Penetration profile and human cadaver skin distribution of finasteride from vesicular nanocarriers

The skin accumulation of therapeutic agents affects the efficiency of topical drug delivery. In this study, in vitro distribution of finasteride of ethosomes and liposomes in human cadaver skin after percutaneous delivery were investigated. Experiments were performed using modified Franz diffusion cells. Finasteride ethosomes, liposomes or hydroethanolic solutions were used as donor medium. Drug distribution at different skin layers and depths were studied by hotplate separation and frozen horizontal slicing technique. The result showed that the accumulation of finasteride in skin ranged from 9.7-24.3 μg/cm² at 12 or 24 hours. The ethosomes demonstrated better enhancing ability to deliver finasteride into the dermis layer than liposomes did. The finasteride concentration in the dermis layer from ethosomes was more than sevenfold higher than from liposomes. The finasteride accumulation in ethosomes group showed a distinctive reversed distribution profile. This distinctive reversed distribution profile is meaningful for exerting a favorable pharmacological effect for finasteride. The drug distribution profile in skin layers showed no significant difference between 12 and 24 hours application (p > 0.05). The study demonstrated that finasteride can be accumulated at target site more effectively and maintained at higher level through the application of novel ethosomal carriers.