pH Sensitive hydrogels based on acryl amides and their swelling and diffusion characteristics with drug delivery behavior

pH Sensitive poly(acryl amide-co-2-acrylamido-2-methyl-1-propanesulfonic acid-co-acrylamidoglycolic acid) hydrogels were synthesized by free-radical copolymerization. These hydrogels were prepared with different ratios of monomers and a crossliker. These hydrogels were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction. The diffusional exponent (n) values of synthesized hydrogels were found to be in the range between 0.49 and 0.59, indicating a quasi-Fickian diffusion mechanism with partly chain relaxation controlled diffusion. The hydrogels demonstrated a sharp change in its water absorbency and molecular weight between crosslinks of the network with a change in pH of the swelling media. 5-fluorouracil has been used as a model drug to study the drug release capability of these hydrogels.