, 48:664 | Cite as

High performance liquid chromatographic analysis of theIn vitro N-dealkylated andN-oxide metabolites ofN-ethyl-N-methylaniline: Methodology for the determination of enzyme activity and stereoselectivity ofN-oxidation

  • M. R. Hadley
  • H. G. Oldham
  • L. A. Damani
  • A. J. Hutt


A robust, sensitive reverse-phase high-performance liquid chromatographic (HPLC) method for the quantification of the majorin vitro oxidative microsomal metabolites of the prochiral tertiary amineN-ethyl-N-methyllaniline (EMA) is described. The analytes were resolved on a Spherisorb 5 ODS1 HPLC column using an acetonitrile/phosphate buffer system under isocratic conditions. Use of solid-phase extraction (SPE) and ultraviolet (UV) detection at low wavelength (210 nm) enabled the detection of EMAN-oxide simultaneously with the majorN-dealkylated metabolites,N-ethyl andN-methylaniline. Previous chromatographic methods described for the quantification ofN,N-dialkylarylamineN-oxides have generally required sample pretreatment to reduce theN-oxide to its parent tertiary amine prior to analysis. The above method, in combination with a previously reported chromatographic resolution based on the Chiralcel OD chiral stationary phase (CSP), allows accurate and precise determination of both the quantity and stereochemical composition of metabolically derived EMAN-oxide.

Key Words

Column liquid chromatography Enantiospecific analysis N-Ethyl-N-methylaniline N-Oxidation N-Dealkylation 


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Copyright information

© Friedr. Vieweg & Sohn Verlagsgesellschaft mbH 1998

Authors and Affiliations

  • M. R. Hadley
    • 1
  • H. G. Oldham
    • 2
  • L. A. Damani
    • 3
  • A. J. Hutt
    • 4
  1. 1.Department of Analytical SciencesSmithKline Beecham PharmaceuticalsTombridgeUK
  2. 2.Department of Drug Metabolism and PharmacokineticsSmithKline Beecham PharmaceuticalsWelwynUK
  3. 3.Department of Pharmacy, Faculty of MedicineThe Chinese University of Hong KongShatin, N.T.Hong Kong
  4. 4.Department of PharmacyKing's College LondonLondonUK

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