Cannabidiol bioavailability after nasal and transdermal application: effect of permeation enhancers

An open-label feasibility trial of transdermal cannabidiol for hand osteoarthritis

Hand osteoarthritis (OA) is an irreversible degenerative condition causing chronic pain and impaired functionality. Existing treatment options are often inadequate. Cannabidiol (CBD) has demonstrated analgesic and anti-inflammatory effects in preclinical models of arthritis. In this open-label feasibility trial, participants with symptomatically active hand OA applied a novel transdermal CBD gel (4% w/w) three times a day for four weeks to their most painful hand. Changes in daily self-reported pain scores were measured on a 0-10 Numeric Pain Rating Scale (NPRS). Hand functionality was determined via daily grip strength measures using a Bluetooth equipped squeeze ball and self-report questionnaire. Quality of life (QoL) ratings around sleep, anxiety, stiffness and fatigue were also measured. All self-report measures and grip strength data were gathered via smartphone application. Urinalysis was conducted at trial end to determine systemic absorption of CBD. Eighteen participants were consented and 15 completed the trial. Pain ratings were significantly reduced over time from pre-treatment baseline including current pain (- 1.91 ± 0.35, p < 0.0001), average pain (- 1.92 ± 0.35, p < 0.0001) and maximum pain (- 1.97 ± 0.34, p < 0.0001) (data represent mean reduction on a 0-10 NPRS scale ± standard error of the mean (SEM)). A significant increase in grip strength in the treated hand (p < 0.0001) was observed although self-reported functionality did not improve. There were significant (p < 0.005) improvements in three QoL measures: fatigue, stiffness and anxiety. CBD and its metabolites were detected at low concentrations in all urine samples. Measured reductions in pain and increases in grip strength seen during treatment reverted back towards baseline during the washout phase. In summary, pain, grip strength and QoL measures, using smartphone technology, was shown to improve over time following transdermal CBD application suggesting feasibility of this intervention in relieving osteoarthritic hand pain. Proof of efficacy, however, requires further confirmation in a placebo-controlled randomised trial.Trial registration: ANZCTR public trials registry (ACTRN12621001512819, 05/11/2021).

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.

Nanosuspension-Loaded Dissolving Microneedle Patches for Enhanced Transdermal Delivery of a Highly Lipophilic Cannabidiol

Purpose

Transdermal Drug Delivery System (TDDS) offers a promising alternative for delivering poorly soluble drugs, challenged by the stratum corneum's barrier effect, which restricts the pool of drug candidates suitable for TDDS. This study aims to establish a delivery platform specifically for highly lipophilic drugs requiring high doses (log P > 5, dose > 10 mg/kg/d), to improve their intradermal delivery and enhance solubility.

Methods

Cannabidiol (CBD, log P = 5.91) served as the model drug. A CBD nanosuspension (CBD-NS) was prepared using a bottom-up method. The particle size, polydispersity index (PDI), zeta potential, and concentration of the CBD-NS were characterized. Subsequently, CBD-NS was incorporated into dissolving microneedles (DMNs) through a one-step manufacturing process. The intradermal dissolution abilities, physicochemical properties, mechanical strength, insertion depth, and release behavior of the DMNs were evaluated. Sprague-Dawley (SD) rats were utilized to assess the efficacy of the DMN patch in treating knee synovitis and to analyze its skin permeation kinetics and pharmacokinetic performance.

Results

The CBD-NS, stabilized with Tween 80, exhibited a particle size of 166.83 ± 3.33 nm, a PDI of 0.21 ± 0.07, and a concentration of 46.11 ± 0.52 mg/mL. The DMN loaded with CBD-NS demonstrated favorable intradermal dissolution and mechanical properties. It effectively increased the delivery of CBD into the skin, extended the action's duration in vivo, and enhanced bioavailability. CBD-NS DMN exhibited superior therapeutic efficacy and safety in a rat model of knee synovitis, significantly inhibiting TNF-α and IL-1β compared with the methotrexate subcutaneous injection method.

