Determination of the new MDR-modifier PFP 6 and its metabolites in human liver microsomes by high-performance liquid chromatography.

A specific and sensitive method for the determination of PFP 6, a new compound for reverting multidrug resistance, and its two main metabolites in human liver microsomes has been developed. Samples were almost quantitatively isolated by solid phase extraction and further analysed by HPLC. Separation was achieved on an endcapped reversed phase C-18 column with triethylamine as an organic modifier in the mobile phase. The method exhibits high recovery and a good sensitivity for analyses of small sample volumes. The application of the method for screening the metabolism of this new drug in human liver microsomes is presented.