Quantification of cocaine and metabolites in exhaled breath by liquid chromatography-high-resolution mass spectrometry following controlled administration of intravenous cocaine

Development and method validation of a sampling technique for a reproducible detection of synthetic cannabinoids in exhaled breath using an in vitro pig lung model

Alternative matrices, especially exhaled breath (EB), have gained increasing attention for a few years. To interpret toxicological findings, knowledge on the toxicokinetic (TK) properties of a substance in EB is indispensable. While such data are already accessible for various drugs (e.g. Δ9-tetrahydrocannabinol), they are still not available for new psychoactive substances, particularly synthetic cannabinoids (SCs). As SCs raise a high public health concern, the aim of this study was to assess these data in future TK studies in pigs. For this purpose, an in vitro sampling technique of EB was initially developed, which is prospectively applied to anesthetized and ventilated pigs for the detection of SCs in a controlled and reproducible manner as exemplified by cumyl-5F-P7AICA. Furthermore, a method for the qualitative and quantitative detection of cumyl-5F-P7AICA in EB using glass fiber filters (GFFs) was established and fully validated. Therefore, cumyl-5F-P7AICA (0.5 mg/mL in ethanol absolute) was initially nebulized using a ventilation machine and a breathing tube, as they are also used in surgeries. The aerosol was delivered into a simulated pig lung. To collect EB, a pump was connected to that part of the breathing tube, which contains EB (expiratory limb), and sampling was performed repeatedly (n = 6) for 15 min (2 l EB/min) each using GFF. For extraction of the substance, the GFFs were macerated with acetone and the remaining experimental components were rinsed with ethanol. After sample preparation, the extracts were analyzed by liquid chromatography tandem mass spectrometry. In the complete experimental setup, about 40% of the initially nebulized cumyl-5F-P7AICA dose was found, with 3.6 ± 1.3% being detected in the GFF. Regarding the comparably high loss of substance, the open ventilation system and a conceivable adsorption of the SC in the ventilator have to be considered. However, the herein introduced approach is promising to determine the TK properties of cumyl-5F-P7AICA in EB.

Validation and application of an automated multitarget LC-MS/MS method for drugs of abuse testing using exhaled breath as specimen

Aerosol microparticles in exhaled breath carry non-volatile compounds from the deeper parts of the lung. When captured and analyzed, these aerosol microparticles constitute a non-invasive and readily available specimen for drugs of abuse testing. The present study aimed to evaluate a simple breath collection device in a clinical setting. The device divides a breath sample into three parallel "collectors" that can be individually analyzed. Urine was used as the reference specimen, and parallel specimens were collected from 99 patients undergoing methadone maintenance treatment. Methadone was used as the primary validation parameter. A sensitive multi-analyte method using tandem liquid chromatography - mass spectrometry was developed and validated as part of the project. The method was successfully validated for 36 analytes with a limit of detection of 1 pg/collector for most compounds. Based on the validation results tetrahydrocannabinol THC), cannabidiol (CBD), and lysergic acid diethylamide (LSD) are suitable for qualitative analysis, but all other analytes can be quantitively assessed by the method. Methadone was positive in urine in 97 cases and detected in exhaled breath in 98 cases. Median methadone concentration was 64 pg/collector. The methadone metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) was detected in 90 % of the cases but below 10 pg/collector in most. Amphetamine was also present in the urine in 17 cases and in exhaled breath in 16 cases. Several other substances were detected in the exhaled breath and urine samples, but at a lower frequency. This study concluded that the device provides a specimen from exhaled breath, that is useful for drugs of abuse testing. The results show that high analytical sensitivity is needed to achieve good detectability and detection time after intake.

Probing for factors influencing exhaled breath drug testing in sports- Pilot studies focusing on the tested individual's tobacco smoking habit and sex

RATIONALE

Exhaled breath (EB) was found to be a promising matrix in the field of sports drug testing due to the non-invasive and non-intrusive sampling procedure, but significant inter-individual variations regarding detected drug concentrations have been observed in previous studies. To investigate whether the detectability of doping agents in EB is affected by sex or tobacco smoking, two administration studies were conducted with male and female smokers and nonsmokers concerning the elimination of the beta blocker propranolol and the stimulant pseudoephedrine into EB.

METHODS

Following the administration of 40 mg propranolol or 30 mg pseudoephedrine, a total of 19 participants, including female and male nonsmokers as well as female and male smokers, collected EB and dried blood spot (DBS) samples over a period of 24 h. Respective analyte concentrations were determined using liquid chromatography and high-resolution tandem mass spectrometry, and semi-quantitative assays were characterized with regard to selectivity, limit of detection and identification, precision, linearity, and carryover.

