ABSTRACT
All detectable biliary butoprozine metabolites can be separated with a specially developed analytical approach based on gradient-elution reversed-phase h.p.l.c. without extraction steps. The high reproducibility of the h.p.l.c. systems allows preliminary intra- and inter-species comparisons based on retention times with single wavelength u.v. detection. Diode array u.v. spectrometry, radioactivity and mass-spectrometric measurements wee used to confirm the metabolic character of peaks in an individual chromatogram, and to obtain more evidence for the structure of metabolites with the same retention time in chromatograms of different bile fractions. Large inter-species differences in the biliary metabolic profiles are seen, indicating that great care must be exercised when trying to extrapolate preclinical drug safety evaluations from animals to man.
Subject(s)
Amiodarone/metabolism , Anti-Arrhythmia Agents/metabolism , Benzofurans/metabolism , Bile/metabolism , Aged , Amiodarone/analogs & derivatives , Animals , Chromatography, High Pressure Liquid , Dogs , Female , Humans , Male , Mass Spectrometry , Middle Aged , Papio , Rats , Rats, Inbred Strains , Species SpecificityABSTRACT
A systematic approach to the recognition, isolation and identification of metabolites of butoprozine in human bile is described as an example of the general approach in this area. Human profiles are compared with those obtained after administration of 14C-labelled drug to the dog. The screening method is based on gradient-elution high-performance liquid chromatography (HPLC). Isolation is by isocratic reversed-phase HPLC and the identification procedure is performed using ultraviolet, mass and nuclear magnetic resonance spectroscopy.
ABSTRACT
The direct coupling of a multi-channel diode array UV-visible spectrophotometer to a powerful reversed-phase HPLC separation system is considered, especially for use in qualitative analysis, e.g., screening/identification of drugs and drug metabolites. The approach is illustrated by the screening for metabolites of butoprozine and ticlopidine directly in human and rat bile.
