Bionanocomposite beads based on montmorillonite and biopolymers as potential systems for oral release of ciprofloxacin

The number of studies of controlled drug-release systems is growing constantly. Bionanocomposite materials which can be prepared from the combination of biopolymers with inorganic solids such as clay minerals offer interesting alternatives for use as drug-delivery systems. In the present study, new bionanocomposite drug-release systems were prepared from the intercalation of the antibiotic drug ciprofloxacin into montmorillonite using an ion-exchange reaction. In order to prepare more stable systems for oral ciprofloxacin release, this ciprofloxacin-clay intercalation compound was incorporated into i-carrageenan-gelatin biopolymer blend to produce bionanocomposite materials. Bionanocomposites of two distinct i-carrageenan and gelatin mass ratios were conformed as beads through an ionic gelification reaction with Ca 2+ ions, and dried by freeze-drying where liquid nitrogen or conventional freezing was adopted in the freezing step. The resulting ciprofloxacin-clay hybrid was characterized by X-ray diffraction (XRD) analysis, Fourier-transform infrared (FTIR) spectroscopy, solid state 13 C Nuclear Magnetic Resonance (NMR), thermal analysis, and scanning electron microscopy (SEM). The montmorillonite-ciprofloxacin hybrid incorporated into the bionanocomposite beads was evaluated by in vitro release studies which showed a significant difference in the release profiles in the aqueous medium used to simulate the gastrointestinal tract, depending on the blend composition and the freezing method employed in the preparation of the beads. The results point to bionanocomposite systems based on ciprofloxacin-clay hybrids and biopolymers that may be used as devices in the biomedical area.