On-site oral fluid Δ9-tetrahydrocannabinol (THC) screening after controlled smoked, vaporized, and oral cannabis administration

Detection of Cannabinoids in Oral Fluid Specimens as the Preferred Biological Matrix for a Point-of-Care Biosensor Diagnostic Device

An increasing number of countries have started to decriminalize or legalize the consumption of cannabis for recreational and medical purposes. The active ingredients in cannabis, termed cannabinoids, affect multiple functions in the human body, including coordination, motor skills, memory, response time to external stimuli, and even judgment. Cannabinoids are a unique class of terpeno-phenolic compounds, with 120 molecules discovered so far. There are certain situations when people under the influence of cannabis may be a risk to themselves or the public safety. Over the past two decades, there has been a growing research interest in detecting cannabinoids from various biological matrices. There is a need to develop a rapid, accurate, and reliable method of detecting cannabinoids in oral fluid as it can reveal the recent intake in comparison with urine specimens, which only show a history of consumption. Significant improvements are continuously made in the analytical formats of various technologies, mainly concerning improving their sensitivity, miniaturization, and making them more user-friendly. Additionally, sample collection and pretreatment have been extensively studied, and specific devices for collecting oral fluid specimens have been perfected to allow rapid and effective sample collection. This review presents the recent findings regarding the use of oral fluid specimens as the preferred biological matrix for cannabinoid detection in a point-of-care biosensor diagnostic device. A critical review is presented, discussing the findings from a collection of review and research articles, as well as publicly available data from companies that manufacture oral fluid screening devices. Firstly, the various conventional methods used to detect cannabinoids in biological matrices are presented. Secondly, the detection of cannabinoids using point-of-care biosensors is discussed, emphasizing oral fluid specimens. This review presents the current pressing technological challenges and highlights the gaps where new technological solutions can be implemented.

Recent advances in the development of portable technologies and commercial products to detect Δ9-tetrahydrocannabinol in biofluids: a systematic review

BACKGROUND

The primary components driving the current commercial fascination with cannabis products are phytocannabinoids, a diverse group of over 100 lipophilic secondary metabolites derived from the cannabis plant. Although numerous phytocannabinoids exhibit pharmacological effects, the foremost attention has been directed towards Δ9-tetrahydrocannabinol (THC) and cannabidiol, the two most abundant phytocannabinoids, for their potential human applications. Despite their structural similarity, THC and cannabidiol diverge in terms of their psychotropic effects, with THC inducing notable psychological alterations. There is a clear need for accurate and rapid THC measurement methods that offer dependable, readily accessible, and cost-effective analytical information. This review presents a comprehensive view of the present state of alternative technologies that could potentially facilitate the creation of portable devices suitable for on-site usage or as personal monitors, enabling non-intrusive THC measurements.

METHOD

A literature survey from 2017 to 2023 on the development of portable technologies and commercial products to detect THC in biofluids was performed using electronic databases such as PubMed, Scopus, and Google Scholar. A systematic review of available literature was conducted using Preferred Reporting Items for Systematic. Reviews and Meta-analysis (PRISMA) guidelines.

RESULTS

Eighty-nine studies met the selection criteria. Fifty-seven peer-reviewed studies were related to the detection of THC by conventional separation techniques used in analytical laboratories that are still considered the gold standard. Studies using optical (n = 12) and electrochemical (n = 13) portable sensors and biosensors were also identified as well as commercially available devices (n = 7).

DISCUSSION

The landscape of THC detection technology is predominantly shaped by immunoassay tests, owing to their established reliability. However, these methods have distinct drawbacks, particularly for quantitative analysis. Electrochemical sensing technology holds great potential to overcome the challenges of quantification and present a multitude of advantages, encompassing the possibility of miniaturization and diverse modifications to amplify sensitivity and selectivity. Nevertheless, these sensors have considerable limitations, including non-specific interactions and the potential interference of compounds and substances existing in biofluids.

CONCLUSION

The foremost challenge in THC detection involves creating electrochemical sensors that are both stable and long-lasting while exhibiting exceptional selectivity, minimal non-specific interactions, and decreased susceptibility to matrix interferences. These aspects need to be resolved before these sensors can be successfully introduced to the market.

