Design, Synthesis, Characterization, Swelling and in Vitro Drug Release Behavior of Composite Hydrogel Beads Based on Methotrexate and Chitosan Incorporating Antipyrine Moiety

Abstract

Novel biodégradable pH and thermal-responsive hydrogels were prepared for controlled drug delivery studies via reaction of chitosan with 4-chloroacetylantipyrine in DMF/H2O, followed by heating of the formed poly [acetylantipyrine-chitosan] with glutaraldehyde as a crosslinking agent to give the hydrogels. These hydrogels were subjected to equilibrium swelling studies at different temperatures (25°C, 37°C and 45°C) in solutions of pH 2.1 and 7.4. Methotrexate (MTX) was entrapped in the hydrogels, and drug release studies were carried out at 37 °C in solutions at pH 2.1 and 7.4.