Lecithin/chitosan nanoparticles of clobetasol-17-propionate capable of accumulation in pig skin.

In this study, clobetasol-17-propionate (CP) loaded lecithin/chitosan nanoparticles were studied with special attention to the transport of the active agent across the skin in vitro. Nanoparticles were characterized by measuring particle size, zeta potential, polydispersity index and encapsulation efficiency. The morphology of nanoparticles was evaluated by transmission electron microscopy. Encapsulation experiments with CP showed high encapsulation efficiency (92.2%). To assess the advantages of this carrier-based formulation in topical administration, the accumulation in and permeation across pig ear skin were compared with chitosan gel and commercially available cream of CP. The results obtained indicate that the incorporation of drug into nanoparticles induced an accumulation of CP especially in the epidermis without any significant permeation across the skin. Dilution of CP loaded nanoparticles with chitosan gel (1:9) produced the same amount of CP in the skin compared with commercial cream, although the former contained ten times less CP. This is a remarkable point for the reduction of the side effects of CP. These results demonstrated the suitability of lecithin/chitosan nanoparticles to induce epidermal targeting and to improve the risk-benefit ratio for topically applied CP. (c) 2009 Elsevier B.V. All rights reserved.