Development and validation of a liquid chromatography-tandem mass spectrometry method for quantification of decitabine in rat plasma

Decitabine is chemically unstable at physiological temperature and pH. In addition, the bioanalysis of decitabine is easily interfered by endogenous 2-deoxycytidine. A simple, sensitive and specific LC-MS/MS method was developed for the analysis of decitabine in rat plasma. No exogenous stabilizers were used to prevent the degradation of decitabine in rat plasma. After deproteinized with acetonitrile at room temperature, rat plasma samples were analyzed on a Hypersil APS-2 NH2 column interfaced with a triple quadrupole tandem mass spectrometer in positive electrospray ionization mode. Decitabine was completely separated from 2-deoxycytidine using gradient elution of water (solvent A) and acetonitrile (solvent B) at a flow rate of 1 mL/min. To quantify decitabine and daidzin (internal standard), respectively, multiple reaction monitoring (MRM) transitions of m/z 251.1 -> 134.7 and m/z 417.3 -> 255.3 was performed. The assay was linear over the concentration range of 5.0-2000 ng/mL. The intra- and inter-day precision was within 12.0% in terms of relative standard deviation (RSD%) and the accuracy within 5.9% in terms of relative error. The LC-MS/MS method was fully validated for its sensitivity, selectivity, stability study, matrix effect and recovery. The data indicate that this LC-MS/MS method is a specific and effective method for the pharmacokinetic study of decitabine in rat plasma. Compared with the previously reported analytical methods, this method showed easy and economic sample preparation, good specificity and high sensitivity with less plasma (50 mu L). (C) 2012 Elsevier B.V. All rights reserved.