Design and Optimization of pH‐Responsive Chitosan‐Coated Zn‐Carboxymethyl Cellulose Hydrogel Bead Carriers for Amoxicillin Trihydrate Delivery

Abstract In the study, chitosan (CS)‐coated carboxymethyl cellulose (CMC) bead carriers were developed via electrostatic interactions in the presence of chitosan and zinc ions, using amoxicillin trihydrate (AMX) as a model drug. The beads were produced by cross‐linking with Zn 2+ ions by varying the drug/polymer ratio, concentration of chitosan and cross‐linker. Their structures were characterized with FTIR, XRD, TGA, DSC, and SEM. AMX release was investigated at two different pH mediums (1.2 and 7.4) at 37 °C. The release profiles of the carriers were highly affected by the degree of cross‐linking, the AMX/polymer ratio, pH, and especially the chitosan coating. As a result, the optimum AMX release was found as 77.4 % for chitosan‐coated beads (A 3 ) with an AMX/polymer ratio of 1/5, ZnCl 2 concentration of 1 %, CS concentration of 1 %. The entrapment efficiency for these carriers (A 3 ) was found to be 57.61 % with high efficiency. It was also determined that AMX release was Fick diffusion and anomalous transport mechanism.