three states of the blend, namely, before end-point, at end-point and after end-point using a sampling plan. An additional six blends were conducted for the granule blend and sampled when the standard deviation had reached a value below 3 x 10-6 at the magnesium stearate wavelength at four consecutive data points (standard deviation value extrapolated from blends carried out to predetermined time intervals). Moisture determination in the fluid bed dryer – Moisture values for two products (Product A and Product B) were retrospectively collected from past production batches. A process capability study was conducted on the moisture values to determine if the current process was in a state of control. Results and Discussion: Incoming raw material identification – The algorithms used for the spectral library were able to distinguish between the raw materials selected. The spectral library positively identified the starch maize and lactose monohydrate samples that were not present in the library. The negative challenge with pregelatinised starch and tablettose demonstrated that the spectral library was able to differentiate between closely related compounds. Blend uniformity analysis – Blends sampled at the predetermined time intervals demonstrated a homogeneous state when the standard deviation of the absorbance was low and a non-homogeneous state when the standard deviation of the absorbance was high, thus near infrared prediction on the state of the blend was confirmed by the standard analytical methods. The series of Ridaq® granule and magnesium stearate blends sampled when the standard deviation was below 3 x 10-6 were homogeneous with the exception of one blend that was marginally out of specification. Blend durations were significantly lower than the standard blend durations used in the facility and ranged from 112 to 198 seconds. Moisture determination in the fluid bed dryer – From the process capability study of the two products it was noted that Product A is stable but can still be optimized while Product B is at a desirable state. The statistical evaluation of the moisture values for Product A and Product B demonstrated that the use of the product temperature to monitor the moisture gave consistent results. The current process is stable and capable of producing repeatable results although near infrared provides a means for continuously monitoring the product moisture and allows one to take action to prevent over-drying or under-drying. Conclusion: From the investigations conducted, it can be seen that there is definitely a niche for process analytical technology at this pharmaceutical company. The implementation is a gradual process of change, which may take time, probably several years (Heinze & Hansen 2005).
- Full Text:
- Date Issued: 2007
The relationship between selected body composition components and self-efficacy among 12-14 year old rural adolescents in the Eastern Cape Province of South Africa
- Authors: Nkopo, Mandisi, S
- Date: 2017
- Subjects: Child development -- South Africa -- Eastern Cape Children -- Growth Body composition
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4536 , vital:28403
- Description: Body composition changes drastically in both males and females during the adolescent years. The changes may have a negative effect on their physical health as well as psychological well-being, with respect to attributes such as self-efficacy. Being either overweight or obese during adolescence has social, economic and psychological consequences, which include low self-efficacy. However, very few international studies and not a single South African study could be found which measured the relationship of anthropometric body composition components, general self-efficacy levels and actual measured body size among adolescents, particularly among rural adolescents. Consequently, the aim of this study was to investigate the relationship between anthropometric body composition components and self efficacy, by conducting a comparison of self-efficacy levels among normal, overweight and obese 12 to 14-year-old rural adolescents in the Eastern Cape Province of South Africa. The sample consisted of boys (n=49) and girls (n=43) between the ages of 12 and 14 years. The body composition components were body weight, stature, body mass index, sum of 3 skinfolds, percentage body fat and hip-to-waist ratio. The sample was also classified into normal, overweight and obese groups, according to body mass index. A self-administered Self-Efficacy Questionnaire for Children (SEQ-C) which was developed by Muris (2001) was used to measure general self-efficacy. Data were analyzed by means of descriptive statistics, the Pearson correlation matrix and Cohen's effect size for significance (Cohen, 1992) and a Mann-Whitney U Test was used to determine statistical differences. Significance was set at p<0.05. Only 17 percent of the participants in the research sample were found to be overweight or obese. Only emotional self-efficacy showed significant (p=0.02) differences between the participants who were classified as having normal weights and the group which comprised the overweight and the obese groups. Overweight and obese boys and girls still had very high levels of self-efficacy, although their body mass index scores were high. Boys scored higher in social self-efficacy and girls in academic self-efficacy. Only girls presented significantly high correlations between body mass index and emotional self-efficacy (r=0.33, p=0.02), total self-efficacy and hip-to-waist ratio (r=0.44, p=0.00), social self-efficacy and hip-towaist ratio (r=0.39, p=0.01) and emotional self-efficacy and hip-to-waist ratio (r=0.33, p=0.02), while boys presented them only with respect to body weight (r=0.31, p=0.02) and stature (r=0.39, p=0.00). The results suggest that a positive relationship exists between body composition, in terms of hip-to-waist ratio, weight and stature, and self-efficacy among South African rural adolescents. However, girls presented significantly strong and positive correlations between hip-to-waist ratio and self-efficacy, whereas boys presented significant, strong and positive correlations between body weight, stature and self-efficacy. Only emotional self-efficacy showed significant differences between normal weight and overweight or obese South African rural adolescents. It seems likely that cultural beliefs may exert an influence on the psychosocial perceptions of adolescents in relation to body size, consequently affecting self efficacy levels.
