Disposition of cannabinoids in oral fluid after controlled around-the-clock oral THC administration

Recent challenges and trends in forensic analysis: Δ9-THC isomers pharmacology, toxicology and analysis

Δ9-tetrahydrocannabinol (Δ9-THC) isomers, especially Δ8-tetrahydrocannabinol (Δ8-THC), are increasing in foods, beverages, and e-cigarettes liquids. A major factor is passage of the Agriculture Improvement Act (AIA) that removed hemp containing less than 0.3 % Δ9-THC from the definition of "marijuana" or cannabis. CBD-rich hemp flooded the market resulting in excess product that could be subjected to CBD cyclization to produce Δ8-THC. This process utilizes strong acid and yields toxic byproducts that frequently are not removed prior to sale and are currently inadequately studied. Pharmacological activity is qualitatively similar for Δ8-THC and Δ9-THC, but most preclinical studies in mice, rats, and monkeys documented greater ∆9-THC potency. Both isomers caused graded dose-response effects on euphoria, blurred vision, mental confusion and lethargy, although Δ8-THC was at least 25 % less potent. The most common analytical methodologies providing baseline resolution of ∆8-THC and ∆9-THC in non-biological matrices are liquid-chromatography coupled to diode-array detection (LC-DAD or LC-PDA), while liquid chromatography coupled to mass spectrometry is preferred for biological matrices. Other available analytical methods are gas-chromatography-mass spectrometry (GC-MS) and quantitative nuclear magnetic resonance (QNMR). Current knowledge on the pharmacology of ∆8-THC and other ∆9-THC isomers are reviewed to raise awareness of the activity of these isomers in cannabis products, as well as analytical methods to discriminate ∆9-THC qualitatively, and quantitatively and ∆8-THC in biological and non-biological matrices.

Pharmacokinetics of Cannabis and Its Derivatives in Animals and Humans During Pregnancy and Breastfeeding

Cannabis is one of the most widely used illicit drugs during pregnancy and lactation. With the recent legalization of cannabis in many countries, health professionals are increasingly exposed to pregnant and breastfeeding women who are consuming cannabis on a regular basis as a solution for depression, anxiety, nausea, and pain. Cannabis consumption during pregnancy can induce negative birth outcomes such as reduced birth weight and increased risk of prematurity and admission to the neonatal intensive care unit. Yet, limited information is available regarding the pharmacokinetics of cannabis in the fetus and newborn exposed during pregnancy and lactation. Indeed, the official recommendations regarding the use of cannabis during these two critical development periods lack robust pharmacokinetics data and make it difficult for health professionals to guide their patients. Many clinical studies are currently evaluating the effects of cannabis on the brain development and base their groups mostly on questionnaires. These studies should be associated with pharmacokinetics studies to assess correlations between the infant brain development and the exposure to cannabis during pregnancy and breastfeeding. Our project aims to review the available data on the pharmacokinetics of cannabinoids in adults, neonates, and animals. If the available literature is abundant in adult humans and animals, there is still a lack of published data on the exposure of pregnant and lactating women and neonates. However, some of the published information causes concerns on the exposure and the potential effects of cannabis on fetuses and neonates. The safety of cannabis use for non-medical purpose during pregnancy and breastfeeding needs to be further characterized with proper pharmacokinetic studies in humans feasible in regions where cannabis has been legalized. Given the available data, significant transfer occurs to the fetus and the breastfed newborn with a theoretical risk of accumulation of products known to be biologically active.

Automation System for the Flexible Sample Preparation for Quantification of Δ9-THC-D3, THC-OH and THC-COOH from Serum, Saliva and Urine

In the life sciences, automation solutions are primarily established in the field of drug discovery. However, there is also an increasing need for automated solutions in the field of medical diagnostics, e.g., for the determination of vitamins, medication or drug abuse. While the actual metrological determination is highly automated today, the necessary sample preparation processes are still mainly carried out manually. In the laboratory, flexible solutions are required that can be used to determine different target substances in different matrices. A suitable system based on an automated liquid handler was implemented. It has been tested and validated for the determination of three cannabinoid metabolites in blood, urine and saliva. To extract Δ9-tetrahydrocannabinol-D3 (Δ9-THC-D3), 11-hydroxy-Δ9-tetrahydrocannabinol (THC-OH) and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH) from serum, urine and saliva both rapidly and cost-effectively, three sample preparation methods automated with a liquid handling robot are presented in this article, the basic framework of which is an identical SPE method so that they can be quickly exchanged against each other when the matrix is changed. If necessary, the three matrices could also be prepared in parallel. For the sensitive detection of analytes, protein precipitation is used when preparing serum before SPE and basic hydrolysis is used for urine to cleave the glucuronide conjugate. Recoveries of developed methods are >77%. Coefficients of variation are <4%. LODs are below 1 ng/mL and a comparison with the manual process shows a significant cost reduction.

