Overcoming interference of plasma phospholipids using HybridSPE for the determination of trimetazidine by UPLC-MS/MS.

An improved, precise and reliable ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed for the quantification of trimetazidine, using trimetazidine-d8 as the internal standard (IS). Interference owing to plasma phospholipids during sample preparation was overcome using a hybrid solid-phase extraction-phospholipid ultra cartridge. The mean extraction recovery of trimetazidine (98.66%) and trimetazidine-d8 (97.63%) from spiked plasma was consistent and reproducible. Chromatographic analysis was performed on a UPLC Ethylene Bridged Hybrid (BEH) C18 (50 × 2.1 mm, 1.7 µm) column with isocratic elution using acetonitrile-5 mm ammonium formate, pH 3.5 (40:60, v/v) as the mobile phase. The parent → product ion transitions for trimetazidine (m/z 267.1 → 181.1) and trimetazidine-d8 (m/z 275.2 → 181.1) were monitored on a triple quadrupole mass spectrometer with electrospray ionization functioning in the positive multiple reaction monitoring mode. The linearity of the method was established in the concentration range of 0.05-100 ng/mL for trimetazidine. The intra-batch and inter-batch accuracy and precision (CV) were 97.3-103.1 and 1.7-5.3%, respectively. Qualitative and quantitative assessment of matrix effect showed no interference of endogenous/exogenous components. The developed method was used to measure plasma trimetazidine concentration for a bioequivalence study with 12 healthy subjects.