Desenvolvimento e caracterização de filmes de quitosana contendo naproxeno

Abstract

Naproxen (NPX) is a non-esteroidal anti-inflammatory drug (NSAID) whose oral use has a high incidence of gastric adverse effects. Its topical use associated with a prolonged release system constitutes na alternative for the use of this drug. Therefore, this study aimed to develop, characterize and evaluate an in vitro release of naproxen from chitosan films containing NPX. Films with the drug (CN Film) were developed after solubilization of chitosan at 1% (p/v) in acetic acid (1% v/v) for 24 hours, addition of NPX solution in absolute ethanol,stirring and drying in na oven of air circulation (50ºC/24h). Films without the drug CHI Film were obtained by the same technique without the addition of NPX. The characterization war performed by Swelling Degree, Digital Optical Microscopy (OM), 3D microstructural analysis, Thermogravimetry and its derivative (TG/DTG), Differential Scanning Calorimetry (DSC) ad Fourier Transform Infrared Spectroscopy (FTIR). An in vitro release assay was also performed in Franz vertical release cells. Under optical microscopy, it was possible to observe the presence of crystalline structures on the surface of the film, which resulted in greater roughness, according to three-dimensional topografic analyses. Films with naproxen showed considerable swelling capacity, increasing their weight by 645,3% (±4,55) after immersion in saline solution for 24 hours. Thermal analyzes (DSC and TG/DTG) showed the physical compatibility between drug and polymer, demonstrating the endothermic melting evento f NPX at approximately 156ºC in the DSC curver of the samples of NPX, CN Film and in the physical mixture of chitosan and naproxen and showing no diferences in termal stability os samples with and without drug on TG/DTG curves. The FTIR spectroscopic analysis showed no evidence of interactions, reactions or chemical incompatibility between chitosan and naproxen, so the spectroscopic profile of CN Film was a predominantly polymeric profile, which correlates with the higher proportion of polymer than drug in the sample. The in vitro release and the analysis of its kinetics showed that the system promoted a modified release of NPX, maintaining its release for 24 h, whose transport mechanism proved to be non-Fickian or anomalous, which demonstrates the importance of the swelling phenomenon in the process of drug release. In conclusion, the association of chitosan and naproxen was compatible and capable of forming a modified delivery system with potential for use in the transdermal route.