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.

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.

Validation of a liquid chromatography-tandem mass spectrometry method for analyzing cannabinoids in oral fluid

A liquid chromatography tandem mass spectrometry method was developed for quantifying ten cannabinoids in oral fluid (OF). This method utilizes OF collected by the Quantisal™ device and concurrently quantifies cannabinol (CBN), cannabidiol (CBD), Δ9-tetrahydrocannabinol (THC), 11-hydroxy-Δ9-THC (11-OH-THC), 11-nor-9-carboxy-Δ9-THC (THC-COOH), 11-nor-9-carboxy-Δ9-THC glucuronide (THC-COOH-gluc), Δ9-THC glucuronide (THC-gluc), cannabigerol (CBG), tetrahydrocannabiverin (THCV), and Δ9-tetrahydrocannabinolic acid A (THCA-A). Solid phase extraction was optimized using Oasis Prime HLB 30 mg 96-well plates. Cannabinoids were separated by liquid chromatography over a BEH C18 column and detected by a Waters TQ-S micro tandem mass spectrometer. The lower limits of quantification (LLOQ) were 0.4 ng/mL for CBN, CBD, THC, 11-OH-THC, THC-gluc, and THCV; and 1.0 ng/mL for THC-COOH, THC-COOH-gluc, CBG and THCA-A. Linear ranges extended to 2000 ng/mL for THC and 200 ng/mL for all other analytes. Inter-day analytical bias and imprecision at three levels of quality control (QC) was within ±15%. Mean extraction efficiencies ranged from 26.0-98.8%. Applicability of this method was tested using samples collected from individuals randomly assigned to smoke either a joint containing <0.1%, 5.9%, or 13.4% THC content. This method was able to identify and calculate the concentration of 6 of 10 cannabinoids validated in this method.

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 &lt;80% due to false negative tests arising from confirmation cutoffs below the DT5000 and DDS2 screening cutoffs; all criteria were &gt;80% with an OF THC ≥5 μg/L cutoff. Performance criteria also were &gt;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

Small Molecule Detection in Saliva Facilitates Portable Tests of Marijuana Abuse

As medical and recreational use of cannabis, or marijuana, becomes more prevalent, law enforcement needs a tool to evaluate whether drivers are operating vehicles under the influence of cannabis, specifically the psychoactive substance, tetrahydrocannabinol (THC). However, the cutoff concentration of THC that causes impairment is still controversial, and current on-site screening tools are not sensitive enough to detect trace amounts of THC in oral fluids. Here we present a novel sensing platform that employs giant magnetoresistive (GMR) biosensors integrated with a portable reader system and smartphone to detect THC in saliva using competitive assays. With a simple saliva collection scheme, we have optimized the assay to measure THC in the range from 0 to 50 ng/mL, covering most cutoff values proposed in previous studies. This work facilitates on-site screening for THC and shows potential for testing of other small molecule drugs and analytes in point-of-care (POC) settings.

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.

Quantification of 11-nor-9-carboxy-δ9-tetrahydrocannabinol in human oral fluid by gas chromatography-tandem mass spectrometry

A sensitive and specific method for the quantification of 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH) in oral fluid collected with the Quantisal and Oral-Eze devices was developed and fully validated. Extracted analytes were derivatized with hexafluoroisopropanol and trifluoroacetic anhydride and quantified by gas chromatography-tandem mass spectrometry with negative chemical ionization. Standard curves, using linear least-squares regression with 1/x weighting were linear from 10 to 1000 ng/L with coefficients of determination >0.998 for both collection devices. Bias was 89.2%-112.6%, total imprecision 4.0%-5.1% coefficient of variation, and extraction efficiency >79.8% across the linear range for Quantisal-collected specimens. Bias was 84.6%-109.3%, total imprecision 3.6%-7.3% coefficient of variation, and extraction efficiency >92.6% for specimens collected with the Oral-Eze device at all 3 quality control concentrations (10, 120, and 750 ng/L). This effective high-throughput method reduces analysis time by 9 minutes per sample compared with our current 2-dimensional gas chromatography-mass spectrometry method and extends the capability of quantifying this important oral fluid analyte to gas chromatography-tandem mass spectrometry. This method was applied to the analysis of oral fluid specimens collected from individuals participating in controlled cannabis studies and will be effective for distinguishing passive environmental contamination from active cannabis smoking.

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.

