5 - Fluorouracil encapsulado em microesferas de bionanocompósitos quitosana/argila: preparação e características de liberação.

Abstract

In this work, chitosan and chitosan/montmorillonite (MMT) microspheres, containing the 5-Fluorouracil (5-FU) antitumor drug, were produced by phase inversion technique using a simple and low cost equipment developed during the development of this study. The effects of montmorillonite and microspheres morphology were studied based on 5-FU release profiles in vitro in phosphate buffered saline (PBS) at pH 1.2; 7,4 and 10, X-ray diffractometry (XRD), scanning electron microscopy (SEM) and computational simulations. The results indicated that the developed equipment allowed manufacturing reproducible and uniform spheres and the incorporation of MMT to chitosan contributed to bionanocomposites formation. The production of bionanocomposites result in an increase in the encapsulation efficiency and reduction of 5-FU diffusion coefficient in the microspheres, contributed to 5-FU slower release rate due to a greater accommodation of the 5-FU molecules in the MMT galleries. In PBS pH 1.2 the release of 5-FU was by microspheres dissolution, resulting in a non-Fickian release behavior. Regarding the microsphere morphology, it was observed that smaller diameter microspheres showed higher release of 5-FU in the simulated gastrointestinal environment. The microspheres with bionanocomposites presented controlled release characteristics with potential to overcome the gastric barrier and release 5-FU into the intestinal environment. In addition, demonstrated compatible morphology for application in specific place, through chemoembolization techniques. Thus, this study suggests that the methodology used was appropriate for chitosan/montmorillonite bionanocomposite microspheres synthesis with high drug encapsulation efficiency and controlled release characteristics, indicating that the bionanocomposites can be promising systems of 5-FU administration by a less invasive therapy than the venous route.