The effects on epidermal DNA synthesis of the butyrate esters of clobetasone and clobetasol, and the propionate ester of clobetasol

Abstract

An animal model [mouse] for evaluating the effects of drugs on epidermal DNA synthesis was used to determine the time of onset, period of maximum activity and duration of effect of 2 topically applied proprietary glucocorticosteroids, clobetasone butyrate and clobetasol propionate. Both drugs produced maximum inhibition of epidermal DNA synthesis by 24 h after application. Clobetasol propionate exhibited a significantly earlier onset (4 1/2 h) and longer duration (36 h) of activity than clobetasone butyrate (6 and 24 h, respectively). A systemic effect was not observed at any time after the application of clobetasone butyrate but was observed for up to 24 h after the application of clobetasol propionate. Clobetasol butyrate was also assayed in this system and was found to be as potent as clobetasol propionate. The alcoholic, as opposed to the ketonic, grouping in the II positions of the steroid ring profoundly alters the potential of this molecule for systemic activity.