Oral fluid cannabinoid concentrations following controlled smoked cannabis in chronic frequent and occasional smokers

Quantitative analysis of cannabinoids and metabolites in oral fluid by volumetric absorptive microsampling combined with UHPLC-HRMS

With recent evolution of cannabis legalization around the world and multiplication of cannabis derived products, identifying and qualifying cannabis consumption has a proven interest. Although blood, plasma, and urine are common matrices widely used in toxicology laboratories, oral fluid presents specific advantages. In the context of doping tests, addiction consultation or roadside checks, where other matrices are impractical to collect or can be adulterated, oral fluid is a promising matrix that allows a non-invasive, rapid, and monitored self-sampling. However, available devices required a consequent volume of oral fluid, more than 250 µL, sometimes difficult to collect. We present here a fully optimized quantitative method for seven cannabinoids, including four metabolites, in oral fluid, Δ9-tetrahydrocannabinol, 11-hydroxy-Δ9-tetrahydrocannabinol and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol; cannabidiol, 7-hydroxy and 7-carboxycannabidiol; and cannabinol. After self-collection of 20 µL using an accurate and precise volumetric absorptive microsampling device (VAMS®), cannabinoids were derivatized with 2-fluoro-1-methylpyridinium p-toluenesulfonate to increase sensitivity. The successive steps of the proposed method, including biosampling, 1 h sample preparation with derivatization, and acquisition by ultrahigh-performance liquid chromatography coupled to high-resolution mass spectrometry, were fully optimized. A limit of quantification of 0.5 ng/mL (≈10 pg per sampling) was thus targeted, adapted to the legal threshold required by the authorities and to clinical monitoring. Applied to six cannabis consumers, the proposed method made it possible to quantify in 20 µL oral fluid samples, Δ9-tetrahydrocannabinol ranging from 0.5 to 6236 ng/mL, cannabidiol from 0.6 to 190 ng/mL and cannabinol from 0.5 to 118 ng/mL.

Concentrations of Delta 9-tetrahydrocannabinol (THC) in oral fluid at different time points after use: An individual participant meta-analysis

Background

Delta 9-tetrahydrocannabinol (THC) concentrations in oral fluid (OF) at different time points after cannabis administration and factors related to these concentrations have not been previously described in a meta-analysis. This information is critical for better understanding of these tests for detection of prior cannabis use and cannabis impairment.

Objectives

1: To describe the summary statistics of THC concentrations at different time points after cannabis administration. 2: To describe the relationship between the variables of dose of THC, frequency of using cannabis, route of administration (i.e., inhaled or ingested), OF collection device and sex, with THC concentrations in OF, based on bivariate analyses. 3: To describe the independent contribution of each of the variables in Objective 2, based on a multivariate analysis of THC concentrations.

Methods

A meta-analysis of studies from two databases (PubMed and Scopus) was conducted. Our inclusion criteria included published empirical articles that administered natural cannabis to subjects in a controlled setting, with OF drug tests showing the exact THC concentrations in OF for each subject (i.e., raw data) for at least two time points after cannabis administration using confirmatory methods. Seven studies of tests with published raw data for OF THC after cannabis administration met these criteria (n observations = 1157).

Results

Summary statistics showed OF THC concentrations by time after use were highly dispersed at every time point, positively skewed, and declined over time. Many positive OF THC concentrations were found after 24-h in one study, but most studies did not conduct observations past 24 h. In a multivariate analysis, we found that increased dose, increased frequency of cannabis use, and inhaled (versus ingested) cannabis were statistically related to higher OF THC concentrations. OF collection with the intercept DOA device was significantly higher than expectorant (i.e. saliva) and being male (versus female) were only significant in a bivariate analysis. Too little data existed to reliably analyze the possible influence of other variables of age, race and body mass index (BMI) on OF THC concentrations.

Discussion

False negatives exist when the tests are used to detect prior use. OF test results are related to confounders of frequency of cannabis use and inhaled (versus ingested) cannabis. OF tests can produce positives at a cut-off 1.0 ng/mL well beyond 24 h. The tests are not valid to detect cannabis impairment. More information is needed on the influence of potential confounders for OF concentrations. We do not have a good idea of the degree to which the subjects in these studies are representative of persons who use cannabis. Overall, more research is needed for these tests to be used in workplace settings.

Detection and quantification of selected cannabinoids in oral fluid samples by protein precipitation and LC-MS/MS

Cannabis is the most widely consumed illicit drug worldwide. As consumption rates increase, partially due to the decriminalization of its use for medicinal and recreational purposes, analytical methods for monitoring different cannabinoids in several biological matrices have been developed. Herein, a simple and fast extraction procedure to extract natural cannabinoids from oral fluid (OF) samples was developed and fully validated according to the ANSI/ASB 2019 Standard Practices for Method Validation in Forensic Toxicology. Using only 0.2 mL of neat OF, the analytes [Δ9-tetrahidrocannabinol (THC), 11-hydroxy-Δ9-tetrahydrocannabinol (THC-OH), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH), cannabinol (CBN) and cannabidiol (CBD)] were extracted by protein precipitation with a mixture of methanol:acetonitrile (80:20, v/v); the extracts were centrifuged, evaporated to dryness and reconstituted in 100 µL of methanol. Analysis was performed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The developed methodology produced linear results for all compounds, with working ranges of 0.1-50 ng/mL for THC, 0.5-50 ng/mL for THC-OH, CBN and CBD, and 0.05-1 ng/mL for THC-COOH. Ion suppression was observed for THC, CBN and CBD, which did not impair sensitivity considering the low limits of quantification (LOQs) and limits of detection (LODs) obtained (which varied between 0.05 and 0.5 ng/mL). The extraction procedure produced great recoveries, and the compounds were stable. No interferences were found, and the method proved to be extremely fast, selective, precise, and accurate for use in routine analysis. The method was successfully applied to authentic samples.

Surgery-Related Considerations in Treating People Who Use Cannabis: A Review

Importance

Cannabis use has experienced substantial growth. Many patients treated by otolaryngologists are using cannabis in various forms, often without the knowledge of the treating surgeon. These cannabinoid substances have various systemic effects, and it is critical for otolaryngologists to recognize how cannabis use may contribute to a patient's care.

