title: Simultaneous determination of unlabeled and deuterium-labeled indinavir in human plasma by high-performance liquid chromatography with tandem mass spectrometric detection.
abstract: A method for the simultaneous determination of indinavir and its hexadeuterated analog (d6-indinavir) in human plasma is described. Isolation of the analytes and internal standard from plasma was achieved via liquid-liquid extraction with methyl-t-butyl ether. The analytes were chromatographed under reversed-phase conditions on a BDS-Hypersil C8 column. A Sciex API III+ tandem mass spectrometer equipped with a turbo ion-spray interface was used as the detector. Multiple reaction monitoring using the parent-->product ion combinations of m/z 614-->465, 620-->471 and 654-->505 were used to quantify indinavir, d6-indinavir, and internal standard, respectively. The method was validated, using 1-mL aliquots of plasma, in the concentration range in plasma of 1 to 200 ng/mL. Precision of the assay, as measured by the coefficient of variation, ranged from 0.9 to 4.3% and 0.9 to 6.2% for indinavir and d6-indinavir, respectively. Indinavir assay accuracy ranged from 95.8 to 105.0% of nominal, whereas the accuracy of the assay for d6-indinavir ranged from 97.4 to 104.0% of nominal. The assay was used to support a clinical study in which the stable isotope technique was used to determine the bioavailability of indinavir.
authors.affiliation: Merck Research Laboratories, Department of Drug Metabolism, West Point, PA 19486, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Woolf
authors.forename: B K
authors.initials: BK
authors.lastname: Matuszewski
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003903:Deuterium; D017320:HIV Protease Inhibitors / Q000097:blood*; D006801:Humans; D019469:Indinavir / Q000097:blood*; D013058:Mass Spectrometry / Q000379:methods; D015203:Reproducibility of Results
chemical_list: D017320:HIV Protease Inhibitors; D019469:Indinavir; D003903:Deuterium