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

Abstract

Summary 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 C18 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 (RF) 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.