title: Development and validation of a liquid chromatographic/electrospray ionization mass spectrometric method for the quantitation of prazepam and its main metabolites in human plasma.
abstract: A method was developed and fully validated for the quantitation of prazepam and its major metabolites, oxazepam and nordiazepam, in human plasma. Sample pretreatment was achieved by solid-phase extraction using Oasis HLB cartridges. The extracts were analysed by high-performance liquid chromatography (HPLC) coupled with single-quadrupole mass spectrometry (MS) with an electrospray ionization interface. The MS system was operated in the selected ion monitoring mode. HPLC was performed isocratically on a reversed-phase XTerra MS C18 analytical column (150 x 3.0 mm i.d., particle size 5 microm). Diazepam was used as the internal standard for quantitation. The assay was linear over a concentration range of 5.0-1000 ng ml(-1) for all compounds analyzed. The limit of quantitation was 5 ng ml(-1) for all compounds. Quality control samples (5, 10, 300 and 1000 ng ml(-1)) in five replicates from three different runs of analysis demonstrated an intra-assay precision (CV) of < or = 9.1%, an inter-assay precision of < or = 6.0% and an overall accuracy (relative error) of < 4.6%. The method can be used to quantify prazepam and its metabolites in human plasma covering a variety of pharmacokinetic or bioequivalence studies.
authors.affiliation: School of Pharmacy, Department of Pharmaceutical Chemistry, University of Athens, Panepistimiopolis, Athens 157 71, Greece.
authors.forename: Paraskevi
authors.initials: P
authors.lastname: Valavani
authors.forename: Julia
authors.initials: J
authors.lastname: Atta-Politou
authors.forename: Irene
authors.initials: I
authors.lastname: Panderi
mesh_terms: D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D003975:Diazepam / Q000097:blood; D006801:Humans; D015394:Molecular Structure; D003708:Nordazepam / Q000097:blood; D010076:Oxazepam / Q000097:blood; D011222:Prazepam / Q000097:blood* / Q000378:metabolism*; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D003708:Nordazepam; D010076:Oxazepam; D011222:Prazepam; D003975:Diazepam