Routine application of SFC-MS in doping control: Analysis of 3 × 1000 urine samples using three different SFC-MS instruments.

Supercritical fluid chromatography-mass spectrometry (SFC-MS) has proved to be a beneficial tool for sample analysis for a wide variety of compounds and, as such, has recently gained the attention of the anti-doping community. We have tested the applicability of SFC-MS for routine doping control analysing approximately 3 × 1000 identical anti-doping samples utilising SFC-MS instruments from three different vendors: Agilent Technologies, Waters Corporation and Shimadzu Corporation. A 'dilute and inject' approach either without or after hydrolysis of glucuronide metabolites was applied. Most of the compounds included in our study demonstrated excellent chromatography, whereas some showed co-elution with endogenous interferences requiring MS discrimination. Retention times typically were very stable within batches (%CV ≤ 0.5%), although this appeared to be analyte and column dependent. Chromatographic peak shape was good (symmetrical) and stable over the period of the testing without any change of column. Our results suggest that SFC-MS is a sensitive, reproducible and robust analytical tool ready to be used in anti-doping laboratories alongside the currently applied techniques such as gas and liquid chromatography coupled to mass spectrometry. Even if instruments are designed slightly differently, all three setups demonstrated their fitness for the purpose in anti-doping testing.

Analysis of doping control samples using supercritical fluid chromatography-tandem mass spectrometry: Ready for routine use.

Supercritical fluid chromatography is proving to be a good separation and sample preparation tool for various analytical applications and, as such, has gained the attention of the anti-doping community. Here, the applicability of supercritical fluid chromatography hyphenated to tandem mass spectrometry for routine doping control analysis was tested. A multi-analyte method was developed to cover 197 drugs and metabolites that are prohibited in sport. More than 1000 samples were analyzed by applying a "dilute and inject" approach after hydrolysis of glucuronide metabolites. Additionally, a comparison with routinely used liquid chromatography-mass spectrometry was performed with 250 of the 1000 samples and a number of past positive anti-doping samples. It revealed some features where supercritical fluid chromatography-tandem mass spectrometry was found to be complementary or advantageous to liquid chromatography-mass spectrometry for anti-doping purposes, such as better retention of analytes that are poorly retained in reversed-phase liquid chromatography. Our results suggest that supercritical fluid chromatography-tandem mass spectrometry is sensitive (limit of detection <50% relevant minimum required performance level required by the World Anti-Doping Agency for anti-doping analysis), reproducible, robust, precise (analytes of interest area coefficient of variation <5%; retention time difference coefficient of variation <1%) and complementary to existing techniques currently used for routine analysis in the World Anti-Doping Agency accredited laboratories.

Stability of drugs of abuse in synthetic oral fluid investigated using a simple "dilute and inject" method of analysis.

Human oral fluid is well established as a matrix for drug screening, particularly in the workplace. The need to synthesise synthetic oral fluid (SOF) has been recognised in order to overcome human oral fluid's composition variability. We have used SOF spiked with six common drugs of abuse or their primary metabolites: morphine, amfetamine, benzoylecgonine, cocaine, diazepam, and (-)-Δ9 -tetrahydrocannabinol (THC) in order to assess the suitability of this matrix for quality assurance purposes. For confirmation of a drug screening test, controls and spiked standards are normally required. All our analytes were detected by LC-MS/MS using a quick and easy "dilute and inject" sample preparation approach as opposed to relatively slower solid-phase extraction. The limit of detection (LOD) was 10 ng/ml for diazepam and THC and 5 ng/ml for morphine, amfetamine, benzoylecgonine and cocaine. Validation results showed good accuracy as well as inter- and intra-assay precision (CV [%] < 5). Our work highlighted the importance of adding Tween® 20 to the SOF and calibrants to reduce losses when handling THC. Furthermore, drug stability was tested at various temperatures (5°C, 20°C and 40°C), for a number of days or after freeze-thaw cycles. Recommendations regarding storage are provided, the spiked SOF being stable at 5°C for up to 1 week without significant drug concentration loss.

In Vitro Metabolic Study of Four Synthetic Cathinones: 4-MPD, 2-NMC, 4F-PHP and bk-EPDP.

