A pilot safety, tolerability and pharmacokinetic study of an oro-buccal administered cannabidiol-dominant anti-inflammatory formulation in healthy individuals: a randomized placebo-controlled single-blinded study

Pharmacokinetics of Cannabidiol: A Systematic Review and Meta-Regression Analysis

Background: In this review, we provide an updated assessment of available evidence on the pharmacokinetics (PK) of CBD and explore the impact of different factors on PK outcomes. Materials and Methods: This systematic review and meta-regression analysis was preregistered (PROSPERO: CRD42021269857). We systematically searched Medline, Embase, PsycInfo, and Web of Science Core Collection up to November 19, 2022. Trials of CBD in healthy adults were included if they reported at least one of the PK parameters of interest, including Tmax, Cmax, AUC0-t, AUC0-inf, and T1/2, in serum or plasma. Studies of patient populations or CBD co-administration with other medications were excluded. The National Heart, Lung, and Blood Institute's Quality Assessment Tool for Before-After Studies with no Control Group was used. Random-effects multivariable meta-regression analysis was conducted. Results: A total of 112 trial arms from 39 studies were included; 26 trial arms had a "Good" quality, 70 "Fair," and 16 "Poor." Eight arms used inhalation CBD, 29 oromucosal, 73 oral, and 2 intravenous. CBD formulations could be categorized to nanotech (n=14), oil-based (n=21), alcohol-based (n=10), water-based (n=12), Sativex (n=17), and Epidiolex® (n=22). For single-dose studies, CBD doses ranged between 2 and 100 mg in inhalation, 5-50 mg in oromucosal, and 0.42-6000 mg in oral administration. Sixty-six trial arms had only male participants or a higher number of male than female participants. The duration of the PK session was between 4 and 164 h. A higher CBD dose was associated with higher Cmax, AUC0-t, and AUC0-inf. Compared with oral administration, oromucosal administration was associated with lower Cmax, AUC0-t, and AUC0-inf. Fed status was associated with higher Cmax and AUC0-t when compared with the fasting status. A higher ratio of female participants was associated with lower Tmax in oral administration and higher Cmax. Conclusion: As expected, CBD dose, route of administration, and diet were major determinants of CBD PK with oral routes providing higher bioavailability and nanotechnology formulations a faster onset. Although CBD appeared to have a faster onset and longer duration in women, more studies are required to delineate the role of biological sex. Factors that influence CBD PK have implications for medication development and appropriate dosing in clinical practice.

Cannabidiol and its application in the treatment of oral diseases: therapeutic potentials, routes of administration and prospects

Cannabidiol (CBD), one of the most important active ingredients in cannabis, has been reported to have some pharmacological effects such as antibacterial and analgesic effects, and to have therapeutic potential in the treatment of oral diseases such as oral cancer, gingivitis and periodontal diseases. However, there is a lack of relevant systematic research and reviews. Therefore, based on the etiology and clinical symptoms of several common oral diseases, this paper focuses on the therapeutic potential of CBD in periodontal diseases, pulp diseases, oral mucosal diseases, oral cancer and temporomandibular joint diseases. The pharmacological effects of CBD and the distribution and function of its receptors in the oral cavity are also summarized. In order to provide reference for future research and further clinical application of CBD, we also summarize several possible routes of administration and corresponding characteristics. Finally, the challenges faced while applying CBD clinically and possible solutions are discussed, and we also look to the future.

