title: Simultaneous determination of praziquantel, pyrantel embonate, febantel and its active metabolites, oxfendazole and fenbendazole, in dog plasma by liquid chromatography/mass spectrometry.
abstract: 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 50 mm ammonium-formate (pH 3). The method was linear (r(2)  ≥ 0.990) over concentration ranges of 3-250 ng/mL for PYR andFEB, 5-250 ng/mL for OXF and FEN, and 24-1000 ng/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.
authors.affiliation: Department of Forensic and Insurance Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Klausz
authors.affiliation: Department of Forensic and Insurance Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Éva
authors.initials: É
authors.lastname: Keller
authors.affiliation: Institute of Health Informatics, Semmelweis University, Budapest, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Sára
authors.affiliation: Department of Food Hygiene, Faculty of Veterinary Science, Szent István University, Budapest, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Székely-Körmöczy
authors.affiliation: Department of Food Hygiene, Faculty of Veterinary Science, Szent István University, Budapest, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Laczay
authors.affiliation: Ominis Ltd., Budapest, Hungary.
authors.forename: Kornélia
authors.initials: K
authors.lastname: Ary
authors.affiliation: Department of Forensic and Insurance Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Sótonyi
authors.affiliation: Department of Forensic and Insurance Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Kálmán
authors.initials: K
authors.lastname: Róna
mesh_terms: D000818:Animals; D001562:Benzimidazoles / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D002853:Chromatography, Liquid / Q000379:methods*; D004285:Dogs; D005260:Female; D005273:Fenbendazole / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D006146:Guanidines / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D057230:Limit of Detection; D016014:Linear Models; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D011223:Praziquantel / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D011716:Pyrantel Pamoate / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D052616:Solid Phase Extraction; D013810:Therapeutic Equivalency
chemical_list: D001562:Benzimidazoles; D006146:Guanidines; D005273:Fenbendazole; D011223:Praziquantel; D011716:Pyrantel Pamoate; C011030:oxfendazole; C017309:febantel
keywords: LC/MS; antihelmintics; bioequivalence; dog plasma; solid-phase extraction