title: Enantioselective determination of ornidazole in human plasma by liquid chromatography-tandem mass spectrometry on a Chiral-AGP column.
abstract: A rapid, sensitive, and enantioselective method was developed and validated for determination of ornidazole enantiomers in human plasma by liquid chromatography-tandem mass spectrometry. Ornidazole enantiomers were extracted from 100μl of plasma using ethyl acetate. Baseline chiral separation (Rs=2.0) was obtained within 7.5min on a Chiral-AGP column (150mm×4.0mm, 5μm) using an isocratic mobile phase of 10mM ammonium acetate/acetic acid (100/0.01, v/v). Stable isotopically labeled R-(+)-d5-ornidazole and S-(-)-d5-ornidazole were synthesized as internal standards. Acquisition of mass spectrometric data was performed in multiple reaction monitoring mode via positive electrospray ionization, using the transitions of m/z 220→128 for ornidazole enantiomers, and m/z 225→128 for d5-ornidazole enantiomers. The method was linear in the concentration range of 0.030-10.0μg/ml for each enantiomer. The lower limit of quantification for each enantiomer was 0.030μg/ml. The relative standard deviation values of intra- and inter-day precision were 1.8-6.2% and 1.5-10.2% for R-(+)-ornidazole and S-(-)-ornidazole, respectively. The relative error values of accuracy ranged from -4.5% to 1.2% for R-(+)-ornidazole and from -5.4% to -0.8% for S-(-)-ornidazole. The validated method was successfully applied to a stereoselective pharmacokinetic study of ornidazole after oral administration of 1000mg racemic ornidazole.
authors.affiliation: Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai 201203, PR China.
authors.forename: Jiangbo
authors.initials: J
authors.lastname: Du
authors.forename: Zhiyu
authors.initials: Z
authors.lastname: Ma
authors.forename: Yifan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Chen
authors.forename: Dafang
authors.initials: D
authors.lastname: Zhong
mesh_terms: D000284:Administration, Oral; D002853:Chromatography, Liquid / Q000379:methods; D006801:Humans; D009950:Ornidazole / Q000008:administration & dosage / Q000097:blood* / Q000737:chemistry*; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D009950:Ornidazole
keywords: APCI; AUC(0–t); AUC(0–∞); C(max); CL/F; ESI; Enantiomers; Enantioselective liquid chromatography–tandem mass spectrometry; FDA; Food and Drug Administration; IS; LC–MS/MS; LLOQ; ME; MRM; MRT; Ornidazole; QC; R(s); RE; RSD; S/N; SIM; Stereoselective pharmacokinetics; T(1/2); ULOQ; V(d); W; area under plasma concentration–time curve to infinity; area under the concentration–time curve to the last measurable concentration; atmospheric pressure chemical ionization; distribution volume; electrospray ionization; elimination half-life; internal standard; liquid chromatography–tandem mass spectrometry; lower limit of quantification; matrix effect; maximum plasma concentration; mean residence time; multiple reaction monitoring; peak width; quality control; relative error; relative standard deviation; resolution; selective ion monitoring; signal to noise ratio; t(max); time to maximum plasma concentration; total body clearance; upper limit of quantification