Estudo in vitro da liberação controlada de clorexidina, incorporada em filme de quitosana, para potencial aplicação na cavidade oral

Abstract

One of the most difficulties for the successful treatment of pathologies in the oral cavity is the dilution and the fast elimination of drugs due mainly the action of saliva. Thus, the devices for controlled release of drugs are important in trying to prolong their retention time in the oral cavity. The use of bioadhesive systems can also reduce the frequency of application and amount of drug administered, which may improve adherence and patient acceptance and reduce the adverse effects. Chitosan is a natural polymer, biologically safe and has been proposed for this application. In this study, chlorhexidine gluconate was used because it is widely used in clinical dentistry, due to their activity against several microorganisms. The purpose of this study was formulate a system from the polymeric chitosan for controlled release of chlorhexidine with potential application in the oral cavity. The chitosan films incorporated with different concentrations of chlorhexidine, glutaraldehyde cross-linked and non-cross-linked were developed, characterized and analyzed in vitro to evaluate semi quantitatively the release and antimicrobial activity. In qualitative analysis of films was observed a high degree of swelling in the non cross-linked causing a large increase in volume of them. Evaluating the FTIR spectra was verified the presence of the band 830-805 cm-1, which corresponds to the CH-bonded aromatic ring, feature of chlorhexidine. The SEM images showed a film mostly homogeneous, but with some light spots, which the EDS analysis show the same chemical composition of the rest of the film, yet with a greater intensity of the band of chlorine. In the study was detected a release of chlorhexidine for 8 hours from the cross-linked chitosan membrane triple and agar diffusion test showed that chlorhexidine remained active after its incorporation into the chitosan film.