Co-crystal formation of pharmaceutical and veterinary tranquilizer molecules
- Mngwengwe, Bongeka Naledi Precious
- Authors: Mngwengwe, Bongeka Naledi Precious
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464532 , vital:76519
- Description: Midazolam, a 1,4-benzodiazepine derivative is commonly used to treat anxiety, insomnia and may be used as a sedative in anaesthesia as it has calming, anti-convulsant and muscle relaxant properties. Midazolam has a rapid onset but a short duration of action resulting in fewer adverse effects. Midazolam also has the potential to form insoluble crystalline precipitates in pharmaceutical dosage forms such as syrups and solutions, which is a challenge in formulation and process development activities. The primary goal of this research was to prepare multicomponent crystals of midazolam free base, specifically targeting interactions with coformers structurally similar to methyl paraben. Key preparation techniques included neat grinding, liquid-assisted grinding, and slow evaporation. The resulting solid forms were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and powder X-Ray Diffraction (PXRD). In addition, Single-Crystal X-Ray Diffraction (SCXRD) was used to elucidate detailed structural information on the novel multicomponent crystals formed. Successful preparation of midazolam free base from the hydrochloride salt was confirmed through FTIR, DSC, and PXRD analysis. Different co-crystals and salts of midazolam with coformers such as salicylic acid (SA), benzoic acid (BA), 3-hydroxybenzoic acid (3-HBA) and p-aminobenzoic acid (PABA) were synthesized and characterized. The structure of the single crystal obtained from a veterinary tranquilizer solution was solved and found to be a salt that had formed between midazolam free base, midazolam HCl, and methyl paraben. This finding inspired further investigation of similar multicomponent crystals of midazolam and methyl paraben analogues. This study demonstrated the effectiveness of both mechanochemical and slow evaporation methods for the preparation of multicomponent crystals. PXRD and DSC provided insights into the stability and purity of the crystals that had formed and the differences in melting points and PXRD patterns were particularly important in this regard. Differences in FTIR spectra were used to distinguish between different solid forms and to confirm the successful formation of new solid forms. Extensive searches in the Cambridge Structural Database (CSD) confirmed that the multicomponent crystals of midazolam, such as MDZ‧SA, MDZ‧BA, MDZ‧3-HBA, and MDZ‧PABA, had not previously been reported, highlighting the novelty of these findings. The research successfully isolated and characterized several novel multicomponent crystals of midazolam, demonstrating the potential of mechanochemistry and solvent evaporation techniques in the development of pharmaceutical and veterinary medicinal applications. These findings contribute to the understanding of cocrystal formation and provide a foundation for future studies in which the stability and efficacy of midazolam-based formulations can be evaluated. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Mngwengwe, Bongeka Naledi Precious
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464532 , vital:76519
- Description: Midazolam, a 1,4-benzodiazepine derivative is commonly used to treat anxiety, insomnia and may be used as a sedative in anaesthesia as it has calming, anti-convulsant and muscle relaxant properties. Midazolam has a rapid onset but a short duration of action resulting in fewer adverse effects. Midazolam also has the potential to form insoluble crystalline precipitates in pharmaceutical dosage forms such as syrups and solutions, which is a challenge in formulation and process development activities. The primary goal of this research was to prepare multicomponent crystals of midazolam free base, specifically targeting interactions with coformers structurally similar to methyl paraben. Key preparation techniques included neat grinding, liquid-assisted grinding, and slow evaporation. The resulting solid forms were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and powder X-Ray Diffraction (PXRD). In addition, Single-Crystal X-Ray Diffraction (SCXRD) was used to elucidate detailed structural information on the novel multicomponent crystals formed. Successful preparation of midazolam free base from the hydrochloride salt was confirmed through FTIR, DSC, and PXRD analysis. Different co-crystals and salts of midazolam with coformers such as salicylic acid (SA), benzoic acid (BA), 3-hydroxybenzoic acid (3-HBA) and p-aminobenzoic acid (PABA) were synthesized and characterized. The structure of the single crystal obtained from a veterinary tranquilizer solution was solved and found to be a salt that had formed between midazolam free base, midazolam HCl, and methyl paraben. This finding inspired further investigation of