Observations

Cannabis use has effects that contribute to every phase of a surgeon's care. Preoperative counseling for tapering use may prevent increased rates of adverse effects. Care with anesthesia must be observed due to increased rates of myocardial ischemia, higher tolerance to standard doses, and prolonged sedation. Although results of studies are mixed, there may be an association with cannabis use and postoperative pain, nausea, and vomiting. Postoperative wound healing may be improved through the use of topical cannabinoids. Significant drug-drug interactions exist with cannabis, most notably with several common anticoagulant medications. Care should be exercised when managing medications for people who use cannabis. While many people who use cannabis consume it infrequently, a substantial population has developed cannabis use disorder, which is associated with increased morbidity and mortality postoperatively. Screening for cannabis use disorder is important and can be done through short screening tools.

Conclusions and Relevance

Patients who use cannabis may require special attention regarding preoperative counseling and workup, intraoperative anesthesia, postoperative pain management, nausea, wound healing, and drug-drug interactions. As patient use continues to increase, otolaryngologists will find an increasing need to remain up to date on how cannabis use contributes to patient care.

"A glimmer of hope" - Perceptions, barriers, and drivers for medicinal cannabis use amongst Australian and New Zealand people with endometriosis

Previous quantitative research has shown that cannabis use, mostly illicit, is used for symptom management amongst those with endometriosis living in Australia or New Zealand, but the drivers and barriers for use of legal, medicinal cannabis in this population are currently unclear. This study sought to investigate, via online focus-groups, the perceptions, barriers, drivers, and experiences associated with cannabis use, whether legal or illicit, amongst 37 Australians and New Zealanders, aged 18-55, with a medical diagnosis of endometriosis. Previous cannabis usage was not required to participate. Discussion topics included strategies employed to manage symptoms, exploration of current medications, previous use of cannabis for pain management, and interest in using medicinal cannabis as a management strategy. Participants with moderate to severe symptoms of medically diagnosed endometriosis reported inadequacies with their current medical and self-management strategies and were inclined to try medicinal cannabis, both as part of their medical management and as part of a clinical trial. Barriers to medicinal cannabis adoption identified in this cohort included high costs of legal cannabis products, lack of clarity and fairness in current roadside drug testing laws and workplace drug testing policies, concern over the impact of stigma affecting familial, social and workplace life domains, and subsequent judgement and the lack of education/engagement from their medical providers regarding cannabis use. Given the interest in medicinal cannabis and the reported lack of effective symptom management, clinical trials are urgently required to determine the potential role that medicinal cannabis may play in reducing the symptoms of endometriosis.

Photochemical Fingerprinting Is a Sensitive Probe for the Detection of Synthetic Cannabinoid Receptor Agonists; toward Robust Point-of-Care Detection

With synthetic cannabinoid receptor agonist (SCRA) use still prevalent across Europe and structurally advanced generations emerging, it is imperative that drug detection methods advance in parallel. SCRAs are a chemically diverse and evolving group, which makes rapid detection challenging. We have previously shown that fluorescence spectral fingerprinting (FSF) has the potential to provide rapid assessment of SCRA presence directly from street material with minimal processing and in saliva. Enhancing the sensitivity and discriminatory ability of this approach has high potential to accelerate the delivery of a point-of-care technology that can be used confidently by a range of stakeholders, from medical to prison staff. We demonstrate that a range of structurally distinct SCRAs are photochemically active and give rise to distinct FSFs after irradiation. To explore this in detail, we have synthesized a model series of compounds which mimic specific structural features of AM-694. Our data show that FSFs are sensitive to chemically conservative changes, with evidence that this relates to shifts in the electronic structure and cross-conjugation. Crucially, we find that the photochemical degradation rate is sensitive to individual structures and gives rise to a specific major product, the mechanism and identification of which we elucidate through density-functional theory (DFT) and time-dependent DFT. We test the potential of our hybrid "photochemical fingerprinting" approach to discriminate SCRAs by demonstrating SCRA detection from a simulated smoking apparatus in saliva. Our study shows the potential of tracking photochemical reactivity via FSFs for enhanced discrimination of SCRAs, with successful integration into a portable device.

Electrochemical biosensors based on saliva electrolytes for rapid detection and diagnosis

In recent years, electrochemical biosensors (ECBSs) have shown significant potential for real-time disease diagnosis and in situ physical condition monitoring. As a multi-constituent oral fluid comprising various disease signaling biomarkers, saliva has drawn much attention in the field of point-of-care (POC) testing. In particular, during the outbreak of the COVID-19 pandemic, ECBSs which hold the simplicity of a single-step assay compared with the multi-step assay of traditional testing methods are expected to relieve the human and economic burden caused by the massive and long-term sample testing process. Noteworthily, ECBSs for the detection of SARS-CoV-2 in saliva have already been developed and may replace current testing methods. Furthermore, the detection scope has expanded from routine indices such as sugar and uric acid to abnormal biomarkers for early-stage disease detection and drug level monitoring, which further facilitated the evolution of ECBSs in the last 5 years. This review is divided into several main sections. First, we discussed the latest advancements and representative research on ECBSs for saliva testing. Then, we focused on a novel kind of ECBS, organic electrochemical transistors (OECTs), which hold great advantages of high sensitivity and signal-to-noise ratio and on-site detection. Finally, application of ECBSs with integrated portable platforms in oral cavities, which lead to powerful auxiliary testing means for telemedicine, has also been discussed.

Phytocannabinoids regulate inflammation in IL-1β-stimulated human gingival fibroblasts

OBJECTIVES

Billions of individuals worldwide suffer from periodontal disease, an inflammatory disease that results in hard-tissue and soft-tissue destruction. A viable therapeutic option to treat periodontal disease may be via cannabinoids that exert immunomodulatory effects, and the endocannabinoid system (ECS) is readily present in periodontal tissues that exhibit cannabinoid type 1 and 2 receptors (CB1R and CB2R). Phytocannabinoids (pCBs), which are a part of a heterogeneous group of molecules acting on cannabinoid receptors (CBR) derived from the cannabis plants, have been attributed to a wide variety of effects including anti-inflammatory activity and some pro-inflammatory effects depending on the cell type. Thus, this study aims to examine the effects of pCBs on primary human gingival fibroblasts (HGFs) in IL-1β stimulated (simulated periodontal disease) HGFs.

