Effects of surfactants on the dissolution rate of sparingly soluble drug nalidixic acid in solid dispersions

Abstract

Solid dispersions of the sparingly soluble drug nalidixic acid were prepared by solvent method with dextrin as the carrier. 1,2 and 3%w/w of each nonionic(SLS), cationic (Cetrimide) and 4, 8 and 12%w/w non-ionic surfactant (Tween-80) were incorporated during the preparation. Immediate instant and complete dissolution was obtained for dispersion with 4%w/w Tween-80, but SLS and Cetrimide had no effect on the dissolution rate when compared with the dispersion without surfactant and pure drug (drug and dextrin). Beyond certain concentration (1%SLS, 1% Cetrimide and 4% Tween-80) there was a marked decrease in the dissolution rate of nalidixic acid. IR and TLC data revealed an interaction between drug and dextrin.