Megan Grabenauer

Potent rewarding and reinforcing effects of the synthetic cathinone 3,4-methylenedioxypyrovalerone (MDPV).

Reports of abuse and toxic effects of synthetic cathinones, frequently sold as ‘bath salts’ or ‘legal highs’, have increased dramatically in recent years. One of the most widely used synthetic cathinones is 3,4‐methylenedioxypyrovalerone (MDPV). The current study evaluated the abuse potential of MDPV by assessing its ability to support intravenous self‐administration and to lower thresholds for intracranial self‐stimulation (ICSS) in rats. In the first experiment, the rats were trained to intravenously self‐administer MDPV in daily 2‐hour sessions for 10 days at doses of 0.05, 0.1 or 0.2 mg/kg per infusion. The rats were then allowed to self‐administer MDPV under a progressive ratio (PR) schedule of reinforcement. Next, the rats self‐administered MDPV for an additional 10 days under short access (ShA; 2 hours/day) or long access (LgA; 6 hours/day) conditions to assess escalation of intake. A separate group of rats underwent the same procedures, with the exception of self‐administering methamphetamine (0.05 mg/kg per infusion) instead of MDPV. In the second experiment, the effects of MDPV on ICSS thresholds following acute administration (0.1, 0.5, 1 and 2 mg/kg, i.p.) were assessed. MDPV maintained self‐administration across all doses tested. A positive relationship between MDPV dose and breakpoints for reinforcement under PR conditions was observed. LgA conditions led to escalation of drug intake at 0.1 and 0.2 mg/kg doses, and rats self‐administering methamphetamine showed similar patterns of escalation. Finally, MDPV significantly lowered ICSS thresholds at all doses tested. Together, these findings indicate that MDPV has reinforcing properties and activates brain reward circuitry, suggesting a potential for abuse and addiction in humans.

Cannabinoids in Disguise: Δ9-Tetrahydrocannabinol-Like Effects of Tetramethylcyclopropyl Ketone Indoles

Synthetic indole-derived cannabinoids have become commonly used recreational drugs and continue to be abused despite their adverse consequences. As compounds that were identified early in the epidemic (e.g., naphthoylindoles) have become legally banned, new compounds have appeared on the drug market. Two tetramethylcyclopropyl ketone indoles, UR-144 [(1-pentyl-1H-indol-3-yl)-(2,2,3,3-tetramethylcyclopropyl)methanone] and XLR-11 [(1-(5-fluoropentyl)-1H-indol-3-yl)-(2,2,3,3-tetramethylcyclopropyl)methanone], recently have been identified in confiscated products. These compounds are structurally related to a series of CB2-selective compounds explored by Abbott Labs. The purpose of the present study was to evaluate the extent to which UR-144 and XLR-11 shared cannabinoid effects with Δ9-tetrahydrocannabinol (Δ9-THC). Indices of in vitro and in vivo activity at cannabinoid receptors were assessed. Similar to other psychoactive cannabinoid agonists, XLR-11 and UR-144 showed low nanomolar (<30) affinity for CB1 and CB2 receptors, activated these receptors as full agonists, and produced dose-dependent effects that were blocked by rimonabant in mice, including antinociception, hypothermia, catalepsy and suppression of locomotor activity. The potency of both compounds was several-fold greater than Δ9-THC. XLR-11 and UR-144 also substituted for Δ9-THC in a Δ9-THC discrimination procedure in mice, effects that were attenuated by rimonabant. Analysis of urine from mice treated with the compounds revealed that both were extensively metabolized, with predominant urinary excretion as glucuronide conjugates. Together, these results demonstrate that UR-144 and XLR-11 share a pharmacological profile of in vitro and in vivo effects with Δ9-THC and other abused indole-derived cannabinoids and would be predicted to produce Δ9-THC-like subjective effects in humans.

AB-CHMINACA, AB-PINACA, and FUBIMINA: Affinity and Potency of Novel Synthetic Cannabinoids in Producing Δ9-Tetrahydrocannabinol–Like Effects in Mice

