Preparation, Characterization, and <i>In Vitro</i> Protein Release Studies in Pharmaceutically relevant Lecithin Microemulsions
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| Language: | English |
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University of Toledo Health Science Campus / OhioLINK
2011
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| Online Access: | http://rave.ohiolink.edu/etdc/view?acc_num=mco1300753350 |
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ndltd-OhioLink-oai-etd.ohiolink.edu-mco1300753350 |
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NDLTD |
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English |
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Pharmaceuticals Pharmacy Sciences Physical Chemistry Lecithin microemulsion DSC microscopy albumin controlled release |
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Pharmaceuticals Pharmacy Sciences Physical Chemistry Lecithin microemulsion DSC microscopy albumin controlled release Parekh, Khushboo K. Preparation, Characterization, and <i>In Vitro</i> Protein Release Studies in Pharmaceutically relevant Lecithin Microemulsions |
| author |
Parekh, Khushboo K. |
| author_facet |
Parekh, Khushboo K. |
| author_sort |
Parekh, Khushboo K. |
| title |
Preparation, Characterization, and <i>In Vitro</i> Protein Release Studies in Pharmaceutically relevant Lecithin Microemulsions |
| title_short |
Preparation, Characterization, and <i>In Vitro</i> Protein Release Studies in Pharmaceutically relevant Lecithin Microemulsions |
| title_full |
Preparation, Characterization, and <i>In Vitro</i> Protein Release Studies in Pharmaceutically relevant Lecithin Microemulsions |
| title_fullStr |
Preparation, Characterization, and <i>In Vitro</i> Protein Release Studies in Pharmaceutically relevant Lecithin Microemulsions |
| title_full_unstemmed |
Preparation, Characterization, and <i>In Vitro</i> Protein Release Studies in Pharmaceutically relevant Lecithin Microemulsions |
| title_sort |
preparation, characterization, and <i>in vitro</i> protein release studies in pharmaceutically relevant lecithin microemulsions |
| publisher |
University of Toledo Health Science Campus / OhioLINK |
| publishDate |
2011 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=mco1300753350 |
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AT parekhkhushbook preparationcharacterizationandiinvitroiproteinreleasestudiesinpharmaceuticallyrelevantlecithinmicroemulsions |
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1719422995166920704 |
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ndltd-OhioLink-oai-etd.ohiolink.edu-mco13007533502021-08-03T05:38:54Z Preparation, Characterization, and <i>In Vitro</i> Protein Release Studies in Pharmaceutically relevant Lecithin Microemulsions Parekh, Khushboo K. Pharmaceuticals Pharmacy Sciences Physical Chemistry Lecithin microemulsion DSC microscopy albumin controlled release The objective of this research project was to prepare and characterize pharmaceutically relevant microemulsions, using lecithin as the surfactant and isopropyl alcohol as the co-surfactant. Visually transparent microemulsions were obtained, by titrating mixtures of lecithin, isopropyl alcohol, and oil with water. The quantity of isopropyl alcohol and lecithin was modulated in the formulations, by changing the Km ratio [Km = (surfactant concentration)/ (co-surfactant concentration)] and using various surfactant-oil mixtures. Pseudoternary phase diagrams were plotted, to identify microemulsion forming compositions. The microemulsions, which incorporated appropriate amounts of water, were selected for further characterization. Samples of the formulations were subjected to polarized light microscopy, to verify the formation of the microemulsions. The electrical conductivity of lecithin/Isopropyl Myristate and lecithin/Ethyl Oleate microemulsions, was measured. The state of the water droplets in the lecithin/Isopropyl Myristate microemulsions, was characterized via subambient differential scanning calorimetry. Microemulsions, were further evaluated using dynamic light scattering experiments, to estimate the particle size distribution. Comparison between poloxamer and isopropyl alcohol as co-surfactants was made by comparing the amount of water incorporated into the microemulsions. Bovine serum albumin was incorporated into these water in oil lecithin microemulsions, anticipating the use of these microemulsions in biocatalysis of proteins/enzymes, thereby preventing their denaturation. Release studies were performed on the microemulsions, containing bovine serum albumin, to evaluate the release profile of the protein from the microemulsion system. The Hartree Lowry assay was used for the determination of albumin, in phosphate buffer of pH 7.4.The pseudo Ternary phase diagrams indicated that stable and clear microemulsions, formed when the Km ratio ranged from 0.5 to 2.0 and the water concentration varied between 3% and 10%. The absence of optical birefringence in the clear formulation samples indicated the production of a water-in-oil microemulsion. The electrical conductivity of the formulations demonstrated a composition dependant change with low conductivity values of 0.0 to 0.4 μSiemens/cm observed in microemulsions. Formulations that exhibited turbidity possessed high conductivity values that ranged from 1.6 to 3.0 μSiemens/cm. The conductivity studies, exhibited a “percolation phenomenon”, in the formulations. Sub-ambient DSC established the existence of different types of water in the formulations. A microemulsion containing 3% water did not show any peak attributable to the freezing of water indicating that all the water present in the microemulsion is tightly bound to the surfactant and remains non-freezable down to –100°C. However, thermal events observed at ~ -70 °C in formulations containing a larger quantity of water confirmed the presence of bound freezable water. The composition of the formulations affected the particle size distribution with larger droplets observed as the percentage of water increased. The estimated droplet diameter in the formulations varied between 5 to 800 nm. Isopropyl alcohol was able to reduce the interfacial tension to a greater extent than the poloxamer in use, and hence was able to incorporate a greater quantity of water than the poloxamer. The presence of albumin did not influence the stability of the microemulsion formulation, as almost similar percentages of albumin solution were incorporated into the lecithin/Ethyl Oleate and lecithin/Isopropyl Myristate mixtures, as compared to that of R.O water. The <i>invitro</o> protein release studies were carried out. Lecithin is capable of forming stable microemulsions in Isopropyl Myristate and Ethyl Oleate in the presence of Isopropyl alcohol. The influence of various formulation parameters such as Km ratio, surfactant/oil ratio, and percentage of water in the system on the type of microemulsion formed was evaluated. These microemulsions are currently being assessed for use as a drug delivery system. 2011-05-25 English text University of Toledo Health Science Campus / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=mco1300753350 http://rave.ohiolink.edu/etdc/view?acc_num=mco1300753350 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws. |