A study on sustained release formulations for oral delivery of 5-fluorouracil based on alginate–chitosan/montmorillonite nanocomposite systems

The objective of this study was to develop a sustained drug release system for 5-fluorouracil (5-FU), an anticancer drug, to improve its half-life. 5-Fluorouracil was loaded on montmorillonite (Mt) layers through the preparation of 5-FU/Mt nanocomposite by an intercalation method. In order to retard the drug release in the gastric environment, the prepared 5-FU/Mt nanocomposite was compounded with alginate (Alg), and further coated with chitosan (CS). This novel drug delivery system was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses. By in vitro experiments the effects of Mt contents and pH of the release media on the release rate of the drug were investigated. According to the results, the Alg–CS/5-FU/Mt nanocomposite system containing 30 wt.% Mt in the release media with the pH of 7.4 effectively sustained the drug release and the time for 50% release, T50%, is about 8 h. The release profile of 5-FU from the Alg–CS/5-FU/Mt nanocomposite system was best fitted by the Korsmeyer–Peppas kinetic model suggesting the diffusion controlled release mechanism. The prepared Alg–CS/5-FU/Mt nanocomposite system is suitable for the delivery of 5-FU in the small intestine with a controlled manner.