Synthesis, characterisation and evaluation of poly[lactose acrylate-N-vinyl-2-pyrrolidinone] hydrogels for drug delivery

New biodegradable polymeric hydrogels based on biocompatible materials, lactose acrylate (LA) and N-vinyl-2-pyrrolidinone were designed and synthesized. LA was synthesized and characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. Hydrogel synthesis was carried out by free-radical polymerization of the co-monomers using azobisisobutyronitrile as initiator and N,N^′-methylenebisacrylamide as crosslinker. These hydrogels were also characterized. Equilibrium swelling of the hydrogels was studied in phosphate buffer of physiological pH, 7.4 and at 37 °C. Propranolol hydrochloride was entrapped into these hydrogels and the in vitro release profile of this drug was established in phosphate buffer. The drug release followed a near zero-order fashion in the first 6 h and thereafter slowed down releasing more than 90% of the entrapped drug at the end of 48 h.