A Rapid and Sensitive LC–MS Method for Determination of Ezetimibe Concentration in Human Plasma: Application to a Bioequivalence Study

摘要

Aselective and highly sensitive high performance liquid chromatography-electrospray ionization mass spectrometry method has been developed for determination of ezetimibe concentrations in human plasma. Ezetimibe was extracted from plasma with ethyl acetate followed by evaporation of the organic layer and, then, reconstitution of the residue in mobile phase before injection to chromatograph. Themobile phase consisted of acetonitrile-ammoniumacetate (10 mM, pH 3.0), 75:25 (v/v). An aliquot of 10 μL was chromatographically analyzed on a prepacked Zorbax XDBODS C_(18) column (2.1 × 100 mm, 3.5 micron). Detection of analytes was achieved by mass spectrometry with atmospheric pressure chemical ionization (APCI) interface in the negative ion mode operated under the multiple-reaction monitoring mode (m/z transition: ezetimibe 408–271). Standard curves were linear (r = 0.998) over the wide ezetimibe concentration range of 0.05–30.0 ng mL~(-1) with acceptable accuracy and precision. The limit of detection was 0.02 ng mL~(-1). The validated LC–APCI–MS method has been used successfully throughout a bioequivalence study on an ezetimibe generic product in 24 healthy male volunteers.