RESULTS

Both propranolol and pseudoephedrine were identified in post-administration EB samples from female and male nonsmokers as well as female and male smokers, and the maximum detected drug levels ranged from 9 to 2847 pg/cartridge for propranolol and from 26 to 4805 pg/cartridge for pseudoephedrine. The corresponding DBS levels were in a range of 4-30 ng/mL for propranolol and 55-186 ng/mL for pseudoephedrine.

CONCLUSIONS

Neither the consumption of cigarettes nor the sex appears to represent a decisive criterion as to the detectability of propranolol or pseudoephedrine in EB, but inter-individual variations regarding the detected drug levels were observed among all studied population groups.

Probing for the presence of doping agents in exhaled breath using chromatographic/mass spectrometric approaches

RATIONALE

Exhaled breath (EB) has been demonstrated to be a promising alternative matrix in sports drug testing due to its non-invasive and non-intrusive nature compared with urine and blood collection protocols. In this study, a pilot-test system was employed to create drug-containing aerosols simulating EB in support of the analytical characterization of EB sampling procedures, and the used analytical method was extended to include a broad spectrum of prohibited substances.

METHODS

Artificial and authentic EB samples were collected using sampling devices containing an electret filter, and doping agents were detected by means of liquid chromatography and tandem mass spectrometry with unispray ionization. The analytical approach was characterized with regard to specificity, limits of detection, carry-over, recovery and matrix effects, and the potential applicability to routine doping controls was shown using authentic EB samples collected after single oral dose applications of glucocorticoids and stimulants.

RESULTS

The analytical method was found to be specific for a total of 49 model substances relevant in sports drug testing, with detection limits ranging from 1 to 500 pg per cartridge. Both ion suppression (-62%) and ion enhancement (+301%) effects were observed, and all model compounds applied to EB sampling devices were still detected after 28 days of storage at room temperature. Authentic EB samples collected after the oral administration of 10 mg of prednisolone resulted in prednisolone findings in specimens obtained from 3 out of 6 participants up to 2 h. In octodrine, dimethylamylamine (DMAA) and isopropylnorsynephrine post-administration EB samples, the drugs were detected over a period of 50, 48, and 8 h, respectively.

CONCLUSIONS

With the analytical approach developed within this study, the identification of a broad spectrum of prohibited doping agents in EB samples was accomplished. Application studies and stability tests provided information to characterize EB as a potential matrix in sports drug testing.

First evaluation of the possibility of testing for drugged driving using exhaled breath sampling

Objective: Driving under the influence of psychoactive drugs causes an increased risk for accidents. In combating this, sobriety tests at the roadside are common practice in most countries. Sampling of blood and urine for forensic investigation cannot be done at the roadside and poses practical problems associated with costs and time. An alternative specimen for roadside testing is therefore warranted and the aerosol particles in exhaled breath are one such alternative. Methods: The present study investigated how the exhaled breath sample compared with the routine legal investigations of blood and urine collected from suspects of drugged driving at 2 locations in Sweden. Exhaled breath was collected using a simple filter collection device and analyzed with state-of-the-art mass spectrometry technique. Results: The total number of cases used for this investigation was 67. In 54 of these cases (81%) the results regarding a positive or negative drug test result agreed and in 13 they disagreed. Out of these, the report from the forensic investigation of blood/urine was negative in 21 cases. In 6 of these, analytical findings were made in exhaled breath and these cases were dominated by the detection of amphetamine. In 7 cases a positive drug test from the forensic investigation was not observed in the breath sample and these cases were dominated by detection of tetrahydrocannabinol in blood. In total, 45 samples were positive with breath testing and the number of positives with established forensic methods was 46. Conclusion: The promising results from this study provide support to exhaled breath as a viable specimen for testing of drugged driving. The rapid, easy, and convenient sampling procedure offers the possibility to collect a drug test specimen at the roadside. The analytical investigation must be done in a laboratory at present because of the need for a highly sensitive instrument, which is already in use in forensic laboratories. The analytical work is not more challenging than for blood or oral fluid and should not cause an increase in cost. However, more studies need to be done before exhaled breath drug testing can be applied routinely for drugged driving investigation.

Does oral fluid contribute to exhaled breath samples collected by means of an electret membrane?

