Autoradiographic studies on percutaneous absorption of clobetasol 17-propionate

The distribution of topically applied radioactive clobetasol 17-propionate was studied by means of autoradiography (direct mounting method). In the time course study, the developed silver grain deposition on the epidermis and skin appendages appeared after 30 minutes of occlusive treatment, and then reached the maximum state after 5 hours. Reservoir phenomenon was noticed 24 hours after removal of the cream. The pattern of deposition on the epithelial component of the skin is similar to that of betamethasone 17-valerate. After 1 hour of simple application of the cream, the deposition was seen only on the horny layer in the in vitro experiment, whereas some deposition was noticed on the Malpighian layer of the epidermis and hair follicle in the in vivo experiment. (auth.)