SIMULTANEOUS DETERMINATION OF METFORMIN AND PIOGLITAZONE IN PHARMACEUTICAL DOSAGE FORM BY HPLC METHOD

A rapid and accurate HPLC method was developed for determination of both metformin hydrochloride and pioglitazone hydrochloride in tablet dosage form. The chromatographic separation was conducted on Shimadzu (Prominence LC 20 UFLC XR) connected with PDA detector; using mixed column ODS/Cyano; ACE, (100 x 4.6 mm, 5 µm). The mobile phase was isocratic consisted of Acetonitrile : Phosphate buffer in ratio of (50 : 50 v/v) (buffer was composed of  3.55 gm disodium hydrogen phosphate per liter, adjusted by 85% phosphoric acid to pH 5) and was delivered to the system at a flow rate of 1.2 ml/min. An injection volume of 20 µl was used for pioglitazone hydrochloride and 5 µl for metformin hydrochloride. The detection wavelength (λ _max) was 235 nm for metformin HCl and 266 nm for pioglitazone hydrochloride. All assays were performed at ambient conditions. The calibration curve of metformin hydrochloride in mobile phase was linear with correlation coefficient (r²) = 0.99995; over a concentration range of 30 – 750 mg/l for; with a retention time of 1.07 minutes. While the calibration curve of pioglitazone HCl in mobile phase was linear with correlation coefficient (r²) = 0.99859; over a concentration range of 1 – 25 mg/l for; with a retention time of 1.85 minutes. The percentage recoveries of metformin hydrochloride and pioglitazone hydrochloride were 100.13% and 100.22%; respectively. The relative standard deviation (RSD) was found to be < 2. The proposed method was validated and successfully applied for simultaneous determination of metformin hydrochloride and pioglitazone hydrochloride HCl in tablets. The method described is quite suitable for routine analysis of tablets and for their dissolution quantitation.