To date, blood (and serum) as well as urine samples are the most commonly collected specimens for routine doping controls, which allow for the analytical coverage of an extensive set of target analytes relevant to sports drug testing programs. In the course of studies to identify potential alternative matrices to complement current testing approaches, exhaled breath (EB) has been found to offer advantageous properties especially with regard to the sample collection procedure, which is less invasive, less intrusive, and less time‐consuming when compared to conventional blood and urine testing. A yet unaddressed question has been the potential contribution of oral fluid (OF) to EB samples. The current investigation focused on characterizing an electret membrane‐based EB collection device concerning a potential introduction of OF during the sampling procedure. For that purpose, EB and OF samples collected under varying conditions from a total of 14 healthy volunteers were tested for the presence of abundant salivary proteins using bottom‐up proteomics approaches such as SDS‐PAGE followed by tryptic digestion and chromatographic‐mass spectrometric analysis. The trapping baffles integrated into the mouthpiece of the EB collection device were found to effectively retain OF introduced into the unit during sample collection as no saliva breakthrough was detectable using the established analytical approach targeting predominantly the highly abundant salivary α‐amylase. Since α‐amylase was found unaffected by storage, smoking, food intake, and exercise, it appears to be a useful marker to reveal possible OF contaminations of EB collection devices.

Measuring antibiotics in exhaled air in critically ill, non-ventilated patients: A feasibility and proof of concept study

PURPOSE

Measurement of antibiotic concentrations is increasingly used to optimize antibiotic therapy. Plasma samples are typically used for this, but other matrices such as exhaled air could be an alternative.

MATERIALS AND METHODS

We studied 11 spontaneously breathing intensive care unit patients receiving either piperacillin/tazobactam or meropenem. Patients exhaled in the ExaBreath® device, from which the antibiotic was extracted. The presence of antibiotics was also determined in the condensate found in the device and in the plasma.

RESULTS

Piperacillin or meropenem could be detected in the filter in 9 patients and in the condensate in 10. Seven patients completed the procedure as prescribed. In these patients the median quantity of piperacillin in the filter was 3083 pg/filter (range 988-203,895 pg/filter), and 45 pg (range 6-126 pg) in the condensate; meropenem quantity was 21,168 pg/filter, but the quantity in the condensate was below the lower limit of quantification. There was no correlation between the concentrations in the plasma and quantities detected in the filter or condensate.

CONCLUSIONS

Piperacillin and meropenem can be detected and quantified in exhaled air of non-ventilated intensive care unit patients; these quantities did not correlate with plasma concentrations of these drugs.

Evolution of clinical and environmental health applications of exhaled breath research: Review of methods and instrumentation for gas-phase, condensate, and aerosols

Human breath, along with urine and blood, has long been one of the three major biological media for assessing human health and environmental exposure. In fact, the detection of odor on human breath, as described by Hippocrates in 400 BC, is considered the first analytical health assessment tool. Although less common in comparison to contemporary bio-fluids analyses, breath has become an attractive diagnostic medium as sampling is non-invasive, unlimited in timing and volume, and does not require clinical personnel. Exhaled breath, exhaled breath condensate (EBC), and exhaled breath aerosol (EBA) are different types of breath matrices used to assess human health and disease state. Over the past 20 years, breath research has made many advances in assessing health state, overcoming many of its initial challenges related to sampling and analysis. The wide variety of sampling techniques and collection devices that have been developed for these media are discussed herein. The different types of sensors and mass spectrometry instruments currently available for breath analysis are evaluated as well as emerging breath research topics, such as cytokines, security and airport surveillance, cellular respiration, and canine olfaction.

Acute effects of intravenous cocaine administration on serum concentrations of ghrelin, amylin, glucagon-like peptide-1, insulin, leptin and peptide YY and relationships with cardiorespiratory and subjective responses

BACKGROUND

Food intake and use of drugs of abuse like cocaine share common central and peripheral physiological pathways. Appetitive hormones play a major role in regulating food intake; however, little is known about the effects of acute cocaine administration on the blood concentrations of these hormones in cocaine users.

METHODS

We evaluated serum concentrations of six appetitive hormones: ghrelin (total and acyl-ghrelin), amylin, glucagon-like peptide-1 (GLP-1), insulin, leptin and peptide YY (PYY), as well as acute cardiorespiratory and subjective responses of 8 experienced cocaine users who received 25mg intravenous (IV) cocaine.

RESULTS

Serum concentrations of GLP-1 (p=0.014) and PYY (p=0.036) were significantly decreased one hour following IV cocaine administration; there was a trend towards a decrease for insulin (p=0.055) and amylin (p=0.063) concentrations, while no significant IV cocaine effect was observed for ghrelin (total or acyl-ghrelin) or leptin concentrations (p's≫>0.5). We also observed associations between hormone concentrations acutely affected by IV cocaine (GLP-1, PYY, insulin, amylin) and some cocaine-related cardiorespiratory and subjective responses (e.g., increased heart and respiratory rates; feeling high and anxious).

