Validated UV Spectrophotometric Method for Simultaneous Estimation of Metoprolol Succinate and Benidipine Hydrochloride in their Combined Tablet Dosage Form

Simple, sensitive and economic spectrophotometric method was developed and validated for simultaneous estimation of Metoprolol succinate and Benidipine hydrochloride in tablet dosage form. The analysis was carried out in JASCO V 560 double beam UV Spectrophotometer. In simultaneous equation method, Metoprolol succinate and Benidipine hydrochloride were quantified using their absorptivity values of at selected wavelengths, 223nm and 237nm respectively. Methanol was used as solvent for both drugs. The developed method was validated as per ICH guidelines. The linearity range was found to be 3-21 µg/mL for both drugs with correlation coefficient of 0.9979 and 0.9978 for Metoprolol succinate and Benidipine hydrochloride respectively.Recovery studies were conducted at three different concentration levels within the linearity limits and the average percentage in tablet dosage form was determined and found to be 99.23% for Metoprolol succinate and 99.20 % for Benidipine hydrochloride. So the developed simultaneous equation method permits simple, rapid and direct determination of Metoprolol succinate and Benidipine hydrochloride in commercially available tablet dosage form without previous separation and can therefore be used for routine analysis of both drugs in quality control laboratories.