Structural characterization of forced degradation products of empagliflozin by high resolution mass spectrometry

Abstract

Eleven unique degradation products (DPs) of empagliflozin (EGF), a sodium glucose cotransporter (SGLT) 2 inhibitor have been reported for the first time. These DPs were generated as per International Conference on Harmonization (ICH) guidelines Q1 (R2) using stress conditions such as acid, base hydrolysis and oxidative environment. The sum of 12 DPs have been successfully resolved by Ultra-High Performance Liquid Chromatography-Mass Spectrometry (UHPLC-MS) method involving Eclipse plus C18 RRHD (2.1 × 50 mm, 1.8µm) column and mobile phase comprising of water with 0.1% formic acid and methanol in 1:1 quotient. Structure of DPs and the degradation pathways have been proposed on the basis of accurate mass and MS/MS fragmentation pattern acquired through Liquid Chromatography-Electrospray Ionization Quadrupole Time of Flight Mass Spectrometer (LC-ESI-QTOF-MS). It has been observed that maximum DPs were formed during acid hydrolysis and the major ones were (2S,3R,4R,5S,6R)-2-(4-chloro-3-(4-(((S)-1,4-dihydroxybutan-2-yl)oxy)benzyl)phenyl)-6-(hydroxymethyl)tetrahydro-2H-pyran-3,4,5-triol (DP1) and (2S,3R,4R,5S,6R)-2-(4-chloro-3-(4-hydroxybenzyl)phenyl)-6-(hydroxymethyl) tetrahydro-2H-pyran-3,4,5-triol (DP2) generated due to ring opening of tetrahydrofuran moiety and elimination of tetrahydrofuran ring respectively. The proposed structures of DPs and their associated pathways will be essential for optimization of manufacturing and quality control parameters of EGF.