Cannabinoid disposition in oral fluid after controlled cannabis smoking in frequent and occasional smokers

Oral fluid (OF) is an increasingly popular alternative matrix for drug testing, with cannabinoids being the most commonly identified illicit drug. Quantification of multiple OF cannabinoids and understanding differences in OF cannabinoid pharmacokinetics between frequent and occasional smokers improve test interpretation. The new Oral-Eze® OF collection device has an elution buffer that stabilizes analytes and improves drug recovery from the collection pad; however, its performance has not been independently evaluated. After controlled smoking of a 6.8% Δ(9) -tetrahydrocannabinol (THC) cannabis cigarette by frequent and occasional smokers, OF was collected with the Oral-Eze device for up to 30 h. Samples were analyzed for multiple cannabinoids by a validated 2D-GC-MS method. Frequent smokers had significantly greater OF THCCOOH concentrations than occasional smokers at all times, and showed positive results for a significantly longer time. We evaluated multiple cannabinoid cut-offs; the shortest last detection times were observed when THC ≥ 1 μg/L was combined with CBD or CBN ≥ 1 μg/L. With these cut-offs, last detection times(1-13.5 h) were not significantly different between groups, demonstrating suitability for short-term cannabinoid detection independent of smoking history. Cut-offs utilizing THC alone or combined with THCCOOH showed significantly different last detection times between groups. The widest detection windows were observed with THC ≥ 1 or 2 μg/L or THCCOOH ≥ 20 ng/L. Our data illustrate the effectiveness of the Oral-Eze® device for OF collection, the impact of self-administered smoked cannabis history on OF cannabinoid results, and the ability to improve interpretation and tailor OF cannabinoid cut-offs to fulfill the detection window needs of a given program.

Current knowledge on cannabinoids in oral fluid

Oral fluid (OF) is a new biological matrix for clinical and forensic drug testing, offering non-invasive and directly observable sample collection reducing adulteration potential, ease of multiple sample collections, lower biohazard risk during collection, recent exposure identification, and stronger correlation with blood than urine concentrations. Because cannabinoids are usually the most prevalent analytes in illicit drug testing, application of OF drug testing requires sufficient scientific data to support sensitive and specific OF cannabinoid detection. This review presents current knowledge of OF cannabinoids, evaluating pharmacokinetic properties, detection windows, and correlation with other biological matrices and impairment from field applications and controlled drug administration studies. In addition, onsite screening technologies, confirmatory analytical methods, drug stability, and effects of sample collection procedure, adulterants, and passive environmental exposure are reviewed. Delta-9-tetrahydrocannabinol OF concentrations could be >1000 µg/L shortly after smoking, whereas minor cannabinoids are detected at 10-fold and metabolites at 1000-fold lower concentrations. OF research over the past decade demonstrated that appropriate interpretation of test results requires a comprehensive understanding of distinct elimination profiles and detection windows for different cannabinoids, which are influenced by administration route, dose, and drug use history. Thus, each drug testing program should establish cut-off criteria, collection/analysis procedures, and storage conditions tailored to its purposes. Building a scientific basis for OF testing is ongoing, with continuing OF cannabinoids research on passive environmental exposure, drug use history, donor physiological conditions, and oral cavity metabolism needed to better understand mechanisms of cannabinoid OF disposition and expand OF drug testing applicability. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

The potential role of oral fluid in antidoping testing

BACKGROUND

Currently, urine and blood are the only matrices authorized for antidoping testing by the World Anti-Doping Agency (WADA). Although the usefulness of urine and blood is proven, issues remain for monitoring some drug classes and for drugs prohibited only in competition. The alternative matrix oral fluid (OF) may offer solutions to some of these issues. OF collection is easy, noninvasive, and sex neutral and is directly observed, limiting potential adulteration, a major problem for urine testing. OF is used to monitor drug intake in workplace, clinical toxicology, criminal justice, and driving under the influence of drugs programs and potentially could complement urine and blood for antidoping testing in sports.

CONTENT

This review outlines the present state of knowledge and the advantages and limitations of OF testing for each of the WADA drug classes and the research needed to advance OF testing as a viable alternative for antidoping testing.

SUMMARY

Doping agents are either prohibited at all times or prohibited in competition only. Few OF data from controlled drug administration studies are available for substances banned at all times, whereas for some agents prohibited only in competition, sufficient data may be available to suggest appropriate analytes and cutoffs (analytical threshold concentrations) to identify recent drug use. Additional research is needed to characterize the disposition of many banned substances into OF; OF collection methods and doping agent stability in OF also require investigation to allow the accurate interpretation of OF tests for antidoping monitoring.

