John E. Fairbrother

THE EFFECT OF SEMI‐PERMEABLE FILM COVERS ON THE BIOVAILABILITY OF BETAMETHASONE VALERATE DELIVERED FROM A TOPICAL CREAM VEHICLE

Plastic occlusive films such as Polythene and Saran wrap are used with topical corticosteroid products to enhance their effectiveness in the treatment of recalcitrant psoriatic lesions. The prevention of moisture loss from the skin surface, leading to a hydration of the stratum comeum, results in an increase in the permeability of steroids through skin. This study was initiated to investigate the control that could be exerted on the bioavailability of a topical corticosteroid in man by the use of different covering films having a wide range of water vapour transmission rates (WVTR), and consequently likely to produce different degrees of stratum comeum hydration.