Pharmacokinetic study of an anti-trypanosome agent with different formulations and administration routes in mice by HPLC-MS/MS.

Previously compound 12 showed great anti-trypanosome activity without toxicity in the in vivo study. In the current study, a sensitive and rapid high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed and validated to investigate the pharmacokinetics of compound 12 in mouse plasma. Protein precipitation method was applied to extract the compound, and it was then separated by using a Kinetex C18 column with a mobile phase consisting of acetonitrile-0.1% formic acid water (50:50, v/v) at a flow rate of 300 μL/min. The analytes were detected with the multiple reaction monitoring (MRM) in negative electrospray ionization source for quantitative response of the compounds. Compound 12 was detected at m/z 477.0→367.2, while the internal standard compound 14 was detected at m/z 499.2→268.2. Precision of the inter- and intra-day was less than 5.22% and 2.79% respectively, while the accuracy range was within ±9.65%. The method was successfully applied to evaluate the pharmacokinetic of compound 12 in mouse plasma with two formulations (20% Cremophor EL or sesame oil) and drug administration routes (oral and intraperitoneal injection). We observed a better drug serum concentration with the Cremophor formulation, and the two different drug administration routes did not show significant difference to the drug distribution.