Taste masking of clarithromycin with ion exchange resins
- Authors: Ntemi, Pascal Vitalis
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65178 , vital:28701
- Description: Expected release date-May 2019
- Full Text:
- Date Issued: 2017
The applicability of anaerobically digested pasteurized pit latrine faecal sludge as a fertilizer to grow radish and garden cress
- Authors: Madikizela, Phindile
- Date: 2017
- Subjects: Sewage sludge as fertilizer , Sewage sludge digestion , Sewage Purification Anaerobic treatment
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59235 , vital:27487
- Description: Pit latrine faecal sludge was recovered from numerous pit latrines in Hlalani Township, Grahamstown, South Africa. This material was used to prepare a fertilizer to demonstrate the value that could be captured from faecal sludge. Further anaerobic digestion, together with a co-feed demonstrated the potential of faecal sludge to produce low cost fertilizer that could be used to grow food crops. Biogas recovered from the anaerobic digester could be used to pasteurize its effluent, although effective biogas recovery and storage needs to be further addressed. Investigating the microbial community of the different depths of the pit latrine through molecular techniques showed that the fermenting bacteria family Clostridiaceae was the most commonly identified family throughout the different depths of the pit latrine, and that the microbial community within pit latrines was very diverse with bacterial families that are involved in nitrogen fixation, denitrification, and iron and sulphate reduction. Additionally, most of the bacterial families that dominated the seven studied pit latrines had members that were known human pathogens (Mycobacteriaceae, Dermatophilaceae Peptostreptococcaceae, Micrococcaceae, Staphylococcaceae, Leptospiraceae, Listeriaceae, Bradyrhizobiaceae and Brucellaceae). Effluent from a wastewater treatment works was selected as a co-feed to augment biogas production. The most successful faecal sludge and co-feed combination was shown to be the one made up of 33% and 66% pit latrine faecal sludge. 180 L of this effluent mixture generated 285 L of biogas over 45 days of anaerobic digestion (29±2°C). However, the recovered quantities were insufficient for pasteurization as 650 L of biogas was required to pasteurize 300 g of faecal sludge for 1 hour at 70±2°C. Therefore, liquid petroleum gas (LPG) was used as an alternative heating energy source. Anaerobic digestion and pasteurization rendered the faecal sludge safe for application as a fertilizer as the quality of the faecal sludge after treatment by anaerobic digestion and pasteurization was within the microbiological (Escherichia coli, Salmonella spp, Enterococcus faecium and helminth eggs) and trace element restrictions (Pb, Ni, Cr, Mo, As, Cu, Mn, Fe, Cd and Hg) of sludge application in agriculture as stipulated by the WHO and the South African Guidelines for Sludge Use in Agriculture. Radish (Raphanus sativus spp) and garden cress (Lepidium sativum) were cultivated to demonstrate the effectiveness of the anaerobically digested and pasteurized pit latrine faecal sludge as a fertilizer. Diluting the fertilizer prepared from faecal sludge did not reduce its efficacy and was comparable to the synthetic fertilizer used as a control in the growth trials in terms of the plant fresh weight, dry weight and plant height. Finally, the exposure to the current state of pit latrines in Hlalani Township provided an incentive to develop a new tool to address sanitation service delivery skill shortage (artisans, plant operation and maintenance workers, and sanitation and hygiene facilitators) through the use of volunteers. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
- Full Text:
- Date Issued: 2017
The comparative bioavailability and in vitro assessment of solid oral dosage forms of paracetamol
- Authors: Braae, Karen
- Date: 1981 , 2013-04-02
- Subjects: Acetaminophen , Bioavailability , Drugs -- Bioavailability , Drugs -- Dosage forms , Analysis of variance
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3827 , http://hdl.handle.net/10962/d1006288 , Acetaminophen , Bioavailability , Drugs -- Bioavailability , Drugs -- Dosage forms , Analysis of variance
- Description: The dissolution profiles of eight lots of paracetamol tablets representing seven different tablet brands are determined in a USP rotating basket assembly and a stationary basket-rotating paddle apparatus. The in vitro data are expressed in terms of dissolution parameters and inter-tablet differences are assessed statistically using analysis of variance (ANOVA) and the Scheffe test. Highly significant differences are observed between a number of the tablets at the 95% confidence level. Representative tablets from the dissolution rate study and a control dose of paracetamol dissolved in water are subsequently investigated in a 4 x 4 latin square design bioavailability trial. Serum and urine samples are collected and assayed for paracetamol alone (serum) and together with its metabolites (urine) by means of high pressure liquid chromatography. The in vivo data are expressed in terms of bioavailability parameters and differences between the test doses are assessed by means of ANOVA. No significant differences are observed between the dosage forms at the 95% confidence level.
