Innovative Sunscreen Formulation Based on Benzophenone-3-Loaded Chitosan-Coated Polymeric Nanocapsules

Aim: To evaluate the effect of cationic coating of polymeric nanocapsules in sunscreen formulations on the in vitro skin penetration of benzophenone-3. Methods: Benzophenone-3-loaded nanocapsules were prepared by the interfacial deposition of poly(epsilon-caprolactone) and coated by using a chitosan solution. The nanoparticles were characterized and incorporated in hydrogels. The presence of nanoparticles in hydroxyethyl cellulose gels was observed by transmission electron microscopy and photon correlation spectroscopy. Penetration studies were carried out using Franz cells with porcine skin membranes. Results: Benzophenone-3-loaded chitosan-coated nanocapsules presented a mean size of 202 +/- 7 nm and positive zeta potential (+21 +/- 1 mV), while these values for the uncoated nanocapsules were 175 +/- 1 nm and -8 +/- 1 mV. Penetration profiles showed that a higher amount of benzophenone-3 remained at the skin surface and a lower amount was found in the receptor compartment after the application of the formulation containing chitosan- coated nanocapsules compared to a formulation containing its free form. Conclusions: Hydrogel containing benzophenone- 3 chitosan- coated nanocapsules represents an innovative formulation to overcome limitations of sunscreen daily use. Copyright (C) 2011 S. Karger AG, Basel