The nonpolymeric high molecular weight substances such as lanolin alcohol, stearyl alcohol, and cetyl alcohol have been investigated for their film-forming potential. Furthermore, the application of this potential in the design of topical drug-delivery systems has also been explored. The utilization of such film-forming systems may offer certain unique advantages not associated with the polymeric systems.
Stearyl alcohol and cetyl alcohol do not form films of acceptable integrity. Lanolin alcohol forms thin films capable of being isolated. Inclusion of appropriate amounts of ethyl cellulose and propylene glycol or hexadecyl alcohol in lanolin alcohol was found to improve the integrity, hardness and modulus of elasticity of these films. These lanolin alcohol films have been shown to reduce the normal in vivo transepidermal moisture loss.
The in vitro release of 3H--triamcinolone acetonide from selected films was investigated. The results suggest that the drug release follows a diffusion-controlled granular matrix model with the release profile proportional to the square root of time. The release rate constants were found to be proportional to the concentration of the dispersed drug. Drug release was found to be maximal from a system containing the drug in a near-saturated solution.
In vitro penetration experiments using human cadaver skin were also conducted from the same matrix-forming compositions. The analysis of the penetration data revealed that the release from the matrix acted as the rate-limiting step for the penetration process. The maximum rate of penetration was observed from a system containing slightly excess solubilizer than required to completely solubilize the steroid. The importance of this finding has been explained.
| Identifer | oai:union.ndltd.org:pacific.edu/oai:scholarlycommons.pacific.edu:uop_etds-4375 |
| Date | 01 January 1979 |
| Creators | Iyer, Balasubramanian Venkataraman |
| Publisher | Scholarly Commons |
| Source Sets | University of the Pacific |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | University of the Pacific Theses and Dissertations |
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