Controlled release of ofloxacin from chitosan–montmorillonite hydrogel

A series of ofloxacin/montmorillonite/chitosan (OFL/MMT/CTS) hydrogels were prepared by solution intercalation and ionic crosslinking with sodium tripolyphosphate (TPP). The structure and drug loading of the beads were characterized by Fourier transform infrared spectroscopy (FTIR). The formation of intercalated nanocomposites was confirmed by X-ray diffraction (XRD). The swelling and degradation of the beads were influenced by the pH of test medium and the MMT content. Compared to pure CTS beads, the incorporation of MMT enhanced the drug entrapment, improved the swelling behavior and reduced the drug release. The CTS beads without MMT dissolved after a 3 h immersion in pH 1.2 solution. No notable disintegration was visually observed for MMT-containing beads even after a 10 h immersion. The observations suggested that the electrostatic interaction between CTS and MMT enhanced the stability of the beads and showed good potential for the use as drug carriers for sustained release.