Estudo da liberação controlada de derivados de ácido cinâmico utilizando sistemas baseados em polímeros biodegradáveis/biocompatíveis

Abstract

In the search of new ways for transportation and controlled release systems for bioactive compounds that seek to minimize the amount of administered substance, stands out promising transdermal ways and nano or microparticles - which can use biodegradable polymers or synthetic. Among the most widely used natural polymers, starch and cellulose acetate are noted for presenting promising characteristics. In fighting diseases such as HIV, a lot is sought in order to reduce the side effects of currently existing methods of administration. In this context the present study aimed at studying the controlled release of cinnamic acid and cinnamates derivatives of eugenila, timila and vanillin with potential inhibitory activity of HIV replication enzymes using systems based on biodegradable/ biocompatible polymers. Thus, was evaluated the properties, morphological, swelling index and the kinetics of release of the bioactive substance incorporated in the cellulose acetate films and starch and micro/nanoparticles of cellulose acetate. The obtained starch films are translucent and good malleability, cellulose acetate films are transparent and rigid. Furthermore it was not observed the presence of particles in the film, indicating good compatibility between the polymers and bioactive substances. Micro and nanoparticles were obtained, which were characterized by scanning electron microscopy, observing the formation of spheres with an average size of 1000 μm to the microparticles, and 100-200 nm for nanoparticles. The swelling test was observed that cellulose acetate films have low permeation liquid (between 5 and 7%), showing that the release process of these films is by diffusion. As for the starch films, which had 100% swelling, suggested that the release of bioactive substances occurs after swelling, diffusion and erosion of the polymer matrix. For controlled release, results showed that the starch films and cellulose acetate obtained a controlled release. For micro/nanoparticles observed that the release of bioactive substances occurred more slowly with the nanoparticles in contact with intestinal fluid simulation. Additionally, bioactive compounds studied were shown to be promising for use in these pharmaceutical forms. Therefore, the results demonstrated that this type of material has a great application potential for controlled pharmaceuticals release systems.