The use of illicit drugs is exceedingly prevalent in society, and several of them can be illegally purchased from the internet. This occurrence is particularly augmented by the rapid emergence of novel psychoactive substances (NPS), which are sold and distributed as "legal highs". Amongst NPS, the class of synthetic cathinones represents stimulant substances exhibiting similar effects to amphetamine and its derivatives. Despite potentially being less psychoactive than amphetamine, synthetic cathinones are harmful substances for humans, and little or no information is available regarding their pharmacology and toxicology. The present study investigated the in vitro metabolism and metabolites of four recent synthetic cathinones, namely, 1-(4-methylphenyl)-2-(methylamino)-pentanone (4-MPD), 1-(4-methylphenyl)-2-dimethylamino-propanone (2-NMC), 1-(4-fluorophenyl)-2-(pyrrolidin-1-yl-hexanone (4F-PHP) and 1-(1,3-benzodioxol-5-yl)-2-(ethylamino)-1-pentanone (bk-EPDP). Our in vitro metabolism study resulted in 24 identified metabolites, including both phase I and phase II metabolites. All metabolites were detected and identified using liquid chromatography-high-resolution mass spectrometry and may serve as additional markers of abuse of these NPS in toxicological analyses.

Advances in the detection of growth hormone releasing hormone synthetic analogs.

The administration of growth hormone releasing hormone (GHRH) and its synthetic analogs is prohibited by the World Anti-Doping Agency (WADA). Although there is evidence of their use, based on admissions and intelligence, they do not appear to have been found in anti-doping samples by WADA accredited laboratories. This might be due to their small concentration in urine and limited knowledge about their metabolism, especially for unapproved synthetic analogs. This study investigates the in vitro metabolism and detection of four of the larger GHRH synthetic analogs (sermorelin, tesamorelin, CJC-1295, and CJC-1295 with drug affinity complex) in fortified urine. Nineteen major in vitro metabolites were identified, selected for synthesis, purified, and characterized in house. These were used as reference materials to spike into urine together with commercially available parent peptides and a metabolite of sermorelin (sermorelin(3-29)-NH2 ) to develop a sensitive liquid chromatography-tandem mass spectrometry method for their detection to help prove GHRH administration. Limits of detection of the target peptides were generally 1 ng/ml (WADA required performance limit) or less.

Towards identifying nicomorphine administration in doping control: synthesis of metabolites.

Aim: Nicomorphine is rapidly metabolized mainly to the biologically active 6-nicotinoyl morphine and morphine. In sport, morphine and nicomorphine use is prohibited whereas codeine use is permitted. Accredited laboratories routinely test for morphine hence must be able to distinguish morphine, as a metabolite of a prohibited substance, from that whose use is permitted. Results: Here we show a relatively simple method to synthesize the nicomorphine metabolites, 3-nicotinoyl and 6-nicotinoyl morphine, and indicate how they may be used to identify nicomorphine administration. Conclusion: This approach should help confirm that it is not codeine, an allowable analgesic in sport, that has been administered.

Artificial oral fluid characterisation: Potential for use as a reference matrix in drug testing.

Quality assurance schemes for drug-screening programmes require access to large quantities of biological matrices for reference or control samples. This presents problems when the availability of a matrix, such as oral fluid (OF) for screening or for confirmatory purposes, limits the collection of large volumes. In such cases, synthetic alternatives of OF may provide a solution. The preparation of an artificial (synthetic) oral fluid (AOF) was conducted by dissolving its components (salts, surfactant, antimicrobial agent and mucin) in water. We characterised the physical properties of AOF to determine its suitability as a matrix for quality assurance purposes. The evaluation of pH, specific gravity (SG), conductivity (mS cm-1 ), freezing point depression (°C), light-scattering and kinematic viscosity (mm2 s-1 ) showed AOF to be a stable, reliable matrix. Synthetic OF was prepared using components (mucin, surfactants and so on) obtained from different suppliers and a comparison was performed. Our results suggest that AOF is a feasible matrix for the preparation of quality assurance samples for confirmatory or drug screening programmes.

In Vitro Phase I Metabolic Profiling of the Synthetic Cannabinoids AM-694, 5F-NNEI, FUB-APINACA, MFUBINAC, and AMB-FUBINACA.

Synthetic cannabinoids (SCs) constitute one of the most rapidly expanding class of new psychoactive substances. SCs pose a health threat to the individual and to the public due to their central (psychoactive) and peripheral effects. Their pharmacology and toxicology are poorly understood, and the substances can be unexpectedly toxic and harmful. The metabolism of SCs is also relevant in clinical and forensic toxicology as SCs are excreted in urine mostly as their metabolites. Thus, SC metabolites are widely used as markers for identifying SC intake. Herein, we used human liver microsome systems to study the in vitro phase I metabolic profiling of five SCs, namely AM-694, 5F-NNEI, FUB-APINACA, MFUBINAC, and AMB-FUBINACA. The metabolites were detected and structurally elucidated by liquid chromatography-high resolution mass spectrometry. The main metabolic pathway of AM-694 (benzoyl-indole SC) is oxidative defluorination; 5F-NNEI (naphthyl-indole carboxamide SC) follows amide hydrolysis and monohydroxylation at the naphthyl moiety. However, indazole carboxamide substituted with an adamantyl group, such as FUB-APINACA, is likely to produce (isomeric) hydroxylation of the adamantyl group as the main metabolite species. For the substrates that contain ester bonds in their structure, like MFUBINAC and AMB-FUBINACA, the ester hydrolysis metabolite is predominant.

