DefinePK

Abstract

The present study aimed at developing and characterizing colon-targeted chitosan microspheres of Felbinac, a non-steroidal anti-inflammatory drug (NSAID), to achieve site-specific drug release for the treatment of inflammatory bowel conditions. Microspheres were prepared using the ionotropic gelation method, employing chitosan as the primary polymer and sodium tripolyphosphate as the cross-linking agent. Six formulations (F1–F6) were evaluated for flow properties, percentage yield, entrapment efficiency, particle size, surface charge (zeta potential), and in vitro drug release. Among the tested batches, formulation F5 demonstrated the best characteristics, with high entrapment efficiency (76.65%), good flow properties, and favorable particle size. In vitro drug release studies conducted under simulated gastrointestinal conditions revealed that uncoated chitosan microspheres showed premature drug release, whereas Eudragit S100-coated microspheres significantly minimized drug release in acidic environments and provided sustained release in colonic pH, reaching 89.98% at 12 hours. Drug release kinetics of F5 followed a first-order model with a non-Fickian diffusion mechanism. Stability studies confirmed that the optimized formulation remained physically and chemically stable over three months. The findings suggest that Eudragit-coated chitosan microspheres of Felbinac provide an effective platform for colon-specific drug delivery, potentially enhancing therapeutic outcomes and minimizing systemic side effects in the treatment of colonic inflammatory diseases