ANALYTICAL LC-MS/MS METHOD FOR EZETIMIBE AND ITS APPLICATION FOR PHARMACOKINETIC STUDY

A sensitive and reliable analytical method for exetimibe in human plasma using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) system was developed and validated for the pharmacokinetic study. Ezetimibe and internal standard, 4-hydroxychalcone, were extracted by liquid-liquid extraction with methyl t-butyl ether. The high performance liquid chromatographic separation was performed on a Phenomenex Luna C18 column (2.0 mm × 100 mm, 3 µm particles) with a mobile phase of acetonitrile:water = 60:40 (v/v). Tandem mass spectrometry was performed in the electrospray ionization (ESI) negative ion mode, using multiple reaction monitoring (MRM) mode for the quantification. The mass transition pairs of m/z 408 → 271 for ezetimibe and m/z 223 → 117 for internal standard were used. The calibration curve was linear in the concentration range of 0.075–20 ng/mL for unchanged ezetimibe and 1–200 ng/mL for total ezetimibe with the lower limit of quantification of 0.075 ng/mL for unchanged ezetimibe and 1 ng/mL ...