MATERIALS AND METHODS

Human gingival fibroblasts (HGFs) obtained from ATCC were cultured per the manufacturer's recommendation. The functional activity of cannabinoid receptors was measured using ACTOne (cAMP)-based CB1R and CB2R assay. The effects of three pCBs (0.1-10 μg/ml or 10^-4.5 -10^-6.5  M) on cell viability were assessed using the CCK-8 cellular dehydrogenase assay. IL-1β (1 ng/ml) was added an hour before the treatment to stimulate inflammation in the HGFs before the addition of cannabinoid ligands. After 24-h incubation, the production of INF-γ, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, and TNF-α was measured using Mesoscale Discovery (MSD) Human Pro-Inflammatory kit. To measure prostaglandin E 2 levels (PGE2), Cisbio HTRF PGE2 assay kit was used per the manufacturer's recommendation to measure after 24-h incubation. The data were analyzed using GraphPad Prism 6.0. The analytes for each group were compared using a one-way ANOVA test with Bonferroni's correction.

RESULTS

Cannabidivarin (CBVN or CBDV) (EC₅₀  = 12 nM) and cannabigerol (CBG) (EC₅₀  = 30 nM) exhibited agonist activity on CB2R with intermediate efficacy. Cannabidiol (CBD) did not exhibit activation of the CB2R, and the CB1R activation was not observed with any of the pCBs. Cytotoxicity results showed that concentrations of 2.50 μg/ml or greater for the pCBs were toxic except for CBVN. Lower concentrations of CBD and CBG (0.1-0.75 μg/ml), and CBVN at 2.50 μg/ml exhibited significant effects on HGF proliferation. In IL-1β-stimulated HGFs, prostaglandin E2 (PGE2) production was significantly suppressed only by CBG and CBVN. CBD and CBG treatment alone did, however, elevate PGE2 production significantly compared to control. IL-1β stimulation resulted in a robust increase in the production of all cytokines tested. Treatment of IL-β-stimulated HGF with the three pCBs (1 μg/ml) significantly reduced INF-ɣ, TNF-α, and IL-2. The significant suppression of IL-4 was seen with CBD and CBVN, while only CBVN exerted suppression of IL-13. The three pCBs significantly increased IL-6, IL-10, and IL-12 levels, while none of the pCBs reduced the expression of IL-8 in IL-1β-stimulated HGF.

CONCLUSION

The effective inhibition of IL-1β-stimulated production of PGE2 and cytokines by the pCB in HGFs suggests that targeting the endocannabinoid system may lead to the development of therapeutic strategies for periodontal therapy. However, each pCB has its unique anti-inflammatory profile, in which certain pro-inflammatory activities are also exhibited. The pCBs alone or in combination may benefit and aid in improving public oral health.

Affinity Assays for Cannabinoids Detection: Are They Amenable to On-Site Screening?

Roadside testing of illicit drugs such as tetrahydrocannabinol (THC) requires simple, rapid, and cost-effective methods. The need for non-invasive detection tools has led to the development of selective and sensitive platforms, able to detect phyto- and synthetic cannabinoids by means of their main metabolites in breath, saliva, and urine samples. One may estimate the time passed from drug exposure and the frequency of use by corroborating the detection results with pharmacokinetic data. In this review, we report on the current detection methods of cannabinoids in biofluids. Fluorescent, electrochemical, colorimetric, and magnetoresistive biosensors will be briefly overviewed, putting emphasis on the affinity formats amenable to on-site screening, with possible applications in roadside testing and anti-doping control.

A GPCR-based yeast biosensor for biomedical, biotechnological, and point-of-use cannabinoid determination

Eukaryotic cells use G-protein coupled receptors to sense diverse signals, ranging from chemical compounds to light. Here, we exploit the remarkable sensing capacity of G-protein coupled receptors to construct yeast-based biosensors for real-life applications. To establish proof-of-concept, we focus on cannabinoids because of their neuromodulatory and immunomodulatory activities. We construct a CB₂ receptor-based biosensor, optimize it to achieve high sensitivity and dynamic range, and prove its effectiveness in three applications of increasing difficulty. First, we screen a compound library to discover agonists and antagonists. Second, we analyze 54 plants to discover a new phytocannabinoid, dugesialactone. Finally, we develop a robust portable device, analyze body-fluid samples, and confidently detect designer drugs like JWH-018. These examples demonstrate the potential of yeast-based biosensors to enable diverse applications that can be implemented by non-specialists. Taking advantage of the extensive sensing repertoire of G-protein coupled receptors, this technology can be extended to detect numerous compounds.

GPCRs are used for diverse sensing in eukaryotes. Here the authors use GPCRs to construct yeast-based biosensors, focussing on cannabinoids, and use these to screen agonists and antagonists, as well as generate a portable detection device.

Bridging Disciplines: Applications of Forensic Science and Industrial Hemp

Forensic laboratories are required to have analytical tools to confidently differentiate illegal substances such as marijuana from legal products (i.e., industrial hemp). The Achilles heel of industrial hemp is its association with marijuana. Industrial hemp from the Cannabis sativa L. plant is reported to be one of the strongest natural multipurpose fibers on earth. The Cannabis plant is a vigorous annual crop broadly separated into two classes: industrial hemp and marijuana. Up until the eighteenth century, hemp was one of the major fibers in the United States. The decline of its cultivation and applications is largely due to burgeoning manufacture of synthetic fibers. Traditional composite materials such as concrete, fiberglass insulation, and lumber are environmentally unfavorable. Industrial hemp exhibits environmental sustainability, low maintenance, and high local and national economic impacts. The 2018 Farm Bill made way for the legalization of hemp by categorizing it as an ordinary agricultural commodity. Unlike marijuana, hemp contains less than 0.3% of the cannabinoid, Δ9-tetrahydrocannabinol, the psychoactive compound which gives users psychotropic effects and confers illegality in some locations. On the other hand, industrial hemp contains cannabidiol found in the resinous flower of Cannabis and is purported to have multiple advantageous uses. There is a paucity of investigations of the identity, microbial diversity, and biochemical characterizations of industrial hemp. This review provides background on important topics regarding hemp and the quantification of total tetrahydrocannabinol in hemp products. It will also serve as an overview of emergent microbiological studies regarding hemp inflorescences. Further, we examine challenges in using forensic analytical methodologies tasked to distinguish legal fiber-type material from illegal drug-types.

