Development and validation of an assay to analyze atazanavir in human hair via liquid chromatography/tandem mass spectrometry. (8th February 2018)

• Record Type: Journal Article
• Authors: Phung, Nhi; Kuncze, Karen; Okochi, Hideaki; Louie, Alexander; Benet, Leslie Z.; Ofokotun, Igho; Haas, David W.; Currier, Judith S.; Chawana, Tariro D.; Sheth, Anandi N.; Bacchetti, Peter; Gandhi, Monica; Horng, Howard
• Is Part Of: Rapid communications in mass spectrometry. Volume 32:Number 5(2018)
• Page Start: 431
• Page End: 441
• Publication Date: 2018-02-08
• Subjects: Mass spectrometry -- Periodicals; 543.65
• DOI: 10.1002/rcm.8058
• Languages: English
• ISSNs: 0951-4198

Abstract

Abstract : Rationale: Assays to quantify antiretrovirals in hair samples are increasingly used to monitor adherence and exposure in both HIV prevention and treatment studies. Atazanavir (ATV) is a protease inhibitor used in combination antiretroviral therapy (ART). We developed and validated a liquid chromatography/tandem mass spectrometry (LC/MS/MS)‐based method to quantify ATV in human hair, per the NIH Division of AIDS Clinical Pharmacology Quality Assurance (CPQA) program and the FDA bioanalytical method validation guidelines. Methods: ATV was extracted from hair using optimized methods and the extracts were injected onto a BDS C‐18 column (5 μm, 4.6 × 100 mm), followed by isocratic elution via a mobile phase composed of 55% acetonitrile, 45% water, 0.15% acetic acid, and 4 mM ammonium acetate, at a flow rate of 0.8 mL/min prior to analysis by MS/MS. Levels were quantified using positive electrospray ionization by multiple reaction monitoring (MRM) for the transitions MH + m/z 705.3 to m/z 168.0 and MH + m/z 710.2 to m/z 168.0 for ATV and ATV‐d5 (internal standard), respectively. Results: Our assay demonstrated a linear standard curve (r = 0.99) over the concentration range of 0.0500 ng ATV/mg hair to 20.0 ng/mg hair. The inter‐ and intraday accuracy of ATV quality control (QC) samples was −1.33 to 4.00% and precision (% coefficient of variation (%CV)) was 1.75 to 6.31%. The %CV for ATV levels in hair samples from highly adherent patients (incurred samples) was less than 10%. No significant endogenous peaks or crosstalk were observed in the specificity test with other HIV drugs. The overall extraction efficiency of ATV from incurred hair samples was greater than 95%. Conclusions: This highly sensitive, highly specific and validated assay can be considered for therapeutic drug monitoring for HIV‐infected patients on ATV‐based ART.