Determination of related substances in empagliflozin tablets by HPLC

Objective:To establish a method for the determination of the related substances of empagliflozin tablets.Methods:The analysis was carried out on a ZORBAX Rx-C8 chromatography column(250 mm×4.6 mm,5 μm).The mobile phase consisted of p H 3.5 phosphoric acid water solution and acetonitrile-methanol(1∶1) with a gradient elution at a flow rate of 1.0 m L·min~(-1) and the detection wavelength was 224 nm.The column temperature was 25 ℃,and the volume of injection was 20 μL.The related substances were qualified and quantified by the established method.Results:The resolutions were both greater than 1.5 among empagliflozin,adjacent impurities and other known impurities.The limits of impurity IMPD(empagliflozin reduction product),impurity IMPC(empagliflozin ring-opened product),impurity EMGA(empagliflozin intermediate),impurity IMPF(empagliflozin condensation product),impurity IMPG(empagliflozin deglucitol product)were 28.30,53.07,73.60,65.00,and 395.57 ng,respectively.The calibration curves of five known impurities were linear in the self-concentration range(r0.999,n=5).The average recovery rates(n=9) were 100.7%,102.9%,97.4%,102.1% and 102.9%,respectively.The total impurities were 0.05%-0.06% in 3 batches of empagliflozin tablets.Conclusion:The established method is easy,sensitive and specific for the determination of the related substances in empagliflozin tablets according to methodology validation.