A rapid assay provides on-site quantification of tetrahydrocannabinol in oral fluid

Tetrahydrocannabinol (THC), the primary psychoactive ingredient of cannabis, impairs cognitive and motor function in a concentration-dependent fashion. Drug testing is commonly performed for employment and law enforcement purposes; however, available tests produce low-sensitive binary results (lateral flow assays) or have long turnaround (gas chromatography–mass spectrometry). To enable on-site THC quantification in minutes, we developed a rapid assay for oral THC analysis called EPOCH (express probe for on-site cannabis inhalation). EPOCH features distinctive sensor design such as a radial membrane and transmission optics, all contained in a compact cartridge. This integrated approach permitted assay completion within 5 min with a detection limit of 0.17 ng/ml THC, which is below the regulatory guideline (1 ng/ml). As a proof of concept for field testing, we applied EPOCH to assess oral fluid samples from cannabis users (n = 43) and controls (n = 43). EPOCH detected oral THC in all specimens from cannabis smokers (median concentration, 478 ng/ml) and THC-infused food consumers. Longitudinal monitoring showed a fast drop in THC concentrations within the first 6 hours of cannabis smoking (half-life, 1.4 hours).

Blood and Oral Fluid Cannabinoid Profiles of Frequent and Occasional Cannabis Smokers

Increased prevalence of cannabis consumption and impaired driving are a growing public safety concern. Some states adopted per se driving laws, making it illegal to drive with more than a specified ∆9-tetrahydrocannabinol (THC) blood concentration of THC in a biological fluid (typically blood). Blood THC concentrations decrease significantly (~90%) with delays in specimen collection, suggesting use of alternative matrices, such as oral fluid (OF). We characterized 10 cannabinoids' concentrations, including THC metabolites, in blood and OF from 191 frequent and occasional users by LC-MS-MS for up to 6 h after ad libitum smoking. Subjects self-titrated when smoking placebo, 5.9 or 13.4% THC cannabis. Higher maximum blood THC concentrations (Cmax) were observed in individuals who received the 5.9% THC versus the 13.4% THC plant material. In blood, the Cmax of multiple analytes, including THC and its metabolites, were increased in frequent compared to occasional users, whereas there were no significant differences in OF Cmax. Blood THC remained detectable (≥5 ng/mL) at the final sample collection for 14% of individuals who smoked either the 5.9% or 13.4% THC cigarette, whereas 54% had detectable THC in OF when applying the same cutoff. Occasional and frequent cannabis users' profiles were compared, THC was detectable for significantly longer in blood and OF from frequent users. Detection rates between frequent and occasional users at multiple per se cutoffs showed larger differences in blood versus OF. Understanding cannabinoid profiles of frequent and occasional users and the subsequent impact on detectability with current drug per se driving limits is important to support forensic interpretations and the development of scientifically supported driving under the influence of cannabis laws.

Analysis of cannabinoids in conventional and alternative biological matrices by liquid chromatography: Applications and challenges

Cannabis is by far the most widely abused illicit drug globe wide. The analysis of its main psychoactive components in conventional and non-conventional biological matrices has recently gained a great attention in forensic toxicology. Literature states that its abuse causes neurocognitive impairment in the domains of attention and memory, possible macrostructural brain alterations and abnormalities of neural functioning. This suggests the necessity for the development of a sensitive and a reliable analytical method for the detection and quantification of cannabinoids in human biological specimens. In this review, we focus on a number of analytical methods that have, so far, been developed and validated, with particular attention to the new "golden standard" method of forensic analysis, liquid chromatography mass spectrometry or tandem mass spectrometry. In addition, this review provides an overview of the effective and selective methods used for the extraction and isolation of cannabinoids from (i) conventional matrices, such as blood, urine and oral fluid and (ii) alternative biological matrices, such as hair, cerumen and meconium.

Delta-9-tetrahydrocannabinol (Δ9-THC) sensing using an aerosol jet printed organic electrochemical transistor (OECT)

Recreational use of marijuana/cannabis was legalized in Canada in 2018 and has been decriminalized in several other countries; however, the detection of impairment has remained elusive for law enforcement. The psychoactive ingredient in cannabis, delta-9-tetrahydrocannabinol (Δ9-THC), can be detected in saliva and be correlated well with the intake of cannabis. Organic electrochemical transistors (OECTs) have been used for a variety of biosensing applications like glucose, pH, ions, etc. In this work, we demonstrate the use of unfunctionalized OECTs for the detection of Δ9-THC down to 0.1 nM and 1 nM diluted in DI water and synthetic saliva buffer, respectively. These OECTs have been aerosol jet printed entirely with PEDOT:PSS as the channel material. Using a platinum gate coupled with an aerosol jet printed OECT, Δ9-THC concentration can be detected due to its oxidation reaction at the gate. These results were consistent with cyclic voltammetry measurements of Δ9-THC using Pt as the working and counter electrode. Utilizing these OECT based sensors, we have achieved high sensitivity of detection of Δ9-THC in the range from 0.1 nM to 5 μM. These OECT based Δ9-THC sensors demonstrate less than 3% error indicating good repeatability which is averaged over 15 measurements on multiple devices.

