title: Utility of high-resolution accurate MS to eliminate interferences in the bioanalysis of ribavirin and its phosphate metabolites.
abstract: BACKGROUND
  The polar nucleoside drug ribavirin (RBV) combined with IFN-α is a front-line treatment for chronic hepatitis C virus infection. RBV acts as a prodrug and exerts its broad antiviral activity primarily through its active phosphorylated metabolite ribavirin 5´-triphosphate (RTP), and also possibly through ribavirin 5´-monophosphate (RMP). To study RBV transport, diffusion, metabolic clearance and its impact on drug-metabolizing enzymes, a LC-MS method is needed to simultaneously quantify RBV and its phosphorylated metabolites (RTP, ribavirin 5´-diphosphate and RMP). In a recombinant human UGT1A1 assay, the assay buffer components uridine and its phosphorylated derivatives are isobaric with RBV and its phosphorylated metabolites, leading to significant interference when analyzed by LC-MS with the nominal mass resolution mode.
  
  
  RESULTS
  Presented here is a LC-MS method employing LC coupled with full-scan high-resolution accurate MS analysis for the simultaneous quantitative determination of RBV, RMP, ribavirin 5´-diphosphate and RTP by differentiating RBV and its phosphorylated metabolites from uridine and its phosphorylated derivatives by accurate mass, thus avoiding interference.
  
  
  CONCLUSIONS
  The developed LC-high-resolution accurate MS method allows for quantitation of RBV and its phosphorylated metabolites, eliminating the interferences from uridine and its phosphorylated derivatives in recombinant human UGT1A1 assays.
authors.affiliation: Bristol-Myers Squibb, Research & Development, Wallingford, CT 06492, USA.
authors.forename: Cong
authors.initials: C
authors.lastname: Wei
authors.forename: James E
authors.initials: JE
authors.lastname: Grace
authors.forename: Tatyana A
authors.initials: TA
authors.lastname: Zvyaga
authors.forename: Dieter M
authors.initials: DM
authors.lastname: Drexler
mesh_terms: D000249:Adenosine Monophosphate; D000998:Antiviral Agents / Q000032:analysis* / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002852:Chromatography, Ion Exchange / Q000379:methods; D014453:Glucuronosyltransferase / Q000032:analysis / Q000378:metabolism; D019698:Hepatitis C, Chronic / Q000188:drug therapy; D006801:Humans; D009711:Nucleotides / Q000032:analysis; D012254:Ribavirin / Q000031:analogs & derivatives / Q000032:analysis* / Q000493:pharmacokinetics*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014529:Uridine / Q000032:analysis; D014530:Uridine Diphosphate / Q000032:analysis; D014542:Uridine Monophosphate / Q000032:analysis; D000099148:UGT1A1 Enzyme
chemical_list: D000249:Adenosine Monophosphate; D000998:Antiviral Agents; D014453:Glucuronosyltransferase; D009711:Nucleotides; D012254:Ribavirin; D014529:Uridine; D014530:Uridine Diphosphate; D014542:Uridine Monophosphate; D000099148:UGT1A1 Enzyme; C009174:ribavirin-5'-phosphate; C055970:ribavirin 5'-diphosphate; C037827:ribavirin 5'-triphosphate