Simultaneous estimation of metoprolol succinate and chlorthalidone in pharmaceutical solid dosage form by using a developed and validated reverse phase high performance liquid chromatographic technique

The separation of both the drugs was achieved on Inertsil ODS 3 column (100 × 4.6 mm, 5 μm) column using a mobile phase of diammonium hydrogen phosphate buffer solution (at pH 5.5): Methanol (70:30 v/v). The flow rate was 1.0 ml/min and detection was done at 254 nm. The retention time for metoprolol succinate was 6.91 min and chlorthalidone was 9.94 min. Metoprolol succinate and chlorthalidone showed a linear response in the concentration range of 50-300 μg/ml and 12.5-75 μg/ml, respectively. The correlation coefficients for metoprolol succinate and chlorthalidone were 0.9999 and 0.9998, respectively. The percentage recoveries obtained for metoprolol succinate and chlorthalidone ranges from 98.9 to 100.6% and 98.5to 99.2%, respectively. The results of analysis have been validated as per International Conference on Harmonization (ICH) guidelines. Validation results indicated that method shows satisfactory linearity, accuracy, precision, and ruggedness. The extremely low flow rate, simple mobile phase composition makes this method cost effective, rapid, and nontedious and can also be successfully employed for simultaneous estimation of both drugs in commercial products.