Evaluation of Mucin as a Release Enhancer for Rectal Delivery of Glibenclamide

In this work mucin was evaluated as a release and absorption enhancer for glibenclamide from rectal glycerogelatin suppository. Glycerogelatin suppositories containing different ratios of glibenclamide to I-mucin (insoluble), Smucin (soluble) and sodium salicylate respectively, were formulated using the fusion method. The suppositories were evaluated using standard parameters. Release studies were carried out in phosphate buffer (pH 7.6). The pharmacodynamic (PD) evaluation of the formulations was carried out on normoglycaemic albino rats. The results of the physical tests showed that the suppositories possessed high resistance to rupture and had uniformity of weight and drug contents. The erosion times of the suppositories with I-mucin, S-mucin and sodium salicylate were shorter than glycerogelatin suppositories BP without any release enhancer (control). Analysis of the release data showed that the release pattern was bi-phasic with initial fast release and subsequent slow release of the glibenclamide from the suppositories. The release mechanism followed first order kinetics. All the suppositories containing either S-mucin, Imucin or sodium salicylate showed better glibenclamide release than the control without any release enhancer (p < 0.05). The pharmacodynamic studies showed that the overall glucose lowering effect in rats was greater in S-mucin suppositories than in sodium salicylate and I-mucin suppositories. The results of this study indicated that mucin extracted from Bovine spp. could be used to enhance the release and subsequent absorption of glibenclamide from rectal glycerolgelatin suppositories.