- Full Text:
- Date Issued: 2017
- Authors: Nkopo, Mandisi, S
- Date: 2017
- Subjects: Child development -- South Africa -- Eastern Cape Children -- Growth Body composition
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4536 , vital:28403
- Description: Body composition changes drastically in both males and females during the adolescent years. The changes may have a negative effect on their physical health as well as psychological well-being, with respect to attributes such as self-efficacy. Being either overweight or obese during adolescence has social, economic and psychological consequences, which include low self-efficacy. However, very few international studies and not a single South African study could be found which measured the relationship of anthropometric body composition components, general self-efficacy levels and actual measured body size among adolescents, particularly among rural adolescents. Consequently, the aim of this study was to investigate the relationship between anthropometric body composition components and self efficacy, by conducting a comparison of self-efficacy levels among normal, overweight and obese 12 to 14-year-old rural adolescents in the Eastern Cape Province of South Africa. The sample consisted of boys (n=49) and girls (n=43) between the ages of 12 and 14 years. The body composition components were body weight, stature, body mass index, sum of 3 skinfolds, percentage body fat and hip-to-waist ratio. The sample was also classified into normal, overweight and obese groups, according to body mass index. A self-administered Self-Efficacy Questionnaire for Children (SEQ-C) which was developed by Muris (2001) was used to measure general self-efficacy. Data were analyzed by means of descriptive statistics, the Pearson correlation matrix and Cohen's effect size for significance (Cohen, 1992) and a Mann-Whitney U Test was used to determine statistical differences. Significance was set at p<0.05. Only 17 percent of the participants in the research sample were found to be overweight or obese. Only emotional self-efficacy showed significant (p=0.02) differences between the participants who were classified as having normal weights and the group which comprised the overweight and the obese groups. Overweight and obese boys and girls still had very high levels of self-efficacy, although their body mass index scores were high. Boys scored higher in social self-efficacy and girls in academic self-efficacy. Only girls presented significantly high correlations between body mass index and emotional self-efficacy (r=0.33, p=0.02), total self-efficacy and hip-to-waist ratio (r=0.44, p=0.00), social self-efficacy and hip-towaist ratio (r=0.39, p=0.01) and emotional self-efficacy and hip-to-waist ratio (r=0.33, p=0.02), while boys presented them only with respect to body weight (r=0.31, p=0.02) and stature (r=0.39, p=0.00). The results suggest that a positive relationship exists between body composition, in terms of hip-to-waist ratio, weight and stature, and self-efficacy among South African rural adolescents. However, girls presented significantly strong and positive correlations between hip-to-waist ratio and self-efficacy, whereas boys presented significant, strong and positive correlations between body weight, stature and self-efficacy. Only emotional self-efficacy showed significant differences between normal weight and overweight or obese South African rural adolescents. It seems likely that cultural beliefs may exert an influence on the psychosocial perceptions of adolescents in relation to body size, consequently affecting self efficacy levels.
- Full Text:
- Date Issued: 2017
The medicinal chemistry of cyclo (Ser-Ser) and cyclo (Ser-Tyr)
- Authors: Kritzinger, André Louis
- Date: 2007
- Subjects: Cyclic peptides , Peptide drugs -- Therapeutic use , Haematostasis , Pharmaceutical chemistry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10155 , http://hdl.handle.net/10948/537 , http://hdl.handle.net/10948/d1011712 , Cyclic peptides , Peptide drugs -- Therapeutic use , Haematostasis , Pharmaceutical chemistry
- Description: Cyclic dipeptides are widely used as models for larger peptides because of their simplicity and limited conformational freedom. Some cyclic dipeptides have been shown to produce antiviral, antibiotic and anti-tumour activity (Milne et al., 1998). In this study the cyclic dipeptides, cyclo(Ser-Ser) and cyclo(Ser-Tyr), were synthesised from their corresponding linear precursors using a modified phenolinduced cyclisation procedure. The phenol-induced cyclisation procedure resulted in good yields and purity of the cyclic dipeptides. Quantitative analysis and evaluation of the physicochemical properties of the cyclic dipeptides was achieved by using high-performance liquid chromatography, scanning electron microscopy, thermal analysis and X-ray powder diffraction. The structures of the synthesised cyclic dipeptides were elucidated using infrared spectroscopy, mass spectrometry, nuclear magnetic resonance spectroscopy and molecular modelling. The study aimed to determine the biological activity of cyclo(Ser-Ser) and cyclo(Ser-Tyr) with respect to their anticancer, antimicrobial, haematological and cardiac effects. Anticancer studies revealed that cyclo(Ser-Ser) and cyclo(Ser- Tyr) inhibited the growth of HeLa (cervical cancer), HT-29 (colon cancer) and MCF (breast cancer) cancer cell lines. Both cyclic dipeptides also inhibited the growth of certain selected Gram-positive, Gram-negative and fungal microorganisms in the antimicrobial study. Although the inhibition of growth in the anticancer and antimicrobial studies was statistically significant, the clinical relevance is questionable, since the inhibition produced by both cyclic dipeptides was very limited compared to other pre-existing anticancer and antimicrobial agents. Cyclo(Ser-Tyr) exhibited significant activity in the haematological studies, where it increased the rate of calcium induced-coagulation, and decreased the rate of streptokinase-induced fibrinolysis. Both cyclic dipeptides, however, failed to produce any significant effects on thrombin-substrate binding and ADPinduced platelet aggregation. Cardiac studies revealed that cyclo(Ser-Ser) and especially cyclo(Ser-Tyr) reduced the heart rate, coronary flow rate and ventricular pressure of isolated rat hearts.
