Evaluation of Ibuprofen Colon Delivery System using Grewia mollis Juss. (Tiliaceae) stem bark gum as Matrix-former

Abstract

Aim: The aim of this research was to evaluate Grewia gum as a matrix-former for colon delivery of ibuprofen. Methodology: The gum was extracted by soaking the dried stem bark powder in aqueous solution of sodium metabisulphite for 48 h. Ibuprofen granules were prepared by wet granulation method using Grewia gum at 10, 20, 30, 40 and 50% w/w. The tablets were compressed using 12 mm punch. The physicochemical parameters-uniformity of weight, thickness, diameter, crushing strength, friability, disintegration time were evaluated. The in vitro drug release studies were conducted in simulated gastric fluid at 37 ± 1° and 100 rpm. The kinetics and mechanism of drug release were determined. The tablets were compared with those of hydroxypropylmethyl cellulose (HPMC) (80-120 cp; H9262) at the same concentrations. Results: The results revealed that Grewia gum is highly viscous, not readily soluble in water and has a high swelling capacity (237.5% w/w). It also has moderate flow profile, and large particle size. The matrix tablets containing 40 and 50 % w/w of Grewia gum exhibited highest swelling capacity and showed better ability to offer barrier to drug release in the upper GIT and delivery to colon. None of the matrix containing HPMC was able to prevent drug release in the upper GIT. The in vitro drug release in the absence and presence of rat cecal contents showed no significant difference (p<0.05) using ANOVA. The release kinetics followed zero-order and the mechanism of release was Korsmeyer-peppas super case II mechanism. Conclusion: The findings show that Grewia gum may be used as an effective matrix-former for the delivery of ibuprofen to colon.