Simultaneous analysis of atorvastatin calcium and losartan potassium in tablet dosage forms by RP-HPLC and HPTLC

Abstract

Two simple and accurate reversed-phase high-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) methods for simultaneous determination of atorvastatin calcium and losartan potassium in tablet dosage forms have been established and validated. The HPLC separation was achieved on a Phenomenex Luna C 18 column (250 mm, 4.6 mm i.d., 5 μm) with 0.05 M potassium dihydrogen phosphate buffer (pH 5.4)-acetonitrile 45:55 (%, v / v ) as isocratic mobile phase at a flow rate of 1 mL min -1 . The retention times were approximately 7.56 and 3.73 min for atorvastatin calcium and losartan potassium, respectively. Quantification was achieved at 238 nm with a photodiode-array (PDA) detector over the concentration range 0.5-5 μg mL -1 , for each compound, with mean recoveries of 100.67 ± 0.58 and 100.51 ± 0.63% for atorvastatin calcium and losartan potassium, respectively. The HPTLC separation was achieved on silica gel 60 F254 HPTLC plates with methanol-carbon tetrachloride-ethyl acetate-glacial acetic acid 8:63.6:28:0.4 ( v / v ) as mobile phase. The retardation factors ( R F) were approximately 0.45 and 0.30 for atorvastatin calcium and losartan potassium, respectively. Quantification was achieved by ultraviolet (UV) detection at 238 nm over the concentration range of 50-500 ng band -1 for each, with mean recoveries of 100.59 ± 0.47 and 100.48 ± 0.81% for atorvastatin calcium and losartan potassium, respectively. Both methods were validated, and the results were compared statistically by use of a paired t -test. The methods were found to be simple, specific, accurate, precise, and robust, and were successfully used for analysis of the drugs in tablet dosage forms without interference from common excipients.