- Full Text:
- Date Issued: 2007
- Authors: Kritzinger, André Louis
- Date: 2007
- Subjects: Cyclic peptides , Peptide drugs -- Therapeutic use , Haematostasis , Pharmaceutical chemistry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10155 , http://hdl.handle.net/10948/537 , http://hdl.handle.net/10948/d1011712 , Cyclic peptides , Peptide drugs -- Therapeutic use , Haematostasis , Pharmaceutical chemistry
- Description: Cyclic dipeptides are widely used as models for larger peptides because of their simplicity and limited conformational freedom. Some cyclic dipeptides have been shown to produce antiviral, antibiotic and anti-tumour activity (Milne et al., 1998). In this study the cyclic dipeptides, cyclo(Ser-Ser) and cyclo(Ser-Tyr), were synthesised from their corresponding linear precursors using a modified phenolinduced cyclisation procedure. The phenol-induced cyclisation procedure resulted in good yields and purity of the cyclic dipeptides. Quantitative analysis and evaluation of the physicochemical properties of the cyclic dipeptides was achieved by using high-performance liquid chromatography, scanning electron microscopy, thermal analysis and X-ray powder diffraction. The structures of the synthesised cyclic dipeptides were elucidated using infrared spectroscopy, mass spectrometry, nuclear magnetic resonance spectroscopy and molecular modelling. The study aimed to determine the biological activity of cyclo(Ser-Ser) and cyclo(Ser-Tyr) with respect to their anticancer, antimicrobial, haematological and cardiac effects. Anticancer studies revealed that cyclo(Ser-Ser) and cyclo(Ser- Tyr) inhibited the growth of HeLa (cervical cancer), HT-29 (colon cancer) and MCF (breast cancer) cancer cell lines. Both cyclic dipeptides also inhibited the growth of certain selected Gram-positive, Gram-negative and fungal microorganisms in the antimicrobial study. Although the inhibition of growth in the anticancer and antimicrobial studies was statistically significant, the clinical relevance is questionable, since the inhibition produced by both cyclic dipeptides was very limited compared to other pre-existing anticancer and antimicrobial agents. Cyclo(Ser-Tyr) exhibited significant activity in the haematological studies, where it increased the rate of calcium induced-coagulation, and decreased the rate of streptokinase-induced fibrinolysis. Both cyclic dipeptides, however, failed to produce any significant effects on thrombin-substrate binding and ADPinduced platelet aggregation. Cardiac studies revealed that cyclo(Ser-Ser) and especially cyclo(Ser-Tyr) reduced the heart rate, coronary flow rate and ventricular pressure of isolated rat hearts.
- Full Text:
- Date Issued: 2007
Antibacterial activity of liposome encapsulated cyclo(TYR-PRO)
- Authors: Tshanga, Siphokazi Sisanda
- Date: 2011
- Subjects: Peptide antibiotics , Antibacterial agents -- Therapeutic use -- Testing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10132 , http://hdl.handle.net/10948/1450 , Peptide antibiotics , Antibacterial agents -- Therapeutic use -- Testing
- Description: Cyclic dipeptides (CDPs) are amino acid-based compounds, some of which possess antibacterial activity. The encapsulation of certain drugs into liposomes has been found to improve their activity in terms of bioavailability and duration of action. Liposomes are small vesicles that are under investigation as drug carriers for the delivery of therapeutic agents. A number of liposome formulations are currently under clinical trial review, whilst some have already been approved for clinical use. The aim of this study was to optimize a liposomal cyclo(Tyr-Pro) formulation and to assess its antibacterial activity against various Gram-positive and Gram-negative bacteria. Response surface methodology (RSM) using the central composite design (CCD) model was used to optimize liposomal formulations of cyclo(Tyr-Pro) for each of the four bacteria, namely Bacillus cereus, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Percent drug encapsulated and bacterial inhibition were investigated with respect to two independent variables, i.e. lipid composition and cholesterol content. Design Expert 8 was used for the purpose of finding the combination of independent variables that would yield an optimal formulation for each bacterium. The model selected by the software failed to adequately correlate the predicted models to the experimental data. The in vitro experiments showed that the antibacterial activity of liposome-encapsulated cyclo(Tyr-Pro) was superior to that of its free counterpart. Binding maximum or Bmax for the encapsulated compound at concentrations as low as 0.412 mg/ml, was significantly higher than that obtained for free cyclo(Tyr-Pro) which was tested at a concentration of 20 mg/ml. Furthermore, encapsulation of cyclo(Tyr-Pro) into a liposome formulation enhanced its potency. This was evident in the lower IC50 values for the liposomal compound when compared to free cyclo(Tyr-Pro).
- Full Text:
- Date Issued: 2011
- Authors: Tshanga, Siphokazi Sisanda
- Date: 2011
- Subjects: Peptide antibiotics , Antibacterial agents -- Therapeutic use -- Testing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10132 , http://hdl.handle.net/10948/1450 , Peptide antibiotics , Antibacterial agents -- Therapeutic use -- Testing
- Description: Cyclic dipeptides (CDPs) are amino acid-based compounds, some of which possess antibacterial activity. The encapsulation of certain drugs into liposomes has been found to improve their activity in terms of bioavailability and duration of action. Liposomes are small vesicles that are under investigation as drug carriers for the delivery of therapeutic agents. A number of liposome formulations are currently under clinical trial review, whilst some have already been approved for clinical use. The aim of this study was to optimize a liposomal cyclo(Tyr-Pro) formulation and to assess its antibacterial activity against various Gram-positive and Gram-negative bacteria. Response surface methodology (RSM) using the central composite design (CCD) model was used to optimize liposomal formulations of cyclo(Tyr-Pro) for each of the four bacteria, namely Bacillus cereus, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Percent drug encapsulated and bacterial inhibition were investigated with respect to two independent variables, i.e. lipid composition and cholesterol content. Design Expert 8 was used for the purpose of finding the combination of independent variables that would yield an optimal formulation for each bacterium. The model selected by the software failed to adequately correlate the predicted models to the experimental data. The in vitro experiments showed that the antibacterial activity of liposome-encapsulated cyclo(Tyr-Pro) was superior to that of its free counterpart. Binding maximum or Bmax for the encapsulated compound at concentrations as low as 0.412 mg/ml, was significantly higher than that obtained for free cyclo(Tyr-Pro) which was tested at a concentration of 20 mg/ml. Furthermore, encapsulation of cyclo(Tyr-Pro) into a liposome formulation enhanced its potency. This was evident in the lower IC50 values for the liposomal compound when compared to free cyclo(Tyr-Pro).
