Simultaneous estimation of olmesartan medoxomil and indapamide from bulk and commercial products using a validated reverse phase high performance liquid chromatographic technique

Aim: A simple, rapid, accurate, precise and economical reverse phase high performance liquid chromatographicmethod is developed for simultaneous separation and quantification of two anti-hypertensive drugs, viz., olmesartan medoxomil and indapamide. Materials and Methods: The separation of both the drugs was achieved on ACE C 18 AR column (250 × 4.6 mm id, 5 μm particle size) column using a mobile phase of sodium perchlorate and triethylamine buffer solution (at pH 3): Acetonitrile (60:40 v/v). The flow rate was 1 ml/min and detection was done at 280 nm. Results: The retention time for indapamide was 5.3 min and for olmesartan medoxomil was 6.8 min. Olmesartan medoxomil and indapamide showed a linear response in the concentration range of 50-300 μg/ml and 3.75-22.5 μg/ml respectively. The correlation co-efficients for olmesartan medoxomil and indapamide were 0.9999 and 0.9998 respectively. The percentage recoveries obtained forolmesartan medoxomil and indapamide ranges from 99.3% to 99.8% and 99.7% to 100.9% respectively. The results of the analysis have been validated as per International conference on Harmonisation (ICH) guidelines. Validation results indicated that method shows satisfactory linearity, accuracy, precision, and ruggedness. Conclusion: The extremely low flow rate, simple mobile phase composition makes this method cost effective, rapid, and non-tedious and can also be successfully employed for simultaneous estimation of both drugs in commercial products.