- Full Text:
- Date Issued: 1981
The design and evaluation of targeted patient-centred health information to improve knowledge and behavioural outcomes in tuberculosis patients with limited literacy
- Authors: Patel, Sonal
- Date: 2015
- Subjects: Tuberculosis Patients , Health literacy , Patient education , Communication in medicine , Picture-writing
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/194071 , vital:45420 , DOI 10.21504/10962/194071
- Description: South Africa carries a significant TB burden as evidenced in the 2013 statistics which report 450 000 new active TB cases and 890 000 TB-related mortalities. For successful treatment outcomes, 90% adherence is necessary, but many patients prematurely discontinue treatment due to poor knowledge and understanding of their complex TB medicines. Patient education is pivotal in improving knowledge, health literacy and behavioural outcomes such as health information seeking, self-efficacy and adherence. In the under-resourced South African healthcare system, time and capacity to adequately counsel patients are limited. The value of written medicine information (WMI) to supplement the verbal information provided by healthcare professionals (HCPs) has been widely investigated but minimal South African research is available. Current WMI distributed in South Africa is mainly generated by pharmaceutical manufacturers and is complex, incomprehensible and undesirable to patients. TB-related WMI focuses mainly on the disease, with little information relating to TB medicines and their use. The overall aim of this project was to improve patient knowledge about their TB medicines through the use of a simple illustrated patient information leaflet (PIL). Objectives to achieve this aim included: investigation of the medicine information seeking behaviour (MISB) of long term patients attending public health sector facilities; the development and validation of a medicine literacy test (MLT) to identify patients with limited health literacy requiring additional support and counselling; the development and evaluation of a patient-centred illustrated PIL for first-line TB treatment; the assessment of self-efficacy and adherence using modified versions of the HIV Treatment Adherence Self-Efficacy Scale (HIV-ASES) and Morisky 8-item Medicine Adherence Scale (MMAS-8), respectively, and the investigation of the impact of the PIL on patient knowledge and these health-related behaviours. Six focus group discussions (FGDs) conducted in 34 isiXhosa-speaking patients with limited formal education taking long-term treatment explored themes related to information needs, information-seeking practices and awareness of and ability to utilize information sources. Codes were analysed and potential themes and subthemes were identified and refined. The findings of this study reflected a passive, disempowered patient due to both patient-related and systemic healthcare factors. Poor awareness of information sources, lack of health-related knowledge, stigma and lack of awareness of the importance of appropriate medicine-related knowledge contributed to a lack of information-seeking practice. Patients neither asked questions nor were encouraged to do so. All expressed an unmet need for information and a desire for receiving relevant, appropriate, written medicine-related information. Feedback from this phase of the study was used to inform the development of the targeted patientcentred PIL. A double-sided A4 PIL containing information about TB medicines was designed giving careful consideration to content, format and layout features. Twenty five pictograms were designed through a rigorous, iterative design process and were included in the PIL that was evaluated in a randomised control trial (RCT) conducted amongst 120 TB patients attending a high burden TB clinic in South Africa. Interviews were conducted in either isiXhosa or Afrikaans via a trained interpreter. Patients were randomly allocated to either a control (standard care) or an experimental group (standard care plus brief counselling using the PIL). Two interviews were conducted using a prepared questionnaire; one at baseline followed by a 4-week follow-up. Baseline data included demographics, medicine literacy test, health information sources, knowledge of TB medicines, self-reported adherence and self-efficacy. Data collected at the 4-week follow-up interview included TB knowledge, self-reported adherence, self-efficacy, opinion of TB medicine information and interpretation of pictograms. Data were analysed using t-test, correlations, chi-square and ANOVA tests at a 0.05 level of significance. The PIL was successful in improving patient knowledge of the disease, TB medicine-taking, side effects, drug-resistant TB and HIV and TB co-infection. At baseline, there was no significant difference in the overall mean percentage knowledge score between the control and experimental groups (p=0.074). At follow-up, the percentage knowledge score for the experimental group increased significantly from 59.0% to 84.6% (p<0.001) and showed a significantly higher score than the control group (p<0.001), displaying evidence of the impact of the PIL as a counselling tool on patient knowledge. The PIL generated a highly positive response in the experimental group who indicated that they had referred to the leaflet over the last month and that it had played an important role in improving their TB medicine-related knowledge. This was reflected in the experimental group knowledge score of greater than 80% for almost three quarters of the patients whereas only 14% in the control group achieved this score. Patients appreciated the inclusion of pictograms and strongly felt that they helped them to recall and understand the textual PIL content. The study found that patients want side effect information and, interestingly, did not perceive the presentation of side effects in pictorial form to constitute a risk factor for nonadherence. Use of the illustrated PIL (experimental group) resulted in a significant improvement in patient self-efficacy (p=0.002), but showed no effect on self-reported adherence (p=0.563). Neither self-efficacy nor adherence was influenced by gender, age or education. An education effect on knowledge was only observed in the control group at baseline. The newly developed MLT was shown to be a valid and reliable tool and a moderate, positive and significant correlation was noted between the MLT score and baseline TB medicine-related knowledge in both the control and experimental groups. As there is a paucity of studies investigating the influence of take-home written leaflets on TB medicine knowledge and on patient behaviour, this study represents a significant knowledge contribution. It is the first study to report the development and evaluation of a patient-centred PIL to address the dearth of available TB medicine information. The use of targeted user-friendly, illustrated information leaflets can be a valuable counselling aid to improve patient knowledge and self-efficacy, particularly among patients with limited literacy. However, careful consideration of the design and content, with input from the endusers at all stages of the process, will optimise its effectiveness. The proposed framework for the development and implementation of patient-centred health and medicines information in a developing country context presented in this thesis could be used as a theoretical basis for informing the development of effective information materials targeting other disease states. Local patients taking TB medicines identified nurses, WMI and media as their current sources of information but they expressed a strong desire to know more about their treatment. Targeted public health interventions that focus on medicine-taking information and behaviours and encourage patients to adopt a more active, questioning role in health consultations could improve health literacy and empower patients in their medicine-taking practices. , Thesis (PhD) -- Faculty of Pharmacy, Pharmacy, 2015
- Full Text:
- Date Issued: 2015
The design, synthesis and antiplasmodial activity of a series of halogenated fosmidomycin analogues and hybrid drugs
- Authors: Afolayan, Anthonia Folake
- Date: 2012
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64370 , vital:28538
- Description: Malaria continues to be a devastating disease and a major cause of death in sub-Saharan Africa. With resistance against most of the available antimalarial drugs, there is a need for ongoing research and development of antimalarial agents. Fosmidomycin and its acetyl analogue FR900098 have been identified as potent inhibitors of Plasmodium falciparum, the causative agent of the most deadly form of malaria. Clinical trials of these agents have revealed poor absorption due to their high hydrophilicity. In the present studies the effect of halogenation of the acyl chain as well as the biological effect of extending the acyl sidechain was explored. This provided the basis on which fosmidomycin hybrids were designed to investigate the feasibility of hybrid extending into NADPH binding pocket. Synthesis of a series of halogenated FR900098 analogues was carried out in three stages. This included i) The introduction of the phosphonate group by reaction with 1,3dibromopropane in an Arbuzov reaction, ii) The introduction of a hydroxamate group by reaction of the propyl phosphonate by means of a nucleophilic substitution reaction with BocNHOBn and iii) The introduction of a halogenated acyl side chain on a protected fosmidomycin backbone. The synthesis of fosmidomycin-hybrids for which chloroquinefosmidomycin hybrids were used as the prototype, involved convergence of the two separately constructed moieties i.e. fosmidomycin and the quinoline moieties in a covalent linkage. The quinoline moiety was easily synthesized from the reaction of 4,7dichloroquinoline with 1,2-diamino ethane. The aminoquinoline so formed resulted in chloroquine-fosmidomycin hybrids 3.8 and 3.9 when reacted with halogenated FR900098 analogues. Antiplasmodial assays were conducted on the chloroquine-fosmidomycin hybrids and the halogenated fosmidomycin derivatives against the chloroquine resistant Gambian FCR-3 strain of P. falciparum. The most potent iodoacetyl fosmidomycin analogues 2.21 gave an IC50 value of 5.54 µM which is eight times more potent than the known antiplasmodial FR900098 which gave an IC50 value of 41.67 µM. All the halogenated FR900098 analogues showed better antiplasmodial activity than their non-halogenated derivatives. This indicated that the presence of halogens in the FR900098 analogues contributes to their biological Chapter 1 Literature review activity. The acetyl and propyl linked hybrids 3.8 and 3.9 showed potent antiplasmodial activity with IC50 values of 0.18 and 0.82 µM respectively. These were by far the most potent hybrids synthesized and provided leads for a new class of promising antimalarial agents. Preliminary E. coli DXR enzyme inhibition assays were carried out on the halogenated fosmidomycin analogues. The results showed good inhibition of the enzyme by the phosphonic acids of the chloroacetyl and chloropropyl analogues 2.1 and 2.2 respectively. Molecular modelling of the compounds on E. coli (PDB code: 2EGH) and P. falciparum (PDB code: 3AUA) DXR showed strong binding of the halogenated fosmidomycin analogues while the hybrids in the absence of docked NADPH showed minimum binding to the enzymes.
