title: Integration of atazanavir into an existing liquid chromatography UV method for protease inhibitors: validation and application.
abstract: Atazanavir (ATV) is a widely used human immunodeficiency virus (HIV)-1 protease inhibitor (PI) that, like other approved PIs, has been considered as a candidate for therapeutic drug monitoring (TDM). To provide ATV assay results that can be applied to patient management through TDM, the assay would need to perform in a manner consistent with Clinical Laboratory Improvement Amendments (CLIA) standards. To quantitate ATV concentrations in human plasma, the authors added ATV to a previously published reversed-phase high-performance liquid chromatography (HPLC) method from their laboratory. Detection was effected with use of a photodiode-array detector (PDA) collecting spectra at 248 nm. This method allows for detection of ATV to a lower limit of quantitation of 0.05 microg/mL, with an intra-assay coefficient of variation (CV%) of 8.9% or less over 5 days of testing and an interassay CV% ranging from 1.4 to 6.4%. The assay has met passing requirements for interlaboratory proficiency testing for 2 years nationally and internationally, with accuracy within +/-15% over all test samples. During 2 years, more than 100 batches of analyses have been performed and have proved the method is rugged, specific, and accurate. This assay method is currently used in the authors' clinical research program in TDM.
authors.affiliation: Pharmacotherapy Research Center, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, Buffalo, New York 14260, USA.
authors.forename: Kim
authors.initials: K
authors.lastname: Keil
authors.forename: Jill
authors.initials: J
authors.lastname: Hochreitter
authors.forename: Robin
authors.initials: R
authors.lastname: DiFrancesco
authors.forename: Barry S
authors.initials: BS
authors.lastname: Zingman
authors.forename: Richard C
authors.initials: RC
authors.lastname: Reichman
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Fischl
authors.forename: Barbara
authors.initials: B
authors.lastname: Gripshover
authors.forename: Gene D
authors.initials: GD
authors.lastname: Morse
mesh_terms: D000069446:Atazanavir Sulfate; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D016903:Drug Monitoring / Q000379:methods; D004359:Drug Therapy, Combination; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy; D017320:HIV Protease Inhibitors / Q000097:blood / Q000627:therapeutic use*; D006801:Humans; D061466:Lopinavir; D009842:Oligopeptides / Q000097:blood / Q000592:standards / Q000627:therapeutic use*; D011725:Pyridines / Q000097:blood / Q000592:standards / Q000627:therapeutic use*; D011744:Pyrimidinones / Q000627:therapeutic use; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D019438:Ritonavir / Q000627:therapeutic use; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D013997:Time Factors
chemical_list: D017320:HIV Protease Inhibitors; D009842:Oligopeptides; D011725:Pyridines; D011744:Pyrimidinones; D061466:Lopinavir; D000069446:Atazanavir Sulfate; D019438:Ritonavir