Estimation of Metoprolol Tartrate and Chlorthalidone in Combined Dosage Form by UV-Spectrophotometric Methods

Two simple, sensitive, rapid and precise UV spectrophotometric methods have been developed and validated for simultaneous estimation of Metoprolol Tartrate and Chlorthalidone. Recently this combination was approved for the treatment of patients with mild to moderate essential hypertension which is available in tablet dosage form. The first method is simultaneous equation method in which wavelength selected for estimation of Metoprolol Tartrate and Chlorthalidone are 275 nm and 284 nm, respectively. The second method is first order derivative method based on measurement at zero crossover point of another drug. Measurement of Metoprolol Tartrate and Chlorthalidone were carried out at 270.5 nm and 280.8 nm, respectively. The linearity was obtained in the concentration range of 25–200 μg/ml for Metoprolol Tartrate and 25–200 μg/ml for Chlorthalidone. The proposed methods are successfully applied for the simultaneous determination of both drugs in synthetic mixture. The method was validated with respect to linearity, accuracy and precision as per the International Conference on Harmonisation (ICH) guidelines.