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

Oral fluid (OF) is an alternative biological matrix for monitoring cannabis intake in drug testing, and drugged driving (DUID) programs, but OF cannabinoid test interpretation is challenging. Controlled cannabinoid administration studies provide a scientific database for interpreting cannabinoid OF tests. We compared differences in OF cannabinoid concentrations from 19 h before to 30 h after smoking a 6.8% THC cigarette in chronic frequent and occasional cannabis smokers. OF was collected with the Statsure Saliva Sampler™ OF device. 2D-GC-MS was used to quantify cannabinoids in 357 OF specimens; 65 had inadequate OF volume within 3 h after smoking. All OF specimens were THC-positive for up to 13.5 h after smoking, without significant differences between frequent and occasional smokers over 30 h. Cannabidiol (CBD) and cannabinol (CBN) had short median last detection times (2.5-4 h for CBD and 6-8 h for CBN) in both groups. THCCOOH was detected in 25 and 212 occasional and frequent smokers' OF samples, respectively. THCCOOH provided longer detection windows than THC in all frequent smokers. As THCCOOH is not present in cannabis smoke, its presence in OF minimizes the potential for false positive results from passive environmental smoke exposure, and can identify oral THC ingestion, while OF THC cannot. THC ≥ 1 μg/L, in addition to CBD ≥ 1 μg/L or CBN ≥ 1 μg/L suggested recent cannabis intake (≤13.5 h), important for DUID cases, whereas THC ≥ 1 μg/L or THC ≥ 2 μg/L cutoffs had longer detection windows (≥30 h), important for workplace testing. THCCOOH windows of detection for chronic, frequent cannabis smokers extended beyond 30 h, while they were shorter (0-24 h) for occasional cannabis smokers.

Oral fluid cannabinoids in chronic cannabis smokers during oral δ9-tetrahydrocannabinol therapy and smoked cannabis challenge

BACKGROUND

Oral Δ(9)-tetrahydrocannabinol (THC) is effective for attenuating cannabis withdrawal and may benefit treatment of cannabis use disorders. Oral fluid (OF) cannabinoid testing, increasing in forensic and workplace settings, could be valuable for monitoring during cannabis treatment.

METHODS

Eleven cannabis smokers resided on a closed research unit for 51 days and received daily 0, 30, 60, and 120 mg of oral THC in divided doses for 5 days. There was a 5-puff smoked cannabis challenge on the fifth day. Each medication session was separated by 9 days of ad libitum cannabis smoking. OF was collected the evening before and throughout oral THC sessions and analyzed by 2-dimensional GC-MS for THC, cannabidiol (CBD), cannabinol (CBN), 11-hydroxy-THC (11-OH-THC), and 11-nor-9-carboxy-THC (THCCOOH).

RESULTS

During all oral THC administrations, THC OF concentrations decreased to ≤ 78.2, 33.2, and 1.4 μg/L by 24, 48, and 72 h, respectively. CBN also decreased over time, with concentrations 10-fold lower than THC, with none detected beyond 69 h. CBD and 11-OH-THC were rarely detected, only within 19 and 1.6 h after smoking, respectively. THCCOOH OF concentrations were dose dependent and increased over time during 120-mg THC dosing. After cannabis smoking, THC, CBN, and THCCOOH concentrations showed a significant dose effect and decreased significantly over time.

CONCLUSIONS

Oral THC dosing significantly affected OF THCCOOH but minimally contributed to THC OF concentrations; prior ad libitum smoking was the primary source of THC, CBD, and CBN. Higher cannabinoid concentrations following active oral THC administrations vs placebo suggest a compensatory effect of THC tolerance on smoking topography.

Oral fluid/plasma cannabinoid ratios following controlled oral THC and smoked cannabis administration

Oral fluid (OF) is a valuable biological alternative for clinical and forensic drug testing. Evaluating OF to plasma (OF/P) cannabinoid ratios provides important pharmacokinetic data on the disposition of drug and factors influencing partition between matrices. Eleven chronic cannabis smokers resided on a closed research unit for 51 days. There were four 5-day sessions of 0, 30, 60, and 120 mg oral ∆(9)-tetrahydrocannabinol (THC)/day followed by a five-puff smoked cannabis challenge on Day 5. Each session was separated by 9 days ad libitum cannabis smoking. OF and plasma specimens were analyzed for THC and metabolites. During ad libitum smoking, OF/P THC ratios were high (median, 6.1; range, 0.2-348.5) within 1 h after last smoking, decreasing to 0.1-20.7 (median, 2.1) by 13.0-17.1 h. OF/P THC ratios also decreased during 5-days oral THC dosing, and after the smoked cannabis challenge, median OF/P THC ratios decreased from 1.4 to 5.5 (0.04-245.6) at 0.25 h to 0.12 to 0.17 (0.04-5.1) at 10.5 h post-smoking. In other studies, longer exposure to more potent cannabis smoke and oromucosal cannabis spray was associated with increased OF/P THC peak ratios. Median OF/P 11-nor-9-carboxy-THC (THCCOOH) ratios were 0.3-2.5 (range, 0.1-14.7) ng/μg, much more consistent in various dosing conditions over time. OF/P THC, but not THCCOOH, ratios were significantly influenced by oral cavity contamination after smoking or oromucosal spray of cannabinoid products, followed by time-dependent decreases. Establishing relationships between OF and plasma cannabinoid concentrations is essential for making inferences of impairment or other clinical outcomes from OF concentrations.

