title: Rapid quantitative determination of L-FMAU-TP from human peripheral-blood mononuclear cells of hepatitis B virus-infected patients treated with L-FMAU by ion-pairing, reverse-phase, liquid chromatography/electrospray tandem mass spectrometry.
abstract: The purpose of this study was to develop an analytical method for the determination of 2'-fluoro-5-methyl-beta-l-arabinofuranosyl uracil triphosphate (L-FMAU-TP) in human peripheral blood mononuclear cells (PBMCs), and its application in the determination of cellular levels of L-FMAU-TP in PBMCs isolated from patients treated with 2'-fluoro-5-methyl-beta-l-arabinofuranosyl uracil (L-FMAU). An ion-pairing liquid chromatography (IPC) method, coupled with negative ion electrospray ionization tandem mass spectrometry (ESI-MS/MS), was developed for the accurate and repeatable detection of L-FMAU-TP, with a limit of detection of 1.6 pmol/10 cells. The calibration curve for L-FMAU-TP was linear over the concentration range 1.6 to 80 pmol/10(6) cells. The intra- and inter-day precision was lower than 11.2%, and the accuracy was between 97.1 and 106.9%. When applied to the determination of L-FMAU-TP in PBMCs isolated from HBV-infected patients undergoing L-FMAU treatment, the levels reached a steady state concentration 4 weeks after daily single oral administration of 20 mg L-FMAU, and these levels were maintained for up to 12 weeks, but then decreased 12 weeks after drug cessation. The terminal half-life of L-FMAU-TP in PBMCs after drug cessation was estimated to be 15.6 days.
authors.affiliation: Bioanalysis and Biotransformation Research Center, Korea Institute of Science and Technology, Chungryang, Seoul, Korea.
authors.forename: Jaeick
authors.initials: J
authors.lastname: Lee
authors.forename: Byung-Chul
authors.initials: BC
authors.lastname: Yoo
authors.forename: Hyo-Suk
authors.initials: HS
authors.lastname: Lee
authors.forename: Hee-Won
authors.initials: HW
authors.lastname: Yoo
authors.forename: Hye-Hyun
authors.initials: HH
authors.lastname: Yoo
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Kang
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use; D001085:Arabinofuranosylcytosine Triphosphate / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D001086:Arabinofuranosyluracil / Q000031:analogs & derivatives / Q000627:therapeutic use; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006207:Half-Life; D006509:Hepatitis B / Q000097:blood* / Q000188:drug therapy; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D008875:Middle Aged; D015203:Reproducibility of Results
chemical_list: D000998:Antiviral Agents; D001085:Arabinofuranosylcytosine Triphosphate; D001086:Arabinofuranosyluracil; C047247:1-(2'-deoxy-2'-fluoro-beta-arabinofuranosyl)-5-methylcytosine triphosphate; C034935:clevudine