Synthesis of xanthan gum graft copolymer and its application for controlled release of highly water soluble Levofloxacin drug in aqueous medium

Graft copolymers (XG-g-PNVP-1 to XG-g-PNVP-5) of xanthan gum (XG) and poly(N-vinyl-2-pyrrolidone) (PNVP) was synthesized by free radical polymerization using peroxymonosulphate/thiourea redox pair. The synthesized graft copolymers were well characterized by 1H NMR, FTIR, XRD, SEM, TGA/DTA and AFM analyses. The optimum conditions for maximum grafting were determined by varying the concentrations of N-vinyl-2-pyrrolidone (NVP) from 10 × 10−2 to 18 × 10−2 mol dm−3; the grafting ratios increases up to 14 × 10−2 mol dm−3, while thereafter decreased. Graft copolymer (XG-g-PNVP-D) hybrid was prepared to load levofloxacin drug, about 15 mg drug was loaded; and its release was studied in phosphate buffer solution (PBS) at pH 7.4 on 37 ± 0.1 °C; About 80% drug was released in 36 h.