Mass spectrometric characterization of urinary hydrafinil metabolites for routine doping control purposes

Abstract

Little information on the human metabolism and urinary elimination of hydrafinil (9-fluorenol) exists. In order to support preventive anti-doping activities concerning compounds such as hydrafinil, a pilot elimination study was conducted with three healthy male volunteers receiving a single oral dose of 50 mg of hydrafinil. Urine samples were collected prior to and up to 72-h post-administration and were subjected to both gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry, which allowed for the identification of the intact drug as well as Phase I and Phase II metabolites, primarily hydroxylated and/or glucuronidated or sulfoconjugated hydrafinil. The identity of these metabolites was corroborated by highresolution/high-accuracy tandem mass spectrometry, and the applicability of routine doping control workflows for the detection of hydrafinil and its main metabolites was assessed. Therefore, two findings of hydrafinil and its metabolites were recorded, which concerned out-of-competition doping control samples and, hence, were not pursued with confirmatory analyses. Yet, the initial testing procedure results indicate that hydrafinil might require consideration in sports drug testing programs to ensure its detection, if classified as prohibited by the World Anti-Doping Agency (WADA).

Unauthorized ingredients in “nootropic” dietary supplements: A review of the history, pharmacology, prevalence, international regulations, and potential as doping agents

“…A number of experimental peptides designed for cognitive enhancement including Pinealon, Selank, Semax, peptide P21 (also marked as P‐21, P021, or CDKN1A), delta sleep‐inducing peptide (DSIP), and peptide PE‐22‐28 were noted. Other examples of new nootropic substances are Ampalex (CX‐516) and IDRA‐21 (benzothiadiazine derivative) along with ampakines with positive allosteric modulator activity against the α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) receptor 176–178 . These substances deserve more scrutiny and analysis in the future, as they are now freely available in the marketplace for consumers or athletes to use.…”

Annual banned‐substance review: Analytical approaches in human sports drug testing 2020/2021

“…Hydrafinil is structurally related to modafinil and has been identified as an (overtly presented) ingredient of a variety of dietary supplements, but little information about its metabolism in humans and the detection of hydrafinil use by urine analysis exists. Therefore, Knoop et al 101 conducted an exploratory elimination study with three volunteers who orally administered a dietary supplement containing 50 mg of hydrafinil, and urine was sampled before and up to 72 h post‐administration. In consideration of the limited compatibility of ESI with the physico‐chemical properties of hydrafinil itself, GC‐ and LC‐MS(/MS)‐based approaches and were assessed concerning routine doping control ITP and CP options.…”

Further exploration of the collision‐induced dissociation of select beta blockers: Acebutolol, atenolol, bisoprolol, carteolol, and labetalol

“…They also appear on the Prohibited Substances list published by the World Anti‐Doping Agency (WADA), where the entire class is prohibited at all times for some sports (e.g., archery and shooting) and prohibited only in competition for certain other sports (e.g., skiing and golf) 4 . Detection and characterization of drug molecules and their metabolites are important in several areas, including antidoping science, 5–8 environmental contamination monitoring, 9–11 toxicology, 12–15 epidemiological monitoring of population‐scale drug use through wastewater, 16–18 and therapy compliance 19 . Mass spectrometry, especially tandem mass spectrometry, is often a technique of choice for characterization and quantitation of (pharmaceutical and illicit) drugs and their metabolites.…”