Design, Characterization, and Colon-Specific Delivery of Berberrubine-Embedded pH-Responsive Polymeric Hydrogel System for Targeted Intervention in Crohn's Disease

Objective: The present study focused on the design, characterization, and in vitro evaluation of a berberrubineembedded pH-responsive polymeric hydrogel system for colon-specific delivery aimed at targeted intervention in Crohn's disease. The hydrogel was synthesized using free radical polymerization of methacrylic acid and acrylamide with controlled crosslinking density to achieve pH-triggered swelling behaviour. Characterization: Drug–polymer compatibility was confirmed through FTIR analysis, demonstrating structural integrity without significant chemical interaction. The optimized formulation (F3) exhibited high encapsulation efficiency (84.6%) and an optimal gel fraction (90.5%), indicating a stable and well-formed polymeric network. Swelling studies revealed minimal expansion in acidic conditions (pH 1.2) and significant swelling at colonic pH (7.4), confirming strong pH responsiveness. In vitro pH-shift dissolution studies demonstrated negligible drug release in gastric conditions followed by enhanced release under simulated colonic conditions. Kinetic and Safety Analysis: Kinetic modeling indicated that the drug release followed the Korsmeyer–Peppas model with super case-II transport behavior, suggesting polymer relaxation-driven release. Surface morphology analysis showed a porous network architecture supporting diffusion-controlled release. Cytocompatibility assessment confirmed high cell viability, indicating formulation safety. Conclusion: Overall, the developed hydrogel system represents a promising colon-targeted delivery platform for localized therapy in inflammatory bowel disorders.