Functionalized pectin hydrogels by cross-linking with monomer: synthesis, characterization, drug release and pectinase degradation studies

摘要

The present research work is focused on development and characterization of copolymerized pectin sulfonic acid hydrogels and to evaluate controlled delivery of captopril. Series of pectin-sulfonic acid-based hydrogels were synthesized by free radical copolymerization technique. Pectin has been chemically cross-linked with 2-acrylamido-2-methylpropane sulfonic acid in the presence of ammonium persulfate and sodium metabisulfite as redox initiator. Methylene bisacrylamide (MBA) was used as cross-linking agent in varying amount to investigate the degree of cross-linking as a function of increased concentration of polymer (pectin) and monomer (AMPS). Captopril was incorporated as model drug in formulated hydrogels. Fourier transform infrared spectroscopy (FTIR) was performed for structural analysis. In vitro swelling and release studies of captopril were carried out at both pH 1.2 and 7.4. Sol-gel fraction was also calculated to determine the amount of uncross-linked polymer fraction in prepared hydrogels. FTIR analysis confirmed the formation of cross-linked network between polymer (pectin) and monomer (AMPS). All formulations showed pH-dependent swelling behavior because of pectin, and drug release pattern was high at pH 1.2, and prolonged release was observed at pH 7.4 because of pH-independent behavior of sulfonic acid. The results of sol-gel analysis confirmed that gel fraction increases as amount of AMPS and MBA was increased. From current research study, it is concluded that stable formulations of pectin-sulfonic acid were formed by optimized copolymerization reaction. This newly developed polymeric network could serve as a potential system for controlled delivery of captopril for prolonged period.