Vol. 7, Issue 1, Part A (2025)

This study aimed to develop and evaluate Eudragit-S100 coated guar gum microspheres for delivering mesalamine hydrochloride specifically to the colon. Guar gum was produced using an emulsion dehydration technique, varying mesalamine hydrochloride and starch ratios (0.5 to 2.0 w/v), stirring speeds (300 to 1200 rpm), and emulsifier concentrations (0.5% to 2% v/v). All microspheres containing mesalamine hydrochloride exhibited high preparation yield and encapsulation efficiency. The best formulation utilized a 40:100 w/w drug to polymer ratio, 600 rpm stirring speed, and 1.5% w/v span 80 as the emulsifying agent. Starch microspheres were coated with Eudragit-S100 using a dip coating method, with a 1:10 core to coat ratio. Both mesalamine hydrochloride microspheres and Eudragit-S100 coated microspheres were analyzed for surface morphology, particle size and distribution, swell ability, drug entrapment percentage, and in vitro drug release in simulated gastrointestinal fluids (SGF). The optimized formulation underwent an in vitro drug release study in simulated colonic fluid with 4% rat cecal content. An organ distribution study in albino rats assessed the formulation's colon-targeting potential. Mesalamine hydrochloride release from Eudragit-S100 coated guar gum microspheres was pH-dependent, with slower release in acidic conditions and faster release at pH 7.4. The study concludes that Eudragit-S100 coated guar gum microspheres show promise as effective controlled release carriers for colon-targeted delivery of 5-mesalamine hydrochloride.