The opinions and assertions expressed herein are those of the authors and do not reflect the official policy or position of the Uniformed Services University or the Department of Defense. The mention of trade names, commercial products, or organizations does not imply endorsement by the Department of Defense, nor the U.S. Government. The authors have no relevant financial interests, activities, relationships, and/or affiliations to disclose. The data that support the findings of this perspective are personal observations or publications available in PubMed.

This study provides data on the prevalence of animal growth promoter residues through a comprehensive US surveillance approach targeting multiple species via retail purchases. Over a year, residue levels were analyzed in beef, pork, and poultry samples from eight US cities, screening for a panel of anabolic steroids, other anabolic agents, selective androgen receptor modulators (SARMs), and non-prohibited controls using sensitive high-resolution tandem mass spectrometry. Thirteen of the 53 beef samples tested positive for ractopamine, with a peak concentration of 14 ng/g in liver-well below CODEX and FDA maximum residue limits (MRLs). Trenbolone-17β and estradiol were also found in beef but remained within MRLs, indicating no health risk. In addition, pork samples showed minimal contamination, with just one pork kidney testing positive for nandrolone (0.08 ng/g) under the limit of detection and estradiol (0.5 ng/g), likely from endogenous hormone production in intact male pigs. Pork muscle and liver samples were residue-free. Chicken samples showed limited residues, with estradiol detected in three out of 35 muscle samples at 0.01 ng/g. These findings highlight the effectiveness of regulatory practices in limiting growth promoter residues in commercial meat, affirming that residue levels in meat products remain within regulatory limits and reinforces consumer safety and confidence.

Pharmacological potential of Hypoxen, previously registered as Olifen is evaluated herein. Hypoxen is categorized as antihypoxic agent. The active substance is polydihydroxyphenylene thiosulfonate sodium. Human studies are limited and no clinical trials following international standards is available. There is however a developed body of knowledge emerging from original studies conducted by the Russian Military Medical Academy in 1980s and 1990s despite limited online access. Hypoxen is promoted to improve oxygen supply or reduce oxygen consumption under hypoxic conditions and physical load. It is thought to support faster recovery, and can be used in complex treatments of diseases accompanied by hypoxia like myocardial ischemia. From clinical perspective, it may enhance cellular respiration by improving coupling in the respiratory chain/accelerating oxidative phosphorylation, but also inhibit succinate dehydrogenase (SDH), and activate mitochondrial ATP-sensitive potassium channels (mitoKATP) in skeletal muscles and myocardium. In 2023, the World Anti-Doping Agency (WADA) added Hypoxen to the Monitoring Program as there had been documented evidence of its use by athletes. On invitro experiments compared the influence of Hypoxen on oxidative phosphorylation with mitochondrial uncoupling agent 2,4-dinitrophenol (DNP) a unique metabolic modulator that strongly accelerates the metabolism rate, prohibited since 2024 by WADA. Most studies focus on exercise performance, and may provide some evidence that Hypoxen has the potential to enhance performance, the first criteria considered for addition of substance to the WADA Prohibited List. Pharmacodynamics and ergogenic effects of Hypoxen suggests potential as metabolic modulator.

2-Hydroxyethyl salicylate (2HES), a nonsteroidal anti-inflammatory drug (NSAID), is a medication to treat musculoskeletal injuries and inflammation swelling of humans and horses. Its misuse could affect the performance of horses and mask injuries, which could pose significant health risks. In horseracing, it is reported as an adverse finding once detected in competition. The metabolism of 2HES in either human or horse has not been reported, and therefore, little is known about its metabolic fate. This paper describes the invivo metabolism of 2HES in horse with an objective to identify the most appropriate target(s) for detecting 2HES administration. To study the elimination and biotransformation of 2HES, topical administrations were performed by giving three castrated horses (geldings) each a total of 100-g Tensolvet gel (equivalent to 5 g of 2HES). The postulated invivo metabolites included glucuronide-conjugated 2HES (2HES-Glu) and sulphate-conjugated 2HES (2HES-SO4) from Phase II conjugation possibly at hydroxyethyl moiety and salicylic acid (SA) from hydrolysis of 2HES. To control the misuse of 2HES in horses effectively, 2HES was found to be the most suitable target. Total 2HES could be detected for up to 10 days in urine, whereas free 2HES could be detected for 16 h in plasma. As the maximum concentration of SA in postadministration urine and plasma sample did not exceed its corresponding international thresholds, monitoring the amount of SA could not be used as an indicator for possible 2HES exposure.

