Table of Contents
ISRN Analytical Chemistry
Volume 2012, Article ID 198683, 5 pages
http://dx.doi.org/10.5402/2012/198683
Research Article

Comparison of LC-MS Assay and HPLC Assay of Busulfan in Clinical Pharmacokinetics Studies

The Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA

Received 24 October 2011; Accepted 16 November 2011

Academic Editors: A. Bouklouze and P. Campíns-Falcó

Copyright © 2012 Hongxia Lin et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Busulfan is used in preparative regimens for bone marrow transplantation and timely busulfan plasma concentration reporting is critical for subsequent dose adjustment. We compared two sensitive methods for pharmacokinetics studies including LC-MS assay and HPLC precolumn derivatization assay. Chromatographic separation was performed on a Gemini C18 column. Liquid-liquid extraction with ethyl acetate was used for plasma sample preparation. Busulfan and internal standard ([2H8]-busulfan) were detected as ammonium adducts at m/z 264.2 and 272.2 for LC-MS assay. For HPLC assay, the extraction from plasma was derivatized with 2-naphathalenethiol using synthesized internal standard (1,6-(methanesulfonyloxy)octane). The Ex and Em wavelength was 255 nm and 370 nm. The limit of detection was 15.6 ng/mL and 7.8 ng/mL for HPLC and LC-MS assay and good linearity ranging from 31.25–1000 ng/mL for HPLC and 15.6-1000 ng/mL for LC-MS assay. The intra and interday assay precision were less than 9.2% and 12.0% for LC-MS and HPLC assay. The pharmacokinetic parameters were estimated using noncompartmental pharmacokinetic model with WinNonlin. Busulfan AUClast showed an average difference of 0.7% between the two methods. The LC-MS method is accurate, reproducible, and requires less specimen, sample preparation and analysis time over the HPLC assay, making busulfan monitoring faster and easier in clinical practice.