Roadside screening tests for cannabis use: A systematic review

As more countries legalize recreational cannabis, roadside screening programs are imperative to detect and deter driving under the influence of cannabis. This systematic review evaluated roadside screening tests for cannabis use. We searched six databases (inception-March 2020) and grey literature sources for primary studies evaluating test characteristics of roadside screening tests for cannabis use compared to laboratory tests for cannabinoids in blood or oral fluid. The synthesis was focused on sensitivity and specificity of delta-9-tetrahydrocannabinol (THC) detection. 101 studies were included. Oral fluid tests were higher in specificity and lower in sensitivity compared to urine tests when evaluated against blood laboratory tests. Oral fluid tests were higher in sensitivity and similar in specificity compared to observational tests when evaluated against blood and oral fluid laboratory tests. Sensitivity was variable among oral fluid tests; two instrumented immunoassays (Draeger DrugTest 5000 [5 ng/mL THC cut-off] and Alere DDS 2 Mobile Test System) appeared to perform best, but definitive conclusions could not be drawn due to imprecise estimates. Specificities were similar. Overall, oral fluid tests showed the most promise for use in roadside screening for blood THC levels over legal limits; their continued development and testing are warranted. Urine tests are generally inadvisable, and observational tests require sensitivity improvements.

Suitability of SoToxa® Oral Fluid Screening Over Time: Re-examination of Drugged Driving in Wisconsin

Drug impaired driver detection is a critical element of traffic safety. However, shifting drug use patterns over time and geography may limit long-term reliability of assay-based screening tools. In this work, we compare qualitative results from the Abbott SoToxa® oral fluid (OF) screening device to Quantisal™ OF and whole blood. Our objective was to examine these three qualitative toxicological approaches, scope applicability of OF collection at the roadside, and compare to a previous analysis of SoToxa® in Wisconsin. OF specimens were screened with the SoToxa® for six drugs or drug classes including amphetamine, benzodiazepines, cocaine, methamphetamine, opioids, and tetrahydrocannabinol (THC). OF and blood specimens were collected from 106 participants. Quantisal™ OF and blood specimens were screened for drugs on ultra-performance liquid chromatography coupled to quadrupole time-of-flight high-resolution mass spectrometry (UPLC-QToF-HRMS) using a data independent acquisition mode. UPLC-QToF-HRMS data was compared to comprehensive spectral libraries and drugs were qualitatively identified. Drug Recognition Expert evaluations were performed, and face sheets submitted for 21 participants in this work. In general, the SoToxa® results were consistent with the combined qualitative results observed in Quantisal™ OF specimens and whole blood specimens. Limitations were uncovered for benzodiazepines, opioids, and THC. The SoToxa® benzodiazepine assay has high cutoff concentrations for diazepam and clonazepam, limiting its sensitivity and positive predictive value when considering these drugs. SoToxa® opioid screening did not detect fentanyl, which is increasingly prevalent among drug users. Finally, ∆9-THC and its major metabolite 11-nor-9-carboxy-∆9-THC are lipophilic, limiting partitioning into oral fluid. Despite these limitations, the SoToxa® instrument may be useful in assisting law enforcement with identifying individuals driving under the influence of drugs and establishing probable cause at roadside for making impaired driving arrests. Furthermore, Quantisal™ OF may be useful as screening specimens due to their ease of collection and results consistent with whole blood.

Emerging trends in point-of-care sensors for illicit drugs analysis

Consumption of illicit narcotic drugs and fatal or criminal activities under their influence has become an utmost concern worldwide. These drugs influence an individual's feelings, perceptions, and emotions by altering the state of consciousness and thus can result in serious safety breaches at critical workplaces. Point-of-care drug-testing devices have become the need-of-the-hour for many sections such as the law enforcement agencies, the workplaces, etc. for safety and security. This review focuses on the recent progress on various electrochemical and optical nanosensors developed for the analysis of the most common illicit drugs (or their metabolites) such as tetrahydrocannabinol (THC), cocaine (COC), opioids (OPs), amphetamines & methamphetamine, and benzodiazepine (BZDs). The paper also highlights the sensitivity and selectivity of various sensing modalities along with evolving parameters such as real-time monitoring and measurement via a smart user interface. An overall outlook of recent technological advances in point of care (POC) devices and guided insights and directions for future research is presented.

