SPECTROPHOTOMETRIC AND REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC METHODS FOR SIMULTANEOUS DETERMINATION OF ATORVASTATIN AND PIOGLITAZONE IN COMBINED TABLET DOSAGE FORM

Abstract

Simple, accurate, precise, and sensitive ultraviolet spectrophotometric and reversed-phase high-performance liquid chromatographic (RP-HPLC) methods for simultaneous estimation of Atorvastatin (ATOR) and Pioglitazone (PIO) in combined tablet dosage form have been developed and validated. The spectroscopic methods employs formation and solving of simultaneous equation at 247 nm and 267 nm as 2 wavelengths for estimation of ATOR and PIO respectively (method 1) While method 2 involves formation of Q- absorbance equation at 233 nm (isoabsorptive point) and 267 nm (I» max of Pioglitazone) with methanol as solvent. Beer’s law is obeyed in the concentration range of 5.0–50.0 mcg/mL for ATOR and PIO, respectively. The RP-HPLC method uses HPLC system with a Phenomenex Luna C18 (5 mm x 25cm x 4.6mm i.d) using Methanol, acetonitrile and potassium dihydrogen phosphate buffer, pH 2.5 adjusted with orthophosphoric acid (60:20:20 v/v) at a flow rate of 1.0 mL/min at ambient temperature as the mobile phase. The detection was carried out using an ultraviolet detector set at 233 nm. For the HPLC method, Beer’s law is obeyed in the concentration range of 5.0-50.0 µg/ml for ATOR and PIO, respectively. LOD values for ATOR and PIO were found to be 57.12µg/ml and 12.01 µg /ml respectively. All the methods have been successfully applied for the analysis of the drugs in a pharmaceutical formulation. Results of analysis were validated statistically and by recovery studies.1-4