Conclusion

NS technology effectively enhances the solubility of the poorly soluble drug CBD, while DMN facilitates penetration, extends the duration of action in vivo, and improves bioavailability. Furthermore, CBD has shown promising therapeutic outcomes in treating knee synovitis. This innovative drug delivery system is expected to offer a more efficient solution for the administration of highly lipophilic drugs akin to CBD, thereby facilitating high-dose administration.

Permeation-Enhancing Strategies for Transdermal Delivery of Cannabinoids

Introduction: This review aims to provide an overview of the advancements and status of clinical studies and potential permeation-enhancing strategies in the transdermal delivery of cannabinoids. Methods: A systematic and comprehensive literature search across academic databases, search engines, and online sources to identify relevant literature on the transdermal administration of cannabinoids. Results: Cannabinoids have proven beneficial in the treatment of wide-ranging physical and psychological disorders. A shift toward legalized cannabinoid products has increased both interests in cannabinoid research and the development of novel medicinal exploitations of cannabinoids in recent years. Oral and pulmonary delivery of cannabinoids has several limitations, including poor bioavailability, low solubility, and potential side effects. This has diverted scientific attention toward the transdermal route, successfully overcoming these hurdles by providing higher bioavailability, safety, and patient compliance. Yet, due to the barrier properties of the skin and the lipophilic nature of cannabinoids, there is a need to increase the permeation of the drugs to the underneath layers of skin to reach desired therapeutic plasma levels. Literature describing detailed clinical trials on cannabinoid transdermal delivery, either with or without permeation-enhancing strategies, is limited. Conclusion: The limited number of reports indicates that increased attention is needed on developing and examining efficient transdermal delivery systems for cannabinoids, including patch design and composition, drug-patch interaction, clinical effectiveness and safety in vivo, and permeation-enhancing strategies.

CFD simulation of cannabidiol delivery through microneedle patches

This study investigates the efficiency and influence of microneedle parameters, specifically Needle Point Angle (a) and Needle Height (h), on the diffusion of Cannabidiol (CBD) across varying skin depths. Utilizing the Latin Hypercube Sampling method, twelve distinct cases were analyzed. Observations reveal a consistent high concentration of CBD delivered via the microneedle patch, with a notable decrease in concentration as the depth increases, displaying a non-linear trend. Multivariate polynomial regression offers a quantitative relationship between the variables, with the third-order bivariate fitting providing the most accurate representation. Compared to other CBD delivery mechanisms, microneedle patches present enhanced CBD concentrations, circumventing challenges faced by other methods such as dosage inaccuracy, systemic absorption issues, and CBD degradation. The results highlight the potential of microneedle patches as a promising avenue for optimized transdermal drug delivery.

Cannabinoids for the treatment of autoimmune and inflammatory skin diseases: A systematic review

In recent years, the medical use of cannabinoids has attracted growing attention worldwide. In particular, anti-inflammatory properties of cannabinoids led to their emergence as potential therapeutic options for autoimmune and inflammatory disorders. Recent studies have also shown that cannabinoid receptors are widely expressed and have endogenous ligands in the skin, suggesting that the skin has its own endocannabinoid system. The aim of this review is to discuss the potential therapeutic effects of cannabinoids in autoimmune and inflammatory skin diseases. Following an overview of cannabinoids and the endocannabinoid system, we describe the cellular and molecular mechanisms of cannabinoids in skin health and disease. We then review the clinical studies of cannabinoids in autoimmune and inflammatory skin diseases including systemic sclerosis (SSc), dermatomyositis (DM), psoriasis (Pso) and atopic dermatitis (AD). A primary literature search was conducted in July 2023, using PubMed and Web of Science. A total of 15 articles were included after excluding reviews, non-human studies and in vitro studies from 389 non-duplicated articles. Available evidence suggests that cannabinoids may be beneficial for SSc, DM, Pso and AD. However, further studies, ideally randomized controlled trials, are needed to further evaluate the use of cannabinoids in autoimmune and inflammatory skin diseases.

