A Stability Indicating Simultaneous Estimation of Rosuvastatin and Clopidogrel Bisulphate in Combined Dosage Formulations by Reverse Phase High Performance Liquid Chromatography

An accurate, rapid, selective and specific reverse phase high performance liquid chromatographic method was developed for the simultaneous estimation of Rosuvastatin and Clopidogrel in a combined formulation. Chromatographic separation was achieved on Inertsil ODS 3 C-18 (250mm x 4.6mm,5µm) column by isocratic elution mode with three mobile phase components, 0.05M potassium phosphate buffer (pH4.2): methanol: acetonitrile (60: 30:10 v/v/v) at a flow rate of 1.0 mL/min and quantified at 238 nm. The average retention times for Rosuvastatin and Clopidogrel were 4.57 and 2.96 min, respectively. The method offers excellent separation of two drugs with resolution > 2.0 and tailing < 1.0 and with no interferences from the excipients. The method is linear over the concentration range of 3.1-18.6 µg/mL for Rosuvastatin and 22.68-136.08 µg/mL for Clopidogrel with a correlation not less than 0.999. The method is accurate with recoveries of both the drugs in between of 98.0 -101.0% and precise with %RSD value less than 2.0% for the Assay of both the drugs. This method is simple, rapid, accurate and specific for the assay of commercial capsules.