- Full Text:
- Date Issued: 2012
The development and assessment of a fixed dose combination tablet of Ranitidine and Metronidazole
- Authors: King'ori, Loti David
- Date: 2011 , 2011-04-07
- Subjects: Ulcers -- Treatment , Ranitidine -- Evaluation , Metronidazole -- Evaluation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3858 , http://hdl.handle.net/10962/d1013359
- Description: The oral route of drug administration is convenient since it is acceptable to most patients and the manufacturing processes used to produce tablets and capsules are relatively simple when compared to those used to manufacture other types of dosage forms. Metronidazole (MTZ) and Ranitidine (RTD) have been used in combination, as part of triple therapy for the treatment of ulcers. However the use of large numbers of tablets and long duration of therapy makes adherence to drug treatment challenging for patients. Therefore the formulation of a fixed dose combination (FDC) of MTZ and RTD may improve patient adherence to therapy and consequently may reduce morbidity and mortality due to ulcers. A stability indicating HPLC method for the simultaneous analysis of MTZ and RTD was developed and validated according to the International Conference on Harmonization (ICH) guidelines. The method was sensitive, selective, precise, accurate and linear.Preformulation studies were performed on the active pharmaceutical ingredients (API) alone and in combination with potential excipients. Differential scanning calorimetry (DSC) studies revealed a potential interaction between MTZ and RTD, however the interaction was not apparent following IR analysis of the same samples. DSC analyses of the API in combination with potential excipients revealed that the compounds were compatible with most materials with the exception of a binary mixture of RTD and Dibasic calcium phosphate (DCP) that exhibited a potential interaction. Thermal gravimetric analysis (TGA) of MTZ and RTD revealed that both compounds exhibited thermal stability. The Carrs Index (CI) and Hausner Ratio (HR) values of MTZ and RTD indicated that both compounds exhibited poor flow and compressibility properties, whereas the CI and HR values for (Microcrystalline cellulose) MCC and DCP indicated better flowability and compressibility characteristics.Direct compression and wet granulation processes were assessed to identify a suitable method of manufacture of FDC tablets of MTZ and RTD. The blends were evaluated using bulk and tapped density and the resultant tablets were evaluated for weight uniformity, crushing strength, tensile strength and disintegration time. The wet granulation method of manufacture produced tablets that showed acceptable pharmacotechnical properties: this approach was therefore used as the method of manufacture of FDC tablets of MTZ and RTD. Tablet formulations comprised of API, viz. MTZ and RTD and different compositions of MCC, DCP, Sodium starch glycolate (SSG) and Croscarmellose sodium (CCS), were manufactured in order to screen for an appropriate diluent and disintegrant composition for use in response surface studies. Assays of tablet content and in vitro drug release were undertaken using the validated HPLC method. Tablets in which MCC and CCS were used appeared to produce better assay and dissolution results as compared to those manufactured using DCP and SSG. Consequently a formulation comprised of MCC and CCS was selected and used in studies in which the effect(s) of level two formulation and composition changes as described in the Scale and Post Approval Changes for Immediate Release (SUPAC-IR) Guidelines on tablet disintegration and in vitro release were assessed. A Box-Behnken statistical design was used for the investigation of the effect of input factors, viz. CCS, (Polyvinyl pyrollidone K30) PVP-K30 and magnesium stearate on measured responses, viz. disintegration time and percent drug release in 10 minutes (Q10). CCS appeared to have an inverse linear relationship on disintegration time and a linear relationship with the Q10 for MTZ and RTD, whereas PVP-K30 and magnesium stearate appeared to have an antagonistic effect on the measured responses. Furthermore CCS and magnesium stearate exhibited an interaction that had an agonistic effect on the Q10 value for RTD. A numerical optimization approach was used to predict a formulation composition that would produce tablets that exhibited a disintegration time and Q10 values for MTZ and RTD that fell within the constraints set in our laboratory. The resultant model was found to be accurate and had a percent prediction error of < 5% for all measured response variables.FDC tablets of MTZ and RTD have been successfully produced. The disintegration of the tablet and dissolution of the API were within compendial specifications and the tablets are of suitable quality and have the potential to be further investigated to reduce the pill burden in the treatment of ulcers.
