Characterization of growth hormone secretagogue small molecule ibutamoren (MK-0677) and its possible metabolites in thoroughbred horses for doping control.

RATIONALE: It is important to remember that performance-enhancing agents such as non-peptide growth hormone secretagogues present a significant risk of abuse. Ibutamoren (MK-0677) is a potent, long-acting, selective non-peptide growth hormone secretagogue that can be taken orally. METHODS: This study examines ibutamoren and its metabolites in thoroughbred horses after oral administration. Liquid chromatography/high-resolution mass spectrometry was used to determine the probable structures of the detected metabolites. RESULTS: In this study, 22 metabolites of ibutamoren were identified (17 phase I and 5 phase II). Oxidation of ibutamoren leads to hydroxylated metabolites (mono and di). The study also detected dissociated side chains (benzyl group and 2-amino-2-methylpropanamide) and hydrogenated metabolites. The glucuronic acid conjugated analogs of ibutamoren were detected during phase II of the study, but no sulfonic acid conjugated analogs were observed. The major metabolites can be detected up to 96 hours after a single dose, and ibutamoren can persist for up to 72 hours. CONCLUSIONS: These findings will aid in the detection of ibutamoren and the detection of its illegal use in competitive sports.

Simultaneous analysis of 44 frequently abused corticosteroid drugs using polysaccharide-based chiral column-HRMS approach.

Corticoids have found their way into the globe of sports, due to their anti-inflammatory properties, and have often found to be added to dietary supplements for illegally improving the effectiveness of their products. Earlier studies describe the detection of corticoids in several matrices, but this can be an incessant and continuous process as long because the doping practices continue. In this study, we report a technique to verify concurrently 44 of the foremost commonly abused synthetic corticoids (including chiral analogs) in equine plasma supported chiral liquid chromatography-electrospray ionization mass spectrometry. Polysaccharide i-cellulose-5 column was used for chromatographic separation with a gradient mode. The validation studies were also meted out by using equine plasma so as to judge the suitability of the strategy. Detection limits were determined between 0.01 and 0.05 ng/mL and therefore the limit of quantification was between 0.1 and 0.5 ng/mL. Recovery and matrix effect on the analytes was further assessed. Since the developed method was ready to separate the corticoids and to differentiate chiral analogs at very low levels (in picograms), this separation techniques may be employed for the determination (confirmatory analysis) of the corticoids in the forensic and anti-doping application.