Quantitative summary on the human pharmacokinetic properties of cannabidiol to accelerate scientific clinical application of cannabis

Cannabidiol (CBD) is a non-psychoactive substance that exerts numerous pharmacological benefits, including anti-inflammatory and antioxidant properties. It has received attention as a useful substance for the treatment of intractable pain, seizures, and anxiety, and related clinical trials have continued. However, the CBD pharmacokinetic results between reports are highly variable, making it difficult to clearly identify the pharmacokinetic properties of CBD. The main purpose of this study was to identify CBD clinical pharmacokinetic properties through meta-analysis. In particular, we sought to derive valid, interpretable independent variables and interpret their pharmacokinetic parameter correlations in relation to the large inter-individual and inter-study variability in CBD pharmacokinetics. For this study, CBD-related clinical trial reports were extensively screened and intercomparisons were performed between internal data sets through systematic classification and extraction of pharmacokinetic parameter values. The candidate independent variables associated with interpretation of CBD pharmacokinetic diversity established and explored in this study were as follows: diet, tetrahydrocannabinol (THC) combination, sample matrix type, liver and renal function, exposure route, dosage form, CBD exposure dose, cannabis smoking frequency, multiple exposure. The results of this study showed that CBD pharmacokinetics were influenced (increased plasma exposure by approximately 2-5 times) by diet immediately before or during CBD exposure, and that THC was not expected to have an antagonistic effect on the CBD absorption. The influence of changes in liver function would be significant in CBD pharmacokinetic diversity. Due to decreased liver function, the plasma exposure of CBD increased 2.57-5.15 times compared to healthy adults, and the half-life and clearance showed a 2.58-fold increase and a 5.15-fold decrease, respectively. CBD can be rapidly absorbed into the body (time to reach maximum concentration within 3.18 h) by oral, transdermal, and inhalation exposures, and lipid emulsification and nanoformulation of CBD will greatly improve CBD bioavailability (up to approximately 2 times). The pharmacokinetics of CBD generally follow linear kinetic characteristics. The importance of this study is that it suggests key factors that should be considered in terms of pharmacokinetics in further clinical trials and formulations of CBD in the future.

Strategies to Improve Cannabidiol Bioavailability and Drug Delivery

The poor physicochemical properties of cannabidiol (CBD) hamper its clinical development. The aim of this review was to examine the literature to identify novel oral products and delivery strategies for CBD, while assessing their clinical implications and translatability. Evaluation of the published literature revealed that oral CBD strategies are primarily focused on lipid-based and emulsion solutions or encapsulations, which improve the overall pharmacokinetics (PK) of CBD. Some emulsion formulations demonstrate more rapid systemic delivery. Variability in the PK effects of different oral CBD products is apparent across species. Several novel administration routes exist for CBD delivery that may offer promise for specific indications. For example, intranasal administration and inhalation allow quick delivery of CBD to the plasma and the brain, whereas transdermal and transmucosal administration routes deliver CBD systemically more slowly. There are limited but promising data on novel delivery routes such as intramuscular and subcutaneous. Very limited data show that CBD is generally well distributed across tissues and that some CBD products enable increased delivery of CBD to different brain regions. However, evidence is limited regarding whether changes in CBD PK profiles and tissue distribution equate to superior therapeutic efficacy across indications and whether specific CBD products might be suited to particular indications.

Cannabidiol for the Treatment of Brain Disorders: Therapeutic Potential and Routes of Administration

The use of cannabidiol (CBD) for treating brain disorders has gained increasing interest. While the mechanism of action of CBD in these conditions is still under investigation, CBD has been shown to affect numerous different drug targets in the brain that are involved in brain disorders. Here we review the preclinical and clinical evidence on the potential therapeutic use of CBD in treating various brain disorders. Moreover, we also examine various drug delivery approaches that have been applied to CBD. Due to the slow absorption and low bioavailability with the current oral CBD therapy, more efficient routes of administration to bypass hepatic metabolism, particularly pulmonary delivery, should be considered. Comparison of pharmacokinetic studies of different delivery routes highlight the advantages of intranasal and inhalation drug delivery over other routes of administration (oral, injection, sublingual, buccal, and transdermal) for treating brain disorders. These two routes of delivery, being non-invasive and able to achieve fast absorption and increase bioavailability, are attracting increasing interest for CBD applications, with more research and development expected in the near future.

