Mixed-mode solid phase extraction combined with LC-MS/MS for determination of empagliflozin and linagliptin in human plasma

• DOI: 10.1016/j.microc.2018.11.015
• Publication Date: 2018-11-14T03:19:07Z
• Authors: Priyanka A. Shah; Pranav S. Shrivastav; Archana George
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract A selective, sensitive, precise and accurate liquid chromatography-tandem mass spectrometry method was developed and validated for the concurrent determination of antidiabetic drugs, empagliflozin and linagliptin in human plasma. Sample preparation was tested on several reversed-phase solid-phase extraction (SPE) sorbents with different chemistries like hydrophilic-lipophilic balance (Oasis HLB), mixed-mode cation exchange (Oasis MCX) and weak-cation exchange (Oasis WCX). SPE conditions like sample pH, washing and elution solvents were suitably optimized. Best results were obtained using Oasis MCX cartridges in terms of extraction recovery (78–88%) and matrix effects (~3.0%) for both the analytes. Chromatographic conditions for the separation of analytes and their labeled internal standards (ISs) were established on XSelect HSS Cyano (50 × 2.1 mm, 3.5 μm) column using 2 mM ammonium acetate buffer and acetonitrile as the mobile phase. Detection of analytes was achieved using electrospray ionization in the positive mode. For quantitative analysis, multiple reaction monitoring transitions were m/z 451.3 → 71.1 for empagliflozin and m/z 473.2 → 420.2 for linagliptin. Standard curve concentrations were validated in the range of 1.50–1500 ng/mL for empagliflozin and 0.015–15.0 ng/mL for linagliptin. The intra-batch and inter-batch precision (% CV) was