- Full Text:
- Date Issued: 2011
The development and assessment of a generic carbamazepine sustained release dosage form
- Authors: Patel, Fathima
- Date: 2006
- Subjects: Carbamazepine Pharmacokinetics Drugs -- Controlled release Drugs -- Dosage forms Tablets (Medicine) Drugs -- Administration
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3784 , http://hdl.handle.net/10962/d1003262
- Description: Carbamazepine (CBZ) is a first-line drug used for the treatment of partial and tonic-clonic seizures. It is also the drug of choice for use during pregnancy and recommended for the treatment of seizure disorders in children. CBZ possesses the ability to induce metabolism of drugs that are transformed in the liver and has the unique ability to induce its own metabolism by a phenomenon known as ‘auto- induction’, where its biological half-life is significantly reduced during chronic administration. Large doses of CBZ are often prescribed as daily divided doses and this often adversely affects patient compliance, with the result that therapy is ineffective. A sustained-release dosage form containing CBZ is currently marketed as Tegretol® CR and the development of a generic product would provide patients with an equivalent product with a similar dosing frequency, at a reduced cost. Therefore, the development of a polymer-based matrix tablet was undertaken to produce a sustained-release dosage form of CBZ, since these dosage forms are relatively simple and cheap to produce when compared to other, more sophisticated forms of sustained-release technology. Preformulation studies were conducted to assess moisture content of excipients and dosage forms and to identify possible incompatibilities between CBZ and potential formulation excipients. Furthermore, studies were conducted to assess the potential for polymorphic transitions to occur during manufacture. Stability testing was conducted to assess the behaviour of the dosage forms under storage conditions that the product may be exposed to. Dissolution testing was undertaken using USP Apparatus 3, which allowed for a more realistic assessment and prediction of in vivo drug release rates. Samples were analysed using a high performance liquid chromatographic method that was developed and validated for the determination of CBZ. Tablets were manufactured by wet granulation and direct compression techniques, and the resultant drug release profiles were evaluated statistically by means of the f1 and f2 difference and similarity factors. The f2 factor was incorporated as an assessment criterion in the design of an artificial neural network that was used to predict drug release profiles and formulation composition. A direct compression tablet formulation was successfully adapted from a prototype wet granulation matrix formulation and a number of formulation variables were assessed to establish their effect(s) on the dissolution rate profile of CBZ that resulted from testing of the dosage forms. The particle size grade of CBZ was also investigated and it was ascertained that fine particle size grade CBZ showed improved drug release profiles when compared to the coarse grade CBZ which was desirable, since CBZ is a highly water insoluble compound. Furthermore, the impact of the viscosity grade and proportion of rate-controlling polymer, viz., hydroxypropyl methylcellulose was also investigated for its effect on drug release rates. The lower viscosity grade was found to be more appropriate for use with CBZ. The type of anti-frictional agent used in the formulations did not appear to affect drug release from the polymeric matrix tablets, however specific compounds may have an effect on the physical characteristics of the polymeric tablets. The resultant formulations did not display zero-order drug release kinetics and a first-order mathematical model was developed to provide an additional resource for athematical analysis of dissolution profiles. An artificial neural network was designed, developed and applied to predict dissolution rate profiles for formulation. Furthermore, the network was used to predict formulation compositions that would produce drug release profiles comparable to the reference product, Tegretol® CR. The formulation composition predicted by the network to match the dissolution profile of the innovator product was manufactured and tested in vitro. The formulation was further manipulated, empirically, so as to match the in vitro dissolution rate profile of Tegretol® CR, more completely. The test tablets that were produced were tested in two health male volunteers using Tegretol® CR 400mg as the reference product. The batch used for this “proof of concept” biostudy was produced in accordance with cGMP guidelines and the protocol in accordance with ICH guidelines. The test matrix tablets revealed in vivo bioavailability profiles for CBZ, however, bioequivalence between the test and reference product could not be established. It can be concluded that the polymeric matrix CBZ tablets have the potential to be used as a twice-daily dosage form for the treatment of relevant seizure disorders.
- Full Text:
- Date Issued: 2006
The development and assessment of both a separate, once-daily modified release matrix formulation of metoprolol tartrate and a combination formulation with hydrochlorothiazide
- Authors: Arjun, Jessica
- Date: 2001
- Subjects: Metoprolol -- Controlled release , Chlorothiazide -- Controlled release , Diuretics , Hypertension -- Treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3742 , http://hdl.handle.net/10962/d1003220 , Metoprolol -- Controlled release , Chlorothiazide -- Controlled release , Diuretics , Hypertension -- Treatment
- Description: The use of controlled release dosage forms has increased significantly in recent years as they result in increased patient compliance and higher therapeutic efficiency. This research focused on the development of a once daily dosage form that could be used for the treatment of hypertension. Both a separate sustained release dosage of metoprolol tartrate and a combination dosage form that included both an immediate release hydrochlorothiazide and a sustained release metoprolol component, were developed and evaluated. A matrix tablet, consisting of an ethylcellulose ranulation of metoprolol tartrate compressed into a hydrophilic hydroxypropyl methylcellulose polymer matrix, effectively sustained metoprolol release over a 22-hour experimental period. A multiparticulate combination dosage form that consisted of six coated mini matrix tablets of metoprolol and a powder blend of hydrochlorothiazide packed into a gelatin capsule, displayed zero order release kinetics for metoprolol release over 22 hours (r2=0.9946). The release of hydrochlorothiazide was found to be comparable to that of a commercially available product tested. Differential Scanning Calorimetry was used to identify possible incompatibilities between MPTA and excipients initially, and long term stability testing was used to assess to behaviour of the dosage form. Dissolution testing of the dosage forms was performed using USP Apparatus III, which was found to be more discriminating between the batches assessed. Dissolution curves were evaluated for similarity and difference using f1 and f2 fit factors. Samples were analyzed using a high performance liquid chromatographic method that was developed and validated for the simultaneous determination of the compounds of interest. Various factors influencing drug release from the developed dosage forms were assessed and recommendations for further optimization of the formulation are made. Factors evaluated included the quantity of granulating fluid, matrix polymer content, drug load and process variables, including drying time and compression force. The influence of various coating levels on drug release was assessed and none of the levels assessed were found to adequately retarded drug release over a 22-hour period. Combinations of tablets coated to different levels allowed for the successful development of a sustained release metoprolol component, which could be included into the combination dosage form.
