The use of nanoparticles in topical formulations is a topic of debate, especially concerning their safety and their ability to penetrate skin layers . In this study, the potential of nanoparticles for the improvement of the topical administration of glucocorticoids was demonstrated by the higher efficacy shown by a gel containing clobetasol propionate-loaded chitosan/lecithin nanoparticles in comparison to a conventional formulation and a commercial cream. In the carrageenan-induced hind paw edema test in rats, the nanoparticle formulation outperformed the other preparations despite containing a drug concentration ten times lower. Edema development after carrageenan injection has been described as a biphasic event, where the initial phase is mainly histamine- and serotonin-mediated, while prostaglandin-like substances are responsible for the second phase that is thus more sensitive to anti-inflammatory drugs .