Synthesis of pH-responsive hydrogel based on PVP grafted with crotonic acid for controlled drug delivery

In the present study polyvinylpyrrolidone (PVP) was grafted with crotonic acid (CrA) in order to obtain novel hydrogels which are pH - responsive. The grafting was performed by mixing the polymer solution with various concentrations of CrA and applying gamma radiation at different doses. The effects of the preparation conditions such as the irradiation dose and CrA concentration on the gelation process and swelling of the synthesized copolymer were investigated. The hydrogel system was used as carrier for a model drug, ketoprofen, the release behaviour of the drug from the hydrogel was monitored in two different release media (pH 1 and pH 7.2), and released amounts of ketoprofen were followed up spectrophotometrically. The release was low in the acidic medium compared to a better and extended release in the neutral medium suggesting the possibility of using this hydrogel as potential drug carrier to allow targeted release in the intestinal medium.