Physical Model Evaluation of Topical Prodrug Delivery—simultaneous Transport and Biocnversion of Vidarabine-5′-valerate II: Parameter Determinations
| Autor: | Jeffrey L. Fox, Cheng der Yu, Norman F.H. Ho, William I. Higuchi |
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| Rok vydání: | 1979 |
| Předmět: |
Male
Kinetics Mice Nude Pharmaceutical Science Models Biological Esterase Permeability Diffusion Mice Reaction rate constant Valerates Stratum corneum medicine Animals Solubility Skin Chromatography integumentary system Chemistry Biological Transport Prodrug Membrane medicine.anatomical_structure Permeability (electromagnetism) Vidarabine |
| Zdroj: | Journal of Pharmaceutical Sciences. 68:1347-1357 |
| ISSN: | 0022-3549 |
| DOI: | 10.1002/jps.2600681105 |
| Popis: | Results of initial studies on methods for determining various model parameters are reported. By employing excised hairless mouse skin in a diffusion cell system, numerous model parameter values were deduced. The stratum corneum permeability was estimated from steady-state fluxes with preparations of heat-separated epidermal membranes. Determinations of dermis diffusivities and enzyme rate constants in situ involved considering the simultaneous transport and the enzyme processes and factoring the diffusivities and enzyme rate constants from the overall kinetics. Dermal diffusivities were on the order of 10−6 cm2/sec for vidarabine and its 5′-valerate ester. The enzyme rate constants were 1.70 × 10−3 sec−1 for the esterase and 8.68 × 10−3 sec−1 for the deaminase. |
| Databáze: | OpenAIRE |
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