Increase of the transdermal penetration of testosterone by miconazole nitrate.

Miconazole nitrate is an imidazole derivative used to treat skin disorders caused by fungi. The aim of this study was to investigate in a systematic way whether miconazole nitrate can have skin penetration enhancing properties. Using Franz diffusion cells, three representative model compounds (caffeine, testosterone and ibuprofen) were applied to human skin as 10 mM aqueous-ethanolic solutions with or without 1 mM of miconazole nitrate. The apparent permeability coefficient K(p) for each of the model compounds was determined with and without miconazole nitrate. While a statistically significant penetration enhancement effect of 33% was found for testosterone, no overall statistically significant effect could be demonstrated for caffeine and ibuprofen. The increase in skin permeability of testosterone is mainly due to an improved partitioning from the dose solution into the skin, thereby resulting in a higher delivery through the human skin. Our results indicate that miconazole can act as a penetration enhancer.