Drug Detection System Tested on Human Samples

In a recent study led by scientists from Uppsala University in Sweden, a new system was developed to detect metabolites of selective androgen receptor modulators (SARMs) in human samples. Their findings were published in the Journal of Chromatography B (1).

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The World Anti-Doping Agency (WADA) was established in 1999 as an international independent agency to lead a collaborative worldwide movement for doping-free sport. Its primary role is to develop and coordinate anti-doping rules and policies across all sports and countries. They accomplish this via scientific and social science research; education; intelligence & investigations; development of anti-doping capacity; and monitoring of compliance with the World Anti-Doping Program. Working with international anti-doping organizations and the committees behind the Olympics and Paralympics, WADA’s mission has helped keep sports fair all over the world (2).

Selective androgen receptor modulators (SARMs) are a pharmacological class of substances that are prohibited in human sports according to WADA. They have anabolic properties and have milder side effects than anabolic androgenic steroids, which is why it is often used for performance enhancement in sports. The metabolite profiles of SARMs are important because drug metabolites are often present in biological samples, such as blood and urine, for longer than the parent compounds. As such, searching for metabolites in doping control can increase the window of detection.

One example of a SARM is ACP-105, which has previously been studied by different in vitro methods and in vivo in both rats and horses. However, its metabolism profile is unknown in humans, which makes it important to investigate. In this study, the scientists hoped to systematically optimize in vitro microsome incubations for improved metabolite yield, all while utilizing a multivariate data analysis (MVDA) approach to aid metabolite discovery. Along with S9 fractions, microsomes were used at optimal conditions, with and without phase II additives. The in vitro derived metabolites were used as analytical targets in doping control by comparison with results from a human post-administration urine sample collected after a single dose of 100 µg ACP-105. Each sample was analyzed with liquid chromatography–Orbitrap mass spectrometry.

In total, 18 in vitro metabolites were tentatively identified, with systematical optimization and MVDA helping simplify the search. The yield of the two main monohydroxylated isomers increased by 24 and 10 times, respectively. In the urine sample, 7 ACP-105 metabolites, which were formed by combining hydroxylations and glucuronic acid conjugations, were tentatively identified. The main metabolites were two monohydroxylated forms suggested as analytical tarfets for human doping control after hydrolysis. Every in vivo metabolite could be detected with the MVDA approach on the in vitro models, showing its effectiveness for predicting in vivo metabolite profiles.

References

(1) Broberg, M. N.; Ohlsson, R. T.; Bondesson, U.; Pettersson, C.; et al. A multivariate data analysis approach for the investigation of in vitro derived metabolites of ACP-105 in comparison with human in vivo metabolites. J. Chromatogr. B. 2023, 1231, 123927. DOI: 10.1016/j.jchromb.2023.123927

(2) Who We Are. World Anti-Doping Agency 2024. https://www.wada-ama.org/en/who-we-are (accessed 2024-4-29)