Visible Spectrophotometric Determination of Sulfamethaxazole in Pharmaceutical Formulations

Abstract

Two simple, precise, accurate, costy effective and rapid spectrophotometric methods (mehod A and method B) were developed for the determination of sulfamethaxazole (SFX) in its bulk and dosage forms. The method A involves formation of chloroform extractable yellow colour ion pair complex of the drug with bromocresol green in acidic medium. Method B is based on the formation of ternary complex between drug, ammomium thiocyanate and ammonium molybdate in presence of ascorbic acid and HCl. The coloured complexes shows absorbance maxima at 430 and 690 nm for methods A and B, respectively. Beer's law is obeyed in the range of 2-10 μg/mL for both methods A and B. Results of analysis for all the methods were validated statistically and by recovery studies.