DISCUSSION

These findings show a significant effect of acute IV cocaine administration on some appetitive hormones and suggest potential associations between these hormones and cocaine-related cardiorespiratory and subjective responses. Additional research is needed to further investigate the potential mechanisms underlining these associations.

A liquid chromatography and tandem mass spectrometry method to determine 28 non-volatile drugs of abuse in exhaled breath

Exhaled breath carries aerosol micro-particles containing nonvolatile organic substances. Recently, the analysis of drugs of abuse (DOA) have become of interest in exhaled breath particles (EBP). In this study, a liquid chromatography - tandem mass spectrometry (LC-MS/MS) method was developed and validated to analyze 28 DOA in 30L of EBP collected on a permeable polymer filter. After extraction, the chromatographic separation was achieved on a UPLC BEH phenyl column using a mobile phase consisting of methanol and water both containing 4mmol/L ammonium formate and 0.05% ammonia. The column temperature was set at 50°C and mobile phase flow rate 0.5mL/min in gradient mode with a total run time of 5min. The mass spectrometer was operated in positive electrospray ionization and selected reaction monitoring mode. Acquired limits of quantification were in the range of 1-66pg/filter for all substances except DM-tramadol. Excellent linearity over the concentration range from LLOQs - 15ng/filter with r2 values >0.99 and satisfactory recoveries (70-116% at 100pg/filter) were achieved. During method application a total 26 samples were analyzed of which 24 were found to be positive for 13 analytes. The highest amount was found for methadone (56ng/filter) and the lowest amount was found for the methadone metabolite EDDP (2pg/filter) in two different samples.

Expanding analytical options in sports drug testing: Mass spectrometric detection of prohibited substances in exhaled breath

RATIONALE

Continuously refining and advancing the strategies and methods employed in sports drug testing is critical for efficient doping controls. Besides improving and expanding the spectrum of target analytes, alternative test matrices have warranted in-depth evaluation as they commonly allow for minimal-/non-invasive and non-intrusive sample collection. In this study, the potential of exhaled breath (EB) as doping control specimen was assessed.

METHODS

EB collection devices employing a non-woven electret-based air filter unit were used to generate test specimens, simulating a potential future application in doping controls. A multi-analyte sports drug testing approach configured for a subset of 12 model compounds that represent specific classes of substances prohibited in sports (anabolic agents, hormone and metabolic modulators, stimulants, and beta-blockers) was established using unispray liquid chromatography/tandem mass spectrometry (LC/MS/MS) and applied to spiked and elimination study EB samples. The test method was characterized concerning specificity, assay imprecision, and limits of detection.

RESULTS

The EB collection device allowed for retaining and extracting all selected model compounds from the EB aerosol. Following elution and concentration, LC/MS/MS analysis enabled detection limits between 5 and 100 pg/filter and imprecisions ranging from 3% to 20% for the 12 selected model compounds. By means of EB samples from patients and participants of administration studies, the elimination of relevant compounds and, thus, their traceability in EB for doping control purposes, was investigated. Besides stimulants such as methylhexaneamine and pseudoephedrine, also the anabolic-androgenic steroid dehydrochloromethyltestosterone, the metabolic modulator meldonium, and the beta-blocker bisoprolol was detected in exhaled breath.

CONCLUSIONS

The EB aerosol has provided a promising proof-of-concept suggesting the expansion of this testing strategy as a complement to currently utilized sports drug testing programs.

Testing for Drugs in Exhaled Breath Collected With ExaBreath in a Drug Dependence Population: Comparison With Data Obtained in Urine After Liquid Chromatographic-Tandem Mass Spectrometric Analyses

BACKGROUND

Exhaled breath is commonly used in alcohol testing but has been recently demonstrated by scientists from Sweden, Switzerland, and the United States to contain a large number of both volatile and nonvolatile substances that can be measured using dedicated devices. ExaBreath is a sampling device that collects the bio-aerosols particles from the donor. Approximately 1-2 minutes exhaled breath is enough for the test. The device collects the very small bio-aerosols on a filter, which is consecutively incubated into methanol to release the drugs at the laboratory.

