A UPLC/DAD method for simultaneous determination of empagliflozin and three related substances in spiked human plasma

A simple, rapid and sensitive ultrahigh performance liquid chromatographic method was developed for the determination of the anti-diabetic drug: empagliflozin (EMPA) and three related substances in spiked human plasma, using dapagliflozin (DAPA) as an internal standard and tetrahydrofuran as a plasma protein precipitating agent. The chromatographic separation was achieved on an Acquity "UPLC^® BEH" C18 column (50 mm × 2.1 mm i.d, 1.7 µm particle size), and a mobile phase consisting of aqueous trifluoroacetic acid (0.1%, pH 2.5): acetonitrile (60:40, v/v) at a flow rate of 0.5 mL/min. Upon using the UPLC system, the run time could be reduced to less than 1.2 min, and the solvents consumption decreased to 0.36 mL of acetonitrile per run. The response was linear over a concentration range of 50-700 ng/mL and 40-200 ng/mL (r² = 0.9994-0.9999) with lower limits of detection and quantification (LOD/LOQ) of 15/50, 11.5/40, 12/40 and 12.5/40 ng/mL for EMPA and the three related substances, respectively. Good accuracy was obtained with mean percentage recoveries ≥ 96.97% for the studied compounds. The method was validated according to the ICH guidelines and was found suitable for routine analysis of EMPA and its related substances in human plasma.