- Full Text:
- Date Issued: 2011
Retrospective analysis of birth HIV PCR testing and follow-up of positive HIV PCR results in Nelson Mandela Bay Health District
- Authors: Makubalo, Nomlindo Princess
- Date: 2020
- Subjects: HIV infections -- South Africa -- Nelson Mandela Bay
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/46351 , vital:39580
- Description: BACKGROUND HIV infection contributes significantly to infant morbidity and mortality, especially in high-prevalence, low-income countries. In view of this evidence-based knowledge, South Africa’s National Department of Health, in April 2015, released the National Consolidated Guidelines of Human Immunodeficiency Virus (HIV) stipulating that all HIV-exposed babies should have a HIV Polymer Chain Reaction (PCR) test performed at birth. Early infant diagnosis (EID) means early initiation of combined antiretroviral treatment (cART) and a reduction in the incidence of early infant HIV-related mortality. However, these guidelines can only be successful if implemented properly across all public sector healthcare institutions. Thus,the research question was,“How well has the Nelson Mandela Bay Health District implemented the EID?”AIM The aim of the study was to review the impact of the consolidated HIV guidelines on birth HIV-PCR testing and initiation of treatment in the Nelson Mandela Bay Health District. METHOD A retrospective quantitative longitudinal non-experimental design was used.The study consisted of two components,namely,analysis of NHLS databases, particularly HIV birth PCR results of infants over a three-year period (June 2015 to June 2018),and analysis of feedback received from the primary health care clinics. The feedback focused on infants with a positive-birth PCR test, using a purpose-designed data collection tool that was used by the clinics for the duration of the same three-year period. The paper-based tool documented antenatal care attendance, enrolment into the prevention of mother-to-child transmission (PMTCT) programme and initiation of ART. RESULTS Over the three-year period, there were approximately 13,096 live births to HIV-positive women in the study area, and a total of 11,066 HIV birth PCR tests were done over xiiithe three-year study period (84.5% of HIV-exposed infants). The birth HIV PCR was negative in 10,909 (98.6%) neonates, while 130 (1.2%) of neonates had positive-birth HIV PCR tests,and a further 27 (0.2%) had indeterminate results. The birth HIV PCR positivity rate reduced from 1.4%(2015)to 1%(2018)over the three-year study period. Of the 130 infants with positive-birth HIV PCR, the files of 42 children were excluded, and further analysis conducted on the files of 88 infants. cART was initiated within seven days in only nine of the 88 infants (10.2%). ARV initiation was delayed for 58 infants (65.9%) and 21 neonates (23.9%) were never initiated on cART. Among the 88 mothers of infants, more than one-third (38.6%) of pregnant women did not attend antenatal care, thus,compromising their opportunity to be enrolled on the PMTCT programme. Of those who attended antenatal care, only 39.1% were reported to attend antenatal care before 20 weeks CONCLUSION AND RECOMMENDATIONS The incidence of positive-birth HIV PCR has reduced from 1.4% in 2015 to 1% in 2018 whilst there has been an increase in birth HIV PCR testing. However, initiation of cART within seven days was achieved in only 10.2% of infants with positive-birth HIV PCR test results. Implementation of point-of-care birth HIV PCR testing would ensure that results are immediately available resulting in increasing the proportion of infants initiated on cART within seven days.
- Full Text:
- Date Issued: 2020
- Authors: Makubalo, Nomlindo Princess
- Date: 2020
- Subjects: HIV infections -- South Africa -- Nelson Mandela Bay
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/46351 , vital:39580
- Description: BACKGROUND HIV infection contributes significantly to infant morbidity and mortality, especially in high-prevalence, low-income countries. In view of this evidence-based knowledge, South Africa’s National Department of Health, in April 2015, released the National Consolidated Guidelines of Human Immunodeficiency Virus (HIV) stipulating that all HIV-exposed babies should have a HIV Polymer Chain Reaction (PCR) test performed at birth. Early infant diagnosis (EID) means early initiation of combined antiretroviral treatment (cART) and a reduction in the incidence of early infant HIV-related mortality. However, these guidelines can only be successful if implemented properly across all public sector healthcare institutions. Thus,the research question was,“How well has the Nelson Mandela Bay Health District implemented the EID?”AIM The aim of the study was to review the impact of the consolidated HIV guidelines on birth HIV-PCR testing and initiation of treatment in the Nelson Mandela Bay Health District. METHOD A retrospective quantitative longitudinal non-experimental design was used.The study consisted of two components,namely,analysis of NHLS databases, particularly HIV birth PCR results of infants over a three-year period (June 2015 to June 2018),and analysis of feedback received from the primary health care clinics. The feedback focused on infants with a positive-birth PCR test, using a purpose-designed data collection tool that was used by the clinics for the duration of the same three-year period. The paper-based tool documented antenatal care attendance, enrolment into the prevention of mother-to-child transmission (PMTCT) programme and initiation of ART. RESULTS Over the three-year period, there were approximately 13,096 live births to HIV-positive women in the study area, and a total of 11,066 HIV birth PCR tests were done over xiiithe three-year study period (84.5% of HIV-exposed infants). The birth HIV PCR was negative in 10,909 (98.6%) neonates, while 130 (1.2%) of neonates had positive-birth HIV PCR tests,and a further 27 (0.2%) had indeterminate results. The birth HIV PCR positivity rate reduced from 1.4%(2015)to 1%(2018)over the three-year study period. Of the 130 infants with positive-birth HIV PCR, the files of 42 children were excluded, and further analysis conducted on the files of 88 infants. cART was initiated within seven days in only nine of the 88 infants (10.2%). ARV initiation was delayed for 58 infants (65.9%) and 21 neonates (23.9%) were never initiated on cART. Among the 88 mothers of infants, more than one-third (38.6%) of pregnant women did not attend antenatal care, thus,compromising their opportunity to be enrolled on the PMTCT programme. Of those who attended antenatal care, only 39.1% were reported to attend antenatal care before 20 weeks CONCLUSION AND RECOMMENDATIONS The incidence of positive-birth HIV PCR has reduced from 1.4% in 2015 to 1% in 2018 whilst there has been an increase in birth HIV PCR testing. However, initiation of cART within seven days was achieved in only 10.2% of infants with positive-birth HIV PCR test results. Implementation of point-of-care birth HIV PCR testing would ensure that results are immediately available resulting in increasing the proportion of infants initiated on cART within seven days.