METHODS

Eighteen drug addicts from a methadone substitution program were recruited for this study. There were 5 women and 13 men, aged 25-50 years. The daily methadone dosage ranged from 10 to 120 mg, mostly as syrup. Urine (in plastic tubes with no preservative) and exhaled breath were simultaneously collected. In both fluids, methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) were tested using a specific liquid chromatographic-tandem mass spectrometric method, whereas all other compounds were screened by liquid chromatographic-tandem mass spectrometric method using a home made library of more than 800 compounds. Linearity, imprecision, and limit of quantitation were established. In each analytical batch, low and high controls were included.

RESULTS

All 18 urine specimens tested positive for methadone and EDDP. Several other compounds were also identified, including morphine, THC-COOH, benzoylecgonine, nicotine, some antidepressants, and neuroleptics. Methadone and EDDP were identified in exhaled breath from all 18 patients, with concentrations in the range 11-1470 and 29-818 pg per filter, respectively. In 13 cases, the ratio methadone/EDDP in exhaled breath was >1 (range 0.4-2.8). Except nicotine (n = 7), no other substance was detectable in exhaled breath.

CONCLUSION

This study gives further support to the possibility of using exhaled breath as a new matrix to document exposure to drugs.

Pharmacodynamic effects and relationships to plasma and oral fluid pharmacokinetics after intravenous cocaine administration

BACKGROUND

No controlled cocaine administration data describe cocaine and metabolite disposition in oral fluid (OF) collected with commercially-available collection devices, OF-plasma ratios, and pharmacodynamic relationships with plasma and OF cocaine and metabolite concentrations.

METHODS

Eleven healthy, cocaine-using adults received 25mg intravenous cocaine. Physiological and subjective effects (visual analogue scales), and plasma were collected one hour prior, and up to 21h post-dose. OF was collected with the Quantisal™ device up to 69h post-dose. Cocaine, benzoylecgonine (BE) and ecgonine methyl ester were quantified in plasma by liquid chromatography-tandem mass spectrometry; cocaine and BE were quantified in OF by two dimensional-gas chromatography-mass spectrometry.

RESULTS

Increases in heart rate, blood pressure and positive subjective effects occurred within the first 15min, persisting up to 1h ("Rush"), with clockwise hysteresis observed for plasma and OF concentrations and some subjective measures. Peak subjective effects ("Rush," "Good drug effect" and "Bad drug effect") occurred prior to peak OF cocaine concentration, whereas observed peak plasma concentrations and subjective measures occurred simultaneously, most likely due to significantly earlier plasma Tmax compared to OF Tmax.Tlast was generally longer in OF (12.5h cocaine; 33.0h BE) than plasma (9.5h cocaine; >21h BE, cutoffs 1μg/L); 8 and 10μg/L OF cocaine confirmatory cutoffs yielded detection times similar to cocaine's impairing effects, suggesting usefulness for DUID testing.

CONCLUSIONS

OF offers advantages as an alternative matrix to blood and plasma for identifying cocaine intake, defining pharmacokinetic parameters at different confirmation cutoffs, and aiding different drug testing programs to best achieve their monitoring goals.

Assessing cocaine abuse using LC-MS/MS measurements in biological specimens

Cocaine use is still a problem in today's world, and this has several implications on human activities. Indeed, important problems related to cocaine derive from its use in situations where concentration and focus skills are necessary, namely while driving and/or working. The need of analytical methods for drug analysis in specimens of biological origin for proper documentation of human exposure is increasing. While GC-MS-based procedures represented the state-of-the-art of analytical techniques a few years ago, there is a growing trend for their replacement by LC-MS/MS, which can be justified by the increased sensitivity presented by these new technologies. This paper will review recently published papers on the use of LC-MS/MS-based procedures for cocaine measurement in biological specimens.

Annual banned-substance review: analytical approaches in human sports drug testing

The aim of improving anti-doping efforts is predicated on several different pillars, including, amongst others, optimized analytical methods. These commonly result from exploiting most recent developments in analytical instrumentation as well as research data on elite athletes' physiology in general, and pharmacology, metabolism, elimination, and downstream effects of prohibited substances and methods of doping, in particular. The need for frequent and adequate adaptations of sports drug testing procedures has been incessant, largely due to the uninterrupted emergence of new chemical entities but also due to the apparent use of established or even obsolete drugs for reasons other than therapeutic means, such as assumed beneficial effects on endurance, strength, and regeneration capacities. Continuing the series of annual banned-substance reviews, literature concerning human sports drug testing published between October 2014 and September 2015 is summarized and reviewed in reference to the content of the 2015 Prohibited List as issued by the World Anti-Doping Agency (WADA), with particular emphasis on analytical approaches and their contribution to enhanced doping controls.