Simultaneous Determination of Atorvastatin Calcium and Losartan potassium in bulk and combined dosage forms by validated RP-HPLC with UV detection

A simple, rapid, and precise RP-HPLC method for simultaneous analysis of Losartan potassium and Atorvastatin calcium in bulk and its pharmaceutical formulations has been developed and validated. Atorvastatin was separated from losartan by using Grace Smart Altima C-18 column (25 cm × 4.6 mm, 5-μm) with a mobile phase consisting of acetonitrile: 10mM phosphate buffer (55:45 %v/v, pH 3.0) a flow rate of 1mL/min and detection wavelength at 240 nm. Aceclofenac was used as an internal standard in this method. Losartan, atorvastatin and aceclofenac were eluted with retention times of 4.85 min, 8.31min and 9.51 min respectively. The method was validated for accuracy, precision, linearity and sensitivity in accordance with ICH (Q2B) guidelines and the results of all the validation parameters were found to be within the acceptable limits. The calibration plots were linear over the concentration ranges from 200-30000ng/mL (r2 = 0.999) for both the drugs. Accuracy and precision were determined by QC sample covering low, medium, and high concentration levels. Intra and inert-day accuracy were found to be 97.16-102.57% for losartan and 97.01-103.05% for atorvastatin. The limit of quantification was found to be166ng/mL and 179ng/mL for losartan and atorvastain respectively. The method was successfully applied for the assay of the dosage form, recovery of the individual drugs from the combined tablet dosage was found to be >97% for both the drugs. From the results it is suggested that the proposed method is simple, reproducible, accurate and precise.