Process, optimization and characterization of mebeverine hydrochloride loaded guar gum microspheres for irritable bowel syndrome

In the present investigation, guar gum microspheres containing mebeverine hydrochloride were prepared and characterized for local drug release in colon. Formulation variables studied include guar gum concentration, drug to polymer ratio, concentration of emulsifier, amount of cross linking agent, rotational speed and cross linking time. In vitro studies of microspheres depict a premature release of drug in the stomach and small intestine. As enteric coating of microspheres is difficult to achieve, they were compressed to tablets. Drug release studies and surface morphological characteristics of tableted microspheres revealed that the microspheres remained intact during the compression process. In vivo roentgenographic evaluation in rabbits revealed that the system remained intact until it reached to the lower part of the gastrointestinal tract, where microspheres were dispersed after the dissolution of the enteric coat, thus, revealing the potential of developed system for colonic targeting.