Development of gum acacia-grafted-poly(N,N-dimethylacrylamide)/CuCoFe2O4 nanocomposite hydrogel for controlled ciprofloxacin HCl delivery: Characterization and release kinetic modelling

In this study, a novel, pH-responsive nanocomposite hydrogel framework was successfully synthesized by grafting poly(N,N-dimethylacrylamide) onto a natural gum acacia backbone in the presence of CuCoFe 2 O 4 nanoparticles for the controlled delivery of ciprofloxacin hydrochloride (HCl). Structural and thermal characterizations via FT-IR, PXRD, FE-SEM, and TGA confirmed successful crosslinking, uniform nanoparticle integration. The hydrogel swelling behavior and in vitro drug release kinetics were systematically investigated across distinct physiological environments (pH 4.0, 7.4, and 9.2), demonstrating optimal swelling capacity and cumulative drug release under alkaline conditions. To elucidate the transport mechanism of Ciprofloxacin HCl from the hydrogel matrix, the experimental data were fitted to multiple mathematical kinetic models, including Zero-order, First-order, Korsmeyer-Peppas, Higuchi square-root, and Hixson-Crowell cube-root equations. The release profiles showed an excellent correlation with the Korsmeyer-Peppas model (R 2 > 0.99) at pH 9.2. Furthermore, the calculated diffusional exponent (n) values across all tested environments consistently ranged between 0.45 and 0.89, revealing that drug transport follows a non-Fickian (anomalous) diffusion mechanism governed by a combination of polymer chain relaxation and diffusion. These findings demonstrate that the developed gum acacia-based nanocomposite hydrogel holds strong potential as an advanced platform for pH-responsive, controlled drug delivery applications.