- Full Text:
- Date Issued: 2020
Dietary diversity amongst adults who buy at shopping malls in the Nelson Mandela Bay area
- Authors: De Bruin, Eunice Mari
- Date: 2017
- Subjects: Nutrition -- South Africa -- Port Elizabeth , Older people -- Nutrition Diet Food security -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/15027 , vital:28114
- Description: Background: Assessing the level of dietary diversity and contributing factors that influence the level of dietary diversity amongst adults can highlight gaps in nutrition interventions, policies and programmes, which aim at combating the double burden of malnutrition. Aim: The aim of this study was to determine which factors and relationships affect the level of dietary diversity of adults in the Nelson Mandela Bay area. Design: An exploratory comparative, cross-sectional, quantitative study design with a qualitative component that was utilised. Both interviewer- and participantadministered questionnaire sections were applied. Data were analysed using IBM SPSS Statistics, Statistica Version 12, Microsoft Office Excel 2007, Spearman rho correlation co-efficient and Pearson’s chi-square test (p-value <0.05). Participants and setting: A convenience-stratified sample (n=480) was used, consisting of adults who reside and shop at shopping centres in the Nelson Mandela area, after obtaining informed consent. Results: The findings indicated that adults in the Nelson Mandela Bay area who shopped at shopping malls had a medium level of dietary diversity. The dietary patterns found were not in line with the South African Food Based Dietary Guidelines. The most consumed food items were ‘cereals' (95%), 'sweetening agents and sweets' (89%) and ‘spices, condiments and beverages’ (87%). Fruit (45,2%) and vegetables (64,8%) were generally poorly consumed. Significance was shown as having an effect on the level of dietary diversity for factors such as ethnicity, level of education, amount of money spent on food purchase per month, distance travelled to purchase food, and nutrition knowledge. Conclusion: The study suggests that adults living in the Nelson Mandela Bay area have a medium level of dietary diversity, with practices that are not in line with the recommended South African Food Based Dietary Guidelines. Strategies, including nutrition education promotion and the implementation of current policies, programmes and interventions, should be implemented and/or strengthened to encourage behaviour change.
- Full Text:
- Date Issued: 2017
- Authors: De Bruin, Eunice Mari
- Date: 2017
- Subjects: Nutrition -- South Africa -- Port Elizabeth , Older people -- Nutrition Diet Food security -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/15027 , vital:28114
- Description: Background: Assessing the level of dietary diversity and contributing factors that influence the level of dietary diversity amongst adults can highlight gaps in nutrition interventions, policies and programmes, which aim at combating the double burden of malnutrition. Aim: The aim of this study was to determine which factors and relationships affect the level of dietary diversity of adults in the Nelson Mandela Bay area. Design: An exploratory comparative, cross-sectional, quantitative study design with a qualitative component that was utilised. Both interviewer- and participantadministered questionnaire sections were applied. Data were analysed using IBM SPSS Statistics, Statistica Version 12, Microsoft Office Excel 2007, Spearman rho correlation co-efficient and Pearson’s chi-square test (p-value <0.05). Participants and setting: A convenience-stratified sample (n=480) was used, consisting of adults who reside and shop at shopping centres in the Nelson Mandela area, after obtaining informed consent. Results: The findings indicated that adults in the Nelson Mandela Bay area who shopped at shopping malls had a medium level of dietary diversity. The dietary patterns found were not in line with the South African Food Based Dietary Guidelines. The most consumed food items were ‘cereals' (95%), 'sweetening agents and sweets' (89%) and ‘spices, condiments and beverages’ (87%). Fruit (45,2%) and vegetables (64,8%) were generally poorly consumed. Significance was shown as having an effect on the level of dietary diversity for factors such as ethnicity, level of education, amount of money spent on food purchase per month, distance travelled to purchase food, and nutrition knowledge. Conclusion: The study suggests that adults living in the Nelson Mandela Bay area have a medium level of dietary diversity, with practices that are not in line with the recommended South African Food Based Dietary Guidelines. Strategies, including nutrition education promotion and the implementation of current policies, programmes and interventions, should be implemented and/or strengthened to encourage behaviour change.
