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

Determination of chlorphenesin in cosmetics, a preservative that can affect anti-doping test result interpretations

Chlorphenesin is a legitimate preservative commonly used in cosmetics. It shares one urinary metabolite of 4-chlorophenoxyacetic acid with meclofenoxate, a prohibited stimulant in sports. Recently, there have been cases where athletes using chlorphenesin-containing products were falsely identified as users of meclofenoxate. This study developed and validated a liquid chromatography method with diode-array detection to determine the chlorphenesin content in 61 selected personal care products with various functions (e.g., facial care, body cleansing, sun protection, make-up, hairstyling, perfume, and oral cleaning). The analytical method demonstrated fit-for-purpose quantitation and provided good linearity, precision, accuracy, and recovery for analyzing different cosmetic matrices. Among the 27 cosmetics labeled with chlorphenesin, the chlorphenesin concentrations ranged from 0.10 to 2.67 mg/g, with three products showing no detection. None of the products exceeded the maximum limit of 3 mg/g (0.3%) set by regulatory authorities. Among the 34 cosmetics not labeled with chlorphenesin, none of them contained chlorphenesin. This study confirmed the absence of undeclared chlorphenesin in the selected cosmetics, supporting the correctness of chlorphenesin labeling in cosmetics sold in Taiwan. Further investigations studying urinary excretion patterns after different types, doses, frequencies, and sites of cosmetics applications could contribute to strengthen current testing approaches in anti-doping.

Phenibutan-an Illegal Food Supplement With Psychotropic Effects and Health Risks

BACKGROUND

Phenibut (β-phenyl-γ-aminobutyric acid) is an analog of the neurotransmitter gamma-aminobutyric acid (GABA). Like abapentin and pregabalin, it inhibits α2-δ-subunits of voltagedependent presynaptic calcium channels. The potential harm resulting from the use of these gabapentinoids is currently a matter of debate.

METHODS

This review is based on pertinent publications retrieved by a selective literature search and on cases reported to the Giftinformationszentrum-Nord (GIZ-Nord), a poison information center at the University of Göttingen, Germany.

RESULTS

Phenibut is a prescription drug in Russia but its production, possession, use, trafficking, or administration is illegal in Germany. The phenibut toxicity syndrome resembles that of gabapentinoids and GABA mimetics: benzodiazepine-like with - drawal symptoms including epileptic seizures, delirium and paradoxical activation have been described, as have cases of abuse and dependence. A few cases of use in the setting of multidrug abuse, and of phenibut-related death, have been described to date in the USA. The GIZ-Nord received 17 inquiries about phenibut, 55 about gabapentin, and 126 about pregabalin over the period 2008-2022. Over the same period, the GIZ-Nord was informed of 1207 cases involving Z substances and 4324 involving benzodiazepines. In the majority of the registered intoxications, including those with phenibut, the symptoms were mild. Overdoses of phenibut (2-100 g) were reported in 15 of the 17 cases; 8 of the persons who had taken an overdose were somnolent. In such cases, observation in intensive care was recommended. Respiratory depression or coma was not encountered in any case, not even in the patient who had taken 100 g of phenibut.

CONCLUSION

Phenibut causes symptoms resembling those of gabapentinoid and benzodiazepine use. There have been reports of phenibut use in combination with other psychotropic drugs; in particular, its use together with opiates could increase the risk of coma and respiratory depression. No deaths due to phenibut intoxication have been published in Germany or elsewhere in Western Europe, although such cases may have been overlooked, as this drug is still largely unknown to Western medicine.

Mexidol, Cytoflavin, and succinic acid derivatives as antihypoxic, anti-ischemic metabolic modulators, and ergogenic aids in athletes and consideration of their potential as performance enhancing drugs

Emoxypine (ethylmethylhydroxypyridine) is a synthetic derivative of vitamin B6 . Emoxypine succinate is a registered drug in Russia and Ukraine under various trade names including Mexidol, Mexicor, and Armadin Long. Mexidol demonstrates antihypoxic and anti-ischemic effects and also modulates metabolism. The use of Mexidol by Russian athletes has been confirmed in the past. Current use by athletes is unknown as this drug is not monitored or included in drug testing protocol. Metabotropic and antihypoxic effects of Mexidol were compared to the effects of meldonium or trimetazidine, both of which are included on the World Anti-Doping Agency (WADA) Prohibited List in category S4.4. Metabolic Modulators. The conjugation of emoxypine with succinate elevates the therapeutic effectiveness of the Mexidol formulation as succinic acid itself has important impacts to consider despite being a common food additive and drug excipient. Other succinic acid salts like ammonium succinate, found as dietary supplement, have been patented as performance enhancers. Available research on healthy subjects suggests that combinations of selected 3-substituted pyridine derivatives with succinate including Mexidol and a related drug Cytoflavin can enhance the performance of athletes. Cytoflavin is a multi-component formula containing meglumine sodium succinate, nicotinamide (vitamin B3 ), inosine (riboxin), and riboflavin. Other related succinate-based drugs include Remaxol, Reamberin, and Cogitum. Mexidol and Cytoflavin and related substances exhibit similar biological effects as drugs on the WADA Prohibited List, and if they are used for performance enhancement by athletes, they could be worthy of consideration as prohibited substances in sport.

Recent advances in mass spectrometry for the detection of doping

INTRODUCTION

The analysis of doping control samples is preferably performed by mass spectrometry, because obtained results meet the highest analytical standards and ensure an impressive degree of reliability. The advancement in mass spectrometry and all its associated technologies thus allow for continuous improvements in doping control analysis.

AREAS COVERED

Modern mass spectrometric systems have reached a status of increased sensitivity, robustness, and specificity within the last decade. The improved sensitivity in particular has, on the other hand, also led to the detection of drug residues that were attributable to scenarios where the prohibited substances were not administered consciously but rather by the unconscious ingestion of or exposure to contaminated products. These scenarios and their doubtless clarification represent a great challenge. Here, too, modern MS systems and their applications can provide good insights in the interpretation of dose-related metabolism of prohibited substances. In addition to the development of new instruments itself, software-assisted analysis of the sometimes highly complex data is playing an increasingly important role and facilitating the work of doping control laboratories.

EXPERT OPINION

The sensitive analysis and evaluation of a higher number of samples in a shorter time is made possible by the ongoing developments in mass spectrometry.

Annual banned-substance review 16th edition-Analytical approaches in human sports drug testing 2022/2023

In this 16th edition of the annual banned-substance review on analytical approaches in human sports drug testing, literature on recent developments in this particular section of global anti-doping efforts that was published between October 2022 and September 2023 is summarized and discussed. Most recent additions to the continuously growing portfolio of doping control analytical approaches and investigations into analytical challenges in the context of adverse analytical findings are presented, taking into account existing as well as emerging challenges in anti-doping, with specific focus on substances and methods of doping recognized in the World Anti-Doping Agency's 2023 Prohibited List. As in previous years, focus is put particularly on new or enhanced analytical options in human doping controls, appreciating the exigence and core mission of anti-doping and, equally, the conflict arising from the opposingly trending extent of the athlete's exposome and the sensitivity of instruments nowadays commonly available in anti-doping laboratories.