Confinement and controlled release of quinine on chitosan–montmorillonite bionanocomposites

To accomplish the controlled‐release systems based on layered clay minerals, one of the best ways is to intercalate organic molecules into the interlayer gallery of clay minerals. Into a series of chitosan (CS) intercalated montmorillonite (MMT) nanocomposites, prepared via ion‐exchange route, antimalarial drug quinine (QUI)] was loaded to act as effective drug delivery systems. Among the CS–MMT nanocomposites, higher drug adsorption with decreasing CS concentration was observed. CS–MMT and CS–MMT/QUI intercalated compounds were characterized by powder X‐ray diffraction, Fourier transform infrared spectroscopy, and thermal analysis. The synthesized nanocomposites, filled in the gelatin capsules followed by coating of Eudragit® L 100, were tested for in vitro drug release performance in the sequential buffer environments at 37 ± 0.5 °C. As no drug release (0%) was observed in the gastric fluid, the coating of Eudragit® L 100 to the capsules is highly adequate. However, the drug release rate was comparatively faster from the CS intercalated clay with compare with pure clay. The drug release kinetic data revealed that the release of QUI from the nanocomposites can be explained by modified Freundlich model. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011