Development of a dissolution medium for glibenclamide

A dissolution medium for slightly soluble drugs was developed using glibenclamide as a model of such drugs. The medium consists of a hydroalcoholic surfactant solution with a relatively low alcohol and Tween 80 content buffered at pH 7.4. The composition of the medium was selected on the basis of solubility data al 37 degrees C obtained according to a central composite experimental design. The discriminating power of the medium selected (phosphate buffer pH 7.4 containing 8.5% alcohol and 0.24% Tween 80) was assessed relative to that of phosphate buffer pH 7.4, a medium usually used for the dissolution testing of glibenclamide and berate buffer pH 9.5, a medium recently recommended by the FDA. The dissolution data obtained for two commercial brands of glibenclamide tablets indicate superiority of the proposed system as a discriminatory dissolution medium for glibenclamide tablets.