Controlled Crystallization of Chlorpropamide from Surfactant and Polymer Solutions

Abstract

Chlorpropamide crystals were prepared by recrystallization technique from alcoholic solution of Polysorbate 80, Polyethylene Glycol and Polyvinyl-pyrrolidone. Marked enhancement in the dissolution rate of the formed crystals was observed. The enhancement was found to be a function of molecular weight of the polymer used Thus the percentage drug dissoluted after three hours at 10% polymer concentration was found to be 37, 41 and 55% for Polyvinylpyrrolidone K30 K64 and K90 respectively, and 27, 31, 32% for Polyethylene Glycol 4000, 6000, and 20000 respectively. This may be due to possible solubilization effect of the surfactant and polymers. Also solution of the polymer may produce an ultrafine crystals of the drug, mainly due to the difficulty of growth of the crystals in highly viscous medium of the polymer. Infrared study revealed that no polymorphic change or complex formation had occurred.