An evaluation of the mechanical, engineering and retails service and training authority staff development project at an Eastern Cape University
- Authors: Masha, Anthony Nkambi
- Date: 2022-00
- Subjects: Evaluation and Training
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/10691 , vital:75213
- Description: Higher Education (HE) has undergone significant changes in recent decades, necessitating the adaptation of Higher Education Institutions (HEIs) to focus on teaching, supporting, and academically developing academic staff. In Africa, some HEIs have requested their staff to obtain certain postgraduate qualifications, as research achievements lead to academic promotion. The MerSETA Staff Development Project was established to train lecturers in the Engineering Department to upgrade their qualifications to the doctorate level and to increase their research skills. This study aimed to evaluate the project's success using project management methodology. A mixed methods approach was used, with a qualitative and quantitative phase. Data was collected through focus group interviews (FGIs) and closed-ended questionnaires. A purposive sampling technique was used in the qualitative phase, while census sampling was used in the quantitative phase. Qualitative data analysis was primarily inductive, with interpretive data analysis techniques (IPA) used to discuss findings with existing literature. Statistical techniques were used in the quantitative phase, with Structural Equation Modelling (SEM) tested. Descriptive statistics were used to describe the features and summaries of the study's sample or data set. Regression analysis was used to test the research hypotheses and establish the relationship between variables under investigation. The study employed appropriate Cronbach alpha formulae to determine a co-efficient above 0.70. The results of this study indicate that the MerSETA Project successfully developed its beneficiaries academically at Walter Sisulu University. However, there are limitations to the study, such as the cross-sectional study design, which cannot reflect changes in variables over time. Further research is required to study the relationships between variables over time using a longitudinal study design. The MerSETA Project demonstrated the importance of understanding project life cycles, knowledge areas, and monitoring and evaluation techniques in managing projects like the MerSETA Project. To enhance causality, further research is needed to study relationships between variables over time using a longitudinal study design. The MerSETA Project, a successful project, requires an understanding of the project life cycle, management knowledge areas, and monitoring and evaluation techniques. The study's findings concluded that the project was a success. , Thesis (Masters) -- Faculty of Education, 2022
- Full Text:
- Date Issued: 2022-00
- Authors: Masha, Anthony Nkambi
- Date: 2022-00
- Subjects: Evaluation and Training
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/10691 , vital:75213
- Description: Higher Education (HE) has undergone significant changes in recent decades, necessitating the adaptation of Higher Education Institutions (HEIs) to focus on teaching, supporting, and academically developing academic staff. In Africa, some HEIs have requested their staff to obtain certain postgraduate qualifications, as research achievements lead to academic promotion. The MerSETA Staff Development Project was established to train lecturers in the Engineering Department to upgrade their qualifications to the doctorate level and to increase their research skills. This study aimed to evaluate the project's success using project management methodology. A mixed methods approach was used, with a qualitative and quantitative phase. Data was collected through focus group interviews (FGIs) and closed-ended questionnaires. A purposive sampling technique was used in the qualitative phase, while census sampling was used in the quantitative phase. Qualitative data analysis was primarily inductive, with interpretive data analysis techniques (IPA) used to discuss findings with existing literature. Statistical techniques were used in the quantitative phase, with Structural Equation Modelling (SEM) tested. Descriptive statistics were used to describe the features and summaries of the study's sample or data set. Regression analysis was used to test the research hypotheses and establish the relationship between variables under investigation. The study employed appropriate Cronbach alpha formulae to determine a co-efficient above 0.70. The results of this study indicate that the MerSETA Project successfully developed its beneficiaries academically at Walter Sisulu University. However, there are limitations to the study, such as the cross-sectional study design, which cannot reflect changes in variables over time. Further research is required to study the relationships between variables over time using a longitudinal study design. The MerSETA Project demonstrated the importance of understanding project life cycles, knowledge areas, and monitoring and evaluation techniques in managing projects like the MerSETA Project. To enhance causality, further research is needed to study relationships between variables over time using a longitudinal study design. The MerSETA Project, a successful project, requires an understanding of the project life cycle, management knowledge areas, and monitoring and evaluation techniques. The study's findings concluded that the project was a success. , Thesis (Masters) -- Faculty of Education, 2022
