Binding effectiveness of Colocassia esculenta gum in poorly compressible drugs-paracetamol and metronidazole tablet formulations.

The effectiveness of a polysaccharide gum obtained from the cormels of Colocassia esculenta was evaluated comparatively with acacia and methylcellulose as binders in the formulation of poorly compressible drugs. The granules of these drugs produced by wet massing method using colocassia and acacia gums as binders have high compressibility index indicating poor flow. Based on this parameter, the granules produced with methylcellulose as binder seem to flow better. The properties of tablets evaluated include breaking strength, friability, disintegration time and dissolution rate. The new polysaccharide gum showed better concentration-strength profile than acacia while methylcellulose yielded mechanically more stable tablets than the two binders. The resistance of tablets to abrasion was poor in metronidazole tablets formulated with colocassia gum. The in vitro availability characteristics showed that tablets produced with the new gum show acceptable disintegration time and release profile within a certain range of its concentration in tablets. At 4% w/w nominal concentration of colocassia gum in metronidazole tablets and 6% w/w in paracetamol, tablets show very long disintegration time and prolonged release profile. The binders used for comparison yielded tablets that show better in vitro release characteristics.