Formulation and Development of Hydrogel for Poly Acrylamide-Co-acrylic acid

Controlled and sustained drug delivery has become the standard in modern pharmaceutical design and an intensive research work is going on in obtaining better drug product effectiveness, reliability and safety. In this regard, many polymers are very useful with majority of hydrogels, which undergo reversible volume and/or sol-gel phase transitions in response to physiological or other external stimuli. The first use of gels for medical applications was presented by Wichterle and Lim in 1960 and involved the manufacturing of soft contact lenses.Poly (Acrylamide-co-acrylic acid) hydrogels,poly(AAm-co-AAc),were synthesized by free radical crosslinking copolymerization in solution using N,N’-methylenebisacrylamide (MBAAm) as the crosslinker. The swelling behaviour of the hydrogels thus obtained was analyzed in buffer solutions at various pH.The pH sensitive hydrogel were characterizedby Fourier transform infrared analysis, differential scanning calorimetry and evaluated for swelling properties,SEM, and in vitro drug release. The use of hydrogels for drug release was investigated with Rabeprazole sodium as the model drug. The release data shows that, as the concentration of acrylic acid was increased, swelling increased resulting in increased release of the drug.