Application of an ultra-performance liquid chromatography-tandem mass spectrometric method for the detection and quantification of cannabis in cerumen samples

In this study, cerumen, a non-conventional biological secretion, was examined as an alternative matrix for forensic analyzis. A fully validated analytical UPLC-MS/MS method was developed for the detection and quantification of the most prevalent psychoactive illicit drug globe wide, Δ⁹-tethrahydrocannabinol, commonly known as THC, and four major cannabinoids found in cannabis Sativa. The method was validated, and standard external calibration curves were established with correlation coefficients > 0.99. A validated experimental procedure, along with a direct extraction of cannabinoids with acidified acetonitrile resulted in a short total analyzis time and a good extraction efficiency for all the analytes under study. LOD and LOQ values were determined to be 0.01-0.08 pg/mg and 0.04-0.23 pg/mg, respectively. To prove applicability of the proposed assay, volunteers were selected, and cerumen samples were examined for cannabis. The analyzis by use of UPLC-MS/MS indicated that all samples were positive, reporting recent cannabis abuse. Surprisingly, both THC and Cannabinol (CBN) were detected, and quantification was possible in 75% of the cases.

Electrochemical Sensing of Cannabinoids in Biofluids: A Noninvasive Tool for Drug Detection

Cannabinoid sensing in biofluids provides great insight into the effects of medicinal cannabis on the body. The prevalence of cannabis for pain management and illicit drug use necessitates knowledge translation in cannabinoids. In this Review, we provide an overview of the current detection methods of cannabinoids in bodily fluids emphasizing electrochemical sensing. First, we introduce cannabinoids and discuss the structure and metabolism of Δ⁹-THC and its metabolites in relation to blood, urine, saliva, sweat, and breath. Next, we briefly discuss lab based techniques for cannabinoids in biofluids. While these techniques are highly sensitive and specific, roadside safety requires a quick, portable, and cost-effective sensing method. These needs motivated a comprehensive review of advantages, disadvantages, and future directions for electrochemical sensing of cannabinoids. The literature shows the lowest limit of detection to be 3.3 pg of Δ⁹-THC/mL using electrochemical immunosensors, while electrodes fabricated with low cost methods such as screen-printing and carbon paste can detect as little as 25 and 1.26 ng of Δ⁹-THC/mL, respectively. Future research will include nanomaterial modified working electrodes, for simultaneous sensing of multiple cannabinoids. Additionally, there should be an emphasis on selectivity for cannabinoids in the presence of interfering compounds. Sensors should be fully integrated on biocompatible substrates with control electronics and intelligent components for wearable diagnostics. We hope this Review will prove to be the seminal work in the electrochemical sensing of cannabinoids.

Identifying and Quantifying Cannabinoids in Biological Matrices in the Medical and Legal Cannabis Era

Background

Cannabinoid analyses generally included, until recently, the primary psychoactive cannabis compound, Δ9-tetrahydrocannabinol (THC), and/or its inactive metabolite, 11-nor-9-carboxy-THC, in blood, plasma, and urine. Technological advances revolutionized the analyses of major and minor phytocannabinoids in diverse biological fluids and tissues. An extensive literature search was conducted in PubMed for articles on cannabinoid analyses from 2000 through 2019. References in acquired manuscripts were also searched for additional articles.

Content

This article summarizes analytical methodologies for identification and quantification of multiple phytocannabinoids (including THC, cannabidiol, cannabigerol, and cannabichromene) and their precursors and/or metabolites in blood, plasma, serum, urine, oral fluid, hair, breath, sweat, dried blood spots, postmortem matrices, breast milk, meconium, and umbilical cord since the year 2000. Tables of nearly 200 studies outline parameters including analytes, specimen volume, instrumentation, and limits of quantification. Important diagnostic and interpretative challenges of cannabinoid analyses are also described. Medicalization and legalization of cannabis and the 2018 Agricultural Improvement Act increased demand for cannabinoid analyses for therapeutic drug monitoring, emergency toxicology, workplace and pain-management drug testing programs, and clinical and forensic toxicology applications. This demand is expected to intensify in the near future, with advances in instrumentation performance, increasing LC-MS/MS availability in clinical and forensic toxicology laboratories, and the ever-expanding knowledge of the potential therapeutic use and toxicity of phytocannabinoids.

Summary

Cannabinoid analyses and data interpretation are complex; however, major and minor phytocannabinoid detection windows and expected concentration ranges in diverse biological matrices improve the interpretation of cannabinoid test results.

Measuring Within-Individual Cannabis Reduction in Clinical Trials: A Review of the Methodological Challenges

Purpose

Cannabis abstinence traditionally is the primary outcome in cannabis use disorder (CUD) treatment trials. Due to the changing legality of cannabis, patient goals, and preliminary evidence that suggests individuals who reduce their cannabis use may show functional improvements, cannabis reduction is a desirable alternative outcome in CUD trials. We review challenges in measuring cannabis reduction and the evidence to support various definitions of reduction.

Findings

Reduction in number of cannabis use days was associated with improvements in functioning across several studies. Reductions in quantity of cannabis used was inconsistently associated with improvements in functioning, though definitions of quantity varied across studies. Different biomarkers may be used depending on the reduction outcome.

Conclusions

Biologically-confirmed reductions in frequency of cannabis use days may represent a viable endpoint in clinical trials for cannabis use disorder. Additional research is needed to better quantify reduction in cannabis amounts.

Oral Fluid Drug Testing: Analytical Approaches, Issues and Interpretation of Results

With advances in analytical technology and new research informing result interpretation, oral fluid (OF) testing has gained acceptance over the past decades as an alternative biological matrix for detecting drugs in forensic and clinical settings. OF testing offers simple, rapid, non-invasive, observed specimen collection. This article offers a review of the scientific literature covering analytical methods and interpretation published over the past two decades for amphetamines, cannabis, cocaine, opioids, and benzodiazepines. Several analytical methods have been published for individual drug classes and, increasingly, for multiple drug classes. The method of OF collection can have a significant impact on the resultant drug concentration. Drug concentrations for amphetamines, cannabis, cocaine, opioids, and benzodiazepines are reviewed in the context of the dosing condition and the collection method. Time of last detection is evaluated against several agencies' cutoffs, including the proposed Substance Abuse and Mental Health Services Administration, European Workplace Drug Testing Society and Driving Under the Influence of Drugs, Alcohol and Medicines cutoffs. A significant correlation was frequently observed between matrices (i.e., between OF and plasma or blood concentrations); however, high intra-subject and inter-subject variability precludes prediction of blood concentrations from OF concentrations. This article will assist individuals in understanding the relative merits and limitations of various methods of OF collection, analysis and interpretation.

