Simultaneous determination of praziquantel, pyrantel embonate, febantel and its active metabolites, oxfendazole and fenbendazole, in dog plasma by liquid chromatography/mass spectrometry

Gabriella Klausz, Éva Keller, Zoltán Sára, Péter Székely-Körmöczy, Péter Laczay, Kornélia Ary, Péter Sótonyi, Kálmán Róna

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4 Citations (Scopus)


A liquid chromatography-electrospray-mass spectrometry method (LC/MS) has been developed and validated for determination of praziquantel (PZQ), pyrantel (PYR), febantel (FBT), and the active metabolites fenbendazole (FEN) and oxfendazole (OXF), in dog plasma, using mebendazole as internal standard (IS). The method consists of solid-phase extractions on Strata-X polymeric cartridges. Chromatographic separation was carried out on a Phenomenex Gemini C6-Phenyl column using binary gradient elution containing methanol and 50mm ammonium-formate (pH3). The method was linear (r2≥0.990) over concentration ranges of 3-250ng/mL for PYR andFEB, 5-250ng/mL for OXF and FEN, and 24-1000ng/mL for PZQ. The mean precisions were 1.3-10.6% (within-run) and 2.5-9.1% (between-run), and mean accuracies were 90.7-109.4% (within-run) and 91.6-108.2% (between-run). The relative standard deviations (RSD) were <9.1%. The mean recoveries of five targeted compounds from dog plasma ranged from 77 to 94%.The new LC/MS method described herein was fully validated and successfully applied to the bioequivalence studies of different anthelmintic formulations such as tablets containing PZQ, PYR embonate and FBT in dogs after oral administration.

Original languageEnglish
Pages (from-to)1859-1865
Number of pages7
JournalBiomedical Chromatography
Issue number12
Publication statusPublished - Dec 2015



  • Antihelmintics
  • Bioequivalence
  • Dog plasma
  • LC/MS
  • Solid-phase extraction

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Molecular Biology
  • Pharmacology
  • Drug Discovery
  • Clinical Biochemistry

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