Simultaneous quantification of Δ(9)-tetrahydrocannabinol, 11-nor-9-carboxy-tetrahydrocannabinol, cannabidiol and cannabinol in oral fluid by microflow-liquid chromatography-high resolution mass spectrometry

Δ(9)-Tetrahydrocannabinol (THC) is the primary target in oral fluid (OF) for detecting cannabis intake. However, additional biomarkers are needed to solve interpretation issues, such as the possibility of passive inhalation by identifying 11-nor-9-carboxy-THC (THCCOOH), and determining recent cannabis smoking by identifying cannabidiol (CBD) and/or cannabinol (CBN). We developed and comprehensively validated a microflow liquid chromatography (LC)-high resolution mass spectrometry method for simultaneous quantification of THC, THCCOOH, CBD and CBN in OF collected with the Oral-Eze(®) and Quantisal™ devices. One milliliter OF-buffer solution (0.25mL OF and 0.5mL of Oral-Eze buffer, 1:3 dilution, or 0.75mL Quantisal buffer, 1:4 dilution) had proteins precipitated, and the supernatant subjected to CEREX™ Polycrom™ THC solid-phase extraction (SPE). Microflow LC reverse-phase separation was achieved with a gradient mobile phase of 10mM ammonium acetate pH 6 and acetonitrile over 10min. We employed a Q Exactive high resolution mass spectrometer, with compounds identified and quantified by targeted-MSMS experiments. The assay was linear 0.5-50ng/mL for THC, CBD and CBN, and 15-500pg/mL for THCCOOH. Intra- and inter-day and total imprecision were <10.8%CV and bias 86.5-104.9%. Extraction efficiency was 52.4-109.2%, process efficiency 12.2-88.9% and matrix effect ranged from -86 to -6.9%. All analytes were stable for 24h at 5°C on the autosampler. The method was applied to authentic OF specimens collected with Quantisal and Oral-Eze devices. This method provides a rapid simultaneous quantification of THCCOOH and THC, CBD, CBN, with good selectivity and sensitivity, providing the opportunity to improve interpretation of cannabinoid OF results by eliminating the possibility of passive inhalation and providing markers of recent cannabis smoking.

Can oral fluid cannabinoid testing monitor medication compliance and/or cannabis smoking during oral THC and oromucosal Sativex administration?

OBJECTIVES

We characterize cannabinoid disposition in oral fluid (OF) after dronabinol, synthetic oral Δ(9)-tetrahydrocannabinol (THC), and Sativex, a cannabis-extract oromucosal spray, and evaluate whether smoked cannabis relapse or Sativex compliance can be identified with OF cannabinoid monitoring.

METHODS

5 and 15 mg synthetic oral THC, low (5.4 mg THC, 5.0 mg cannabidiol (CBD)) and high (16.2 mg THC, 15.0 mg CBD) dose Sativex, and placebo were administered in random order (n=14). Oral fluid specimens were collected for 10.5 h after dosing and analyzed for THC, CBD, cannabinol (CBN), and 11-nor-9-carboxy-THC (THCCOOH).

RESULTS

After oral THC, OF THC concentrations decreased over time from baseline, reflecting residual THC excretion from previously self-administered smoked cannabis. CBD and CBN also were rarely detected. After Sativex, THC, CBD and CBN increased greatly, peaking at 0.25-1 h. Median CBD/THC and CBN/THC ratios were 0.82-1.34 and 0.04-0.06, respectively, reflecting cannabinoids' composition in Sativex. THCCOOH/THC ratios within 4.5 h post Sativex were ≤ 1.6 pg/ng, always lower than after oral THC and placebo. THCCOOH/THC ratios increased throughout each dosing session.

CONCLUSIONS

Lack of measurable THC, CBD and CBN in OF following oral THC, and high OF CBD/THC ratios after Sativex distinguish oral and sublingual drug delivery routes from cannabis smoking. Low THCCOOH/THC ratios suggest recent Sativex and smoked cannabis exposure. These data indicate that OF cannabinoid monitoring can document compliance with Sativex pharmacotherapy, and identify relapse to smoked cannabis during oral THC medication but not Sativex treatment, unless samples were collected shortly after smoking.

11-Nor-9-carboxy-∆9-tetrahydrocannabinol quantification in human oral fluid by liquid chromatography-tandem mass spectrometry

