In vitro evaluation of 5-fluorouracil release by microspheres based on chitosan / montmorillonite/ avaliação in vitro da libertação de 5-fluorouracil por microesferas à base de quitosano / montmorilonite

5-fluorouracil (5-FU) is one of the most widely used chemotherapeutic compounds for cancer treatment and its rapid metabolization and non-uniform oral absorption are the limitations for its use as an oral chemotherapy. Therefore, this study was performed to evaluate the influence of a 5-fluorouracil (5-FU) nanocomposite microspheres with different diameters to test on a controlled release system in the gastrointestinal environment. 5-FU was incorporated into the chitosan/montmorillonite nanocomposite microspheres through the intercalation method. The microspheres containing the 5-FU were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical microscopy (OM). In vitro release fractions at different pHs (1.2, 7.4 and 10.0) were investigated by UV-vis spectroscopy. The release profile of 5-FU for the systems studied was adjusted through the Korsmeyer-Peppas kinetic model, and the results suggested that the mechanism of controlled release at pH 7.4 and 10 occurs by diffusion. In addition, the 5-FU microspheres diameter and roughness directly interfere with the release rate and the released fraction, since the F1 / F2 systems showed a difference in the released fraction of 5-FU of 7.97% and for the systems F3 / F4 the difference was 2.86%. The prepared F1, F2, F3 and F4 systems are suitable for delivery of 5-FU to the gastrointestinal environment in a controlled manner.