Bioavailability of Clobetasol Propionate – Quantification of Drug Concentrationsin the Stratum Corneum by Dermatopharmacokinetics UsingTape Stripping

Abstract

The concentration of clobetasol propionate in the stratum corneum after application of three different formulations was determined, quantifying the influence of the formulations on the bioavailability of the drug. The stratum corneum was sampled by tape stripping. The concentrations of clobetasol propionate were determined quantitatively by HPLC. After application of Clobetasol Propionate Cream USP, 0.05%, and Temovate Cream, 0.05%, identical amounts of the drug were found in the stratum corneum, whereas after application of Temovate ε Emollient, 0.05%, the quantity was clearly decreased. From results obtained measuring the drug concentration in the adjacent sites of the skin where the creams had not been applied, it became clear that clobetasol propionate in Temovate ε Emollient, migrated to a large extent in the lateral direction. This explains the lower concentration measured for this formulation in the skin areas where the cream had been applied. In general, a lateral distribution of the applied drug must be taken into account when positioning the application areas on the forearm.