Abstract

Our policy of conducting biotransformation studies with extended chromatography prior to pharmacokinetic bioanalyses allowed us to quickly detect an unusual, cis/trans metabolite in rat plasma that was inseparable using a short chromatographic method. We caution investigators that short methods invite unknown isobaric metabolites to cause inaccuracies in plasma concentration measurements.

Keywords: Pharmacokinetics, metabolite, isomer, chromatography, coelution, aminocyclohexanol