similar multicomponent crystals of midazolam and methyl paraben analogues. This study demonstrated the effectiveness of both mechanochemical and slow evaporation methods for the preparation of multicomponent crystals. PXRD and DSC provided insights into the stability and purity of the crystals that had formed and the differences in melting points and PXRD patterns were particularly important in this regard. Differences in FTIR spectra were used to distinguish between different solid forms and to confirm the successful formation of new solid forms. Extensive searches in the Cambridge Structural Database (CSD) confirmed that the multicomponent crystals of midazolam, such as MDZ‧SA, MDZ‧BA, MDZ‧3-HBA, and MDZ‧PABA, had not previously been reported, highlighting the novelty of these findings. The research successfully isolated and characterized several novel multicomponent crystals of midazolam, demonstrating the potential of mechanochemistry and solvent evaporation techniques in the development of pharmaceutical and veterinary medicinal applications. These findings contribute to the understanding of cocrystal formation and provide a foundation for future studies in which the stability and efficacy of midazolam-based formulations can be evaluated. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Date Issued: 2024-10-11
Synthesis and characterization of high energy milled silicon nanoparticles for electronic applications
- Authors: Mnguni, Nomvula Bianca
- Date: 2023-00
- Subjects: Chemical and Physical Sciences
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/9936 , vital:74651
- Description: This study demonstrates that high energy milling using a planetary disc mill offers a new simple route to the production of polycrystalline silicon nanoparticles which are suitable for electronic applications. By manipulating process variables such as milling duration and mass of the feedstock load, the microstructure of the nanoparticles can be tuned to meet requirements. The internal structure of the nanoparticles prepared by high energy milling was found to predominantly consist of nanocrystalline silicon and their surfaces are characterised by a disordered layer of silicon sub-oxides and an insignificant proportion of fully oxidized silicon. X-ray diffraction (XRD) patterns and Raman spectra were used to calculate the average crystallite size and correlating it to the milling process variables. The surface chemistry of the nanoparticles was elucidated using X-ray photo spectroscopy (XPS) and was also related to the milling parameters. The internal structure, agglomeration and aggregation of the particles were tested using high resolution transmission microscopy (HRTEM) and complemented by scanning electron microscopy (SEM). Conductivity tests were done on the particles to ascertain their suitability for electronic applications. It is demonstrated that the longer the milling time, the smaller the sizes of particles and crystals. The sizes also depended on the mass of feedstock load. 30 g feedstock loads resulted in average nanoparticle size which were 30 - 40 % larger than for 10 g loads. The average size of nanoparticles produced were in the range 50 – 80 nm as measured by SEM. The distribution of the size of particles became less polydisperse with increase in milling time and a reduction in feedstock load. The particles were devoid of significant SiO2 layer and hence were confirmed by conductivity tests to be electrically active. Data from XPS indicate that the silicon nanoparticles have a unique surface chemistry which is consistent with the silicon surfaces being dominantly oxygen terminated. , Thesis (Masters) -- Faculty of Commerce and Administration, 2022
- Full Text:
- Date Issued: 2023-00
- Authors: Mnguni, Nomvula Bianca
- Date: 2023-00
- Subjects: Chemical and Physical Sciences
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/9936 , vital:74651
- Description: This study demonstrates that high energy milling using a planetary disc mill offers a new simple route to the production of polycrystalline silicon nanoparticles which are suitable for electronic applications. By manipulating process variables such as milling duration and mass of the feedstock load, the microstructure of the nanoparticles can be tuned to meet requirements. The internal structure of the nanoparticles prepared by high energy milling was found to predominantly consist of nanocrystalline silicon and their surfaces are characterised by a disordered layer of silicon sub-oxides and an insignificant proportion of fully oxidized silicon. X-ray diffraction (XRD) patterns and Raman spectra were used to calculate the average crystallite size and correlating it to the milling process variables. The surface chemistry of the nanoparticles was elucidated using X-ray photo spectroscopy (XPS) and was also related to the milling parameters. The internal structure, agglomeration and aggregation of the particles