Preparation, Swelling and Drug Release Study of Hydrogels Based on Different Composition of Acrylamide/Acrylic Acid

The aim of current work was to develop controlled drug delivery system which is capable of releasing the drug over an extended period of time. For this purpose, pH sensitive acrylamide-acrylic acid hydrogels were prepared using N,N-methylenebisacrylamide (MBA) as crosslinking agent and ammonium persulphate (APS) as an initiator by employing free radical polymerization technique. Different formulations were prepared by varying the content of monomers and crosslinking agent and subjected to designed experiments for analyzing their behavioral changes. Dynamic and equilibrium swelling studies and in vitro drug release studies for release of loaded drug ivabradine HCl were carried out over a pH range of 1.2, 6.5, and 7.5. Various structural parameters which affect the swelling and drug release performance of hydrogels such as sol-gel analysis, average molecular weight between crosslinks (Mc), solvent interaction parameters (chi), volume fraction of polymers (V-2s) and diffusion coefficient were also determined. Hydrogels were characterized by FTIR. Prepared hydrogels showed pulsatile behavior i.e minimum and maximum swelling was noticed at pH 1.2 and 7.5, respectively. Drug release studies were carried out at pH 1.2, 5.5, and 7.5. Zero order, first order, Higuchi and Korsmeyer-Peppas kinetic model were applied to drug release data to evaluate the behavior of drug release of hydrogels. Results of drug release studies indicated that the release of drug was according to zero order kinetics and occurred through non-fickian mechanism. Above mentioned characterization revealed successful formation of hydrogels and the drug release behavior suggest that the polymer rate chain relaxation and rate of drug diffusion from these hydrogels are comparable which also predicts their possible use for site specific drug delivery.