2-Deoxyglucose and hydroxychloroquine HPLC-MS-MS analytical methods and pharmacokinetic interactions after oral co-administration in male rats

Our previous work has shown a synergistic tumoricidal action of the hexokinase (HK) inhibitor 2-deoxyglucose (2-DG) and the autophagy inhibitor chloroquine (CQ) on HK2-addicted prostate cancers in animal models through intraperitoneal injections. Here we developed high performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS) methods for 2-DG and clinically favored drug hydroxychloroquine (HCQ) and explored PK interaction of the orally administered drugs in a jugular vein cannulated male rat model, which allowed serial blood collection before and 0.5, 1, 2, 4 and 8 h after a single gavage dose of each drug alone or simultaneously after appropriate washout periods between the drugs. The results demonstrated a rapid and satisfactory separation of 2-DG standard from common monosaccharides by HPLC-MS-MS multi-reaction monitoring (MRM) and the presence of endogenous "2-DG". Application of the HPLC-MS-MS 2-DG and HCQ methods to sera samples of 9 evaluable rats showed a peak time (Tmax) of 2-DG of 0.5 h after 2-DG dosing alone or with HCQ and glucose-like PK behavior. With a seemingly bi-modal time course for HCQ, the Tmax for HCQ dosing alone (1.2 h) was faster than that for the combination (2 h; p = 0.013, 2-tailed t-test). After combination dosing, the peak concentration (Cmax) and area under the curve (AUC) of 2-DG were decreased by 54% (p < 0.0001) and 52%, whereas those for HCQ were decreased by 40% (p = 0.026) and 35%, respectively, compared to single dosing. The data suggest significant negative PK interactions between the two oral drugs taken simultaneously and warrant optimization efforts for the combination regimen.