title: Quantitative determination of free/bound atazanavir via high-throughput equilibrium dialysis and LC-MS/MS, and the application in ex vivo samples.
abstract: OBJECTIVE
  The determination of drug-protein binding is important in the pharmaceutical development process because of the impact of protein binding on both the pharmacokinetics and pharmacodynamics of drugs. Equilibrium dialysis is the preferred method to measure the free drug fraction because it is considered to be more accurate. The throughput of equilibrium dialysis has recently been improved by implementing a 96-well format plate. Results/methodology: This manuscript illustrates the successful application of a 96-well rapid equilibrium dialysis (RED) device in the determination of atazanavir plasma-protein binding.
  
  
  CONCLUSIONS
  This RED method of measuring free fraction was successfully validated and then applied to the analysis of clinical plasma samples taken from HIV-infected pregnant women administered atazanavir. Combined with LC-MS/MS detection, the 96-well format equilibrium dialysis device was suitable for measuring the free and bound concentration of pharmaceutical molecules in a high-throughput mode.
authors.affiliation: R&D, Bristol-Myers Squibb, Mail Stop J22-06, PO Box 4000, Princeton, NJ 08543, USA.
authors.forename: Xiaohui Sophia
authors.initials: XS
authors.lastname: Xu
authors.forename: Anne
authors.initials: A
authors.lastname: Rose
authors.forename: Roger
authors.initials: R
authors.lastname: Demers
authors.forename: Timothy
authors.initials: T
authors.lastname: Eley
authors.forename: John
authors.initials: J
authors.lastname: Ryan
authors.forename: Bruce
authors.initials: B
authors.lastname: Stouffer
authors.forename: Laura
authors.initials: L
authors.lastname: Cojocaru
authors.forename: Mark
authors.initials: M
authors.lastname: Arnold
mesh_terms: D019380:Anti-HIV Agents / Q000097:blood* / Q000737:chemistry / Q000378:metabolism*; D000069446:Atazanavir Sulfate; D001774:Blood Chemical Analysis / Q000379:methods*; D002853:Chromatography, Liquid; D002986:Clinical Trials as Topic; D003956:Dialysis; D005260:Female; D006801:Humans; D009842:Oligopeptides / Q000097:blood* / Q000737:chemistry / Q000378:metabolism*; D011247:Pregnancy; D011485:Protein Binding; D011725:Pyridines / Q000097:blood* / Q000737:chemistry / Q000378:metabolism*; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry
chemical_list: D019380:Anti-HIV Agents; D009842:Oligopeptides; D011725:Pyridines; D000069446:Atazanavir Sulfate
keywords: atazanavir; clinical; equilibrium dialysis; high-throughput; protein binding