Identification of a benzhydrolic metabolite of ketoprofen in horses by gas chromatography-mass spectrometry and high-performance liquid chromatography.

The article investigates a benzhydrolic metabolite of the anti-inflammatory drug, ketoprofen in horses. It utilizes gas chromatography-mass spectrometry and high-performance liquid chromatography to identify the metabolite in horse plasma and urine and understand its duration. This knowledge enhances antidoping control analysis.

Metabolite Identification

• The researchers discovered a metabolite through the reduction of ketoprofen’s keto group. This metabolite is of the benzhydrolic type, a recognized category of organic compounds.
• This identification was carried out using gas chromatography-mass spectrometry, a method that combines the advantages of gas chromatography’s separation power with mass spectrometry’s detection and identification strength. This technique helped to analyze and identify the substance in the equine plasma and urine samples.

Structure and Kinetics Analysis

• After discerning the presence of this metabolite, its structure was authenticated using UV (Ultraviolet), IR (Infrared), and 1H NMR (Proton nuclear magnetic resonance) spectroscopy. These techniques allowed the researchers to analyze the molecule’s structure and behavior further.
• The researchers performed kinetic monitoring of ketoprofen and the benzhydrolic metabolite in the plasma, using high-performance liquid chromatography, a technique mainly used in biochemistry and analytical chemistry to identify, quantify, and purify the individual components of a mixture.

Dosing and Quantifying

• Upon administering a single intravenous dose of 2.2 mg/kg of ketoprofen to horses, both the drug and it’s metabolite were quantified in plasma up to 4 and 3 hours, respectively. They were also detected in urine up to 72 and 24 hours, respectively.
• This suggests that the production and excretion of the metabolite follow relatively predictable timelines after medication administration, providing a valuable reference for anti-doping analysis.

Significance for Antidoping Analysis

• The study’s findings are potentially impactful in the sphere of anti-doping control. The routine capability to detect and quantify both ketoprofen and its benzhydrolic metabolite in horse plasma and urine significantly increases the reliability of anti-doping detection.