- Full Text:
- Date Issued: 2017
The experiences of professional nurses regarding the management of health services rendered to tuberculosis patients
- Authors: Jantjies, Leigh-Anne Rene
- Date: 2011
- Subjects: Tuberculosis -- Nursing -- South Africa -- Port Elizabeth , Health services administration -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10025 , http://hdl.handle.net/10948/1399 , Tuberculosis -- Nursing -- South Africa -- Port Elizabeth , Health services administration -- South Africa -- Port Elizabeth
- Description: The World Health Organisation (WHO) declared tuberculosis (TB) a global emergency, and this infectious disease remains a health threat by being the leading cause of death amongst adults (Naidoo, Dick & Cooper, 2008:55). In 2005, South Africa was ranked seventh in the world for having the highest TB rate and the lowest TB success rate in the world. As a professional nurse involved in the tuberculosis programme at a clinic in the Nelson Mandela Bay Municipality at local government level for approximately three years, the researcher observed that the morale of professional nurses who provide TB services appeared to be low. They also appeared to be frustrated because they feel that they are not winning the battle with regard to the TB epidemic in their communities irrespective of their efforts to try and curb the spread of the disease. The extent of the workload per person also appeared to add to the low morale and frustration of the professional nurses rendering TB health services because they feel that they are unable to manage everything. The objectives of the study were therefore to explore and describe how professional nurses experienced the management of health services being rendered to TB patients in Sub district B of the Nelson Mandela Bay Municipality (NMBM) in order to make recommendations that could be used by the district manager to address the research findings. The research study was based on a qualitative, explorative, descriptive and contextual research design. The research population consisted of all professional nurses who worked in the TB services of Sub district B. Non-probability, purposive sampling was used to select the participants for the study. Seven in-depth and three follow-up interviews were conducted before data saturation was achieved. The data gathered during the interview process by the researcher were transcribed and coded by an independent coder using Tech’s model for data analysis. Ethical considerations were adhered to throughout the research study. The aspect of trustworthiness according to Guba’s model was implemented in the research study and included credibility, applicability, consistency and neutrality. iii One theme, two sub themes and categories were identified relating to the diverse experiences expressed by the participants relating to the management of health services being rendered to TB patients. The experiences expressed by the professional nurses included both negative and positive experiences. The negative experiences expressed by the participants were for example, a lack of resources as hampering adequate service delivery, a concern regarding the number of staff contracting TB due to a lack of infection control measures, a difference in conditions of service between the two local authorities and the DOTS supporters as being a threat to patient confidentiality. The positive experiences expressed by the participants included experiences relating to job satisfaction in rendering TB health services, the DOTS supporters as being supportive to the staff, the TB meetings serving as an appropriate platform for problem solving and the audits conducted by managers as being remedial. The study concludes with recommendations made with regard to the areas of nursing practice, education and research.
- Full Text:
- Date Issued: 2011
- Authors: Jantjies, Leigh-Anne Rene
- Date: 2011
- Subjects: Tuberculosis -- Nursing -- South Africa -- Port Elizabeth , Health services administration -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10025 , http://hdl.handle.net/10948/1399 , Tuberculosis -- Nursing -- South Africa -- Port Elizabeth , Health services administration -- South Africa -- Port Elizabeth
- Description: The World Health Organisation (WHO) declared tuberculosis (TB) a global emergency, and this infectious disease remains a health threat by being the leading cause of death amongst adults (Naidoo, Dick & Cooper, 2008:55). In 2005, South Africa was ranked seventh in the world for having the highest TB rate and the lowest TB success rate in the world. As a professional nurse involved in the tuberculosis programme at a clinic in the Nelson Mandela Bay Municipality at local government level for approximately three years, the researcher observed that the morale of professional nurses who provide TB services appeared to be low. They also appeared to be frustrated because they feel that they are not winning the battle with regard to the TB epidemic in their communities irrespective of their efforts to try and curb the spread of the disease. The extent of the workload per person also appeared to add to the low morale and frustration of the professional nurses rendering TB health services because they feel that they are unable to manage everything. The objectives of the study were therefore to explore and describe how professional nurses experienced the management of health services being rendered to TB patients in Sub district B of the Nelson Mandela Bay Municipality (NMBM) in order to make recommendations that could be used by the district manager to address the research findings. The research study was based on a qualitative, explorative, descriptive and contextual research design. The research population consisted of all professional nurses who worked in the TB services of Sub district B. Non-probability, purposive sampling was used to select the participants for the study. Seven in-depth and three follow-up interviews were conducted before data saturation was achieved. The data gathered during the interview process by the researcher were transcribed and coded by an independent coder using Tech’s model for data analysis. Ethical considerations were adhered to throughout the research study. The aspect of trustworthiness according to Guba’s model was implemented in the research study and included credibility, applicability, consistency and neutrality. iii One theme, two sub themes and categories were identified relating to the diverse experiences expressed by the participants relating to the management of health services being rendered to TB patients. The experiences expressed by the professional nurses included both negative and positive experiences. The negative experiences expressed by the participants were for example, a lack of resources as hampering adequate service delivery, a concern regarding the number of staff contracting TB due to a lack of infection control measures, a difference in conditions of service between the two local authorities and the DOTS supporters as being a threat to patient confidentiality. The positive experiences expressed by the participants included experiences relating to job satisfaction in rendering TB health services, the DOTS supporters as being supportive to the staff, the TB meetings serving as an appropriate platform for problem solving and the audits conducted by managers as being remedial. The study concludes with recommendations made with regard to the areas of nursing practice, education and research.