Pharmacokinetics and pharmacodynamics of five distinct commercially available hemp-derived topical cannabidiol products

Products containing cannabidiol (CBD) have proliferated after the 2018 Farm Bill legalized hemp (cannabis with ≤0.3% delta-9-tetrahydrocannabinol (Δ9-THC)). CBD-containing topical products have surged in popularity, but controlled clinical studies on them are limited. This study characterized the effects of five commercially available hemp-derived high CBD/low Δ9-THC topical products. Healthy adults (N = 46) received one of six study drugs: a CBD-containing cream (N = 8), lotion (N = 8), patch (N = 7), balm (N = 8), gel (N = 6) or placebo (N = 9; matched to an active formulation). The protocol included three phases conducted over 17 days: (i) an acute drug application laboratory session, (ii) a 9-day outpatient phase with twice daily product application (visits occurred on Days 2, 3, 7 and 10) (iii) a 1-week washout phase. In each phase, whole blood, oral fluid and urine specimens were collected and analyzed via liquid chromatography with tandem mass spectrometry (LC-MS-MS) for CBD, Δ9-THC and primary metabolites of each and pharmacodynamic outcomes (subjective, cognitive/psychomotor and physiological effects) were assessed. Transdermal absorption of CBD was observed for three active products. On average, CBD/metabolite concentrations peaked after 7-10 days of product use and were highest for the lotion, which contained the most CBD and a permeation enhancer (vitamin E). Δ9-THC/metabolites were below the limit of detection in blood for all products, and no urine samples tested "positive" for cannabis using current US federal workplace drug testing criteria (immunoassay cut-off of 50 ng/mL and confirmatory LC-MS-MS cut-off of 15 ng/mL). Unexpectedly, nine participants (seven lotions, one patch and one gel) exhibited Δ9-THC oral fluid concentrations ≥2 ng/mL (current US federal workplace threshold for a "positive" test). Products did not produce discernable pharmacodynamic effects and were well-tolerated. This study provides important initial data on the acute/chronic effects of hemp-derived topical CBD products, but more research is needed given the diversity of products in this market.

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.

Cutaneous Delivery and Biodistribution of Cannabidiol in Human Skin after Topical Application of Colloidal Formulations

The objective of this study was to investigate the cutaneous delivery of cannabidiol (CBD) from aqueous formulations developed for the targeted local treatment of dermatological conditions. CBD was formulated using a proprietary colloidal drug delivery system (VESIsorb®) into an aqueous colloidal solution at 2% (ACS 2%) and two colloidal gels (CG 1% and CG 2%, which contained 1% and 2% CBD, respectively). Two basic formulations containing CBD (5% in propylene glycol (PG 5%) and a 6.6% oil solution (OS 6.6%)) and two marketed CBD products (RP1 and RP2, containing 1% CBD) were used as comparators. Cutaneous delivery and cutaneous biodistribution experiments were performed using human abdominal skin (500-700 µm) under infinite- and finite-dose conditions with 0.5% Tween 80 in the PBS receiver phase. The quantification of CBD in the skin samples was performed using a validated UHPLC-MS/MS method and an internal standard (CBD-d3). The cutaneous deposition of CBD under finite-dose conditions demonstrated the superiority of CG 1%, CG 2%, and ACS 2% over the marketed products; CG 1% had the highest delivery efficiency (5.25%). Cutaneous biodistribution studies showed the superiority of the colloidal systems in delivering CBD to the viable epidermis, and the upper and lower papillary dermis, which are the target sites for the treatment of several dermatological conditions.

