BIOTRANSFORMATION OF 17-ALKYL STEROIDS IN THE EQUINE - HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY MASS-SPECTROMETRIC AND GAS-CHROMATOGRAPHY MASS-SPECTROMETRIC ANALYSIS OF FLUOXYMESTERONE METABOLITES IN URINE SAMPLES

In this study the equine metabolism of fluoxymesterone (9 alpha-fluoro -11 beta-17 beta-dihydroxy-17 alpha-methylandrost-4-ene-3-one) given o rally has been investigated. The parent material was not detected, but two major 16-hydroxy metabolites which corresponded to a mono- and a di-hydroxylation product were evident. One of the hydroxylation positi ons was identified as C-16. Phase II metabolism in the form of glucuro nide formation was also common. These steroids will provide target com pounds for confirming abuse of this drug in the horse. (C) 1997 Elsevi er Science B.V.