- Full Text:
- Date Issued: 2022-00
Maternal health care services in waiting mothers’ shelters: the case of Mawadza village in Bonda, Manicaland, Zimbabwe
- Authors: Muchabveyo, Brenda Hamufari
- Date: 2021
- Subjects: Pregnant women Zimbabwe Manicaland Province , Women's shelters Zimbabwe Manicaland Province , Maternal health services Zimbabwe Manicaland Province , Integrative medicine , Childbirth Social aspects Zimbabwe Manicaland Province
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/476912 , vital:78017 , DOI 10.21504/10962/476912
- Description: This study explores the experiences and perceptions of expectant mothers during prenatal, intra-, and postpartum care. It focuses on expectant mother‘s use or non-use of a waiting mothers' shelter within a medical pluralistic village within a context where hospitals and maternal health care facilities are not proximate. Special focus was on Mawadza village in the Mutasa district in Manicaland Province of Zimbabwe. A sample of 48 participants was used for collecting data in this study. The sample consisted of 15 women some of whom were expectant mothers in the waiting mothers‘ shelter (11) and others had used (4) the shelter once or twice since 2015. Participants were drawn mainly from Mawadza village and Bonda Mission Hospital while others were from the district and provincial offices of the Ministry of Health and Child Care of Zimbabwe. The study adopted a qualitative research methodology, which employed in-depth interviews; key informant interviews (KIIs) and focus group discussions (FGDs) as the main data gathering strategies. In-depth interviews were conducted with the expectant mothers and those who had formerly used the shelter since 2015, while, key informant interviews were conducted with the hospital staff members, traditional healers and the midwives from Mawadza village. Focus group discussions were also conducted with both male and female community members from Mawadza village. The study carried out face to face interviews and notes were handwritten and transcribed at the end of each day. Data coding was used to analyse data. The paradigms and theoretical underpinnings of the study were influenced by the symbolic interactionist theory. The theory made it possible to understand the social processes of pregnancy and childbirth in the waiting mothers' shelter due to its interpretive approach to social research and the legitimacy it places on the social interaction and meanings that social actors place on interactions in their environments. The study documented the ways pregnancy and childbirth are perceived, understood, and experienced in Mawadza village within the context of medical pluralism. In Mawadza village, pregnancy and childbirth are highly embedded in the cultural beliefs of the local people, hence, treated with importance and assumed important symbolic meanings. On the contrary, the waiting mothers‘ shelter as a biomedical facility handles pregnancy and childbirth from a biomedical approach, basing its practices and operations on pure science. Expectant mothers who await labour in this facility are therefore involved in several biomedical activities during prenatal, intra- and post-partum care in the waiting mothers‘ shelter. The need to access skilled birth attendants and the criminalisation of home births in Mawadza village have been the major reasons that influence the expectant mothers to use the waiting mothers‘ shelter. Nevertheless, factors such as medical pluralism, child care, and family commitments, lack of understanding of the importance of the waiting mothers‘ shelter, lack of privacy in the shelter, and cost of food and utilities during the expectant mothers' stay in this facility among others are factors that deter expectant mothers from using the waiting mothers' shelter. Lack of practice of bodily agency where practices common in preparation for childbirth such as opening the birth canal which is not accepted was also reported among common problems that discourage expectant mothers from preferring use of the shelters. The study also revealed that the community is involved in the operations of the waiting mothers‘ shelter, although, the involvement is gendered since there are more women involved as compared to men. The study concluded that even biological processes such as pregnancy and childbirth can only be fully understood within a social context given the different meanings which are attached to the various aspects of the childbirth process by the various actors such as expectant mothers, mothers, biomedical practitioners, traditional healers and communities in Mawadza village. Also, in a medical pluralistic village, the different health care providers who deal with pregnant women do not necessarily conflict as evidenced by the complementary role of these two (complementary insofar as they achieve collectively desired outcomes, albeit in parallel and (mutually) exclusive means) in caring for women during pregnancy and childbirth. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021