Diversion of synthetic cannabinoids for abuse began in the early 2000s. Despite legislation banning compounds currently on the drug market, illicit manufacturers continue to release new compounds for recreational use. This study examined new synthetic cannabinoids, AB-CHMINACA (N-[1-amino-3-methyl-oxobutan-2-yl]-1-[cyclohexylmethyl]-1H-indazole-3-carboxamide), AB-PINACA [N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-pentyl-1H-indazole-3-carboxamide], and FUBIMINA [(1-(5-fluoropentyl)-1H-benzo[d]imadazol-2-yl)(naphthalen-1-yl)methanone], with the hypothesis that these compounds, like those before them, would be highly susceptible to abuse. Cannabinoids were examined in vitro for binding and activation of CB1 receptors, and in vivo for pharmacological effects in mice and in Δ9-tetrahydrocannabinol (Δ9-THC) discrimination. AB-CHMINACA, AB-PINACA, and FUBIMINA bound to and activated CB1 and CB2 receptors, and produced locomotor suppression, antinociception, hypothermia, and catalepsy. Furthermore, these compounds, along with JWH-018 [1-pentyl-3-(1-naphthoyl)indole], CP47,497 [rel-5-(1,1-dimethylheptyl)-2-[(1R,3S)-3-hydroxycyclohexyl]-phenol], and WIN55,212-2 ([(3R)-2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-naphthalenyl-methanone, monomethanesulfonate), substituted for Δ9-THC in Δ9-THC discrimination. Rank order of potency correlated with CB1 receptor-binding affinity, and all three compounds were full agonists in [35S]GTPγS binding, as compared with the partial agonist Δ9-THC. Indeed, AB-CHMINACA and AB-PINACA exhibited higher efficacy than most known full agonists of the CB1 receptor. Preliminary analysis of urinary metabolites of the compounds revealed the expected hydroxylation. AB-PINACA and AB-CHMINACA are of potential interest as research tools due to their unique chemical structures and high CB1 receptor efficacies. Further studies on these chemicals are likely to include research on understanding cannabinoid receptors and other components of the endocannabinoid system that underlie the abuse of synthetic cannabinoids.

Use of SPME-HS-GC -MS for the Analysis of Herbal Products Containing Synthetic Cannabinoids

The increasing prevalence and use of herbal mixtures containing synthetic cannabinoids presents a growing public health concern and legal challenge for society. In contrast to the plant-derived cannabinoids in medical marijuana and other cannabinoid-based therapeutics, the commonly encountered synthetic cannabinoids in these mendaciously labeled products constitute a structurally diverse set of compounds of relatively unknown pharmacology and toxicology. Indeed, the use of these substances has been associated with an alarming number of hospitalizations and emergency room visits. Moreover, there are already several hundred known cannabinoid agonist compounds that could potentially be used for illicit purposes, posing an additional challenge for public health professionals and law enforcement efforts, which often require the detection and identification of the active ingredients for effective treatment or prosecution. A solid-phase microextraction headspace gas chromatography-mass spectrometry method is shown here to allow for rapid and reliable detection and structural identification of many of the synthetic cannabinoid compounds that are currently or could potentially be used in herbal smoking mixtures. This approach provides accelerated analysis and results that distinguish between structural analogs within several classes of cannabinoid compounds, including positional isomers. The analytical results confirm the continued manufacture and distribution of herbal materials with synthetic cannabinoids and provide insight into the manipulation of these products to avoid legal constraints and prosecution.

Analytical surveillance of emerging drugs of abuse and drug formulations

Uncontrolled recreational drugs are proliferating in number and variety. Effects of long-term use are unknown, and regulation is problematic, as efforts to control one chemical often lead to several other structural analogs. Advanced analytical instrumentation and methods are continuing to be developed to identify drugs, chemical constituents of products, and drug substances and metabolites in biological fluids. Several mass spectrometry based approaches appear promising, particularly those that involve high resolution chromatographic and mass spectrometric methods that allow unbiased data acquisition and sophisticated data interrogation. Several of these techniques are shown to facilitate both targeted and broad spectrum analyses, the latter of which are often of particular benefit when dealing with misleadingly labeled products or assessing a biological matrix for illicit drugs and metabolites. The development and application of novel analytical approaches such as these will help to assess the nature and degree of exposure and risk and, where necessary, inform forensics and facilitate implementation of specific regulation and control measures.

Evaluation of Laser Diode Thermal Desorption–Tandem Mass Spectrometry (LDTD–MS-MS) in Forensic Toxicology

Many forensic laboratories experience backlogs due to increased drug-related cases. Laser diode thermal desorption (LDTD) has demonstrated its applicability in other scientific areas by providing data comparable with instrumentation, such as liquid chromatography-tandem mass spectrometry, in less time. LDTD-MS-MS was used to validate 48 compounds in drug-free human urine and blood for screening or quantitative analysis. Carryover, interference, limit of detection, limit of quantitation, matrix effect, linearity, precision and accuracy and stability were evaluated. Quantitative analysis indicated that LDTD-MS-MS produced precise and accurate results with the average overall within-run precision in urine and blood represented by a %CV <14.0 and <7.0, respectively. The accuracy for all drugs in urine ranged from 88.9 to 104.5% and 91.9 to 107.1% in blood. Overall, LDTD has the potential for use in forensic toxicology but before it can be successfully implemented that there are some challenges that must be addressed. Although the advantages of the LDTD system include minimal maintenance and rapid analysis (∼10 s per sample) which makes it ideal for high-throughput forensic laboratories, a major disadvantage is its inability or difficulty analyzing isomers and isobars due to the lack of chromatography without the use of high-resolution MS; therefore, it would be best implemented as a screening technique.

