In contrast to oral administration, topical cyclosporin is not effective in the treatment of psoriasis. This may be due to the drug's inability to penetrate the stratum corneum or to a need for systemic metabolism of cyclosporin to active metabolites. We conducted a preliminary evaluation of the ability of cyclosporin, in a variety of vehicles, to penetrate excised human skin in a two-compartment diffusion cell, a standard in vitro technique for evaluating percutaneous drug delivery. A high-pressure liquid chromatography assay for cyclosporin did not detect the passage of cyclosporin through skin. This finding was consistent through multiple trials, some of which evaluated Azone or liposomal formulation, which are reported to enhance the penetrability of certain compounds. These results indicate that cyclosporin is unable to penetrate human skin in the vehicles tested. This may explain the lack of clinical efficacy we demonstrated in 5 patients with psoriasis treated with topical cyclosporin for 14-16 days.
|Original language||English (US)|
|Number of pages||4|
|Publication status||Published - 1988|
ASJC Scopus subject areas
- Pharmacology (medical)
- Pharmacology, Toxicology and Pharmaceutics(all)