Pectin Hydrogel Copolymers for Sustained Drug Release : SYNTHESES AND CONTROL

The present work describes preparation, optimization and characterization of pectin grafted poly (vinylpyrrolidone) hydrogels and pectin grafted poly (N-isopropylacrylamide) followed by controllable theophylline drug release. The gels were prepared in the presence of N,N'-methylenebisacrylamide (MBAA) crosslinker and ceric ammonium nitrate (CAN) initiator under N2 atmosphere. Hydrogels were characterized by FTIR, TGA, DSC, XRD and SEM. In vitro controllable release of theophylline model drug was studied using different [NVP]/[MBAA] ratios, different [NIPAAm]/[MBAA] ratios and different polymerization temperatures at two pH values, namely 5.5 and 7.4. The optimum conditions for colon-targeted vehicles that could provide the least theophylline release at pH 5.5, and the most theophylline release at pH 7.4, for pectin-g-PVP were as follows: [NVP]/[MBAA] = 4.33, polymerization temperature = 10 C and %G = 62.2. While for pectin- g-PNIPAAm were as follows: [NIPAAm]/[MBAA] = 47.34, polymerization temperature = 10 C and %G = 50.5. Such promising hydrogel characteristics may play the key role in many future drug release implementations.