Synthesis, characterization and swelling behavior of a novel bio-adsorbent based on pectin grafted poly (acrylic acid -co- itaconic acid) hydrogels for adsorption and controlled release of ciprofloxacin

Abstract In the current study, a novel bio-adsorbent based on pectin grafted poly (acrylic acid -co-itaconic acid) hydrogel is synthesized by free radical copolymerization using acrylic acid and itaconic acid as monomers grafted on natural pectin. N, N′-Methylenebisacrylamide is used as a crosslinking agent, and potassium persulfate as an initiator. Various techniques, such as FTIR, SEM, XRD, and TGA, were used to characterize the synthesized bio-adsorbent hydrogel. The effect of several variables on the swelling behavior of the synthesized hydrogel was examined, like cross linker amount, pectin amount, initiator amount, and monomers amount. Furthermore, the swelling process was investigated at various pH levels. In order to establish suitable adsorption conditions, several adsorption parameters were examined, such as pH, equilibrium time, adsorbent amount, and temperature. The adsorption data were examined using the Langmuir, Freundlich, and Temkin models. The results showed that the adsorption is typically heterogeneous and of the multilayer type, as they were more consistent with the Freundlich model. The adsorption process is exothermic and spontaneous, according to thermodynamic parameters measured. In vitro drug release experiment results showed that after 30 hours, the CIP drug was released significantly higher in the simulated intestinal fluid (pH = 7.4) than in the simulated stomach fluid (pH = 1.2). The drug release of CIP from the hydrogel was measured at different temperatures: 30°Cand 40°C. These findings demonstrate that the hydrogel is highly efficient in ciprofloxacin adsorption and pH sensitive, making it appropriate for drug delivery in the small intestine.