Bionanocompósitos quitosana/argila para liberação controlada de ibuprofeno.

Abstract

The objective of this research was to prepare chitosan/clay bionanocomposites (in the form of microspheres), by the precipitation method, for the immobilization of the drug ibuprofen, aiming the study of the controlled release of the same, by in vitro test. The effects of the process parameters and the clay content on the microsphere properties were evaluated. The results of optical microscopy (OM) and scanning electron microscopy (SEM) showed that the clay content (10 and 20% by mass) had little influence on the size and size distribution of the microspheres. On the other hand, the condition of preparation of the microspheres (air flow of the drag system: 2.5 and 10 mL.min-1) had a more effective influence. The microspheres prepared with higher air flow showed smaller diameters and oval shape. Regarding the roughness and the average pore size, evaluated by SEM, similar behavior was observed for the two air flows and the two clay contents studied. However, compared to chitosan microspheres, chitosan/clay showed a considerably smaller pore size. The incorporation of the drug also contributed to the reduction of the pore size of the microspheres. X-ray diffraction (XRD) data suggest that both the chitosan biopolymer and the drug ibuprofen are intercalated between the clay layers, and that the amount of clay mixed with chitosan affected the morphology of the bionanocomposites obtained. Bionanocomposites with intercalated morphology were obtained when prepared with 20% clay and exfoliated when prepared with 10% clay. Finally, the drug release assays in PBS buffer solutions pH 7.2 performed on a UV-vis spectrophotometer showed that the amount of ibuprofen released by the microspheres was affected by process parameters and clay content. Higher air velocity and lower clay content resulted in the greater amount of drug released. The materials prepared were based on natural mineral and biopolymer abundant, low cost and synthesized with a laboratory developed equipment.