تاثير آيونتوفورز بر آزادسازي ترتينويين از فراورده هاي نيمه جامد و عبور آن از پوست موش صحرايي

The Influence of Iontophoresis on Tretinoin Release from Topical Preparations and Its Penetration across Rat Skin.

Introduction & Objective: Acne vulgaris is one of the most prevalent skin diseases which is common in adolescent of both sexes. Tretinoin has been used therapeutically for its comedolitic effects and inhibition of comedone rupture in acne. It is available in 0.01% to 0.1% as cream, gel or lotion. There have been a few clinical reports of the positive effects of iontophoresis with tretinoin on acne scars. The aim of this study was to investigate the effect of iontophoresis field on transport of tretinoin across synthetic membrane and excised rat skin. Materials & Methods: Topical formulations of tretinoin marketed in Iran ( Retin-A cream, Retin-A gel, Tretinoin cream 0.025% and Tretinoin gel 0.025%) were assessed in terms of drug assay and content uniformity. The in vitro release and penetration characteristics of tretinoin from dermatological preparation was studied through a hydrophilic Dora pore diffusion barriers and membrane excised rat skin using Franz diffusion cell over a period of 2h. These two tests were also accomplished either with or without the presence of an iontophoresis field. The current density of iontophoresis applied field was constant, 0.5 mA/cm2. The amount of drug released from preparations was determined spectrophotometrically at Amax =352nm. Results: The in vitro release of tretinoin through synthetic barrier with an iontophoresis field showed that the cumulative percent of released drug at the end of each experiment was 17.5%, 26.5%, 19% and 54% for Tretinoin gel, Retin-A gel, Tretinoin cream and Retin-A cream, respectively. This was significantly higher than the observed one for release of tretinoin without application of a DC electric field. In addition, the results showed a significantly higher iontophoretic transport of tretinoin compared to passive flux for excised rat skin. Conclusion: The application of an electric current for a limited period of time produced higher post-iontophoresis fluxes of tretinoin than passive diffusion. With application of iontophoresis field, the in vitro release and transport of drug for different formulations of tretinoin follow the zero order kinetics.