Carboxymethyl cellulose-based nanocomposite hydrogel grafted with vinylic comonomers: synthesis, swelling behavior and drug delivery investigation

Carboxymethyl cellulose-based nanocomposite hydrogel was produced through in-situ free-radical copolymerization for use in drug delivery study. The pure hydrogel and their nanocomposite structure were systematically identified by XRD, FTIR, SEM, TEM, TGA-DTA techniques. The swelling and deswelling properties, which are affected by several factors such as pH (due to the carboxylate groups) and time were studied. The swelling rate improved with the SiO2 nanoparticles. Also, the swelling ratio in NaCl, CaCl2 and AlCl3 salt solutions were investigated and it was found that swelling capacity was 41 and 37 g/g for pure and nanocomposite hydrogel in NaCl solution, respectively. Diclofenac sodium was utilized as a model of drug and the drug release after loaded in the nanocomposite hydrogels was studied. The results revealed essential performances on the subject of physiological-simulated pH media. The maximum cumulative drug releases attained were 90.13% and 79.26% at pH values of 7.4 for nanocomposite and pure hydrogel, respectively. The applicability of drug release kinetic models such as Ritger–Peppas, zero and first-order kinetic models was proved. According to the information obtained from Ritger–Peppas model, the drug release mechanism follows non-Fickian diffusion and indicates an anomalous transport.