Preparation and evaluation of fast-disintegrating effervescent tablets of glibenclamide

Fast-dissolving effervescent tablets (FETs) were prepared by the modification of nonreactive liquid-based wet granulation technique. Effervescent systems are not stable in the presence of trace amount of moisture, and elimination or inactivation of free water is the key to stability apart from manufacturing in controlled humidity environment. Our main objective of the project was to develop FETs of glibenclamide based on highly plastic granules that can be compressed at low pressure to form fast-melting pharmaceutical tablets. In this study, we have screened various acid and carbonate sources for the effervescent system. Citric acid was coated with plastic materials such as polyethylene glycol (PEG), which provide a physical barrier to the reaction. The inherent hygroscopic nature of PEG could decrease the affinity for moisture of effervescent mixtures and can provide a stabilizing effect. Sodium bicarbonate was blended with sugar alcohol like mannitol, which would give a protective coating. PEG 1000 melts at body temperature (approximately 37 degrees C) and thereby does not delay the reaction between the acid source and base. The present formulation using citric acid-sodium bicarbonate and citric acid-sodium glycine carbonate tablet with PEG and mannitol was found to have better reaction properties and reaction stability than does the standard citric acid-sodium bicarbonate tablet. FETs of glibenclamide might aid in dissolution due to increase in microenvironmental pH around the granules and saliva. Sensory study on disintegration time and mouth feel attributes ranked the present formulation based on grittiness, chalkiness, and overall preference as best.