title: A high-performance liquid chromatographic method for benznidazole quantitation in plasma of patients with Chagas disease.
abstract: BACKGROUND
  Chagas disease is endemic in Latin America, affecting 16-18 million people with more than 100 million exposed to risk of infection. Its etiological agent is Trypanosoma cruzi. To date, benznidazole is the only treatment of Chagas disease available in Europe.
  
  
  METHODS
  A high-performance reversed-phase isocratic liquid chromatographic method for benznidazole analysis in human plasma is described. The mobile phase consists of 60% ultrafiltered water and 40% acetonitrile. Samples were precipitated with trichloroacetic acid (0.3 M) (1/1, v/v). The injection volume was 100 μL. Benzocaine was used as internal standard.
  
  
  RESULTS
  The assay was linear over a benznidazole concentration range of 1.6-100 μg/mL. The method showed good agreement of results (n=15): inaccuracy (5.6%), intra- and inter-day variability (1.1% and 3.9%, respectively), recovery (94.9%), limit of detection (0.8 μg/mL), lower limit of quantitation (1.6 μg/mL) and acceptable stability over 24 h in the auto-sampler. Only 25 samples (58%) showed values within the therapeutic range. Three samples were subtherapeutic and 15 were in the toxic range.
  
  
  CONCLUSIONS
  The method offers a fast and simple approach to determining benznidazole in human plasma which could be of use in pharmacokinetic and safety studies.
authors.affiliation: Pharmacy Service, Hospital Clínic Barcelona/IDIBAPS, University of Barcelona, Barcelona, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Guerrero
authors.forename: Ma Jesús
authors.initials: MJ
authors.lastname: Pinazo
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Posada
authors.forename: Joaquim
authors.initials: J
authors.lastname: Gascón
authors.forename: Josep
authors.initials: J
authors.lastname: Ribas
authors.forename: Dolors
authors.initials: D
authors.lastname: Soy
mesh_terms: D000328:Adult; D014355:Chagas Disease / Q000097:blood* / Q000188:drug therapy; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009593:Nitroimidazoles / Q000097:blood* / Q000627:therapeutic use; D015203:Reproducibility of Results; D014344:Trypanocidal Agents / Q000097:blood / Q000627:therapeutic use
chemical_list: D009593:Nitroimidazoles; D014344:Trypanocidal Agents; C009999:benzonidazole