Synthesis and Characterization of Starch-Graft-Acrylamide Hydrogel for Oral Drug Delivery

In this research, starch was extracted from fresh sweet potato and was used to prepare starch-g-acrylamide hydrogel using free radical polymerization method with potassium per sulphate and N’N-Methylene bisacrylamide as initiator and cross-linker, respectively. The swelling capacity and pH sensitivity of the synthesized hydrogel were investigated in solutions of various pH (1-12). The drug loading and release experiment was also carried out using promethazine (PMZ) as the model drug at 25oC and 37oC, respectively while the release study was carried out in an enzyme-free simulated gastric intestinal fluid (SGF) and simulated intestinal fluid (SIF). The result showed a 905% swelling at pH 11, suggesting increased swelling capacity at higher pH values. Drug loading result indicated 99% of the drug was entrapped by the hydrogel as confirmed by UV-visible spectrophotometry. SIF and SGF Simulation indicated a 24% and 9% drug release for the first ten hours. At the end of 48 hours the release was 96% and 89%, respectively indicating the hydrogel released more promethazine in SIF than in SGF. The results obtained in this work suggest that starch-graft-acrylamide hydrogel is a potential vehicle for oral drug delivery. Keywords: Starch, Acrylamide, Hydrogel, Drug delivery