NEW STABILITY INDICATING UFLC METHOD FOR SIMULTANEOUS ESTIMATION OF METFORMIN HCL AND VILDAGLIPTIN IN BULK AND SOLID DOSAGE FORM

A new stability indicating Ultra-Fast Liquid Chromatography (UFLC) method was validated for the simultaneous estimation of Metformin hydrochloride (MET) and Vildagliptin (VILDA) in bulk and tablet dosage form as per the International Council for Harmonization guidelines. Chromatography developed on Shimatzu UPLC, X-Bridge C18 column equipped with PDA detector. Mobile phase composed of phosphate buffer (25 mM) pH 3.0: acetonitrile: methanol (85:13:2). Sodium 1-octanesulfonate monohydrate (0.25 g/L) added in aqueous buffer. The effluent was passing through the column 1.0 ml/min at 40 ºC. The retention time of MET and VILDA were found to be 2.964 min and 6.358 min. The specificity study was determined by the addition of known impurities 1-cynoguanidine and vildagliptin amide of MET and VILDA, respectively. The forced degradation studies indicated that MET was stable while VILDA was susceptible to alkaline hydrolysis and peroxide oxidation. The degradation product peaks were well resolved from the MET and VILDA peaks. Purity angle and purity threshold of the MET and VILDA peak showed spectral homogeneity over the entire peak region indicated its peak purity. The proposed UFLC method can be employed for simultaneous estimation of MET and VILDA in bulk drugs and formulations.