Simultaneous quantification of nineteen Non-Steroidal Anti-Inflammatory Drugs in oral fluid by liquid chromatography - high resolution mass spectrometry. Application on ultratrail runner's oral fluid

Comparative study between direct analysis in whole blood, oral fluid, and declaration of consumption for the prevalence of nonsteroidal anti-inflammatory drugs and acetaminophen in ultratrail runners

Ultratrail running is a sport with growing number of adherents. To complete ultratrail despite physical issues such as joint and muscle pain, many runners use nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen. Studies asking participants about their consumption of drugs during ultratrail revealed a prevalence of NSAIDs and acetaminophen up to 70% and 25%, respectively. The aims of the present study were to determine the prevalence of NSAIDs and acetaminophen for 81 runners during the 2021 Ultratrail du Mont Blanc® (UTMB®) using direct analysis of dried blood spots (DBS) and oral fluid (OF) and to compare results with the declaration of consumption by runners; this is to identify the most relevant method to study the prevalence of drugs. Our results show a prevalence of NSAIDs of 46.6% using DBS, 18.5% using OF, and 13.8% based on a questionnaire. Prevalence of acetaminophen were 30.1%, 30.9%, and 22.5% using DBS, OF, and questionnaire, respectively. From this study, we conclude that the analysis of drugs directly in DBS is the most relevant tool to determine the prevalence in ultratrail events.

Determination of IQZ23 in rat plasma using LC-MS/MS: consideration for matrix effect and internal standard interference

Aim: IQZ23, a novel β-indoloquinazoline derivative, is a potential therapeutic agent for obesity and related metabolic disorders. To assist pharmacokinetics evaluation, a quantitative method for IQZ23 in rat plasma is required. Methods & Results: An LC-MS/MS assay for the determination of IQZ23 in rat plasma was developed and validated for the first time. Chromatographic conditions were optimized to ameliorate matrix effect with direct monitoring of typical phospholipids, including phosphatidylcholine and lysophosphatidylcholine. The structural analog internal standard (SYSU-3d) was set at a proper concentration to avoid analyte sensitivity loss caused by internal standard interference. The well-validated method was employed in the pharmacokinetics study of IQZ23 in Sprague-Dawley rats. Conclusion: This study provided valuable references for the further preclinical study of IQZ23.