Pharmacokinetics of Cannabidiol: A systematic review and meta-regression analysis

Background

In this review, we provide an updated assessment of available evidence on the pharmacokinetics (PK) of cannabidiol (CBD) and explore the impact of different factors on PK outcomes.

Materials and Methods

This systematic review and meta-regression analysis was pre-registered (PROSPERO: CRD42021269857). We systematically searched Medline, Embase, PsychInfo, and Web of Science Core Collection up to November 19, 2022. Trials of CBD in healthy adults were included if they reported at least one of the PK parameters of interest, including Tmax, Cmax, AUC0-t, AUC0-inf, and T 1/2 , in serum or plasma. Studies of patient populations or CBD co-administration with other medications were excluded. The National Heart, Lung, and Blood Institute's Quality Assessment Tool for Before-After Studies with no Control Group was used. Random-effects multivariable meta-regression analysis was conducted.

Results

A total of 112 trial arms from 39 studies were included; 26 trial arms had a "Good" quality, 70 "Fair," and 16 "Poor." Eight arms used inhalation CBD, 29 oromucosal, 73 oral, and 2 intravenous. CBD formulations could be categorized to nanotech (n=14), oil-based (n=21), alcohol-based (n=10), water-based (n=12), Sativex (n=17), and Epidiolex (n=22). For single-dose studies, CBD doses ranged between 2-100mg in inhalation, 5-50mg in oromucosal, and 0.42-6000mg in oral administration. Sixty-six trial arms had only male participants or a higher number of males than females. The duration of the PK session was between 4h-164h. A higher CBD dose was associated with higher Cmax, AUC0-t, and AUC0-inf. Compared to oral administration, oromucosal administration was associated with lower Cmax, AUC0-t, and AUC0-inf. Fed status was associated with higher Cmax and AUC0-t when compared to the fasting status. A higher ratio of female participants was associated with lower Tmax in oral administration and higher Cmax.

Conclusion

As expected, CBD dose, route of administration, and diet were major determinants of CBD pharmacokinetics with oral routes providing higher bioavailability and nanotechnology formulations a faster onset. Though CBD appeared to have a faster onset and longer duration in females, more studies are required to delineate the role of biological sex. Factors that influence CBD PK have implications for medication development and appropriate dosing in clinical practice.

Pilot clinical and pharmacokinetic study of Δ9-Tetrahydrocannabinol (THC)/Cannabidiol (CBD) nanoparticle oro-buccal spray in patients with advanced cancer experiencing uncontrolled pain

This pilot study aimed to assess the safety, tolerability, pharmacokinetics and exploratory analgesic effect of a novel water-soluble oro-buccal nanoparticle spray of a cannabis-based medicine (MDCNS-01) in patients with advanced incurable malignancy with unrelieved pain from opioid analgesic. The study was a non-blinded single arm 2 stage study. Stage I was a single escalating dose (n = 5) [2.5 mg Δ9-THC and 2.5 mg CBD) versus a 3-fold escalated dose. Stage II was an up-titrated dose in patients with advanced cancers and intractable pain (n = 25). During Stage I with an increased cannabis-based medicine dose, maximum observed plasma concentrations of cannabinoids were dose dependant. The water-soluble formulation in the current study resulted in a higher median (min, max) systemic exposure of Δ9-THC than CBD (AUC from 2.5 mg each of Δ9-THC and CBD, was 1.71 ng mL.h-1 (1.1, 6.6) and 0.65 ng mL.h-1 (0.49, 4.1), respectively). During stage II a subgroup of patients diagnosed with breast and prostate cancers with bone metastases, had the highest mean pain score improvement from baseline of 40% (unadjusted) and 33% (adjusted for rescue medication use). For all patients the most reported adverse events were mild or moderate drowsiness affecting 11 (44%) and 4 (6%) patients, respectively, and nausea and vomiting that affected 18 (72%) patients. The water-soluble cannabis-based medicine provided acceptable bioavailability for Δ9-THC/CBD, appeared safe and tolerable in advanced incurable cancers with uncontrolled pain with preliminary evidence of analgesic efficacy.