Currently, ∆9-tetrahydrocannabinol (THC) is the analyte quantified for oral fluid cannabinoid monitoring. The potential for false-positive oral fluid cannabinoid results from passive exposure to THC-laden cannabis smoke raises concerns for this promising new monitoring technology. Oral fluid 11-nor-9-carboxy-∆9-tetrahydrocannabinol (THCCOOH) is proposed as a marker of cannabis intake since it is not present in cannabis smoke and was not measureable in oral fluid collected from subjects passively exposed to cannabis. THCCOOH concentrations are in the picogram per milliliter range in oral fluid and pose considerable analytical challenges. A liquid chromatography-tandem mass spectrometry (LCMSMS) method was developed and validated for quantifying THCCOOH in 1 mL Quantisal-collected oral fluid. After solid phase extraction, chromatography was performed on a Kinetex C18 column with a gradient of 0.01% acetic acid in water and 0.01% acetic acid in methanol with a 0.5-mL/min flow rate. THCCOOH was monitored in negative mode electrospray ionization and multiple reaction monitoring mass spectrometry. The THCCOOH linear range was 12-1,020 pg/mL (R(2) > 0.995). Mean extraction efficiencies and matrix effects evaluated at low and high quality control (QC) concentrations were 40.8-65.1 and -2.4-11.5%, respectively (n = 10). Analytical recoveries (bias) and total imprecision at low, mid, and high QCs were 85.0-113.3 and 6.6-8.4% coefficient of variation, respectively (n = 20). This is the first oral fluid THCCOOH LCMSMS triple quadrupole method not requiring derivatization to achieve a <15 pg/mL limit of quantification. The assay is applicable for the workplace, driving under the influence of drugs, drug treatment, and pain management testing.

Influence of ethanol on the pharmacokinetic properties of Δ9-tetrahydrocannabinol in oral fluid

Oral fluid (OF) tests aid in identifying drivers under the influence of drugs. In this study, 17 heavy cannabis users consumed alcohol to achieve steady blood alcohol concentrations of 0 to 0.7 g/L and smoked cannabis 3 h afterward. OF samples were obtained before and up to 4 h after smoking and on-site tests were performed (Dräger DrugTest 5000 and Securetec DrugWipe 5+). Maximum concentrations of tetrahydrocannabinol (THC) immediately after smoking (up to 44,412 ng/g) were below 4,300 (median 377) ng/g 1 h after smoking and less than 312 (median 88) ng/g 3 h later with 5 of 49 samples negative, suggesting that recent cannabis use might occasionally not be detectable. An influence of alcohol was not observed. Drinking 300 mL variably influenced THC concentrations (median only -29.6%), which suggests that drinking does not markedly affect on-site test performance. Many (92%) Dräger tests performed 4 h after smoking were still positive, indicating sufficient sensitivity for recent cannabis use. Differences in the results of a roadside study with DrugTest 5000 (sensitivity 84.8%, specificity 96.0%, accuracy 84.3%) could be explained by a higher number of true negatives, differences between OF and serum and differences between occasional and chronic users.

Psychomotor performance, subjective and physiological effects and whole blood Δ⁹-tetrahydrocannabinol concentrations in heavy, chronic cannabis smokers following acute smoked cannabis

Δ⁹-Tetrahydrocannabinol (THC) is the illicit drug most frequently observed in accident and driving under the influence of drugs investigations. Whole blood is often the only available specimen collected during such investigations, yet few studies have examined relationships between cannabis effects and whole blood concentrations following cannabis smoking. Nine male and one female heavy, chronic cannabis smokers resided on a closed research unit and smoked ad libitum one 6.8% THC cannabis cigarette. THC, 11-hydroxy-THC and 11-nor-9-carboxy-THC were quantified in whole blood and plasma. Assessments were performed before and up to 6 h after smoking, including subjective [visual analog scales (VAS) and Likert scales], physiological (heart rate, blood pressure and respirations) and psychomotor (critical-tracking and divided-attention tasks) measures. THC significantly increased VAS responses and heart rate, with concentration-effect curves demonstrating counter-clockwise hysteresis. No significant differences were observed for critical-tracking or divided-attention task performance in this cohort of heavy, chronic cannabis smokers. The cannabis influence factor was not suitable for quantifying psychomotor impairment following cannabis consumption and was not precise enough to determine recent cannabis use with accuracy. These data inform our understanding of impairment and subjective effects following acute smoked cannabis and interpretation of whole blood cannabinoid concentrations in forensic investigations.

Cannabinoid stability in authentic oral fluid after controlled cannabis smoking

BACKGROUND

Defining cannabinoid stability in authentic oral fluid (OF) is critically important for result interpretation. There are few published OF stability data, and of those available, all employed fortified synthetic OF solutions or elution buffers; none included authentic OF following controlled cannabis smoking.

METHODS

An expectorated OF pool and a pool of OF collected with Quantisal™ devices were prepared for each of 10 participants. Δ⁹-tetrahydrocannabinol (THC), 11-nor-9-carboxy-THC (THCCOOH), cannabidiol (CBD), and cannabinol (CBN) stability in each of 10 authentic expectorated and Quantisal-collected OF pools were determined after storage at 4 °C for 1 and 4 weeks and at -20 °C for 4 and 24 weeks. Results within ±20% of baseline concentrations analyzed within 24 h of collection were considered stable.

