Introduction and Aims. Selective androgen receptor modulators (SARMs) represent an emerging class of drugs likely abused in sport. For clinical applications, these substances provide an alternative to testosterone replacement therapies whose advantages include oral bioavailability, androgen receptor specificity, tissue selectivity and the lack of steroid-related side effects. Since January 2008 SARMs are enclosed in the prohibited list yearly issued by WADA, so that control laboratories are forced to updated their procedures to detect either the parent drugs or their metabolites. Within this context, we synthesized two 2-quinolinone SARM models and we performed in vitro experiments to elucidate their metabolic transformations. Furthermore, SARMs fragmentation patterns and their physico-chemical properties were studied. Our last goal was to include the new target analytes in the existing routine laboratory protocols used for anti-doping controls. Validation parameters according to ISO 17025 and WADA guidelines were successfully determined. Methods. In vitro metabolism experiments using rats liver microsomes were performed. For analytical determinations, spiked urine samples were hydrolysed and extracted at pH 9.6 with 10 mL of tert-butyl methyl ether. The analytes were subsequently converted into trimethylsilyl derivatives and detected by GC/MS. Results. Preliminary data about metabolism studies indicate that only one SARM model is partially metabolized by hydroxylation. Parent drugs and the new metabolite were included in the SIM detection method for anabolic steroids. The absence of interferents, together with excellent repeatability of both retention times and relative abundances of diagnostic ions, allowed proper identification of all analytes. The method was linear from 0 to 500 ng/mL for the analytes and precision criteria were satisfied (CV% <25 at 10 ng/mL). LODs were calculated at 1 ng/mL concentration, while recovery values were between 95.5 and 99.3%. Conclusions. The method previously used for anabolic steroids was updated and validated for the urine screening of the tested 2-quinolinone-derived SARMs. Further phase II metabolism experiments are in progress.
Validation of a GC/MS method for the detection of two quinolinone-derived selective androgen receptor modulators in doping control analysis
GERACE, ENRICO;A. Salomone;DI STILO, Antonella;VINCENTI, Marco
2010-01-01
Abstract
Introduction and Aims. Selective androgen receptor modulators (SARMs) represent an emerging class of drugs likely abused in sport. For clinical applications, these substances provide an alternative to testosterone replacement therapies whose advantages include oral bioavailability, androgen receptor specificity, tissue selectivity and the lack of steroid-related side effects. Since January 2008 SARMs are enclosed in the prohibited list yearly issued by WADA, so that control laboratories are forced to updated their procedures to detect either the parent drugs or their metabolites. Within this context, we synthesized two 2-quinolinone SARM models and we performed in vitro experiments to elucidate their metabolic transformations. Furthermore, SARMs fragmentation patterns and their physico-chemical properties were studied. Our last goal was to include the new target analytes in the existing routine laboratory protocols used for anti-doping controls. Validation parameters according to ISO 17025 and WADA guidelines were successfully determined. Methods. In vitro metabolism experiments using rats liver microsomes were performed. For analytical determinations, spiked urine samples were hydrolysed and extracted at pH 9.6 with 10 mL of tert-butyl methyl ether. The analytes were subsequently converted into trimethylsilyl derivatives and detected by GC/MS. Results. Preliminary data about metabolism studies indicate that only one SARM model is partially metabolized by hydroxylation. Parent drugs and the new metabolite were included in the SIM detection method for anabolic steroids. The absence of interferents, together with excellent repeatability of both retention times and relative abundances of diagnostic ions, allowed proper identification of all analytes. The method was linear from 0 to 500 ng/mL for the analytes and precision criteria were satisfied (CV% <25 at 10 ng/mL). LODs were calculated at 1 ng/mL concentration, while recovery values were between 95.5 and 99.3%. Conclusions. The method previously used for anabolic steroids was updated and validated for the urine screening of the tested 2-quinolinone-derived SARMs. Further phase II metabolism experiments are in progress.
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