Determination of Cannabinoid Vapor Pressures to Aid in Vapor Phase Detection of Intoxication

The quest for a reliable means to detect cannabis intoxication with a breathalyzer is ongoing. To design such a device, it is important to understand the fundamental thermodynamics of the compounds of interest. The vapor pressures of two important cannabinoids, cannabidiol (CBD) and Δ⁹-tetrahydrocannabinol (Δ⁹-THC), are presented, as well as the predicted normal boiling temperature (NBT) and the predicted critical constants (these predictions are dependent on the vapor pressure data). The critical constants are typically necessary to develop an equation of state (EOS). EOS-based models can provide estimations of thermophysical properties for compounds to aid in designing processes and devices. An ultra-sensitive, quantitative, trace dynamic headspace analysis sampling called porous layered open tubular-cryoadsorption (PLOT-cryo) was used to measure vapor pressures of these compounds. PLOT-cryo affords short experiment durations compared to more traditional techniques for vapor pressure determination (minutes versus days). Additionally, PLOT-cryo has the inherent ability to stabilize labile solutes because collection is done at reduced temperature. The measured vapor pressures are approximately 2 orders of magnitude lower than those measured for n-eicosane, which has a similar molecular mass. Thus, the difference in polarity of these molecules must be impacting the vapor pressure dramatically. The vapor pressure measurements are presented in the form of Clausius-Clapeyron (or van't Hoff) equation plots. The predicted vapor pressures that would be expected at near ambient conditions (25 °C) are also presented.

Cannabinoid disposition in oral fluid after controlled smoked, vaporized, and oral cannabis administration

Oral fluid (OF) is an important matrix for monitoring drugs. Smoking cannabis is common, but vaporization and edible consumption also are popular. OF pharmacokinetics are available for controlled smoked cannabis, but few data exist for vaporized and oral routes. Frequent and occasional cannabis smokers were recruited as participants for four dosing sessions including one active (6.9% Δ9 -tetrahydrocannabinol, THC) or placebo cannabis-containing brownie, followed by one active or placebo cigarette, or one active or placebo vaporized cannabis dose. Only one active dose was administered per session. OF was collected before and up to 54 (occasional) or 72 (frequent) h after dosing from cannabis smokers. THC, 11-hydroxy-THC (11-OH-THC), 11-nor-9-carboxy-THC (THCCOOH), tetrahydrocannabivarin (THCV), cannabidiol (CBD), and cannabigerol (CBG) were quantified by liquid chromatography-tandem mass spectrometry. OF cannabinoid Cmax occurred during or immediately after cannabis consumption due to oral mucosa contamination. Significantly greater THC Cmax and significantly later THCV, CBD, and CBG tlast were observed after smoked and vaporized cannabis compared to oral cannabis in frequent smokers only. No significant differences in THC, 11-OH-THC, THCV, CBD, or CBG tmax between routes were observed for either group. For occasional smokers, more 11-OH-THC and THCCOOH-positive specimens were observed after oral dosing than after inhaled routes, increasing % positive cannabinoid results and widening metabolite detection windows after oral cannabis consumption. Utilizing 0.3 µg/L THCV and CBG cut-offs resulted in detection windows indicative of recent cannabis intake. OF pharmacokinetics after high potency CBD cannabis are not yet available precluding its use currently as a marker of recent use. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Cannabis Edibles: Blood and Oral Fluid Cannabinoid Pharmacokinetics and Evaluation of Oral Fluid Screening Devices for Predicting Δ9-Tetrahydrocannabinol in Blood and Oral Fluid following Cannabis Brownie Administration

BACKGROUND

Roadside oral fluid (OF) Δ9-tetrahydrocannabinol (THC) detection indicates recent cannabis intake. OF and blood THC pharmacokinetic data are limited and there are no on-site OF screening performance evaluations after controlled edible cannabis.

CONTENT

We reviewed OF and blood cannabinoid pharmacokinetics and performance evaluations of the Draeger DrugTest®5000 (DT5000) and Alere™ DDS®2 (DDS2) on-site OF screening devices. We also present data from a controlled oral cannabis administration session.

SUMMARY

OF THC maximum concentrations (Cmax) were similar in frequent as compared to occasional smokers, while blood THC Cmax were higher in frequent [mean (range) 17.7 (8.0–36.1) μg/L] smokers compared to occasional [8.2 (3.2–14.3) μg/L] smokers. Minor cannabinoids Δ9-tetrahydrocannabivarin and cannabigerol were never detected in blood, and not in OF by 5 or 8 h, respectively, with 0.3 μg/L cutoffs. Recommended performance (analytical sensitivity, specificity, and efficiency) criteria for screening devices of ≥80% are difficult to meet when maximizing true positive (TP) results with confirmation cutoffs below the screening cutoff. TPs were greatest with OF confirmation cutoffs of THC ≥1 and ≥2 μg/L, but analytical sensitivities were <80% due to false negative tests arising from confirmation cutoffs below the DT5000 and DDS2 screening cutoffs; all criteria were >80% with an OF THC ≥5 μg/L cutoff. Performance criteria also were >80% with a blood THC ≥5 μg/L confirmation cutoff; however, positive OF screening results might not confirm due to the time required to collect blood after a crash or police stop. OF confirmation is recommended for roadside OF screening.