RESULTS

All Quantisal OF cannabinoid concentrations were stable for 1 week at 4 °C. After 4 weeks at 4 °C, as well as 4 and 24 weeks at -20 °C, THC was stable in 90%, 80%, and 80% and THCCOOH in 89%, 40%, and 50% of Quantisal samples, respectively. Cannabinoids in expectorated OF were less stable than in Quantisal samples when refrigerated or frozen. After 4 weeks at 4 and -20 °C, CBD and CBN were stable in 33%-100% of Quantisal and expectorated samples; by 24 weeks at -20 °C, CBD and CBN were stable in ≤ 44%.

CONCLUSIONS

Cannabinoid OF stability varied by analyte, collection method, and storage duration and temperature, and across participants. OF collection with a device containing an elution/stabilization buffer, sample storage at 4 °C, and analysis within 4 weeks is preferred to maximize result accuracy.

Cannabinoid disposition in oral fluid after controlled smoked cannabis

BACKGROUND

We measured Δ(9)-tetrahydrocannabinol (THC), 11-nor-9-carboxy-THC (THCCOOH), cannabidiol (CBD), and cannabinol (CBN) disposition in oral fluid (OF) following controlled cannabis smoking to evaluate whether monitoring multiple cannabinoids in OF improved OF test interpretation.

METHODS

Cannabis smokers provided written informed consent for this institutional review board-approved study. OF was collected with the Quantisal™ device following ad libitum smoking of one 6.8% THC cigarette. Cannabinoids were quantified by 2-dimensional GC-MS. We evaluated 8 alternative cutoffs based on different drug testing program needs.

RESULTS

10 participants provided 86 OF samples -0.5 h before and 0.25, 0.5, 1, 2, 3, 4, 6, and 22 h after initiation of smoking. Before smoking, OF samples of 4 and 9 participants were positive for THC and THCCOOH, respectively, but none were positive for CBD and CBN. Maximum THC, CBD, and CBN concentrations occurred within 0.5 h, with medians of 644, 30.4, and 49.0 μg/L, respectively. All samples were THC positive at 6 h (2.1-44.4 μg/L), and 4 of 6 were positive at 22 h. CBD and CBN were positive only up to 6 h in 3 (0.6-2.1 μg/L) and 4 (1.0-4.4 μg/L) participants, respectively. The median maximum THCCOOH OF concentration was 115 ng/L, with all samples positive to 6 h (14.8-263 ng/L) and 5 of 6 positive at 22 h.

CONCLUSIONS

By quantifying multiple cannabinoids and evaluating different analytical cutoffs after controlled cannabis smoking, we determined windows of drug detection, found suggested markers of recent smoking, and minimized the potential for passive contamination.

Cannabinoids and metabolites in expectorated oral fluid following controlled smoked cannabis

BACKGROUND

∆(9)-Tetrahydrocannabinol (THC) in oral fluid (OF) implies cannabis intake, but eliminating passive exposure and improving interpretation of test results requires additional research.

METHODS

Ten adult cannabis users smoked ad libitum one 6.8% THC cigarette. Expectorated OF was collected for up to 22 h, and analyzed within 24h of collection. THC, 11-nor-9-carboxy-THC (THCCOOH), cannabidiol, and cannabinol were quantified by 2-dimensional-GCMS.

RESULTS

Eighty specimens were analyzed; 6 could not be collected due to dry mouth. THC was quantifiable in 95.2%, cannabidiol in 69.3%, cannabinol in 62.3%, and THCCOOH in 94.7% of specimens. Highest THC, cannabidiol, and cannabinol concentrations were 22370, 1000, and 1964 μg/l, respectively, 0.25 h after the start of smoking; THCCOOH peaked within 2h (up to 560 ng/l). Concentrations 6h after smoking were THC (0.9-90.4 μg/l) and THCCOOH (17.0-151 ng/l) (8 of 9 positive for both); only 4 were positive for cannabidiol (0.5-2.4 μg/l) and cannabinol (1.0-3.0 μg/l). By 22 h, there were 4 THC (0.4-10.3 μg/l), 5 THCCOOH (6.0-24.0 ng/l), 1 cannabidiol (0.3 μg/l), and no cannabinol positive specimens.

CONCLUSIONS

THCCOOH in OF suggests no passive contamination, and CBD and CBN suggest recent cannabis smoking. Seventeen alternative cutoffs were evaluated to meet the needs of different drug testing programs.

Oral fluid and plasma cannabinoid ratios after around-the-clock controlled oral Δ(9)-tetrahydrocannabinol administration

BACKGROUND

Oral fluid (OF) testing is increasingly important for drug treatment, workplace, and drugged-driving programs. There is interest in predicting plasma or whole-blood concentrations from OF concentrations; however, the relationship between these matrices is incompletely characterized because of few controlled drug-administration studies.

