SC lipid model membranes designed for studying impact of ceramide species on drug diffusion and permeation, part III: influence of penetration enhancer on diffusion and permeation of model drugs.

The impact of the lipophilic penetration enhancer, oleic acid (OA), on the barrier properties of stratum corneum (SC) lipid model membranes was investigated based on diffusion and permeation studies of model drugs covering a broad range of lipophilicities. Diffusion and permeation experiments of urea, caffeine and diclofenac sodium were conducted using Franz-type diffusion cells. HPLC and capillary electrophoresis techniques were employed to analyze the amount of permeated drug.

SC lipid model membranes designed for studying impact of ceramide species on drug diffusion and permeation--part II: diffusion and permeation of model drugs.

The barrier function of two quaternary stratum corneum (SC) lipid model membranes, which were previously characterized with regard to the lipid organization, was investigated based on diffusion studies of model drugs with varying lipophilicities. Diffusion experiments of a hydrophilic drug, urea, and more lipophilic drugs than urea (i.e.