THE EFFECT OF DOSING VOLUME ON THE DISPOSITION OF CYCLOSPORINE-A IN HAIRLESS MOUSE SKIN AFTER TOPICAL APPLICATION OF A NONIONIC LIPOSOMAL FORMULATION - AN IN-VITRO DIFFUSION STUDY

This study reports the effects of dosing volume and occlusion on the k inetics and extent of uptake of cyclosporin A from a non-ionic liposom al formulation (Novasome 1) after topical application to hairless mous e skin using in vitro diffusion experiments. Under non-occluded condit ions, the kinetics of uptake of cyclosporin A in the deeper skin strat a and in the receiver compartment are strongly dependent on the Novaso meTM dose volume applied and an inverse relationship is seen between t he amount of drug deposited and application volume. The reduced rate o f uptake with increasing application volume of formulation is consiste nt with the greater periods of time required for the applied formulati ons to dehydrate in the non-occluded systems.