Water uptake and drug release behaviour of methyl methacrylate-co-itaconic acid [P(MMA/IA)] hydrogels cross-linked with methylene bis-acrylamide

Hydrogels are water-swollen, cross-linked polymeric structures. The objective of this study was to synthesize a new pH-sensitive copolymer, which shows no water uptake at lower pH values but a maximum water uptake at higher pH values. Methyl methacrylate-co-itaconic acid [P(MMAI IA)] hydrogels cross-linked with methylene bis-acrylamide were synthesized. To determine the effect of monomeric composition, copolymers were prepared with different proportions of methyl methacrylale and itaconic acid i.e. 100:0, 90:10, 85:15, 80:20 and 75:25 keeping the degree of cross-linking constant i.e. 0.30 mol %. It was concluded from this study that the MMA/IA 75:25 (x = 0.3 mol %) polymer fulfilled our objective. It seems suitable for delivering the drug above pH 6.