ClinicalTrials.gov identification number: NCT02177513

Long-term stability of cannabinoids in oral fluid after controlled cannabis administration

Cannabinoid stability in oral fluid (OF) is important for assuring accurate results since OF has become a valid alternative matrix of choice for drug testing. We previously published OF cannabinoid stability studies using Quantisal™, Oral-Eze®, and StatSure™ devices stored at room temperature for 1 week, 4 °C for up to 4 weeks, and at -20 °C up to 24 weeks. Extending refrigerated stability up to 3 months would be helpful for clinical and forensic testing, for re-analysis of OF samples and for batching research analyses. Individual authentic OF pools were prepared after controlled smoking of a 6.9% ∆⁹ -tetrahydracannabinol cannabis cigarette; the Quantisal™ device was utilized for OF collection. Fifteen healthy volunteers participated in the Institutional Review Board-approved study. Stability for THC, 11-nor-9-carboxy-THC (THCCOOH), ∆⁹ -tetrahydrocannabivarin (THCV), cannabidiol (CBD), and cannabigerol (CBG) were determined after storage at 4 °C for 1, 2, and 3 months. Results within ±20% of baseline concentrations were considered stable. All analytes were stable for up to 2 months at 4 °C for all participants with positive baseline concentrations. Baseline concentrations were highly variable. In total, THC, THCCOOH, THCV, CBD, and CBG were stable for 3 months at 4 °C for pooled positive specimens from 14 of 15, 8 of 9, 7 of 8, 8 of 9, and 9 of 10 participants, respectively. In conclusion, Quantisal™-collected OF specimens should be stored at 4 °C for no more than two months to assure accurate THC, THCCOOH, THCV, CBD, and CBG quantitative results; only one participant's OF was unstable at three months. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Water-compatible imprinted pills for sensitive determination of cannabinoids in urine and oral fluid

A novel molecularly imprinted solid phase extraction (MISPE) methodology followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) has been developed using cylindrical shaped molecularly imprinted pills for detection of Δ(9)-tetrahydrocannabinol (THC), 11-nor-Δ(9)-tetrahydrocannabinol carboxylic acid (THC-COOH), cannabinol (CBN) and cannabidiol (CBD) in urine and oral fluid (OF). The composition of the molecular imprinted polymer (MIP) was optimized based on the screening results of a non-imprinted polymer library (NIP-library). Thus, acrylamide as functional monomer and ethylene glycol dimethacrylate as cross-linker were selected for the preparation of the MIP, using catechin as a mimic template. MISPE pills were incubated with 0.5 mL urine or OF sample for adsorption of analytes. For desorption, the pills were transferred to a vial with 2 mL of methanol:acetic acid (4:1) and sonicated for 15 min. The elution solvent was evaporated and reconstituted in methanol:formic acid (0.1%) 50:50 to inject in LC-MS/MS. The developed method was linear over the range from 1 to 500 ng mL(-1) in urine and from 0.75 to 500 ng mL(-1) in OF for all four analytes. Intra- and inter-day imprecision were <15%. Extraction recovery was 50-111%, process efficiency 15.4-54.5% and matrix effect ranged from -78.0 to -6.1%. Finally, the optimized and validated method was applied to 4 urine and 5 OF specimens. This is the first method for the determination of THC, THC-COOH, CBN and CBD in urine and OF using MISPE technology.

Nonsmoker Exposure to Secondhand Cannabis Smoke. III. Oral Fluid and Blood Drug Concentrations and Corresponding Subjective Effects

The increasing use of highly potent strains of cannabis prompted this new evaluation of human toxicology and subjective effects following passive exposure to cannabis smoke. The study was designed to produce extreme cannabis smoke exposure conditions tolerable to drug-free nonsmokers. Six experienced cannabis users smoked cannabis cigarettes [5.3% Δ(9)-tetrahydrocannabinol (THC) in Session 1 and 11.3% THC in Sessions 2 and 3] in a closed chamber. Six nonsmokers were seated alternately with smokers during exposure sessions of 1 h duration. Sessions 1 and 2 were conducted with no ventilation and ventilation was employed in Session 3. Oral fluid, whole blood and subjective effect measures were obtained before and at multiple time points after each session. Oral fluid was analyzed by ELISA (4 ng/mL cutoff concentration) and by LC-MS-MS (limit of quantitation) for THC (1 ng/mL) and total THCCOOH (0.02 ng/mL). Blood was analyzed by LC-MS-MS (0.5 ng/mL) for THC, 11-OH-THC and free THCCOOH. Positive tests for THC in oral fluid and blood were obtained for nonsmokers up to 3 h following exposure. Ratings of subjective effects correlated with the degree of exposure. Subjective effect measures and amounts of THC absorbed by nonsmokers (relative to smokers) indicated that extreme secondhand cannabis smoke exposure mimicked, though to a lesser extent, active cannabis smoking.

Oral fluid cannabinoids in chronic frequent cannabis smokers during ad libitum cannabis smoking

Oral fluid (OF) offers a simple, non-invasive, directly observable sample collection for clinical and forensic drug testing. Given that chronic cannabis smokers often engage in drug administration multiple times daily, evaluating OF cannabinoid pharmacokinetics during ad libitum smoking is important for practical development of analytical methods and informed interpretation of test results. Eleven cannabis smokers resided in a closed research unit for 51 days, and underwent four, 5-day oral delta-9-tetrahydrocannabinol (THC) treatments. Each medication period was separated by 9 days of ad libitum cannabis smoking from 12:00 to 23:00 h daily. Ten OF samples were collected from 9:00-22:00 h on each of the last ad libitum smoking days (Study Days 4, 18, 32, and 46). As the number of cannabis cigarettes smoked increased over the study days, OF THC, cannabinol (CBN), and 11-nor-9-carboxy-THC (THCCOOH) also increased with a significant effect of time since last smoking (Δtime; range, 0.0-17.4 h) and ≥88% detection rates; concentrations on Day 4 were significantly lower than those on Days 32 and 46 but not Day 18. Within 30 min of smoking, median THC, CBN, and THCCOOH concentrations were 689 µg/L, 116 µg/L, and 147 ng/L, respectively, decreasing to 19.4 µg/L, 2.4 µg/L, and 87.6 ng/L after 10 h. Cannabidiol and 11-hydroxy-THC showed overall lower detection rates of 29 and 8.6%, respectively. Cannabinoid disposition in OF was highly influenced by Δtime and composition of smoked cannabis. Furthermore, cannabinoid OF concentrations increased over ad libitum smoking days, in parallel with increased cannabis self-administration, possibly reflecting development of increased cannabis tolerance.

