Effect of degree of cross-linking on swelling and drug release behaviour of poly(methyl methacrylate-co-itaconic acid) [P(MMA/IA)] hydrogels for site specific drug delivery

In this research work the effect of the degree of cross-linking on swelling and drug release behavior of poly (methyl methacrylate-co-itaconic acid) [P(MMA/IA)] hydrogels for site specific drug delivery was studied. In MMA/IA polymer, considering both dynamic and equilibrium swelling of monomeric ratios i.e. 70:30 and 80:20, the degrees of cross-linking of 0.15, 025 and 0.30 mol% seem better than 0.35 and 0.45 mol%. For all degrees of cross-linking, the 70:30 proportions seem suitable for achieving the required objectives, because in these samples, swelling was very high at higher pH values and absent at low pH values as compared with 80:20 proportions. MMA/IA copolymer was also examined in vitro for their suitability for lactulose delivery to the colon. It was observed that the MMA/IA polymer is suitable for delivering the drug above pH 6. In this polymer, whatever the degree of cross-linking, limited drug released at pH 1.2, 5.5 and significant at pH 6.5 but maximum release was at pH 7.