Design of Experiment based Optimized RP-HPLC Method for Simultaneous Estimation of Amlodipine and Valsartan in Bulk and Tablet Formulations

A simple and precise RP-HPLC method was developed and validated for the simultaneous determination of amlodipine and valsartan combination in bulk and tablet dosage form. This method involves the design of experiments approach for the optimization of mobile phase by taking methanol, pH and flow rate as the dependent variable and their effect was seen on retention time of amlodipine (4.35min) and valsartan (10.26 min). A linear response was observed over the concentration range of 5?50 μg/mL for amlodipine and 10-100μg/ mL for valsartan. Limit of detection (LOD) and limit of quantitation (LOQ) for amlodipine were found to be 1.20μg/mL and 3.71μg/mL, and for valsartan were 1.45μg/mL and 4.39μg/mL, respectively. The method was successfully validated in accordance with ICH guideline acceptance criteria for linearity, accuracy, precision, specificity, robustness. The analysis concluded that the method was selected for simultaneous estimation of amlodipine and valsartan, further can be potentially used for estimation of these drugs in combined dosage form.