- Full Text:
- Date Issued: 2001
The development and assessment of sustained release nevirapine tablets
- Authors: Mwila, Chiluba
- Date: 2013
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54667 , vital:26598
- Description: The use of antiretroviral (ARV) agents in the management of HIV/AIDS has significantly improved the lifestyle and wellbeing of patients. Despite the success that has been achieved with the use of ARV therapy, the occurrence of adverse effects and unpredictable bioavailability associated with most of these drugs remains a major concern. Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) that is used in combination with other ARV compounds for the treatment of HIV-1 infections. It is also used for the prevention of mother to child transmission of the HIV-1 virus. NVP is a Biopharmaceutics Classification System (BCS) Class II compound. Although NVP exhibits good oral absorption, it induces self-metabolism leading to low and sometimes unpredictable bioavailability. NVP is commercially available as an immediate release and extended release dosage form, viz., Viramune® XR. Formulation of a generic sustained release (SR) dosage form for once daily dosing would result in delivery of constant amount of the drug to the circulation, reduce dose related adverse effects, improve patient compliance to medication and reduce the costs of therapy. A simple RP-HPLC method was developed and optimised using a central composite design approach. The method was validated using ICH guidelines and was found to be linear, precise, specific and accurate for the analysis of NVP both in bulk and dosage forms. Direct compression was used as the method of tablet manufacture. Different polymers were assessed for suitability as rate retarding polymers and included Methocel® K4M, Carbopol® 71G NF and Eudragit® RSPO. Powder blends were assessed for flow properties using the angle of repose, bulk and tapped density, Carr’s Compressibility index and Hausner’s ratio. The traditional approach of changing the amount of polymers and diluents systematically to achieve a desired NVP release profile was used for the development of a preliminary formulation. Response surface methodology was used for the optimisation of the formulation using a Box-Behnken quadratic design. Physical characteristics of the tablets such as thickness, weight, hardness, tensile strength and friability were assessed and the tablets passed Pharmacopoeial testing. NVP assay and content uniformity were assessed using a validated RP-HPLC method. Initially, USP Apparatus 2 was used to study NVP release over a 24 hour period and subsequently dissolution studies were performed using USP Apparatus 3 as it can be used to simulate GIT conditions. The dissolution profiles generated were used to determine the agitation rate for USP Apparatus 3 that would be equivalent to an agitation rate of 50 rpm when using USP Apparatus 2. The effect of the mesh screen pore size, buffer molarity strength and concentration of surfactant on NVP release were also investigated in order to select discriminatory dissolution test conditions for the test formulation. Dissolution profiles were compared to those of the commercially available Viramune® XR using the FDA recommended difference (f1) and similarity (f2) factors. The calculated values for f1 and f2 revealed that the dissolution profile for the optimised formulation that was identified was statistically similar to Viramune® XR. In vitro release data were fitted to different kinetic models to study the release kinetics of NVP. The overall mechanism of NVP release was best described using the Korsmeyer-Peppas diffusion exponent value, n. NVP release was found to be anomalous, implying that the release was influenced by a combination of diffusion, swelling and polymer chain relaxation. The Hixson-Crowell model revealed that there was constant change in surface area of the dosage form suggesting that erosion and swelling were significant factors affecting NVP release from the hydrophilic matrix technology. The release kinetics data were also used to design the optimised formulation. Tablets manufactured using the optimised formulation were subjected to water uptake and erosion studies and the results revealed that swelling and erosion occur simultaneously. The effects of pH and molarity on the swelling and erosion of the tablets were also investigated. The data suggest that increase in pH resulted in a slight increase in swelling while an increase in molarity did not have a significant effect on swelling. The change in pH did not have a significant effect on erosion while an increase in molarity strength resulted in a decrease in matrix erosion. The effect of HPMC grade on swelling, erosion and NVP release revealed that the grade of HPMC used had a significant effect on NVP release, with the release rate decreasing, swelling increasing and erosion decreasing as the viscosity of the HPMC grade increased. The effect of the particle size of MCC on NVP release was also studied by manufacturing tablets containing different grades of MCC and these studies revealed that particle size did not appear to have a significant effect on NVP release. Similarly the use of different types of lactose did not appear to have a significant impact on NVP release. In conclusion a sustained release NVP tablet formulation that has the potential for further development and optimisation has been developed, assessed and manufactured successfully and has been shown to exhibit similar dissolution behaviour to Viramune® XR, a commercially available NVP extended release product.
- Full Text:
- Date Issued: 2013
The development of an orodispersible sildenafil citrate tablet intended for paediatric use
- Authors: Dagnolo, Bianca
- Date: 2012
- Subjects: Drug development -- Children -- Research -- South Africa , Pulmonary hypertension -- Children -- Research , Tablets (Medicine) -- Development , Pharmaceutical chemistry -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3751 , http://hdl.handle.net/10962/d1003229 , Drug development -- Children -- Research -- South Africa , Pulmonary hypertension -- Children -- Research , Tablets (Medicine) -- Development , Pharmaceutical chemistry -- Research
- Description: Sildenafil citrate (SC) is a phosphodiesterase-5 inhibitor that is used to treat pulmonary hypertension (PH) in paediatric patients. The purpose of these studies was to develop a formulation and manufacture an orodispersible tablet (ODT) that can be easily administered to neonates and children with PH. The advantages of ODT dosage forms include ease of administration, rapid dissolution of the API, SC. Furthermore the dosage form can be taken without water which is beneficial to patients without immediate access to potable fluids. A simple, rapid, accurate, precise and selective reversed-phase HPLC method was developed and validated in accordance with International Conference on Harmonization (ICH) guidelines and was successfully used for the analysis of SC as raw material and in SC containing pharmaceutical dosage forms. Preformulation studies were performed on SC, alone and in combination with potential excipients that could be used to make tablets. Investigations into potential interactions between SC and the excipients were performed using Differential Scanning Calorimetry (DSC) and Infrared Spectroscopy (IR). DSC results revealed that SC was compatible with all potential excipients except mannitol and magnesium stearate. However these interactions were not observed with IR and therefore it was concluded that the interactions were induced by the high temperatures that DSC operates at. Particle size and shape was also established by use of Scanning Electron Microscopy (SEM) and flow properties were monitored by calculating Carr’s Index (CI) and the Hausner Ratio (HR). Direct compression was used as the method of manufacture for SC tablets as this approach is simple and the most economic production approach. The powder blends were assessed for bulk and tapped density and the CI and HR were used to determine the flowability of the blends. The quality attributes of the resultant tablets that were monitored included uniformity of weight, friability, crushing strength, tensile strength, disintegration, wetting and in vitro dispersion times. Design of Experiments is an efficient statistical approach that has become a popular tool used in the pharmaceutical industry to optimize formulation compositions, as it allows for the investigation of several input factors at the same time whilst not using the tedious and traditional “ modification of one variable at a time” approach. A Central composite experimental design was chosen as the most appropriate means to optimize the formulation as it produces more accurate results as opposed to other experimental designs approaches as input factors are investigated at five different levels. Through the use of mathematical modelling, optimum concentrations of disintegrant(s) and an appropriate blending time were established. Analysis of the data from the experimental design and mathematical modelling studies reveal that no changes in disintegrant concentration or blending time altered the disintegration time of the formulation to any significant extent. This result is most likely due to the fact that the critical disintegrant concentration has been reached and increasing the disintegrant concentration further has no effect on disintegration time. It was also established that a change in the concentration of CMS and CRP altered the wetting time of the tablet significantly. Finally it was noted that there was a linear relationship between blending time and the uniformity of content of the tablets produced in these studies. The optimized product was a white tablet with a diameter of 7.31 mm with a thickness of 2.80mm.The dosage form had no visible cracks or evidence of picking or sticking. The tablet exhibits suitable friability and tensile strength while exhibiting a disintegration time of only 8s. Therefore an orodispersible tablet containing SC intended for paediatric use has been successfully developed, manufactured and optimized through the use of preformulation studies, appropriate quality control monitoring and mathematical modelling. These formulations require further optimization in respect of addition of flavours and or additional sweetening agents.
