Abstract
Poly(2-ethyl-2-oxazoline) and acrylic acid were copolymerized in different compositions using gamma-rays-induced polymerization and cross-linking to obtain a series of pH-sensitive hydrogels. The preparation parameters that may affect the copolymerization process such as the feed solution composition and irradiation dose were optimized. Swelling characteristics of the obtained polymeric hydrogels were evaluated. The results show the significant effects of the hydrogel composition, soaking time, and pH on the swelling equilibrium. The diffusion parameters obtained at pH 1 and 7 show the possibility of using the prepared hydrogels in the field of colon-specific drug delivery systems. Ibuprofen as a model drug was loaded into (poly(2-ethyl-2-oxazoline)/acrylic acid) copolymer hydrogel to investigate their drug release behavior at different pH values. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 120: 3071-3077, 2011