title: Rapid determination of gemifloxacin in human plasma by high-performance liquid chromatography-tandem mass spectrometry.
abstract: A method was developed for the determination of gemifloxacin (I) in human plasma using high-performance liquid chromatography-tandem mass spectrometry. Prior to analysis, the protein in plasma samples was precipitated with acetonitrile containing [13C2H3] gemifloxacin (II) to act as an internal standard. The supernatant was injected onto a PLRP-S column without any further clean-up. The mass spectrometer was operated in positive ion mode, employing a heat assisted nebulisation. electrospray interface. Ions were detected in multiple reaction monitoring (MRM) mode. The assay requires 50 microl of plasma and is precise and accurate within the range 10-5,000 ng/ml. The average within-run and between-run coefficients of variation were <11% at 10 ng/ml and greater concentrations. The average accuracy of validation standards was generally within +/-7% of the nominal concentration. There was no evidence of instability of I in human plasma following three complete freeze-thaw cycles and samples can safely be stored for at least 6 months at -20 degrees C. The method proved very robust and was successfully applied to the analysis of clinical samples from patients dosed with gemifloxacin.
authors.affiliation: Department of Drug Analysis, SmithKline Beecham Pharmaceuticals, Welwyn, Hertfordshire, UK.
authors.forename: E
authors.initials: E
authors.lastname: Doyle
authors.forename: S E
authors.initials: SE
authors.lastname: Fowles
authors.forename: D F
authors.initials: DF
authors.lastname: McDonnell
authors.forename: R
authors.initials: R
authors.lastname: McCarthy
authors.forename: S A
authors.initials: SA
authors.lastname: White
mesh_terms: D000890:Anti-Infective Agents / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D024841:Fluoroquinolones; D000077735:Gemifloxacin; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D009287:Naphthyridines / Q000097:blood*; D015203:Reproducibility of Results
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D009287:Naphthyridines; D000077735:Gemifloxacin