were tested using high resolution transmission microscopy (HRTEM) and complemented by scanning electron microscopy (SEM). Conductivity tests were done on the particles to ascertain their suitability for electronic applications. It is demonstrated that the longer the milling time, the smaller the sizes of particles and crystals. The sizes also depended on the mass of feedstock load. 30 g feedstock loads resulted in average nanoparticle size which were 30 - 40 % larger than for 10 g loads. The average size of nanoparticles produced were in the range 50 – 80 nm as measured by SEM. The distribution of the size of particles became less polydisperse with increase in milling time and a reduction in feedstock load. The particles were devoid of significant SiO2 layer and hence were confirmed by conductivity tests to be electrically active. Data from XPS indicate that the silicon nanoparticles have a unique surface chemistry which is consistent with the silicon surfaces being dominantly oxygen terminated. , Thesis (Masters) -- Faculty of Commerce and Administration, 2022
- Full Text:
- Date Issued: 2023-00
A sociological exploration of whether culture inhibits comprehensive sexual education in schools: the case of urban schools in Mpika district of Zambia
- Authors: Nyoni, Kaliza
- Date: 2022-10-14
- Subjects: Sex instruction Zambia , Sex instruction Social aspects Zambia , Culture , High school students Attitudes , Sex educators Attitudes , Influence (Psychology) , Language and culture Zambia
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406796 , vital:70308
- Description: This study investigated the impact and influence of culture in the provisioning of comprehensive sexuality education , the case of urban schools of Mpika district of Zambia. The specific objectives were to investigate the frameworks that inform the teaching of CSE in schools, explore ways in which influence of culture on the framework affects the leaners participation in learning CSE, explore the influence of cultural norms, metaphors, and values on that framework, explore whether cultural norms have an impact and influence on teachers and explore whether there is a discrepancy between cultural values and CSE. The methodology which was used in carrying out the research was descriptive research design and purposive sampling was used in which a sample of 21 respondents who are leaners were picked and 5 teachers who teach CSE were chosen. The interview schedule was used to collect data from the sample which was drawn. The data gathered was analysed using concepts and themes as well as observer impression. The findings of this research are that there is a framework that informs the teaching of CSE in schools whose aim is to curb school drop outs by reducing teen pregnancies and high infection rates of STIs and HIV/AIDS. The framework seeks to empower knowledge on the adolescents in relation to gender norms, rights in relationships and sexuality. The major findings of the research are that culture has an influence on the teachers and leaners. Of particular discovery is the use of symbols through charts which display human private parts. This is construed by the teachers and learners to be against their cultural beliefs. Furthermore, language that this subject uses is culturally seen to be too strong and vulgar , to both teachers and leaners. This study found out that open discussion in class of the topic on sexuality does not sit well with the leaners as it is against their cultural orientation. The research also found out that there are lessons in CSE that are beneficial to the learners such as , how to prevent contracting of STIs and HIV/AIDS and prevention of unwanted pregnancies. , Thesis (MA) -- Faculty of Humanities, Sociology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Nyoni, Kaliza
- Date: 2022-10-14
- Subjects: Sex instruction Zambia , Sex instruction Social aspects Zambia , Culture , High school students Attitudes , Sex educators Attitudes , Influence (Psychology) , Language and culture Zambia
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406796 , vital:70308
- Description: This study investigated the impact and influence of culture in the provisioning of comprehensive sexuality education , the case of urban schools of Mpika district of Zambia. The specific objectives were to investigate the frameworks that inform the teaching of CSE in schools, explore ways in which influence of culture on the framework affects the leaners participation in learning CSE, explore the influence of cultural norms, metaphors, and values on that framework, explore whether cultural norms have an impact and influence on teachers and explore whether there is a discrepancy between cultural values and CSE. The methodology which was used in carrying out the research was descriptive research design and purposive sampling was used in which a sample of 21 respondents who are leaners were picked and 5 teachers who teach CSE