ABSTRACTThe presence of nitrosamines in numerous human medicinal products (HMP) has recently emerged as a cause for concern. Following the initial discovery of carcinogenic low molecular weight nitrosamines such as nitrosodimethylamine (NDMA) in HMP, regulatory authorities worldwide requested marketing authorization holders to perform risk assessments for the presence of nitrosamines in their products. The initially observed contaminations—mainly low molecular weight nitrosamines—were generated by organic solvent impurities or by‐products from synthesis and nitrite carried over to finished products (FP). More recently, complex nitrosamine drug substance‐related impurities (NDSRIs) have been reported arising from direct nitrosation of active pharmaceutical ingredients (APIs) at secondary amine groups in the presence of nitrite derived from excipients. In addition, an alternative route of API nitrosation is conceivable due to interaction with gastric acid and physiological nitrite after drug intake. Within this study, 13 secondary amine bearing APIs were selected to individually identify susceptibilities for nitrosation by using high physiological limit values in terms of pH and nitrite. Therefore, artificial gastric media were fortified with 200 μM sodium nitrite and increasing concentrations of APIs at pH 3.15 and 37°C for 2 h. All NDSRI concentrations were quantitatively determined via validated liquid chromatography–tandem mass spectrometry (LC–MS/MS) methodology. Additionally, time‐dependent nitrosations of selected APIs were monitored to kinetically assess the proportion of NDSRIs after the gastric passage. All results and observations were further processed by means of structure activity relationship (SAR) predictions to identify highly susceptible compounds in the group of concern.

Since 2021, products claiming to contain Δ9-tetrahydrocannabinol (Δ9-THC) analogs have been distributed online and in physical stores, including liquid cartridges for electronic cigarettes, herbal products, and gummy products. This study identified the ingredients in products claiming to contain THC analogs distributed online. Seven oil products and one herbal product were analyzed via gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-photodiode array-mass spectrometry (LC-PDA-MS). After isolating and purifying the unknown components from the products, structural analysis was performed by measuring 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and various two-dimensional NMR (COSY, HMQC, HMBC, and NOESY). The analysis revealed the presence of Δ8-tetrahydrocannabinol acetate (Δ8-THC-O), Δ9-tetrahydrocannabinol acetate (Δ9-THC-O), Δ4(8)-iso-THC-O-acetate, Δ9-tetrahydrocannabihexol acetate (Δ9-THCH-O), Δ9-tetrahydrocannabiphorol acetate (Δ9-THCP-O), Δ8-THC-O-propionate, Δ9-THC-O-propionate, Δ4(8)-iso-THC-O-propionate, Δ9-THCB-O-butanoate, and Δ9-THCP-O-butanoate in these products.

The use of transdermal patches, primarily for pain relief, has grown significantly in recent years. This increase in legitimate use has been accompanied by a rise in their illegal use. Consequently, forensic laboratories are facing a growing number of these complex samples requiring analysis. These systems often involve complex sample matrices, demanding analytical techniques that are both efficient and highly sensitive. This study introduces the application of QuickProbe GC-MS for the rapid identification of fentanyl and buprenorphine in transdermal patches. Utilizing insitu extraction, the method eliminates the need for time-consuming sample preparation, achieving a full analysis cycle time of under 2 min. QP GC-MS successfully detected fentanyl and buprenorphine at concentrations as low as 4.125 and 5 mg, respectively, while adhering to the highest selectivity guidelines. This rapid and streamlined approach has broader implications for forensic investigations, enabling high-throughput screening of seized drug samples and potentially extending to the analysis of emerging drugs of abuse. The speed and efficiency of QP GC-MS make it a valuable tool for law enforcement, public health agencies, and toxicology labs facing the challenge of keeping pace with evolving drug trends.

An increasing number of novel Fc-fusion proteins and monoclonal antibodies (mAbs) are being developed as therapeutic agents for treating various diseases. Among these, there are inhibitors of the activin Type II receptor (ActRIIA and ActRIIB) signaling pathways and mAbs against nerve growth factor (NGF), which may be misused for performance enhancement in horseracing and equestrian sports. This study is aimed at developing a generic detection method for doping control analysis of nine targeted proteins, each containing the Fc domain of human IgG or IgG from other species in equine plasma, namely, three recombinant Fc-fusion proteins (sotatercept, follistatin-Fc (FST-Fc), and erythropoietin-Fc (EPO-Fc)) and six mAbs (bimagrumab, domagrozumab, garetosmab, landogrozumab, bedinvetmab (Librela), and frunevetmab (Solensia)). A generic workflow has been developed, involving affinity purification with commercially available Protein A magnetic beads followed by tryptic digestion and detection of 20 targeted peptides (with 2-3 diagnostic peptides for each targeted protein) using capillary flow high-performance liquid chromatography-high-resolution tandem mass spectrometry (HPLC-HRMS). The method identified all nine targeted proteins in spiked equine plasma with adequate sensitivity and precision, and for the first time, bedinvetmab (Librela) was detected and identified in plasma for at least 34 days after a single subcutaneous administration (0.5 mg/kg) to a Thoroughbred horse. The results have demonstrated the method's applicability to equine doping control. This generic method involving affinity purification by Protein A has provided a pragmatic and effective approach to cope with the doping control of novel Fc domain-containing proteins.