Synthesis of carboxymethyl cellulose based drug carrier hydrogel using ionizing radiation for possible use as site specific delivery system

A unique natural polymer based colon specific drug carrier was prepared from carboxymethyl cellulose (CMC) and acrylic acid (AAc) in aqueous solution employing gamma-radiation induced copolymerization and crosslinking. The effect of preparation conditions such as the natural polymer content and irradiation dose on gelation process was investigated. The swelling behavior of the prepared hydrogels was characterized by investigating the time and pH dependent swelling of the (CMC/AAc) hydrogels of different CMC content. The effects of the hydrogel composition and pH of the swelling medium on the swelling indices were estimated. The results show that the increment in the CMC content in the feed solution enhances the gelation process. The results also show the dependence of the swelling indices on both hydrogel composition and pH value of the swelling medium. To evaluate the ability of the prepared hydrogel to be used as a colon-specific drug carrier, the release profile of theophylline was studied as a function of time at pH 1 and pH 7.