- Full Text:
- Date Issued: 2012
The development of captopril pellets using the principles of quality by design
- Authors: Veerubhotla, Hari Mani Krishna
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64769 , vital:28599
- Description: Expected release date-May 2018
- Full Text:
- Date Issued: 2016
The development, formulation and characterization of an optimized metronidazole loaded solid lipid nanoparticle formulation for ocular drug delivery
- Authors: Sikhondze, Simise Siphelele
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/403014 , vital:69914
- Description: Thesis embargoed. To be released early 2026. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2023
- Full Text:
- Date Issued: 2022-10-14
The development, manufacture and assessment of solid dispersions of gliclazide
- Authors: Govere, Grace Shalom
- Date: 2018
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63390 , vital:28405
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
The development, manufacture and characterisation of niosomes intended to deliver nevirapine to the brain
- Authors: Witika, Bwalya Angel
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65257 , vital:28715
- Description: Expected release date-May 2019
- Full Text:
- Date Issued: 2017
The development, manufacture and evaluation of a selfmicro-emulsifying drug delivery system for efavirenz
- Authors: Musakana, Tanyaradzwa Gracious
- Date: 2018
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/62643 , vital:28223
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
The development, manufacture and evaluation of sustained release gastric-resistant isoniazid and gastroretentive microporous rifampicin microspheres
- Authors: Mwila, Chiluba
- Date: 2018
- Subjects: Biodegradation , Microspheres (Pharmacy) , Drug delivery systems , Rifampin , Isoniazid
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/63497 , vital:28421 , DOI 10.21504/10962/63497
- Description: According to the World Health Organization Global Tuberculosis (TB) 2017 Report, there were an estimated 10.4 million new TB cases worldwide of which, in 2016, 65 % occurred in men, 28.1 % in women and 6.9 % in children. TB is the ninth leading cause of death globally and is the leading cause due to an infectious organism surpassing HIV/AIDS. Treatment is long-term and the use of a combination of medicines is required for success. The concern related to the use of fixed dose combination products for the treatment of TB is the issue of low bioavailability of rifampicin observed from a number of fixed dose combination (FDC) formulations. The hydrolysis of rifampicin, in acidic media, to form insoluble 3-formyl rifamycin SV contributes to poor bioavailability of rifampicin. The degradation of rifampicin to form this poorly absorbed compound is accelerated in the presence of isoniazid via the reversible formation of isonicotinyl hydrazone is a further factor contributing to the poor bioavailability of rifampicin. Therefore, the development of a novel drug delivery technology that prevents interactions between rifampicin and isoniazid in an acidic medium is required. A Box Behnken design was successfully used for the optimisation of a rapid and accurate stability-indicating gradient elution RP-HPLC method for the simultaneous analysis of isoniazid, pyrazinamide and rifampicin. The method was validated using ICH guidelines and the results indicate it can be used for the rapid analysis of commercially available TB FDC formulations containing the active pharmaceutical ingredients, API. The method is precise, sensitive and has the necessary selectivity for use during formulation development and optimisation studies for a combination of rifampicin, isoniazid and pyrazinamide. Initially formulation activities were undertaken with rifampicin and isoniazid for the development of an approach to enhance the effective delivery of these compounds. The characterisation of rifampicin and isoniazid was undertaken using spectroscopic, thermal and microscopic analysis. The studies revealed that the compounds are crystalline and exhibit distinct characteristic sharp peaks in X-ray diffractograms and Differential Scanning Calorimetry thermograms. The thermograms, 13C Nuclear Magnetic Resonance and Fourier Transform Infrared spectroscopy results identified that rifampicin occurs as the form II polymorph however, as there are no significant biopharmaceutic differences between the polymorphic forms of rifampicin this information was used for identification purposes only. The results were used as baseline data for comparative purposes to monitor changes that may occur when rifampicin and isoniazid are used in formulation development, dosage form manufacture and characterisation activities for a FDC technology designed to deliver both compounds simultaneously. Hydroxypropylmethylcellulose acetate succinate (HPMC-AS) and Eudragit® L100 polymers were successfully used for manufacture of isoniazid loaded gastric-resistant sustained release microspheres using an o/o solvent emulsification and evaporation approach. A Hybrid experimental design was used to investigate the influence of input variables viz., homogenisation speed and amount of HPMC-AS and Eudragit® L100 on gastric-resistance, INH release and encapsulation efficiency. The approach of using coating polymers viz., HPMC-AS and Eudragit® L100, to manufacture gastric resistant sustained release microspheres of isoniazid is unique and was efficient for preventing the release of isoniazid in an acidic environment. Only 0.523 % isoniazid was released from the optimised formulation after 2 h exposure to pH 1.2 0.1 M HCl suggesting there is also the possibility of minimising the accelerated degradation of rifampicin that occurs in the presence of isoniazid in acidic media. The microspheres also exhibited sustained release properties without burst release in pH 6.8 0.1 M phosphate buffer as < 5 % isoniazid was released at 0.5 h and only 11 % isoniazid was released at 2 h. The release of isoniazid was sustained over the entire period of dissolution testing with > 85 % isoniazid released at 24 h, implying that the majority of encapsulated isoniazid would be available for absorption. The manufacturing process resulted in the production of hard spherical particles and particle size analysis revealed that the microspheres ranged between 415.76 ± 76.93 μm and 903.35 ± 197.10 μm in diameter. The microspheres exhibited excellent flow properties attributed to the spherical nature of particles. Carr‟s index (CI) was 4.934 ± 0.775 % and the Hausner ratio (HR) was 1.148 ± 0.033 indicating good packability of the microspheres that would help in achieving weight and content uniformity of capsule dosage units. The manufacturing process however produced a low % yield suggesting that scale up difficulties may be encountered. However the high encapsulation efficiency observed may counter the challenges associated with the low yield. The DSC thermograms and FT Raman spectra of 1:1 mixtures of isoniazid, excipients and the microspheres did not reveal any potential detrimental