A molecularly imprinted receptor for separation of testosterone and epitestosterone, based on a steroidal cross-linker.

A series of molecularly imprinted polymers have been prepared and investigated as stationary phases in high performance liquid chromatography for the separation of testosterone and epitestosterone using non-polar mobile phases. The polymers were imprinted using 5α-dihydrotestosterone as template, and all retain testosterone more strongly than its 17α-OH epimer. The best polymer was prepared using trifluoromethylacrylic acid as functional monomer (interacting with the template via hydrogen bonds), divinylbenzene as 'inert' cross-linker, and chloroform as porogen. It also included a steroid-based cross-linker, which may interact with the template via van der Waals interactions to lend additional 'shape selectivity'. A 250×4.6mm column packed with this polymer gave baseline resolution of testosterone and epitestosterone (15 µg each) in under 20 min. Preparation of the steroid based cross-linker included the selective reduction of 5α-dihydrotestosterone (17ß-hydroxy-5α-androstan-3-one) to the 3α,17ß-diol using K-selectride.

PWZ-029, a compound with moderate inverse agonist functional selectivity at GABA(A) receptors containing alpha5 subunits, improves passive, but not active, avoidance learning in rats.

Benzodiazepine (BZ) site ligands affect vigilance, anxiety, memory processes, muscle tone and epileptogenic propensity through modulation of neurotransmission at GABA(A) receptors containing alpha1, alpha2, alpha3 or alpha5 subunits, and may have numerous experimental and clinical applications. The ability of non-selective BZ site inverse agonists to enhance cognition, documented in animal models and human studies, is clinically not feasible due to potentially unacceptable psychomotor effects. Most investigations to date have proposed the alpha1 and/or alpha5 subunit-containing GABA(A) receptors as comprising the memory-modulating population of these receptors. The novel ligand PWZ-029, which we synthesized and characterized electrophysiologically, possesses in vitro binding selectivity and moderate inverse agonist functional selectivity at alpha5-containing GABA(A) receptors. This ligand has also been examined in rats in the passive and active avoidance, spontaneous locomotor activity, elevated plus maze and grip strength tests, primarily predictive of the effects on the memory acquisition, basal locomotor activity, anxiety level and muscle tone, respectively. The improvement of task learning was detected at the dose of 5 mg/kg in the passive, but not active avoidance test. The inverse agonist PWZ-029 had no effect on anxiety or muscle tone, whereas at higher doses (10 and 20 mg/kg) it decreased locomotor activity. This effect was antagonized by flumazenil and also by the lower (but not the higher) dose of an agonist (SH-053-R-CH3-2'F) selective for GABA(A) receptors containing the alpha5 subunit. The hypolocomotor effect of PWZ-029 was not antagonized by the antagonist ss-CCt exhibiting a preferential affinity for alpha1-subunit-containing receptors. These data suggest that moderate negative modulation at GABA(A) receptors containing the alpha5 subunit is a sufficient condition for eliciting enhanced encoding/consolidation of declarative memory, while the influence of higher doses of modulators at these receptors on motor activity shows an intricate pattern whose relevance and mechanism await to be defined.

Optimization of ultrasound and microbubbles targeted gene delivery to cultured primary endothelial cells.

Ultrasound and microbubbles targeted gene delivery (UMTGD) is a promising technique for local gene delivery. As the endothelium is a primary target for systemic UMTGD, this study aimed at establishing the optimal parameters of UMTGD to primary endothelial cells. For this, an in vitro ultrasound (US) setup was employed in which individual UMTGD parameters were systematically optimized. The criteria for the final optimized protocol were: (1) relative high reporter gene expression levels, restricted to the US exposed area and (2) induction of not more than 5% cell death. US frequency and timing of medium replacement had a strong effect on UMTGD efficiency. Furthermore, US intensity, DNA concentration and total duration of US all affected UMTGD efficiency. Optimal targeted gene delivery to primary endothelial cells can be accomplished with Sonovue microbubbles, using 20 microg/ml plasmid DNA, a 1 MHz US exposure of Ispta 0.10 W/cm(2) for 30 s with immediate medium change after UMTGD. This optimized protocol resulted in both an increase in the number of transfected cells (more than three fold) and increased levels of transgene expression per cell (170%).