Chitosan based hybrid superabsorbent for controlled drug delivery application

In the present study, a hybrid chitosan-alginate superabsorbent is prepared using maleic acid as a cross-linker and acrylamide as a grafting agent using the free radical mechanism. The composite hydrogel shows good swelling capacity along with hemocompatibility and biocompatibility and hence it is utilized as a drug delivery device. The characterization techniques including x-ray diffraction, Fourier transform infrared, x-ray photoelectron spectroscopy, and thermal analysis indicate the successful synthesis of stable hydrogel with rich functionalities. Metformin hydrochloride is used as a model drug which is used to treat diabetes. The drug encapsulation is done using the swelling diffusion method after the synthesis of hydrogel. The release of metformin from the drug-loaded hydrogel at physiological pH highlights the role of non-covalent interactions between the drug and hydrogel. In vitro release studies of Metformin from the drug-loaded hydrogel show higher release profiles at intestinal pH (7.4) compared to stomach pH (1.2). The observed cumulative release is 82.71% at pH 7.4 and 45.67% at pH 1.2 after 10 h. Brunauer-Emmett-Teller analysis reveals the effect of surface area, pore size, and pore volume of hydrogel on the drug release. The drug release from the hybrid chitosan-alginate hydrogel is found to be more sustained in comparison to the pure chitosan hydrogel. For the present drug delivery system, the swelling-controlled release is found to be more dominating than the pH-controlled release. The synthesized hydrogel can be successfully employed as a potential drug delivery system for controlled drug delivery.