Elimination profiles of flurbiprofen and its metabolites in equine urine for doping analysis.

The research article is about the detection and monitoring of flurbiprofen and its metabolites in horse urine to regulate doping in equestrian sports.

Research Objective

The objective of this study was to identify and quantify flurbiprofen (a non-steroidal anti-inflammatory drug), and its associated metabolites in equine urine. The researchers wanted to establish their presence and patterns after administering a single dose of the drug to horses. The study is aimed at aiding in equine doping control routine analysis in equestrian sports.

Methodology

• The research used two female horses of approximately 2.5-3.5 years old.
• A single-dose of 500 mg flurbiprofen was administered to the horses.
• Urine samples were collected and analyzed at various intervals after the drug administration.
• The concentrations of flurbiprofen and its metabolites in urine were determined using Gas Chromatography/Mass Spectrometry (GC/MS).
• The structure of the proposed metabolites was confirmed by high-resolution mass spectrometry (HRMS) for accurate mass measurements.

Findings

• The primary drug, flurbiprofen, and five of its acidic metabolites were found in horse urine following administration.
• The highest concentration of flurbiprofen was 204 µg/ml between 1-3 hours post administration.
• The presence of flurbiprofen could be detected for 24-37 hours in the urine using the standard screening procedure.
• All metabolites were present 25 hours post administration, suggesting that the body had metabolized the drug in this timeframe.
• 4′-hydroxyflurbiprofen was found in urine samples for more than 48 hours and was thus identified as the long-term metabolite of flurbiprofen in horses.

Implication

The results demonstrate that flurbiprofen and its metabolites could be reliably detected and quantified in horse urine for a specific time frame following administration. This knowledge could aid anti-doping authorities in effectively monitoring the use of flurbiprofen, and possibly other similar drugs, in horses participating in competitive sports events. Therefore, this study has implications for the regulation of doping in equestrian sports.