Curcumin Loaded Microsponges for Colon Targeting in Inflammatory Bowel Disease: Fabrication, Optimization, and In Vitro and Pharmacodynamic Evaluation

The present study was aimed to develop and optimize the microsponges of curcumin for colon specific drug delivery in a view to bypass the upper gastrointestinal tract (GIT) for enhanced therapeutic effect. Microsponges were developed by quasi emulsion solvent diffusion method using 3(2) full factorial design. Prepared microsponges were optimized in order to analyze the effects of independent variables (volume of ethanol and Eudragit L100) on the encapsulation efficiency, particle size, and drug release. The optimized formulation was subjected to in vivo study using acetic acid induced colitis model in rats. The F7 was selected as optimized formulation based on particle size of 41.63 μm, % entrapment efficiency of 78.13%, and % cumulative drug release of 84.12%, and desirability factor of 0.83. Release studies revealed that microsponges prevented the premature release of curcumin in upper GIT and specifically released the drug at colonic pH. The drug release profile of F7 formulation was subjected to different kinetic models and based upon the best correlation coefficient (r(2) = 0.9927) the release was found to follow Higuchi model, which suggested diffusion as the main mechanism of drug release. Pharmacodynamic study showed that curcumin loaded microsponges causes a significant decrease in edema, necrosis, and hemorrhage of colon as compared to free curcumin. This study proves that curcumin loaded microsponges may act as a promising drug delivery system for treatment of ulcerative colitis.