title: Liquid chromatography-electrospray mass spectrometry determination of carbamazepine, oxcarbazepine and eight of their metabolites in human plasma.
abstract: Carbamazepine (CBZ) and oxcarbazepine (OXCBZ) are both antiepileptic drugs, which are prescribed as first-line drugs for the treatment of partial and generalized tonic-clonic epileptic seizures. In this paper, a specific and sensitive liquid chromatography-electrospray ionization mass spectrometry method was described for the simultaneous determination of carbamazepine (CBZ), oxcarbazepine (OXCBZ) and eight of their metabolites [CBZ-10,11-epoxide (CBZ-EP), 10,11-dihydro-10,11-trans-dihydroxy-carbamazepine (DiOH-CBZ), 10-hydroxy-10,11-dihydroCBZ (10-OH-CBZ), 2-hydroxycarbamazepine (2-OH-CBZ), 3-hydroxycarbamazepine (3-OH-CBZ), iminostilbene (IM), acridone (AO) and acridine (AI)] in human plasma. The work-up procedure involved a simple precipitation with acetone. Separation of the analytes was achieved within 50 min using a Zorbax eclipse XD8 C8 analytical column. The mobile phase consisted of a mixture of acetonitrile-formate buffer (2 mM, pH 3). Detection was performed using a quadrupole mass spectrometer fitted with an electrospray ion source. Mass spectrometric data were acquired in single ion recording mode at m/z 237 for CBZ, m/z 180 for CBZ-EP and AI, m/z 236 for OXCBZ, m/z 237 for 10-OH-CBZ, m/z 253 for 2-OH-CBZ, 3-OH-CBZ and DiOH-CBZ, m/z 196 for AO and m/z 194 for IM. For all analytes, the drug/internal standard peak height ratios were linked via a quadratic relationship to plasma concentrations. The extraction recovery averaged 90% for CBZ, 80% for OXCBZ and was 80-105% for the metabolites. The lower limit of quantitation was 0.5mg/l for CBZ, 0.4 mg/l for OXCBZ and ranged from 0.02 to 0.3 mg/l for the metabolites. Precision ranged from 2 to 13% and accuracy was between 86 and 112%. This method was found suitable for the analysis of plasma samples collected during therapeutic drug monitoring of patients treated with CBZ or OXCBZ.
authors.affiliation: INSERM U 454, Arnaud de Villeneuve Hospital, Montpellier, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Breton
authors.forename: Marylène
authors.initials: M
authors.lastname: Cociglio
authors.forename: Françoise
authors.initials: F
authors.lastname: Bressolle
authors.forename: Hélène
authors.initials: H
authors.lastname: Peyriere
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Blayac
authors.forename: Dominique
authors.initials: D
authors.lastname: Hillaire-Buys
mesh_terms: D000096:Acetone / Q000737:chemistry; D002220:Carbamazepine / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood*; D011232:Chemical Precipitation; D002853:Chromatography, Liquid / Q000379:methods*; D016903:Drug Monitoring; D006801:Humans; D013058:Mass Spectrometry; D000078330:Oxcarbazepine; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D000096:Acetone; D002220:Carbamazepine; D000078330:Oxcarbazepine