Detection and quantification of codeine-6-glucuronide, hydromorphone-3-glucuronide, oxymorphone-3-glucuronide, morphine 3-glucuronide and morphine-6-glucuronide in human hair from opioid users by LC-MS-MS

Current hair testing methods that rely solely on quantification of parent drug compounds are unable to definitively distinguish between drug use and external contamination. One possible solution to this problem is to confirm the presence of unique drug metabolites that cannot be present through contamination, such as phase II glucuronide conjugates. This work demonstrates for the first time that codeine-6-glucuronide, hydromorphone-3-glucuronide, oxymorphone-3-glucuronide, morphine-3-glucuronide and morphine-6-glucuronide are present at sufficient concentrations to be quantifiable in hair of opioid users and that their concentrations generally increase as the concentrations of the corresponding parent compounds increase. Here, we present a validated liquid chromatography tandem mass spectrometry method to quantify codeine-6-glucuronide, dihydrocodeine-6-glucuronide, hydromorphone-3-glucuronide, morphine-3-glucuronide, morphine-6-glucuronide, oxymorphone-3-glucuronide, codeine, dihydrocodeine, dihydromorphine, hydrocodone, hydromorphone, morphine, oxycodone, oxymorphone and 6-acetylmorphine in human hair. The method was used to analyze 46 human hair samples from known drug users that were confirmed positive for opioids by an independent laboratory. Glucuronide concentrations in samples positive for parent analytes ranged from ~1 to 25 pg/mg, and most samples had glucuronide concentrations in the range of ~1 to 5 pg/mg. Relative to the parent concentrations, the average concentrations of the four detected glucuronides were as follows: codeine-6-glucuronide, 2.33%; hydromorphone-3-glucuronide, 0.94%; oxymorphone-3-glucuronide, 0.77%; morphine 3-glucuronide, 0.59%; and morphine-6-glucuronide, 0.93%.

Identification of Eight Synthetic Cannabinoids, Including 5F‐AKB48 in Seized Herbal Products Using DART‐TOF‐MS and LC‐QTOF‐MS as Nontargeted Screening Methods

Synthetic cannabinoids are sprayed onto plant material and smoked for their marijuana‐like effects. Clandestine manufacturers modify synthetic cannabinoid structures by creating closely related analogs. Forensic laboratories are tasked with detection of these analog compounds, but targeted analytical methods are often thwarted by the structural modifications. Here, direct analysis in real time coupled to accurate mass time‐of‐flight mass spectrometry (DART‐TOF‐MS) in combination with liquid chromatography quadruple time‐of‐flight mass spectrometry (LC‐QTOF‐MS) are presented as a screening and nontargeted confirmation method, respectively. Methanol extracts of herbal material were run using both methods. Spectral data from four different herbal products were evaluated by comparing fragmentation pattern, accurate mass and retention time to available reference standards. JWH‐018, JWH‐019, AM2201, JWH‐122, 5F‐AKB48, AKB48‐N‐(4‐pentenyl) analog, UR144, and XLR11 were identified in the products. Results demonstrate that DART‐TOF‐MS affords a useful approach for rapid screening of herbal products for the presence and identification of synthetic cannabinoids.

Development of a Quantitative LC–MS-MS Assay for Codeine, Morphine, 6-Acetylmorphine, Hydrocodone, Hydromorphone, Oxycodone and Oxymorphone in Neat Oral Fluid

Recent advances in analytical capabilities allowing for the identification and quantification of drugs and metabolites in small volumes at low concentrations have made oral fluid a viable matrix for drug testing. Oral fluid is an attractive matrix option due to its relative ease of collection, reduced privacy concerns for observed collections and difficulty to adulterate. The work presented here details the development and validation of a liquid chromatography tandem mass spectrometry (LC-MS-MS) method for the quantification of codeine, morphine, 6-acetylmorphine, hydrocodone, hydromorphone, oxycodone and oxymorphone in neat oral fluid. The calibration range is 0.4-150 ng/mL for 6-acetylmorphine and 1.5-350 ng/mL for all other analytes. Within-run and between-run precision were <5% for all analytes except for hydrocodone, which had 6.2 %CV between runs. Matrix effects, while evident, could be controlled using matrix-matched controls and calibrators with deuterated internal standards. The assay was developed in accordance with the proposed mandatory guidelines for opioid confirmation in federally regulated workplace drug testing. The use of neat oral fluid, as opposed to a collection device, enables collection of a single sample that can be split into separate specimens.