Influence of electrical current on transdermal flux of rolipram

Application of an electrical current is an attractive idea to increase and/or control the transdermal flux of drugs. In order to investigate if transdermal fluxes can be influenced by direct current (DC) and/or alternating current (AC), in vitro studies with the investigational antidepressive rolipram with nude mouse and human cadaver skin using the Chien-Valia diffusion cell were performed. Transdermal flux of rolipram depended on DC polarity and was highest when the epidermal side was positive. Flux increased with time and increasing DC current. Application of DC current led to pH changes which can change dissociation of ionizable substances. Avoiding pH changes by increasing ionic strength of buffer and/or application of AC current increased transdermal fluxes only approximately 2-fold compared to controls.