Amperometric and Conductimetric Methods for Simultaneous Determination of Captopril and Bendroflumethiazide

Abstract

The mixture of captopril (antihypertensive) and bendroflumethiazide (diuretic) was assayed using conductimetric and amperometric methods. Each method was applied for the analysis of laboratory-made sample mixtures in authentic and dosage forms. For captopril, the amperometric and conductimetric methods gave mean percent recoveries of 100.2 .+-. 1.2 and 99.6 .+-. 1.2, respectively. These results have shown good agreement when compared with other methods in the literature. When applied to bendroflumethiazide the conductimetric method gave percent recovery of 98.5 .+-. 1.6 which agreed closely with the spectrophotometric pharmacopoeial method. The pK1 for captopril was determined potentiometrically at room temperature (25.degree. C) in aqueous medium. The calculated value, based on Henderson equation was 3.78.