The in vivo metabolism of Furazadrol in greyhounds

• DOI: 10.1002/dta.3128
• Publication Date: 2021-07-13T08:18:54Z
• Authors: Andy Pranata; Blake Curtis; Christopher C. Wa...; Karen Caldwell; Paul W. Zahra; Steven L. Karamatic; Malcolm D. McLeod
• Keywords: Anabolic-Androgenic Steroids; Enzymatic Hydrolysis

Samples of the 'dietary supplement' Furazadrol sourced through internet have been reported to contain designer anabolic androgenic steroids [1',2']isoxazolo[4',5':2,3]-5α-androstan-17β-ol (furazadrol F) and [1',2']isoxazolo[4',3':2,3]-5α-androstan-17β-ol (isofurazadrol IF). These an isoxazole fused A-ring were designed offer activity while evading detection, raising concerns over potential for abuse this preparation in sports. The metabolism (F:IF, 10:1) was studied by vivo methods greyhounds. Urinary phase II metabolites detected as glucuronides after a controlled administration. subjected enzymatic hydrolysis Escherichia coli β-glucuronidase afford corresponding I metabolites. Using library synthetically derived reference materials, identities seven urinary confirmed. Major confirmed isofurazadrol IF, 4α-hydroxyfurazadrol 4α-HF 16α-hydroxy oxidised furazadrol 16α-HOF, whereas minor F, 4β-hydroxyfurazadrol 4β-HF, 16β-hydroxyfurazadrol 16β-HF 16β-hydroxy 16β-HOF. One major hydroxyfurazadrol two dihydroxyfurazadrol remained unidentified. Qualitative excretion profiles, limits detection extraction recoveries established F investigations identify key following oral administration, which can be incorporated into routine screening anti-doping laboratories aid regulation greyhound racing.