Pharmacokinetic evaluation of guar gum-based colon-targeted drug delivery systems of mebendazole in healthy volunteers

The pharmacokinetic evaluation of guar gum-based colon-targeted tablets of mebendazole against an immediate release tablet was carried out in human volunteers. Six healthy volunteers participated in the study and a crossover design was followed. Mebendazole was administered at a dose of 50 mg both in immediate release tablet and colon-targeted tablets. On oral administration of colon-targeted tablets, mebendazole started appearing in the plasma at 5 h, and reached the peak concentration ( C max of 25.7±2.6 ng/ml) at 9.4±1.7 h ( T max) whereas the immediate release tablets produced peak plasma concentration ( C max of 37.2±6.8 ng/ml) at 3.4±0.9 h ( T max). Colon-targeted tablets showed delayed t max and absorption time, and decreased C max and absorption rate constant when compared to the immediate release tablets. The results of the study indicated that the guar gum-based colon-targeted tablets of mebendazole did not release the drug in stomach and small intestine, but delivered the drug to the colon resulting in a slow absorption of the drug and making the drug available for local action in the colon.