interactions. Microporous floating sustained release microspheres for the delivery of rifampicin in the stomach have been successfully manufactured using emulsification and a diffusion/evaporation process. A novel approach using solvent mixture of acetone and dichloromethane that has not been reported for the manufacture of rifampicin microspheres was successfully used and resulted in the formation of a stable emulsion and the manufacture of rifampicin-loaded microspheres with uniform characteristics. In addition the manufacturing process was shorter than most other reported methods. A Box-Behnken experimental design was successfully used to study the influence of ethylcellulose, Eudragit® RLPO and d-glucose content on the floating properties, encapsulation efficiency and % yield of microspheres. The optimised formulation did not yield desired floating characteristics as the % buoyancy was low and floating lag times were high. The optimised formulation was modified by addition of NaHCO3 to increase the % buoyancy and reduce the floating lag time. Rifampicin release from the microspheres of the modified batch was 87.10 % at 12 h and the microspheres exhibited a % buoyancy of 87.66 ± 1.28 % (n = 6) and floating lag time of 15 ± 3.2 (n = 6) seconds. The microspheres remained buoyant for up to 12 h and an encapsulation efficiency of 88.26 ± 1.25 % was achieved. SEM images of microspheres following exposure to dissolution fluid revealed that the microspheres had numerous pores on their surface. The mean particle size distribution ranged between 423.19 ± 121.86 μm to 620.07 ± 102.67 μm. The microspheres exhibited similar flow characteristics to isoniazid microspheres with a CI of 1.422 ± 0.074 %, and HR of 1.034 ± 0.002. The excellent flow characteristics indicate that filling of the microspheres into hard gelatin capsules was unlikely to pose a challenge in respect of producing a product with uniform content. Rifampicin-excipient compatibility studies did not reveal any potential or significant interactions suggesting that the excipients used for the manufacture of the microspheres were compatible, although long term stability studies would be required to ascertain this is, indeed the case. The microporous floating sustained release microspheres manufactured in these studies has the potential to increase the bioavailability of rifampicin as they may be retained in the stomach where the solubility of rifampicin is high and from which absorption is best achieved. The degradation of rifampicin after 12 h dissolution testing in pH 1.2 0.1 M HCl in the presence of isoniazid gastric-resistant sustained release microspheres was only 4.44%. These results indicate that the degradation of rifampicin in the presence of isoniazid in acidic media can be overcome by encapsulation of both active pharmaceutical ingredients in a manner that ensure release in different segments of the gastrointestinal tract. The use of sustained release microporous gastroretentive rifampicin microspheres in combination with sustained release isoniazid gastric-resistant microspheres revealed that accelerated degradation of rifampicin in the presence of isoniazid is reduced significantly when using this approach and a FDC of rifampicin and isoniazid microspheres has the potential to improve the bioavailability of rifampicin thereby enhancing therapeutic outcomes. In vivo studies would be required to confirm the potential benefits of using this approach to deliver rifampicin in combination with isoniazid. , Thesis (PhD) -- Faculty of Pharmacy, Pharmacy, 2018
- Full Text:
- Date Issued: 2018
The effect of tricyclic antidepressant drugs on the uptake and metabolism of serotonin by the pineal gland in organ culture
- Authors: Pillay, Manoranjenni
- Date: 1983 , 2013-04-05
- Subjects: Antidepressants , Pineal gland -- Metabolsim , Serotonin
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3828 , http://hdl.handle.net/10962/d1007053 , Antidepressants , Pineal gland -- Metabolsim , Serotonin
- Description: The effect of tricyclic antidepressants (TADs) on a variety of pineal functions was assessed. TADs affected the uptake of ³H-5HT into bovine pineal slices within a particular concentration range of these drugs, DESI, CLOMI and IMI appeared to inhibit uptake slightly, within a limited concentration range. Surprisingly, DESI appeared to be a relatively potent 5HT uptake inhibitor. The 5-HT re-uptake system in the pineal probably differes from that in brain tissue. TADs had a marked effect on the metabolism of ³H-5HT in the rat pineal, in an organ culture system, MEL and N-acetylserotonin synthesis increased for the first 11 days and thereafter a slight decrease was observed. HTOH and HIAA also showed an initial increase followed by a slight decrease in synthesis. The synthesis of MTOH and MIAA was decreased. The possibility that TADs could affect HIOMT and SNAT synthesis and thereby change the metabolic pattern of 5-HT was investigated. TADs appeared to stimulate SNAT initially and thereafter a slight decrease from peak activity was observed. This is probably due to stimulation followed by development of subsensitivity of β-receptors, HIOMT activity also appeared to be affected by TADs. The existence of two types of HIOMT is suggested. There is a possibility that these changes in the metabolism of 5-HT could be implicated in the mechanism of action of TADs. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 1983
The evaluation of indomethacin and theophylline oral controlled/modified-release dosage forms in vitro-in vivo correlations
- Authors: Tandt, Ludo Alfons Germaan Luc
- Date: 1992
- Subjects: Theophylline , Indomethacin , Drugs -- Controlled release , Drugs -- Dosage forms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3794 , http://hdl.handle.net/10962/d1003272 , Theophylline , Indomethacin , Drugs -- Controlled release , Drugs -- Dosage forms
- Description: Over the past few decades many researchers have investigated the utility of in vitro - in vivo correlations for the assessment of dosage forms. These investigations are, however, dependent on reproducible dissolution data and well conducted biostudies in order to establish meaningful and robust correlations. Despite the fact that the establishment of such correlations is perhaps idealistic, considerable interest has still been shown in this area of research. Various Controlled/Modified Release Dosage Forms (CMRD's) of theophylline, a weakly basic drug, and indomethacin, a weakly acidic drug, were assessed in order to establish in vitro - in vivo correlations. Dissolution rate studies were carried out using either the USP basket or paddle apparatus. The dissolution rate studies were conducted in a range of dissolution media of varying pH. Bioavailability studies were conducted on the dosage forms used by the Biopharmaceutics Research Institute at Rhodes University. The results of these biostudies were kindly made available for use in this research project. Type A correlations were established using a mathematical simulation process whereby expected in vivo responses are simulated and