Orally administered cannabidiol does not produce false-positive tests for Δ9 -tetrahydrocannabinol on the Securetec DrugWipe® 5S or Dräger DrugTest® 5000

Many jurisdictions use point‐of‐collection (POC) oral fluid testing devices to identify driving under the influence of cannabis, indexed by the presence of Δ⁹‐tetrahydrocannabinol (THC), an intoxicating cannabinoid, in oral fluid. Although the use of the non‐intoxicating cannabinoid, cannabidiol (CBD), is not prohibited among drivers, it is unclear whether these devices can reliably distinguish between CBD and THC, which have similar chemical structures. This study determined whether orally administered CBD produces false‐positive tests for THC on standard, POC oral fluid testing devices. In a randomised, double‐blind, crossover design, healthy participants (n = 17) completed four treatment sessions involving the administration of either placebo or 15‐, 300‐ or 1500‐mg pure CBD in a high‐fat dietary supplement. Oral fluid was sampled, and the DrugWipe®‐5S (DW‐5S; 10 ng·ml⁻¹ THC cut‐off) and Drug Test® 5000 (DT5000; 10 ng·mL⁻¹ THC cut‐off) devices administered, at baseline (pretreatment) and ~20‐, ~145‐ and ~185‐min posttreatment. Oral fluid cannabinoid concentrations were measured using ultra‐high performance liquid chromatography–tandem mass spectrometry. Median (interquartile range [IQR]) oral fluid CBD concentrations were highest at ~20 min, quantified as 0.4 (6.0), 15.8 (41.6) and 167 (233) ng·ml⁻¹ on the 15‐, 300‐ and 1500‐mg CBD treatments, respectively. THC, cannabinol and cannabigerol were not detected in any samples. A total of 259 DW‐5S and 256 DT5000 tests were successfully completed, and no THC‐positive tests were observed. Orally administered CBD does not appear to produce false‐positive (or true‐positive) tests for THC on the DW‐5S and DT5000. The likelihood of an individual who is using a CBD (only) oral formulation being falsely accused of DUIC therefore appears low.

Quantitation of Δ8-THC, Δ9-THC, Cannabidiol, and Ten Other Cannabinoids and Metabolites in Oral Fluid by HPLC-MS/MS

Quantitative analysis of Δ9-tetrahydrocannabinol (Δ9-THC) in oral fluid has gained increasing interest in clinical and forensic toxicology laboratories. New medicinal and/or recreational cannabinoid products require laboratories to distinguish different patterns of cannabinoid use. This study validated a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for 13 different cannabinoids, including (-)-trans-Δ8-tetrahydrocannabinol (Δ8-THC), (-)-trans-Δ9-tetrahydrocannabinol (Δ9-THC), cannabidiol (CBD), Δ9-tetrahydrocannabinolic acid-A (Δ9-THCA-A), cannabidiolic acid (CBDA), 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-Δ9-THC), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (Δ9-THCCOOH), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabidiorcol (CBD-C1), cannabichromene (CBC), cannabinol (CBN) and cannabigerol (CBG) in oral fluid. Baseline separation was achieved in the entire quantitation range between Δ9-THC and its isomer Δ8-THC. The quantitation range of Δ9-THC, Δ8-THC, and CBD was from 0.1 ng/mL to 800 ng/mL. Two hundred human subject oral fluid samples were analyzed with this method after solid phase extraction (SPE). Among the 200 human subject oral fluid samples, all 13 cannabinoid analytes were confirmed in at least one sample. Δ8-THC was confirmed in 11 samples, with or without the present of Δ9-THC. A high concentration of 11-OH-Δ9-THC or Δ9-THCCOOH (>400 ng/mL) was confirmed in three samples. CBD, Δ9-THCA-A, THCV, CBN, and CBG were confirmed in 74, 39, 44, 107, and 112 of the 179 confirmed Δ9-THC positive samples, respectively. The quantitation of multiple cannabinoids and metabolites in oral fluid simultaneously provides valuable information for revealing cannabinoid consumption and interpreting cannabinoid-induced driving impairment.

