Evaluation of whey protein isolate-graft-carbopol-polyacrylamide pH-sensitive composites for controlled release of pamidronate

Abstract

Whey protein isolate-graft-carbopol-polyacrylamide pH sensitive hydrogel composites were prepared by simultaneous redox cross-linked polymerization of whey protein isolate, acrylamide and carbopol. The hydrogel composites were characterized by SEM, FTIR, XRD and swelling analysis was performed on the hydrogels. The hydrogels were pH sensitive, degradable and protected the entrapped drug in the matrix. The aforementioned factors were influenced by the grafting of whey protein isolate onto the composite networks. The release of pamidronate from the hydrogel followed a super case 2 transport suggesting that the release mechanism was a combination of erosion and diffusion at pH 7.4. At pH 1.2, the release mechanism of pamidronate from the hydrogels was a quasi-Fickian diffusion. The SEM images of the hydrogels after drug release indicated degradability of the hydrogels. The results obtained suggested that whey protein isolate is a potential biopolymer for controlled drug delivery systems with enhanced drug bioavailability.