An Overview of Cannabidiol as a Multifunctional Drug: Pharmacokinetics and Cellular Effects

Cannabidiol (CBD), a non-psychoactive compound derived from Cannabis Sativa, has garnered increasing attention for its diverse therapeutic potential. This comprehensive review delves into the complex pharmacokinetics of CBD, including factors such as bioavailability, distribution, safety profile, and dosage recommendations, which contribute to the compound's pharmacological profile. CBD's role as a pharmacological inhibitor is explored, encompassing interactions with the endocannabinoid system and ion channels. The compound's anti-inflammatory effects, influencing the Interferon-beta and NF-κB, position it as a versatile candidate for immune system regulation and interventions in inflammatory processes. The historical context of Cannabis Sativa's use for recreational and medicinal purposes adds depth to the discussion, emphasizing CBD's emergence as a pivotal phytocannabinoid. As research continues, CBD's integration into clinical practice holds promise for revolutionizing treatment approaches and enhancing patient outcomes. The evolution in CBD research encourages ongoing exploration, offering the prospect of unlocking new therapeutic utility.

Investigation of Cannabinoid Acid/Cyclodextrin Inclusion Complex for Improving Physicochemical and Biological Performance

This study aimed to investigate the enhancement of cannabinoid acid solubility and stability through the formation of a cannabinoid acid/cyclodextrin (CD) inclusion complex. Two cannabinoid acids, tetrahydro-cannabinolic acid (THCA) and cannabidiolic acid (CBDA), were selected as a model drug along with five types of CD: α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD), and methylated-β-cyclodextrin (M-β-CD). Phase solubility studies were conducted using various types of CD to determine the complex stoichiometry. The preparation methods of the CD inclusion complex were optimized by adjusting the loading pH solution and the drying processes (spray-drying, freeze-drying, spray-freeze-drying). The drying process of the cannabinoid acid/M-β-CD inclusion complex was further optimized through the spray-freeze-drying method. These CD complexes were characterized using solubility determination, differential scanning calorimetry (DSC), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and 1H NMR spectroscopy. DSC, XRD, and FE-SEM studies confirmed the non-crystalline state of the cannabinoid acid/CD inclusion complex. The permeation of THCA or CBDA from the M-β-CD spray-freeze-dried inclusion complex was highly improved compared to those of cannabis ethanolic extracts under simulated physiological conditions. The stability of the cannabinoid acid/M-β-CD inclusion complex was maintained for 7 days in a simulated physiological condition. Furthermore, the minimum inhibitory concentration of cannabinoid acid/M-β-CD inclusion complex had superior anti-cancer activity in MCF-7 breast cancer cell lines compared to cannabinoid acid alone. The improved physicochemical and biological performances indicated that these CD inclusion complexes could provide a promising option for loading lipophilic cannabinoids in cannabis-derived drug products.

Systematic Review on Transdermal/Topical Cannabidiol Trials: A Reconsidered Way Forward

Introduction: This systematic review aimed to assess efficacy and safety for skin-applied formulations containing CBD. Methods: Bibliographic and clinical trial registries were searched for interventional human trials using cutaneously administered CBD or reported plasma CBD concentrations (any species). Results: Eight of 544 articles fitted the selection criteria: 3 placebo-controlled randomized and 5 single-arm trials. Eleven more studies were found in clinical trial databases but not accessible. Symptoms targeted were dermatopathologies or safety (two studies), pain (two), and behavior (one). Doses were 50-250 mg or 0.075-1.0% CBD, but coformulated with other ingredients. Risk of bias was high and reporting deficiencies further compromised data reliability. Diverse methodologies and formulations hampered syntheses for CBD dose, efficacy, and safety. Plasma CBD levels in dogs and rodents were 0.01-5 μM translating to <100 nM free, unbound CBD in humans. Adverse events were uncommon and mild, but meaningless without CBD's contribution to efficacy data. Achievable free CBD plasma concentrations ∼100 nM can interact predominantly with high-affinity CBD targets, for example, TRPA1 and TRPM8 membrane channels that are abundantly expressed in pathological conditions. Even if reached, higher CBD concentrations on less susceptible targets risk complex and unsafe CBD therapy. A conceptual framework is proposed where dermal capillary loops create sinking for topical CBD demonstrating parallels between topical and transdermal CBD administration. Conclusions: Users risk generalizing inadequately designed trials to all CBD preparations. New clinical trials are urgently needed: they must demonstrate that outcomes are solely from CBD pharmacology, are reliable, unbiased, safe, and comparable. Measurements of sustained plasma CBD levels are mandatory, irrespective of administration route for successful translation from in vitro systems that express human molecular targets. Placebos must be appropriate. Transcutaneous and topical formulations need preliminary in vitro studies to optimize CBD skin penetration. Then, users can rationally balance efficacy against potential harms and cost-effectiveness of CBD formulations.

