Detection of sildenafil and its 9 metabolites in a post-race horse urine sample: A case report.

This study deals with the detection of sildenafil and several of its metabolites in a post-race horse urine sample, serving as a novel piece of data on horse doping that could inform future anti-doping analyses.

Objective and Context

• The research aimed to identify prohibited substances in horse racing, a serious issue as it compromises both the integrity of the sport and the health of the horses. Misuse of both licensed and unlicensed drugs contribute to this problem.
• The researchers were part of the Pendik Veterinary Control Institute Doping Control Laboratory, operating under the guidelines established by the International Federation of Horse Racing Authority. An important part of their role is to monitor the usage of such substances in racehorses.

Research Method

• The study began with a post-race horse urine sample that was subjected to screening analysis via Liquid Chromatography Triple Quadrupole Mass Spectrometry (LC-QQQ-MS), a powerful technique used for the separation, identification, and quantification of various components in a mixture.
• The LC-QQQ-MS detected the presence of sildenafil, a drug typically used to treat erectile dysfunction in humans, and its major metabolite n-desmethyl sildenafil.
• The identification of these substances was then further verified using Q Exactive Orbitrap Mass Spectrometry, another high-resolution analytical technique.

Findings

• Additional analysis of the sample led to a noteworthy find – nine metabolites of sildenafil were detected in horse urine, two of which had never been documented before.
• This discovery constituted a valuable piece of preliminary data for future investigations of doping practices in horse racing, and should also prove useful in the development of more efficient anti-doping analyses.

Impact and Conclusion

• The findings from this study represent significant progress in the understanding of doping in horse racing. The identification and confirmation of two previously undetected metabolites, in particular, enhance the integrity of the process.
• The data collected sets a promising foundation for subsequent research and improvements in the analysis of potential doping cases. The insights brought forth could lead to more robust anti-doping frameworks and consequently, cleaner, fairer competitions in the world of horse racing.