- Authors: Muchabveyo, Brenda Hamufari
- Date: 2021
- Subjects: Pregnant women Zimbabwe Manicaland Province , Women's shelters Zimbabwe Manicaland Province , Maternal health services Zimbabwe Manicaland Province , Integrative medicine , Childbirth Social aspects Zimbabwe Manicaland Province
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/476912 , vital:78017 , DOI 10.21504/10962/476912
- Description: This study explores the experiences and perceptions of expectant mothers during prenatal, intra-, and postpartum care. It focuses on expectant mother‘s use or non-use of a waiting mothers' shelter within a medical pluralistic village within a context where hospitals and maternal health care facilities are not proximate. Special focus was on Mawadza village in the Mutasa district in Manicaland Province of Zimbabwe. A sample of 48 participants was used for collecting data in this study. The sample consisted of 15 women some of whom were expectant mothers in the waiting mothers‘ shelter (11) and others had used (4) the shelter once or twice since 2015. Participants were drawn mainly from Mawadza village and Bonda Mission Hospital while others were from the district and provincial offices of the Ministry of Health and Child Care of Zimbabwe. The study adopted a qualitative research methodology, which employed in-depth interviews; key informant interviews (KIIs) and focus group discussions (FGDs) as the main data gathering strategies. In-depth interviews were conducted with the expectant mothers and those who had formerly used the shelter since 2015, while, key informant interviews were conducted with the hospital staff members, traditional healers and the midwives from Mawadza village. Focus group discussions were also conducted with both male and female community members from Mawadza village. The study carried out face to face interviews and notes were handwritten and transcribed at the end of each day. Data coding was used to analyse data. The paradigms and theoretical underpinnings of the study were influenced by the symbolic interactionist theory. The theory made it possible to understand the social processes of pregnancy and childbirth in the waiting mothers' shelter due to its interpretive approach to social research and the legitimacy it places on the social interaction and meanings that social actors place on interactions in their environments. The study documented the ways pregnancy and childbirth are perceived, understood, and experienced in Mawadza village within the context of medical pluralism. In Mawadza village, pregnancy and childbirth are highly embedded in the cultural beliefs of the local people, hence, treated with importance and assumed important symbolic meanings. On the contrary, the waiting mothers‘ shelter as a biomedical facility handles pregnancy and childbirth from a biomedical approach, basing its practices and operations on pure science. Expectant mothers who await labour in this facility are therefore involved in several biomedical activities during prenatal, intra- and post-partum care in the waiting mothers‘ shelter. The need to access skilled birth attendants and the criminalisation of home births in Mawadza village have been the major reasons that influence the expectant mothers to use the waiting mothers‘ shelter. Nevertheless, factors such as medical pluralism, child care, and family commitments, lack of understanding of the importance of the waiting mothers‘ shelter, lack of privacy in the shelter, and cost of food and utilities during the expectant mothers' stay in this facility among others are factors that deter expectant mothers from using the waiting mothers' shelter. Lack of practice of bodily agency where practices common in preparation for childbirth such as opening the birth canal which is not accepted was also reported among common problems that discourage expectant mothers from preferring use of the shelters. The study also revealed that the community is involved in the operations of the waiting mothers‘ shelter, although, the involvement is gendered since there are more women involved as compared to men. The study concluded that even biological processes such as pregnancy and childbirth can only be fully understood within a social context given the different meanings which are attached to the various aspects of the childbirth process by the various actors such as expectant mothers, mothers, biomedical practitioners, traditional healers and communities in Mawadza village. Also, in a medical pluralistic village, the different health care providers who deal with pregnant women do not necessarily conflict as evidenced by the complementary role of these two (complementary insofar as they achieve collectively desired outcomes, albeit in parallel and (mutually) exclusive means) in caring for women during pregnancy and childbirth. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021
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
- 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
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