- Title
- Optimization of liposomes for enhanced stability against degradation by gastrointestinal fluid content
- Creator
- Scholtz, Carla Chleo
- Subject
- Port Elizabeth (South Africa)
- Subject
- Eastern Cape (South Africa)
- Subject
- South Africa
- Date Issued
- 2021-12
- Date
- 2021-12
- Type
- Master's theses
- Type
- text
- Identifier
- http://hdl.handle.net/10948/54117
- Identifier
- vital:46305
- Description
- Motivation: Liposomes are nanoparticulate carriers consisting of a hydrophobic bilayer and a hydrophilic core. Their application as drug carrier systems arises from their unique physiochemical structure, biocompatibility and biodegradability. Their biphasic nature is significant in the delivery of peptide and protein drug molecules as it is thus able to encompass both hydrophobic and hydrophilic molecules. Liposomes are actively being used for drug delivery intravenously. These formulations have been successful in reducing side effects and improving therapeutic efficacy. However, the intravenous route poses many challenges and is not the preferred route of administration amongst patients. The oral route of administration is non-invasive, and administration is of ease, therefore it is the preferred route of administration amongst patients, especially those with complex medicine regimes. Problem: The gastrointestinal tract is a harsh environment. In order for liposomes to maintain their integrity during their course they require a level of stability against gastric and intestinal fluids and its associated constituents such as gastric and pancreatic enzymes, low pH and bile acid. Methodology: Based on recommendations extrapolated from literature, the incorporation of a bile salt, sodium glycocholate, into liposomes in conjunction with coating the surface with chitosan was selected as the optimization strategies to enhance the stability of liposomes against degradation in the gastrointestinal tract. Bilosomes with encapsulated calce in were produced using the thin-film hydration method and coated with chitosan. An in vitrocalce in release assay was conducted in simulated gastric and intestinal fluids which presented with in vivo conditions in terms of pH and enzymes and additional constituents such as a bile salt. Stability was determined by the extent of digestion within the simulated fluids with time. Results: Characterization results suggested that the addition of chitosan and sodium glycocholate to the liposomal formulation has significant effects on the physiochemical properties. The colloidal dispersions could not retain their stability during storage which was noticeable during HRTEM. Despite optimization of the liposomes, in vitro studies showed significant release in both simulated gastric and intestinal fluids, with majority release seen in the presence of pepsin and pancreatic, at low pH and in the presence of bile acid.
- Description
- Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Format
- computer
- Format
- online resource
- Format
- application/pdf
- Format
- 1 online resource (112 pages)
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Science
- Language
- English
- Rights
- Nelson Mandela University
- Rights
- All Rights Reserved
- Rights
- Open Access
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | Scholtz, C.pdf | 2 MB | Adobe Acrobat PDF | View Details Download |