title: High-performance liquid chromatographic analysis of angiotensin II receptor antagonist valsartan using a liquid extraction method.
abstract: OBJECTIVE
  To develop an easy assay for the quantitation of the angiotensin II receptor antagonist valsartan in human plasma using a liquid extraction procedure.
  
  
  METHODS
  The method involves acid extraction from 1 ml human plasma with methyl-tert.-butyl ether followed by back-extraction into a basic medium. An isocratic HPLC equipped with reverse phase column and a fluorescence detector was used at room temperature.
  
  
  RESULTS
  The response to 10-2000 ng/ml valsartan was linear. In plasma of three human subjects given 160 mg valsartan orally, concentrations of 25-1540 ng/ml were observed.
  
  
  CONCLUSIONS
  This convenient method is suitable for pharmacokinetic studies of valsartan.
authors.affiliation: Faculty of Pharmacy and Pharmaceutical Sciences and Department of Physiology, University of Alberta, Edmonton, Canada.
authors.forename: Noriko
authors.initials: N
authors.lastname: Daneshtalab
authors.forename: Richard Z
authors.initials: RZ
authors.lastname: Lewanczuk
authors.forename: Fakhreddin
authors.initials: F
authors.lastname: Jamali
mesh_terms: D000804:Angiotensin II / Q000378:metabolism*; D057911:Angiotensin Receptor Antagonists; D000959:Antihypertensive Agents / Q000097:blood* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D011945:Receptors, Angiotensin / Q000378:metabolism; D012015:Reference Standards; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence; D013777:Tetrazoles / Q000097:blood* / Q000493:pharmacokinetics; D014633:Valine / Q000031:analogs & derivatives / Q000097:blood* / Q000493:pharmacokinetics; D000068756:Valsartan
chemical_list: D057911:Angiotensin Receptor Antagonists; D000959:Antihypertensive Agents; D011945:Receptors, Angiotensin; D013777:Tetrazoles; D000804:Angiotensin II; D000068756:Valsartan; D014633:Valine