Determination of Exposure Multiples of Human Metabolites for MIST Assessment in Preclinical Safety Species without Using Reference Standards or Radiolabeled Compounds

A simple reliable and accurate method was developed for quantitative assessment of metabolite coverage in preclinical safety species by mixing equal volumes of human plasma with blank plasma of animal species and vice versa followed by an analysis using high resolution full scan accurate mass spectrometry This approach provided comparable results (within +/- 15%) to those obtained from regulated bioanalysis and did not require synthetic standards or radiolabeled compounds In addition both qualitative and quantitative data were obtained from a single LC MS analysis on all metabolites and therefore the coverage of any metabolite of interest can be obtained