- Full Text:
- Date Issued: 2011
Formulation and stability testing of eye drop preparations containing phenylephrine hydrochloride
- Authors: Okafor, Chinedum Oluchukwu
- Date: 2012
- Subjects: Phenylpropanolamine , Viscosity , Glycerin
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10164 , http://hdl.handle.net/10948/d1020985
- Description: Phenylephrine hydrochloride is a potent adrenergic agent and β-receptor sympathomimetic drug, used in its optically active form (Pandey et al., 2003; Pandey et al., 2006). As an α1-adrenergic receptor agonist, phenylephrine hydrochloride is used ocularly as a decongestant for uveitis and as an agent to dilate the pupil (Lang, 1995). High intraocular doses have been reported to cause tachycardia, hypertension, and headache. These side effects are caused by large amounts of the drop draining into the nasal cavity. Eye drops that contain phenylephrine hydrochloride have proven to have low intra-ocular bioavailability because of a short contact time with the eyes which reduces the amount of drug reaching the site of action. Formulations of phenylephrine hydrochloride eye drops have varying shelf-lives of approximately two to four years. The aim of this study was to formulate and manufacture an eye drop product containing phenylephrine hydrochloride. Important characteristics that were targeted were increased ocular absorption by increasing the viscosity of the product and reduced degradation of phenylephrine hydrochloride. A variety of phenylephrine hydrochloride formulations were manufactured on a laboratory scale using hydroxypropyl methylcellulose (HPMC), glycerol, and sodium carboxy methylcellulose as viscosity modifying agents (VMA). The concentration of phenylephrine hydrochloride was ten percent. Ten millimeters of each formulation was made in triplicate. The quantity in each was evaluated using a previously validated high performance (pressure) liquid chromatography method. Physicochemical properties including pH and colour were also evaluated. Stability was assessed using real time and accelerated stability conditions in accordance with the International Conference on Harmonization (ICH) guidelines. Formulations containing hydroxypropyl methylcellulose (HPMC) as the viscosity modifying agents proved to be stable under all storage conditions when compared with formulations containing other viscosity modifying agents (VMA). However, sodium citrate dihydrate; sodium metabisulphite and EDTA also stabilized the formulations to a certain extent Changes in the appearance and colour of products containing glycerol under accelerated storage conditions were observed. The sodium carboxy methylcellulose (SCMC) containing formulation was found to be physically and chemically stable in two conditions, namely 30 °C/65 percent RH and 25 °C/60 percent RH. The formulations containing hydroxypropyl methylcellulose along with an antioxidant showed to be most stable as it remained aesthetically pleasing did not change colour and did not have a reduction in phenylephrine hydrochloride concentrations. This meant that phenylephrine hydrochloride did not degrade while the viscosity modifying agents remained stable. Rheological tests showed differences in the viscosities of the formulations as glycerol had increased in viscosity over time while HMPC and SCMC displayed relative similarities. The formulations were compared to a marketed eye drop containing polyvinyl alcohol as a VMA. After rheological analysis the formulation containing HPMC displayed better viscosity than the product with polyvinyl alcohol. The preservatives in the formulations were active against the microbial organisms use to challenged them.
- Full Text:
- Date Issued: 2012
- Authors: Okafor, Chinedum Oluchukwu
- Date: 2012
- Subjects: Phenylpropanolamine , Viscosity , Glycerin
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10164 , http://hdl.handle.net/10948/d1020985
- Description: Phenylephrine hydrochloride is a potent adrenergic agent and β-receptor sympathomimetic drug, used in its optically active form (Pandey et al., 2003; Pandey et al., 2006). As an α1-adrenergic receptor agonist, phenylephrine hydrochloride is used ocularly as a decongestant for uveitis and as an agent to dilate the pupil (Lang, 1995). High intraocular doses have been reported to cause tachycardia, hypertension, and headache. These side effects are caused by large amounts of the drop draining into the nasal cavity. Eye drops that contain phenylephrine hydrochloride have proven to have low intra-ocular bioavailability because of a short contact time with the eyes which reduces the amount of drug reaching the site of action. Formulations of phenylephrine hydrochloride eye drops have varying shelf-lives of approximately two to four years. The aim of this study was to formulate and manufacture an eye drop product containing phenylephrine hydrochloride. Important characteristics that were targeted were increased ocular absorption by increasing the viscosity of the product and reduced degradation of phenylephrine hydrochloride. A variety of phenylephrine hydrochloride formulations were manufactured on a laboratory scale using hydroxypropyl methylcellulose (HPMC), glycerol, and sodium carboxy methylcellulose as viscosity modifying agents (VMA). The concentration of phenylephrine hydrochloride was ten percent. Ten millimeters of each formulation was made in triplicate. The quantity in each was evaluated using a previously validated high performance (pressure) liquid chromatography method. Physicochemical properties including pH and colour were also evaluated. Stability was assessed using real time and accelerated stability conditions in accordance with the International Conference on Harmonization (ICH) guidelines. Formulations containing hydroxypropyl methylcellulose (HPMC) as the viscosity modifying agents proved to be stable under all storage conditions when compared with formulations containing other viscosity modifying agents (VMA). However, sodium citrate dihydrate; sodium metabisulphite and EDTA also stabilized the formulations to a certain extent Changes in the appearance and colour of products containing glycerol under accelerated storage conditions were observed. The sodium carboxy methylcellulose (SCMC) containing formulation was found to be physically and chemically stable in two conditions, namely 30 °C/65 percent RH and 25 °C/60 percent RH. The formulations containing hydroxypropyl methylcellulose along with an antioxidant showed to be most stable as it remained aesthetically pleasing did not change colour and did not have a reduction in phenylephrine hydrochloride concentrations. This meant that phenylephrine hydrochloride did not degrade while the viscosity modifying agents remained stable. Rheological tests showed differences in the viscosities of the formulations as glycerol had increased in viscosity over time while HMPC and SCMC displayed relative similarities. The formulations were compared to a marketed eye drop containing polyvinyl alcohol as a VMA. After rheological analysis the formulation containing HPMC displayed better viscosity than the product with polyvinyl alcohol. The preservatives in the formulations were active against the microbial organisms use to challenged them.
