Development and validation of a highly sensitive LC-MS/MS method for determination of brain active agent dianhydrogalactitol in mouse plasma and tissues: Application to a pharmacokinetic study

A sensitive and specific liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was developed and validated for quantitative analysis of 1,2:5,6-dianhydrogalactitol (DAG) in mouse plasma and tissues. Sodium diethyldithiocarbamate (DDTC) was used as the derivatization reagent to improve its LC-MS/MS behavior. Analytes were separated on a Welch Ultimate XB-CN column with a mobile phase consisting of acetonitrile and 0.1% formic acid solution (65:35). The MS analysis was conducted by positive electrospray ionization in multiple-reaction monitoring (MRM) mode. Good linearity (r2 > 0.9958) was observed over the concentration range of 1-1000 ng/mL in plasma and tissue homogenates (brain, liver, heart, spleen, lung and kidney). The intra- and inter-batch precision and accuracy of DAG in plasma and brain samples were all within the acceptable limits. The extraction recovery was stable and no significant matrix effects were observed. The method was successfully applied to study the pharmacokinetic and tissue distribution of DAG in mice after intravenous administration. DAG could cross the blood-brain barrier and had limited liver distribution. Rat primary hepatocytes in vitro experiments demonstrated that DAG had a safe profile in liver.