were chosen. The interview schedule was used to collect data from the sample which was drawn. The data gathered was analysed using concepts and themes as well as observer impression. The findings of this research are that there is a framework that informs the teaching of CSE in schools whose aim is to curb school drop outs by reducing teen pregnancies and high infection rates of STIs and HIV/AIDS. The framework seeks to empower knowledge on the adolescents in relation to gender norms, rights in relationships and sexuality. The major findings of the research are that culture has an influence on the teachers and leaners. Of particular discovery is the use of symbols through charts which display human private parts. This is construed by the teachers and learners to be against their cultural beliefs. Furthermore, language that this subject uses is culturally seen to be too strong and vulgar , to both teachers and leaners. This study found out that open discussion in class of the topic on sexuality does not sit well with the leaners as it is against their cultural orientation. The research also found out that there are lessons in CSE that are beneficial to the learners such as , how to prevent contracting of STIs and HIV/AIDS and prevention of unwanted pregnancies. , Thesis (MA) -- Faculty of Humanities, Sociology, 2022
- Full Text:
- Date Issued: 2022-10-14
Development of a Mobile-Based Livestock Breeding Management System for Communal Farmers in Eastern Cape, South Africa
- Authors: Aduradola, Oluwatobi John
- Date: 2021-05
- Subjects: Mobile communication systems , Mobile computing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20600 , vital:46364
- Description: More than a decade ago, South Africa realized the significance of Information and Communication Technology (ICT) and its use in delivering several services; there are still several challenges that block implementing an ICT-based system to deliver services and information better. Since communal development is still one of the country's biggest concerns, ICT is among several advances and views recognized for speeding up communal development and providing for the country's economic growth. This research aimed to investigate and implement ICT tools for communal farmers in the context of information needs and information dissemination. The research concentrated on the technical tools and skills needed to implement an ICT tool for communal farmers and other stakeholders. A prototyping methodology was used in this research in the development of the required prototype. A study was then conducted to understand the present state and the information needs of communal farmers where the questionnaire was administered. The research results demonstrated the critical need for communal farmers to get information timely at their convenience. A mobile database system was then designed and developed that suits communal farmers' nature. This system was an offline android application that assists with their information need and its dissemination, and it allows the sharing of the communal farmer's data to other stakeholders. , Thesis (MSc) (Computer Science)-- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Aduradola, Oluwatobi John
- Date: 2021-05
- Subjects: Mobile communication systems , Mobile computing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20600 , vital:46364
- Description: More than a decade ago, South Africa realized the significance of Information and Communication Technology (ICT) and its use in delivering several services; there are still several challenges that block implementing an ICT-based system to deliver services and information better. Since communal development is still one of the country's biggest concerns, ICT is among several advances and views recognized for speeding up communal development and providing for the country's economic growth. This research aimed to investigate and implement ICT tools for communal farmers in the context of information needs and information dissemination. The research concentrated on the technical tools and skills needed to implement an ICT tool for communal farmers and other stakeholders. A prototyping methodology was used in this research in the development of the required prototype. A study was then conducted to understand the present state and the information needs of communal farmers where the questionnaire was administered. The research results demonstrated the critical need for communal farmers to get information timely at their convenience. A mobile database system was then designed and developed that suits communal farmers' nature. This system was an offline android application that assists with their information need and its dissemination, and it allows the sharing of the communal farmer's data to other stakeholders. , Thesis (MSc) (Computer Science)-- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-05
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