Characterization of CGK012 in rat plasma by high performance liquid chromatography and mass spectrometry (HPLC-MS/MS): Application to a pharmacokinetic study.

CGK012 is a newly synthesized pyranocoumarin substance suppressing the activation and transcription of ß-catenin related to Wnt3a-CM. A bioanalytical method for CGK012 was developed and validated in rat plasma, and the method was applied to determine the plasma concentrations after intravenous administration. Plasma was cleaned-up by protein precipitation by acetonitrile including an internal standard. The substances were separated on a reversed-phase column, and the mobile phase was a mixture of water and acetonitrile (3:7, v/v; 0.1 % formic acid). The mass transition occurred at m/z 358.2→229.2 for CGK012 [M+H]+. CGK012 was stable in the various conditions, and the present assay met the criteria of bioanalytical method validation. CGK012 bi-exponentially decayed with the half-life of 4.0 h at the terminal phase. Mean Vd and clearance were 0.69 L/kg and 1.31 L/h/kg, respectively. This is the first bioanalytical method developed for quantification of CGK012 in rat plasma using LC-MS/MS, which would be useful to examine pharmacokinetic study of the substance.