compared to actual profiles obtained for the dosage forms. In order to perform the simulations the dissolution rate profiles were stripped and using linear regression and the methods of residuals the dissolution rate order and the relevant dissolution rates were obtained. The results of the s imulations indicated that the in vivo serum concentration-time curves could be accurately predicted for the theophylline dosage forms but to a lesser extent, for the indomethacin formulations. The dissolution rate studies indicated that the paddle method is a suitable method for dissolution rate studies of theophylline CMRD's, although it appeared that the optimum pH of the dissolution medium was formulation dependent. Dissolution rate studies conducted on indomethacin formulations indicated that the USP specified basket method for extended-release indomethacin formulations was not able to distinguish between two formulations which exhibited different in vivo profiles. The conversion to the paddle method was, however, able to highlight the differences between these formulations. The use of three dimensional topographs to depict dissolution rate profiles was demonstrated for formulations of both theophylline and indomethacin. The topographs enabled the successful differentiation between bioinequivalent formulations. The dissolution rate profiles were also fitted to the Wei bull equation and the parameters obtained from this were compared to the Weibull parameters obtained from the in vivo absorption plots obtained using the Wagner-Nelson method. The results indicated that the Weibull function was suitable to describe both the in vivo and in vitro data. The following recommendations for the preformulation dissolution studies of weakly acidic and weakly basic drugs are proposed. The dissolution rate studies of weakly acid drugs, such as indomethacin, should be carried out over a range of pH utilising the paddle apparatus. Three dimensional topographs based on the dissolution data should be constructed and used as a comparative tool for different formulations. Based on these comparisons the appropriate formulation can then be selected for a pilot scale in vivo bioavailability study. The dissolution rate studies of weakly basic drugs, such as theophylline, should be carried out over a range of pH utilising the paddle apparatus. The dissolution data should then be used to simulate the expected in vivo profile and on this basis the appropriate formulation selected for a pilot scale bioavailability study. The above approach to the preformulation studies of new CMRO's would allow for the more careful selection of new dosage forms and could thus eliminate costly and unnecessary bioavailability studies performed on inferior formulations.
- Full Text:
- Date Issued: 1992
The evaluation of melatonin as a possible antidepressive
- Authors: Skene, Debra Jean
- Date: 1980
- Subjects: Melatonin , Antidepressants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3728 , http://hdl.handle.net/10962/d1001465
- Description: Melatonin, a hormone of the pineal gland, was evaluated in a variety of animal models of depression. Measurements of the frog righting reflex and rat locomotor activity showed that low doses of melatonin have a serotonin-like potentiating effect following monoamine oxidase inhibition. High doses of melatonin caused a reduction in the duration of rat immobility in the Porsolt model of depression and exerted a chlorpromazine-like effect on conditioned avoidance behaviour. In view of the indoleamine hypothesis of depressive disorders, the possibility of melatonin being a potential antidepressive is discussed and it is concluded that melatonin might be useful in the treatment of "agitated" depressions
- Full Text:
- Date Issued: 1980
The impact of HAART on sexuality and medicine taking behaviours among people living with HIV/AIDS in Grahamstown
- Authors: Chizanga, Tongai Aldridge
- Date: 2010
- Subjects: AIDS (Disease) -- Treatment -- South Africa -- Grahamstown HIV infections -- Treatment -- South Africa -- Grahamstown Antiretroviral agents -- South Africa -- Grahamstown Patient compliance -- South Africa -- Grahamstown AIDS (Disease) -- Social aspects -- South Africa -- Grahamstown HIV infections -- Social aspects -- South Africa -- Grahamstown AIDS (Disease) -- Patients -- South Africa -- Grahamstown -- Sexual behavior HIV-positive persons -- South Africa -- Grahamstown -- Sexual behavior Patient education -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: vital:3750 , http://hdl.handle.net/10962/d1003228
- Description: Introduction: Adherence to Highly Active Antiretroviral Therapy (HAART) is critical for optimal therapeutic outcomes. A possible factor in adherence is the impact of HAART on sexual functioning. Methods: A mixed methods approach was used. A cohort of 14 people living with HIV/AIDS (PLWHA) in Grahamstown was identified. Two semi-structured interviews and two structured questionnaires were administered. In-depth interviews were conducted with two HIV counsellors in so as to obtain a different perspective on the topics. The theoretical framework used three health behaviour models: the Health Belief Model, Leventhal‘s Common-Sense Model of self regulation and the Transtheoretical model. Results: The participants were between 27 and 49 years old and had been on HAART for between 9 months and 10 years. Six participants were support staff members from Rhodes University and eight from the Raphael Centre – a local NGO which assists PLWHA.In most of the participants HAART was associated with increased libido and improved sexual functioning (sexual activity and sexual enjoyment). The use of alcohol increased risky sexual behaviour. Issues of adherence were seemingly not directly affected by the effects of HAART on sexuality. PLWHA, especially women, face challenges related to their sexuality, some of which are not directly related to their illness and treatment. The fear of transmitting drug resistant HIV or getting re-infected, stigma, disclosure issues,difficulties negotiating for safe sex among women, HAART-related lipodystrophic changes that affect one‘s sense of self and unmet reproductive needs are some of the problems that were reported. The men‘s dislike for condoms was overt and blatant. Discussion: Being diagnosed with HIV and reaching a point where treatment is requiredare life-changing events. Making decisions about one‘s life (including adherence to HAART, alcohol use and knowingly partaking in risky sexual encounters) become all the more significant in the context of AIDS. Intentional non-adherence is informed by the individual‘s assessment of the costs and benefits of taking treatment. Cultural influences,gendered power relations and misconceptions strongly influence sexual behaviours. Conclusion: The general lack of attention among health care providers concerning issues related to PLWHA‘s sexuality and reproductive issues needs to be addressed. Insights fromthe theoretical models should be integrated with empirical findings in designing adherence interventions.
- Full Text:
- Date Issued: 2010