Rapid, Routine Method for the Analysis of Some Drugs with Bromate and Celestine Blue

Abstract

Abstract A simple and sensitive method is proposed for the spectrophotometric determination of drugs, viz. isoniazid, trimeprazine tartarate, pyridoxine HCl and captopril based on their reactivity with potassium bromate. The method involves the addition of excess KBrO3 of known concentration in the presence of 0.7M HCl and the unreacted KBrO3 is determined by the measurement of the decrease in the absorbance of the dye, celestine blue (Λmax 540 nm). This method was applied to the determination of drug contents in pharmaceutical formulations and enabled the determination of the drugs in microgram quantities (0.4–4.0 μg.ml−1).