Cumulative release of cefotaxim from interpenetrating networks of poly(vinyl alcohol-g-acrylamide) and chitosan-g-polyacrylamide chains

In this study, novel interpenetrating networks comprising of poly(vinyl alcohol-g-acrylamide) and chitosan-g-polyacrylamide chains were designed by redox polymerization method and their potential for controlled release of an antibiotic drug cefotaxim, and antibacterial and cytotoxic behaviors were evaluated. The polymer matrix hydrogel was loaded with cefotaxim drug by allowing it to swell in the drug solution reservoirs of concentrations varying in the range 0.1–0.5 mg/mL. The polymer network was examined by FTIR, SEM and DSC techniques for structural, morphological and thermal characterization. The FTIR spectra clearly confirmed the presence of functional groups of constituent polymers; the SEM image suggested a mesh-type morphology with approximate mesh dimensions of 10 μm × 20 μm. The DSC studies revealed a fall in glass transition temperature (Tg) of both chitosan and poly(vinyl alcohol) to 50 and 70 °C, respectively, from their native values. The release studies were performed in PBS (pH 7.4) under in vitro conditions and the drug release kinetics was investigated. It was found that the amount of drug released increases from 5.4 to 8.4 mg when the drug loading increases from 5.0 to 16.0 %. It was also found that when the pH rises from 1.8 to 7.4, an increase in drug release was noticed, while a further increase in pH to 8.6 resulted in a fall in the amount of released drug. The polymer matrix also showed fair antibacterial properties against E. coli and no cytotoxicity for L-929 mouse fibroblast cells.