Determination of 4-methylpiperaine-1-carbodithioc acid 3-cyano-3,3-diphenylpropyl ester hydrochloride in rats' plasma by online-SPE-HPLC-DAD: application to a pharmacokinetic study

A specific, simple, and fast online-solid-phase extraction-high performance liquid chromatography-diode array detector (SPE-HPLC-DAD) method was developed and validated to quantify 4-methylpiperaine-1-carbodithioc acid 3-cyano-3,3-diphenylpropyl ester hydrochloride (TM208) in small volume samples of rats' plasma for the first time. In this method, the 50-μL plasma sample was taken to perform protein precipitation with 75 μL methanol, and then 50 μL supernatant containing the target analytes was injected and concentrated automatically in a C18 solid-phase extraction (SPE) cartridge. After that the sample was separated on a C18 RP analytical column and analyzed by DAD. The run cycle time is 6.0 min for each sample, and the calibration curve over the range of 0.03 to 25.00 μg/mL has a good linear relationship (r > 0.9998). The recoveries of the quality control samples were all greater than 90%. The limit of detection and the lowest limit of quantification were 0.01 and 0.03 μg/mL, respectively. Finally, this method was successfully applied to a pharmacokinetic study of TM208 in rats.