Topical review on monitoring tetrahydrocannabinol in breath

Legalization of cannabis for recreational use has compelled governments to seek new tools to accurately monitor Δ9-tetrahydrocannabinol (Δ9-THC) and understand its effect on impairment. Various methods have been employed to measure Δ9-THC, and its respective metabolites, in different biological matrices. Recently, breath analysis has gained interest as a non-invasive method for the detection of chemicals that are either produced as part of biological processes or are absorbed from the environment. Existing breath analyzers function by analyzing previously collected samples or by direct real-time analysis. Portable hand-held devices are of particular interest for law enforcement and personal use. This paper reviews and compares both commercially available and prototype devices that proclaim Δ9-THC detection in exhaled breath using methods such as Field Asymmetric Ion Mobility Spectrometry, Semiconductor-Enriched Single-Walled Carbon Nanotube chemiresistors, Liquid Chromatography Tandem-mass Spectrometry, microfluidic-based artificial olfaction, and optical-based gas sensing.

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.

Using Sesame Seed Oil to Preserve and Preconcentrate Cannabinoids for Paper Spray Mass Spectrometry

Cannabinoids present a unique set of analytical challenges. An increasing number of states have voted to decriminalize recreational marijuana use, creating a need for new kinds of rapid testing. At the same time, synthetic compounds with activity similar to THC, termed synthetic cannabinoids, have become more prevalent and pose significant health risks. A rapid method capable of detecting both natural and synthetic cannabinoids would be useful in cases of driving under the influence of drugs, where it might not be obvious whether the suspect consumed marijuana, a synthetic cannabinoid, or both. Paper spray mass spectrometry is an ambient ionization technique which allows for the direct ionization of analyte from a biofluid spot on a piece of paper. Natural cannabinoids like THC, however, are labile and rapidly disappear from dried sample spots, making it difficult to detect them at clinically relevant levels. Presented here is a method to concentrate and preserve THC and synthetic cannabinoids in urine and oral fluid on paper for analysis by paper spray mass spectrometry. Sesame seed oil was investigated both as a means of preserving THC and as part of a technique, termed paper strip extraction, wherein urine or oral fluid is flowed through an oil spot on a strip of paper to preconcentrate cannabinoids. This technique preserved THC in dried biofluid samples for at least 27 days at room temperature; paper spray MS/MS analysis of these preserved dried spots was capable of detecting THC and synthetic cannabinoids at low ng/mL concentrations, making it suitable as a rapid screening technique. The technique was adapted to be used with a commercially available autosampler.

Detection of Δ9 THC in oral fluid following vaporized cannabis with varied cannabidiol (CBD) content: An evaluation of two point-of-collection testing devices

Point‐of‐collection testing (POCT) for Δ⁹‐tetrahydrocannabinol (THC) in oral fluid is increasingly used to detect driving under the influence of cannabis (DUIC). However, previous studies have questioned the reliability and accuracy of two commonly used POCT devices, the Securetec DrugWipe^® 5 s (DW5s) and Dräger DrugTest^® 5000 (DT5000). In the current placebo controlled, double‐blind, crossover study we used liquid chromatography‐tandem mass spectrometry (LC–MS/MS) to accurately quantify cannabinoid concentrations in the oral fluid of 14 participants at various timepoints (10, 60, 120, and 180 minutes) following vaporization of 125 mg of THC‐dominant (11% THC; <1% CBD), THC/CBD equivalent (11% THC; 11% CBD) and placebo (<1% THC; <1% CBD) cannabis. At each timepoint, oral fluid was also screened using the DW5s (10 ng/mL THC cut‐off) and DT5000 (10 ng/mL THC cut‐off). LC–MS/MS analysis showed peak oral fluid THC concentrations at the 10 minute timepoint with a rapid decline thereafter. This trajectory did not differ with THC dominant and THC/CBD equivalent cannabis. With a 10 ng/mL confirmatory cut‐off, 5% of DW5s test results were false positives and 16% false negatives. For the DT5000, 10% of test results were false positives and 9% false negatives. Neither the DW5s nor the DT5000 demonstrated the recommended >80% sensitivity, specificity and accuracy. Accuracy was lowest at 60 minutes, when THC concentrations were often close to the screening cut‐off (10 ng/mL). POCT devices can be useful tools in detecting recent cannabis use; however, limitations should be noted, and confirmatory LC–MS/MS quantification of results is strongly advisable.