Evaluation of in vitro release and skin irritation of benzoyl peroxide-containing products

Benzoyl peroxide (BPO) has been known as a highly effective topical agent in acne vulgaris therapy for a long time. It induces an irritant dermatitis with erythema and scaling. Therefore, the aim of this study was to formulate BPO containing w/o/w multiple emulsion and gel formulations with and without chitosan microparticles to decrease skin irritation and to compare the release profiles through cellulose acetate, cellophane membranes and excised rat skin. A commercial preparation was also used and the similarities between commercial and experimental formulations were assessed by difference factor (f(1)). The release results indicated that gel base exhibited a higher drug release than the other experimental formulations (p <= 0.05). The release rate of BPO from different membranes was found to be statistically different (p < 0.05). Histological examinations realized by light microscopy on wistar rat skin indicated no observable damage to whole experimental formulations. The results described in this study pointed out that w/o/w multiple emulsion system containing chitosan microparticles has shown the lowest release rate and could be suggested as an effective carrier for BPO to achieve sustained release, to prevent skin irritation and to protect the drug from environmental factors. Moreover, this system could present additional therapeutic benefits due to the wound healing effects of chitosan