A qualitative estimate of the influence of halcinonide concentration and urea on the reservoir formation in the stratum corneum.

The existence of a stratum corneum reservoir for topically applied substances is well known. Data concerning the stratum corneum retention time are important for the elaboration of optimal topical treatment. We used the re-occlusion technique followed by skin colour measurements (Chromametry) for the evaluation of the stratum corneum retention time of halcinonide. We found a significant reservoir for halcinonide up to 5 days after the initial application. The retention was found to be corticosteroid concentration and formulation dependent.