Determination of fenofibric acid in human plasma by ultra performance liquid chromatography-electrospray ionization mass spectrometry: application to a bioequivalence study.

A rapid, specific and sensitive ultra-performance liquid chromatography tandem mass spectrometry method was developed for the determination of fenofibric acid in human plasma. The method involves simple, one-step liquid-liquid extraction procedure coupled with an Acquity UPLC(TM) BEH C(18) column (50 x 2.1 mm, i.d., 1.7 microm) with isocratic elution at a flow-rate of 0.2 mL/min and mefenamic acid was used as the internal standard. The Quattro Premier XE mass spectrometry was operated under the multiple reaction-monitoring mode using the electrospray ionization technique. Using 250 microL plasma, the methods were validated over the concentration rang 0.05-7.129 microg/mL, with a lower limit of quantification of 0.05 microg/mL. The intra- and inter-day precision and accuracy were within 9.3%. The recovery was 66.7% and 52.6% for fenofibric acid, and mefenamic acid, respectively. Total run time was 1.8 min only for each sample, which makes it possible to analyze more than 350 samples per day.