Tetrahydrocannabinol and cannabidiol medicines for chronic pain and mental health conditions

Combination tetrahydrocannabinol (THC)/cannabidiol (CBD) medicines or CBD-only medicines are prospective treatments for chronic pain, stress, anxiety, depression, and insomnia. THC and CBD increase signaling from cannabinoid receptors, which reduces synaptic transmission in parts of the central and peripheral nervous systems and reduces the secretion of inflammatory factors from immune and glial cells. The overall effect of adding CBD to THC medicines is to enhance the analgesic effect but counteract some of the adverse effects. There is substantial evidence for the effectiveness of THC/CBD combination medicines for chronic pain, especially neuropathic and nociplastic pain or pain with an inflammatory component. For CBD-only medication, there is substantial evidence for stress, moderate evidence for anxiety and insomnia, and minimal evidence for depression and pain. THC/CBD combination medicines have a good tolerability and safety profile relative to opioid analgesics and have negligible dependence and abuse potential; however, should be avoided in patients predisposed to depression, psychosis and suicide as these conditions appear to be exacerbated. Non-serious adverse events are usually dose-proportional, subject to tachyphylaxis and are rarely dose limiting when patients are commenced on a low dose with gradual up-titration. THC and CBD inhibit several Phase I and II metabolism enzymes, which increases the exposure to a wide range of drugs and appropriate care needs to be taken. Low-dose CBD that appears effective for chronic pain and mental health has good tolerability and safety, with few adverse effects and is appropriate as an initial treatment.

Enhancing Endocannabinoid Control of Stress with Cannabidiol

The stress response is a well-defined physiological function activated frequently by life events. However, sometimes the stress response can be inappropriate, excessive, or prolonged; in which case, it can hinder rather than help in coping with the stressor, impair normal functioning, and increase the risk of somatic and mental health disorders. There is a need for a more effective and safe pharmacological treatment that can dampen maladaptive stress responses. The endocannabinoid system is one of the main regulators of the stress response. A basal endocannabinoid tone inhibits the stress response, modulation of this tone permits/curtails an active stress response, and chronic deficiency in the endocannabinoid tone is associated with the pathological complications of chronic stress. Cannabidiol is a safe exogenous cannabinoid enhancer of the endocannabinoid system that could be a useful treatment for stress. There have been seven double-blind placebo controlled clinical trials of CBD for stress on a combined total of 232 participants and one partially controlled study on 120 participants. All showed that CBD was effective in significantly reducing the stress response and was non-inferior to pharmaceutical comparators, when included. The clinical trial results are supported by the established mechanisms of action of CBD (including increased N-arachidonylethanolamine levels) and extensive real-world and preclinical evidence of the effectiveness of CBD for treating stress.

Effect of Cannabidiol (CBD) on Canine Inflammatory Response: An Ex Vivo Study on LPS Stimulated Whole Blood

The use of cannabidiol (CBD) for animal species is an area of growing interest, for example for its anti-inflammatory and immuno-modulating properties, even though all of its biological effects are still not fully understood, especially in veterinary medicine. Therefore, the aim of this study was to investigate the anti-inflammatory and immuno-modulating properties of CBD for the first time directly in canine inflammatory response. We used an ex vivo model of LPS-stimulated whole dog blood. We stimulated the whole blood from healthy dogs with LPS 100 ng/mL for 24 h in the presence or not of CBD 50 and 100 μg/mL. We observed a reduction in IL-6 and TNF-α production from the group treated with CBD, but non-altered IL-10 levels. Moreover, we also observed from the CBD-treated group a reduction in Nf-κB and COX-2 expression. In conclusion, we demonstrated for the first time the anti-inflammatory and immuno-modulating properties of CBD directly in dogs' immune cells, using a canine ex vivo inflammatory model. The results obtained from these studies encourage further studies to better understand the possible therapeutic role of CBD in veterinary medicine.