Anti-beer Evaluation of Hydrochlorothiazide and Losartan by UV Derivative Spectrophotometry

Abstract

Abstract An UV derivative method for the simultaneous determination of Hydrochlorothiazide (HCT) and Losartan (LST) in the commercial forms was developed. The fourth derivative spectrum from the alcoholic solution was used. HCT can be determined by a specific signal at 330–340 nm, while LST uses the signal around 280–290 nm, common to both products. Into the concentration range of HCT (10.8–500)10−3 mg mL−1 and of LST (20–2400)10−3 mg mL−1, for their mixture in the ratio 1:4, two intervals were identified, one for lower values, for which the absorbance grows with concentration, and one for higher values, in which the absorbance of the solution diminishes as concentration increases. The second behaviour seems to be due to intramolecular reactions of the drugs. For both the intervals, linear regressions were obtained by correlating the spectra signals with the drug concentrations. The best results were obtained by employing the regression equations from the downward section.