Synthesis and Characterization of pH-Sensitive Pectin/Acrylic Acid Hydrogels for Verapamil Release Study

The objective of the present work was to synthesize the novel hybrid based polymeric networks of pectin and acrylic acid (AA) showing pH-sensitive swelling performance in relation to acrylic acid component of the gel. A series of hydrogels were prepared using pectin and acrylic acid (AA) in the presence of N,Nmethylene bisacrylamide (MBAAm) as cross-linker and benzoyl peroxide as initiator. FTIR confirms the formation of network. The prepared hydrogels were evaluated for swelling, sol-gel fraction and porosity. Furthermore, the values of equilibrium water content (EWC), diffusion coefficient (D) and volume fraction of the polymer within hydrogels (Φ2) were calculated. Hydrogels were characterized for surface morphology using scanning electron microscopy (SEM). Swelling data werefitted into Peppas model for evaluating the swelling mechanism. Hydrogels showed pH and monomeric composition-dependent swelling behaviour. Selected samples were loaded with verapamil as a model drug. Drug release was performed in USP phosphate buffers of pH 1.2 and 7.5. Drug release data were fitted into various kinetic models like zero order, first order, Higuchi and Peppas models for investigating the optimum composition suitable for controlled drug delivery. A significant difference in drug release kinetics was observed by varying the composition of pectin/AA and degree of cross-linking.