[Biologic availability of diflucortolone-21-valerate in human skin]

The concentration of diflucortolone-21-valerate (DFV) in the different layers of human skin was investigated after topical application of Nerisona (0.1%) as a function of the formulation (fatty ointment, ointment and creme), of the duration of exposition and of the condition of the skin. From all galenic formulations DFV penetrated rapidly into the horny layer. Mean highest concentrations were determined 4 h after application with approx. 300 micrograms/ml (ca. 600 mumol/l) after treatment with fatty ointment and ointment and with approx. 500 micrograms/ml (ca. 1000 mumol/l) after treatment with the cream. The corticoid concentration decreased in the horny layer from distal to proximal by 1.5 to 2 decades. After application to damaged skin - as a model for diseased skin - the local corticoid concentrations in all skin layers were distinctly higher than after application to intact skin at all time points investigated. DFV penetrates selectively into the damaged skin. The systemic load caused by percutaneous absorption through intact skin is neglectable.