Identification of a tolfenamic acid metabolite in the horse by gas chromatography-mass spectrometry.

The research identifies a metabolite of tolfenamic acid in horse plasma and urine samples through gas chromatography-mass spectrometry, with the method also enabling the tracing of drug and metabolite elimination from plasma. It proposes this dual detection as a more reliable anti-doping control analysis mechanism.

Methodology

• The research used gas chromatography-mass spectrometry, a method effective in identifying and quantifying the specific compounds in a sample.
• Two modes, electron-impact and chemical-ionization, were applied in this investigation for the effective traceability of the metabolite.

Findings

• The researchers identified a metabolite of tolfenamic acid, which is a hydroxylated product, in equine plasma and urine samples.
• The method applied also allowed for qualitative monitoring of the elimination of the drug and its metabolites from the plasma.
• The drug and its metabolite were detectable up to 48 and 24 hours respectively after single oral administration of a 30 mg/kg dose.

Implication

• This finding translates into a significant improvement in anti-doping control analysis.
• The simultaneous detection of the two products— the drug and its metabolite— increases the reliability of the analysis since they provide more evidence of the presence or absence of the drug.