Assay method

A specific, rapid, reliable and precise reversed phase ultra-performance liquid chromatographic method has been developed and validated for the simultaneous estimation of aspirin, clopidogrel and atorvastatin in tablet dosage form. Chromatography was carried out on a 100 × 2.1 mm i.d., 1.7 µm C18 column with gradient flow programming mobile phase The mobile phase is a mixture of two solutions mobile phase A and mobile phase B in the ratio of 30:70. The mobile phase – A, contains buffer and methanol in the ratio of 93:7, the buffer used is 2.76 gms of Sodium phosphate in 100 ml. The mobile phase – B, contains 0.1% orthophosphoric acid and acetonitrile (60:40, v/v), at a flowrate of 0.5 mL/min. The detection was carried out by PDA detector. The retention times were about 0.55, 0.98 and 2.75 min for Aspirin, Clopidogrel and Atorvastatin, respectively. The runtime was 5 mins. The method was validated according to ICH guidelines and the acceptance criteria for accuracy, precision, linearity, specificity and system suitability were found to be under ICH limits. The method was linear in the range of 5-25 µg/mL of Aspirin, 5-25 µg/mL of Clopidogrel and 1-5 µg/mL of Atorvastatin. Limit of detection obtained were 0.02 µg/mL of Aspirin, 0.05 µg/mL of Clopidogrel and 0.07 µg/mL of Atorvastatin.