METHODS

Ten male daily cannabis smokers received around-the-clock escalating 20-mg oral Δ(9)-tetrahydrocannabinol (THC, dronabinol) doses (40-120 mg/day) for 8 days. Plasma and OF samples were simultaneously collected before, during, and after dosing. OF THC, 11-hydroxy-THC and 11-nor-9-carboxy-THC (THCCOOH) were quantified by GC-MS at 0.5-μg/L, 0.5-μg/L, and 7.5-ng/L limits of quantification (LOQs), respectively. In plasma, the LOQs were 0.25 μg/L for THC and THCCOOH, and 0.5 μg/L for 11-hydroxy-THC.

RESULTS

Despite multiple oral THC administrations each day and increasing plasma THC concentrations, OF THC concentrations generally decreased over time, reflecting primarily previously self-administered smoked cannabis. The logarithms of the THC concentrations in oral fluid and plasma were not significantly correlated (r = -0.10; P = 0.065). The OF and plasma THCCOOH concentrations, albeit with 1000-fold higher concentrations in plasma, increased throughout dosing. The logarithms of OF and plasma THCCOOH concentrations were significantly correlated (r = 0.63; P < 0.001), although there was high interindividual variation. A high OF/plasma THC ratio and a high OF THC/THCCOOH ratio indicated recent cannabis smoking.

CONCLUSIONS

OF monitoring does not reliably detect oral dronabinol intake. The time courses of THC and THCCOOH concentrations in plasma and OF were different after repeated oral THC doses, and high interindividual variation was observed. For these reasons, OF cannabinoid concentrations cannot predict concurrent plasma concentrations.

Cannabinoids in oral fluid following passive exposure to marijuana smoke

The concentration of tetrahydrocannabinol (THC) and its main metabolite 11-nor-Δ(9)-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) as well as cannabinol (CBN), and cannabidiol (CBD) were measured in oral fluid following realistic exposure to marijuana in a Dutch coffee-shop. Ten healthy subjects, who were not marijuana smokers, volunteered to spend 3h in two different coffee shops in Groningen, The Netherlands. Subjects gave two oral fluid specimens at each time point: before entering the store, after 20 min, 40 min, 1h, 2h, and 3h of exposure. The specimens were collected outside the shop. Volunteers left the shop completely after 3h and also provided specimens approximately 12-22 h after beginning the exposure. The oral fluid specimens were subjected to immunoassay screening; confirmation for THC, cannabinol and cannabidiol using GC/MS; and THC-COOH using two-dimensional GC-GC/MS. THC was detectable in all oral fluid specimens taken 3h after exposure to smoke from recreationally used marijuana. In 50% of the volunteers, the concentration at the 3h time-point exceeded 4 ng/mL of THC, which is the current recommended cut-off concentration for immunoassay screening; the concentration of THC in 70% of the oral fluid specimens exceeded 2 ng/mL, currently proposed as the confirmatory cut-off concentration. THC-COOH was not detected in any specimens from passively exposed individuals. Therefore it is recommended that in order to avoid false positive oral fluid results assigned to marijuana use, by analyzing for only THC, the metabolite THC-COOH should also be monitored.

Cannabinoids and metabolites in expectorated oral fluid after 8 days of controlled around-the-clock oral THC administration

Oral fluid (OF) is an increasingly accepted matrix for drug testing programs, but questions remain about its usefulness for monitoring cannabinoids. Expectorated OF specimens (n = 360) were obtained from 10 adult daily cannabis smokers before, during, and after 37 20-mg oral Δ(9)-tetrahydrocannabinol (THC) doses over 9 days to characterize cannabinoid disposition in this matrix. Specimens were extracted and analyzed by gas chromatography-mass spectrometry with electron-impact ionization for THC, 11-hydroxy-THC, cannabidiol, and cannabinol, and negative chemical ionization for 11-nor-9-carboxy-THC (THCCOOH). Linear ranges for THC, 11-hydroxy-THC, and cannabidiol were 0.25-50 ng/mL; cannabinol 1-50 ng/mL; and THCCOOH 5-500 pg/mL. THCCOOH was the most prevalent analyte in 344 specimens (96.9%), with concentrations up to 1,390.3 pg/mL. 11-hydroxy-THC, cannabidiol, and cannabinol were detected in 1, 1, and 3 specimens, respectively. THC was detected in only 13.8% of specimens. The highest THC concentrations were obtained at admission (median 1.4 ng/mL, range 0.3-113.6) from previously self-administered smoked cannabis. A total of 2.5 and 3.7% of specimens were THC-positive at the recommended Substance Abuse and Mental Health Services Administration (2 ng/mL) and Driving Under the Influence of Drugs, Alcohol and Medicines (DRUID) (1 ng/mL) confirmation cutoffs, respectively. THC is currently the only analyte for monitoring cannabis exposure in OF; however, these data indicate chronic therapeutic oral THC administration and illicit oral THC use are unlikely to be identified with current guidelines. Measurement of THCCOOH may improve the detection and interpretation of OF cannabinoid tests and minimize the possibility of OF contamination from passive inhalation of cannabis smoke.