Availability of isoconazole in human skin after dermal application as free base and as nitrate in vitro

The concentration of isoconazole has been investigated in different layers of the human skin after dermal application of 4 different (3H-labelled) isoconazole containing solutions (Travogen) by the tangential section technique. Two vehicles (ethanol/propylene glycol and polyethylene glycol) containing 1% isoconazole either as nitrate or as free base have been used. Use of the ethanol/propylene glycol vehicle led to higher concentrations of both compounds in the stratum corneum. A 10-fold increase in the concentration of antimycotic has been observed in the viable epidermis and dermis after the application of isoconazole free base in ethanol/propylene glycol.