- Full Text:
- Date Issued: 2012
The women's health initiative study: impact on the prescribing of hormone replacement therapy in a defined South African population
- Authors: Hanly, Teia
- Date: 2006
- Subjects: Women -- Health and hygiene -- South Africa , Women's health services -- South Africa , Menopause -- Hormone therapy -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10156 , http://hdl.handle.net/10948/519 , http://hdl.handle.net/10948/d1011713 , Women -- Health and hygiene -- South Africa , Women's health services -- South Africa , Menopause -- Hormone therapy -- South Africa
- Description: Context: The Women’s Health Initiative (WHI) study, published in July 2002, had a significant impact on the prescribing of hormone replacement therapy (HRT). The controversy surrounding the findings, however, has led to much uncertainty regarding the prescription of HRT. Aims and Objectives: The aim of this study is to determine both the initial and the continued impact of the WHI study on the prescribing of HRT in a defined South African population and to determine whether HRT was appropriately individualised based on recommendations published subsequent to the WHI study. Setting: Claims data from a Managed Healthcare Organisation (MHO) that administers for a number of medical aid schemes in South Africa. Method: A retrospective drug utilisation review (DUR) was conducted to identify HRT-related prescribing patterns in the defined populations. The time-frame of the dataset included January 2002, to assess prescribing patterns prior to the publication of the WHI study, January 2003 to determine the initial impact of the WHI study, and January 2005 to assess the continued impact. An extensive, additional dataset of all the HRT users in the defined populations was utilised to conduct a sub-group analysis and determine whether HRT had been appropriately individualised. Key Findings: The percentage of patients in the dataset using HRT decreased from 30.05 percent in January 2002 to 28.30 percent in January 2003 and to 23.24 percent in January 2005, with the latter decrease reaching statistical significance. Although sex hormones and modulators (G03) of the genital system were the most frequently prescribed drug class in all three years of the study period, the prescribing frequency decreased significantly from 10.40 percent in January 2002 to 9.32 percent in January 2003 and 7.44 percent in January 2005. The most noteworthy change in the prescribing of HRT was a 3.95 percent decrease in the prescribing of conjugated equine estrogen (CEE), with a corresponding 2.53 percent increase in the prescribing of estradiol between January 2002 and January 2003. However, less pronounced changes were observed in the prescribing frequencies of other types of HRT, including medroxyprogesterone and estrogen (the HRT type investigated in the estrogen plus progestin phase of the WHI study). Patients initiating HRT post-WHI publication were generally found to be in the younger menopausal age categories (40 to 49 years). These patients were more likely to have been initiated on HRT types other than those investigated in the WHI study and were at a higher risk for disease states for which HRT use is beneficial, such as osteoporosis. Patients discontinuing HRT post-WHI publication were generally found to be in the older menopausal age categories (60 to 69 years), were more likely to have been combined HRT users (although not necessarily the type investigated in the WHI study) and were at a higher risk for disease states for which HRT use is considered harmful or has an uncertain effect, such as diseases affecting the cardiovascular system. Conclusion: It can be concluded that the WHI study did have an impact on the prescribing of HRT in the defined South African population of this study, but that the impact was considerably less than the impact reported in global studies. It was also determined that HRT was appropriately individualised according to recommendations made subsequent to publication of the WHI study.
- Full Text:
- Date Issued: 2006
- Authors: Hanly, Teia
- Date: 2006
- Subjects: Women -- Health and hygiene -- South Africa , Women's health services -- South Africa , Menopause -- Hormone therapy -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10156 , http://hdl.handle.net/10948/519 , http://hdl.handle.net/10948/d1011713 , Women -- Health and hygiene -- South Africa , Women's health services -- South Africa , Menopause -- Hormone therapy -- South Africa
- Description: Context: The Women’s Health Initiative (WHI) study, published in July 2002, had a significant impact on the prescribing of hormone replacement therapy (HRT). The controversy surrounding the findings, however, has led to much uncertainty regarding the prescription of HRT. Aims and Objectives: The aim of this study is to determine both the initial and the continued impact of the WHI study on the prescribing of HRT in a defined South African population and to determine whether HRT was appropriately individualised based on recommendations published subsequent to the WHI study. Setting: Claims data from a Managed Healthcare Organisation (MHO) that administers for a number of medical aid schemes in South Africa. Method: A retrospective drug utilisation review (DUR) was conducted to identify HRT-related prescribing patterns in the defined populations. The time-frame of the dataset included January 2002, to assess prescribing patterns prior to the publication of the WHI study, January 2003 to determine the initial impact of the WHI study, and January 2005 to assess the continued impact. An extensive, additional dataset of all the HRT users in the defined populations was utilised to conduct a sub-group analysis and determine whether HRT had been appropriately individualised. Key Findings: The percentage of patients in the dataset using HRT decreased from 30.05 percent in January 2002 to 28.30 percent in January 2003 and to 23.24 percent in January 2005, with the latter decrease reaching statistical significance. Although sex hormones and modulators (G03) of the genital system were the most frequently prescribed drug class in all three years of the study period, the prescribing frequency decreased significantly from 10.40 percent in January 2002 to 9.32 percent in January 2003 and 7.44 percent in January 2005. The most noteworthy change in the prescribing of HRT was a 3.95 percent decrease in the prescribing of conjugated equine estrogen (CEE), with a corresponding 2.53 percent increase in the prescribing of estradiol between January 2002 and January 2003. However, less pronounced changes were observed in the prescribing frequencies of other types of HRT, including medroxyprogesterone and estrogen (the HRT type investigated in the estrogen plus progestin phase of the WHI study). Patients initiating HRT post-WHI publication were generally found to be in the younger menopausal age categories (40 to 49 years). These patients were more likely to have been initiated on HRT types other than those investigated in the WHI study and were at a higher risk for disease states for which HRT use is beneficial, such as osteoporosis. Patients discontinuing HRT post-WHI publication were generally found to be in the older menopausal age categories (60 to 69 years), were more likely to have been combined HRT users (although not necessarily the type investigated in the WHI study) and were at a higher risk for disease states for which HRT use is considered harmful or has an uncertain effect, such as diseases affecting the cardiovascular system. Conclusion: It can be concluded that the WHI study did have an impact on the prescribing of HRT in the defined South African population of this study, but that the impact was considerably less than the impact reported in global studies. It was also determined that HRT was appropriately individualised according to recommendations made subsequent to publication of the WHI study.
- Full Text:
- Date Issued: 2006