Trends in drug testing in oral fluid and hair as alternative matrices

The use of alternative matrices such as oral fluid and hair has increased in the past decades because of advances in analytical technology. However, there are still many issues that need to be resolved. Standardized protocols of sample pretreatment are needed to link the detected concentrations to final conclusions. The development of suitable proficiency testing schemes is required. Finally, interpretation issues such as link to effect, adulteration, detection markers and thresholds will hamper the vast use of these matrices. Today, several niche areas apply these matrices with success, such as drugs and driving for oral fluid and drug-facilitated crimes for hair. Once those issues are resolved, the number of applications will markedly grow in the future.

Impact of oral fluid collection device on cannabinoid stability following smoked cannabis

Evaluation of cannabinoid stability in authentic oral fluid (OF) is critical, as most OF stability studies employed fortified or synthetic OF. Participants (n = 16) smoked a 6.8% delta-9-tetrahydrocannabinol (THC) cigarette, and baseline concentrations of THC, 11-nor-9-carboxy-THC (THCCOOH), cannabidiol (CBD), and cannabinol (CBN) were determined within 24 h in 16 separate pooled samples (collected 1 h before to 10.5 or 13 h after smoking). OF was collected with the StatSure Saliva Sampler™ and Oral-Eze® devices. Oral-Eze samples were re-analyzed after room temperature (RT) storage for 1 week, and for both devices after 4 °C for 1 and 4 weeks, and -20 °C for 4 and 24 weeks. Concentrations ±20% from initial concentrations were considered stable. With the StatSure device, all cannabinoids were within 80-120% median %baseline for all storage conditions. Individual THC, CBD, CBN and THCCOOH pool concentrations were stable in 100%, 100%, 80-94% and >85%, respectively, across storage conditions. With the Oral-Eze device, at RT or refrigerated storage (for 1 and 4 weeks), THC, CBD and THCCOOH were stable in 94-100%, 78-89%, and 93-100% of samples, respectively, while CBN concentrations were 53-79% stable. However, after 24 weeks at -20 °C, stability decreased, especially for CBD, with a median of 56% stability. Overall, the collection devices' elution/stabilizing buffers provided good stability for OF cannabinoids, with the exception of the more labile CBN. To ensure OF cannabinoid concentration accuracy, these data suggest analysis within 4 weeks at 4 °C storage for Oral-Eze collection and within 4 weeks at 4 °C or 24 weeks at -20 °C for StatSure collection. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Cannabinoids in oral fluid by on-site immunoassay and by GC-MS using two different oral fluid collection devices

Oral fluid (OF) enables non-invasive sample collection for on-site drug testing, but performance of on-site tests with occasional and frequent smokers' OF to identify cannabinoid intake requires further evaluation. Furthermore, as far as we are aware, no studies have evaluated differences between cannabinoid disposition among OF collection devices with authentic OF samples after controlled cannabis administration. Fourteen frequent (≥4 times per week) and 10 occasional (less than twice a week) adult cannabis smokers smoked one 6.8% ∆(9)-tetrahydrocannabinol (THC) cigarette ad libitum over 10 min. OF was collected with the StatSure Saliva Sampler, Oral-Eze, and Draeger DrugTest 5000 test cassette before and up to 30 h after cannabis smoking. Test cassettes were analyzed within 15 min and gas chromatography-mass spectrometry cannabinoid results were obtained within 24 h. Cannabinoid concentrations with the StatSure and Oral-Eze devices were compared and times of last cannabinoid detection (t(last)) and DrugTest 5000 test performance were assessed for different cannabinoid cutoffs. 11-nor-9-Carboxy-THC (THCCOOH) and cannabinol concentrations were significantly higher in Oral-Eze samples than in Stat-Sure samples. DrugTest 5000 t(last) for a positive cannabinoid test were median (range) 12 h (4-24 h) and 21 h (1- ≥ 30 h) for occasional and frequent smokers, respectively. Detection windows in screening and confirmatory tests were usually shorter for occasional than for frequent smokers, especially when including THCCOOH ≥20 ng L(-1) in confirmation criteria. No differences in t(last) were observed between collection devices, except for THC ≥2 μg L(-1). We thus report significantly different THCCOOH and cannabinol, but not THC, concentrations between OF collection devices, which may affect OF data interpretation. The DrugTest 5000 on-site device had high diagnostic sensitivity, specificity, and efficiency for cannabinoids.

Evaluation of Δ(9) -tetrahydrocannabinol detection using DrugWipe5S(®) screening and oral fluid quantification after Quantisal™ collection for roadside drug detection via a controlled study with chronic cannabis users

Oral fluid (OF) is potentially useful to detect driving under the influence of drugs because of its ease of sampling. While cannabis is the most prevalent drug in Europe, sensitivity issues for Δ(9) -tetrahydrocannabinol (THC) screening and problems during OF collection are observed. The ability of a recently improved OF screening device - the DrugWipe5S(®) , to detect recent THC use in chronic cannabis smokers, was studied. Ten subjects participated in a double-blind placebo-controlled study. The subjects smoked two subsequent doses of THC; 300 µg/kg and 150 µg/kg with a pause of 75 min using a Volcano vapourizer. DrugWipe5S(®) screening and OF collection using the Quantisal™ device were performed at baseline, 5 min after each administration and 80 min after the last inhalation. Blood samples were drawn simultaneously. The screening devices (n = 80) were evaluated visually after 8 min, while the corresponding OF and serum samples were analyzed respectively with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) or gas chromatography-mass spectrometry (GC-MS). Neat OF THC concentrations ranged from 12 361 ng/g 5 min after smoking down to 34 ng/g 80 min later. Under placebo conditions, a median THC concentration of 8 ng/g OF (0-746 ng/g) and < 1 ng/ mL serum (0-7.8 ng/mL) was observed. The DrugWipe5S(®) was positive just after smoking (90%); however, sensitivity rapidly decreased within 1.5 h (50%). Sensitivity of DrugWipe5S(®) should be improved. As chronic cannabis users have high residual THC concentrations in their serum and OF, confirmation cut-offs should be set according to the aim of detecting recent drug use or establishing zero tolerance.