A simple liquid chromatography tandem mass spectrometry method was developed and validated according to the guidelines of the US Food and Drug Administration and the European Medicines Agency for a simultaneous quantification of @entity4677 (LEV) and its metabolite, UCB L057 in the plasma of @entity1 . A 0.050 mL plasma sample was prepared by a simple and direct protein precipitation with 0.450 mL @entity1626 ( @entity2830 ) containing 1   g/mL of internal standard (IS, @entity3933 ), then vortex mixed and centrifuged. A 0.100 mL of the clear supernatant was diluted with 0.400 mL water and well mixed. A 0.010 mL of the resultant solution was injected into an Agilent Zorbax SB-C18 (2.1 mm*100 mm, 3.5   m) column with an isocratic elution at 0.5 mL/min using a mixture of 0.1% @entity5189 in water and @entity2830 (40:60 v/v). Detection was performed using an AB Sciex API 3000 triple quadrupole mass spectrometer, equipped with a Turbo Ion Spray source, operating in a positive mode: LEV at transition 171.1>154.1, UCB L057 at 172.5>126.1, and IS at 256.3>167.3; with an assay run time of 2 minutes. The lower limit of quantification (LLOQ) for both LEV and UCB L057 was validated at 0.5   g/mL, while their lower limit of detection (LOD) was 0.25   g/mL. The calibration curves were linear between 0.5 and 100   g/mL for both analytes. The inaccuracy and imprecision of both intra-assay and inter-assay were less than 10%. Matrix effects were consistent between sources of plasma and the recoveries of all compounds were between 100% and 110%. Stability was established under various storage and processing conditions. The carryovers from both LEV and UCB L057 were less than 6% of the LLOQ and 0.13% of the IS. This assay method has been successfully applied to a population pharmacokinetic study of LEV in @entity1 with @entity302 .

Rapid and simultaneous quantification of @entity4677 and its carboxylic metabolite in XXXX plasma by liquid chromatography tandem mass spectrometry.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity3933 :: ('MESH:D004155', 'Chemical') :: ['diphenhydramine'] @entity4677 :: ('MESH:C026098', 'Chemical') :: ['levetiracetam'] @entity2830 :: ('MESH:C084683', 'Chemical') :: ['ACN'] @entity1626 :: ('MESH:C032159', 'Chemical') :: ['acetonitrile'] @entity302 :: ('MESH:D004827', 'Disease') :: ['epilepsy'] @entity5189 :: ('MESH:C030544', 'Chemical') :: ['formic acid']
@entity1 :: (9606,Species) :: ['human']