The Skin and Natural Cannabinoids-Topical and Transdermal Applications

The chemical constituents of the Cannabis plant known as cannabinoids have been extensively researched for their potential therapeutic benefits. The use of cannabinoids applied to the skin as a potential method for both skin-related benefits and systemic administration has attracted increasing interest in recent years. This review aims to present an overview of the most recent scientific research on cannabinoids used topically, including their potential advantages for treating a number of skin conditions like psoriasis, atopic dermatitis, and acne. Additionally, with a focus on the pharmacokinetics and security of this route of administration, we investigate the potential of the transdermal delivery of cannabinoids as a method of systemic administration. The review also discusses the restrictions and difficulties related to the application of cannabinoids on the skin, emphasizing the potential of topical cannabinoids as a promising route for both localized and systemic administration. More studies are required to fully comprehend the efficacy and safety of cannabinoids in various settings.

Cannabidiol-Loaded Nanoparticles Based on Crosslinked Starch: Anti-Inflammatory Activity and Improved Nose-to-Brain Delivery

Cannabidiol (CBD) has previously been shown to inhibit inflammatory cytokine production in both in vitro and in vivo studies of neurodegenerative diseases. To date, the CBD treatment of these diseases by quantitative targeting directly to the brain is one of the greatest challenges. In this paper, we present a new particulate system capable of delivering CBD into the brain via the intranasal route. Intranasal administration of CBD-loaded starch nanoparticles resulted in higher levels of cannabidiol in the brain compared to an identically administered cannabidiol solution. The production and the characterization of starch-based nanoparticles was reported, as well as the evaluation of their penetration and anti-inflammatory activity in cells. Cannabidiol-loaded starch nanoparticles were prepared by crosslinking with divanillin, using the nanoprecipitation method. Evaluation of the anti-inflammatory activity in vitro was performed using the BV2 microglia cell line. The starch nanoparticles appeared under electron microscopy in clusters sized approximately 200 nm in diameter. In cultures of lipopolysaccharide-induced inflamed BV2 cells, the cannabidiol-loaded starch nanoparticles demonstrated low toxicity while effectively reducing nitric oxide production and IL-6 levels. The anti-inflammatory effect was comparable to that of a glucocorticoid. Starch-based nanoparticle formulations combined with intranasal administration may provide a suitable platform for efficacious cannabidiol delivery and activity in the central nervous system.

Propylene glycol and Kolliphor as solvents for systemic delivery of cannabinoids via intraperitoneal and subcutaneous routes in preclinical studies: a comparative technical note

BACKGROUND

Substance administration to laboratory animals necessitates careful consideration and planning in order to enhance agent distribution while reducing any harmful effects from the technique. There are numerous methods for administering cannabinoids; however, several parameters must be considered, including delivery frequency, volume of administration, vehicle, and the level of competence required for staff to use these routes properly. There is a scarcity of information about the appropriate delivery method for cannabinoids in animal research, particularly those that need the least amount of animal manipulation during the course of the investigation. This study aims to assess the feasibility and potential side effects of intraperitoneal and subcutaneous injection of CBD and THC using propylene glycol or Kolliphor in animal models. By evaluating the ease of use and histopathological side effects of these solvents, this study intends to help researchers better understand an accessible long-term delivery route of administration in animal experiments while minimizing the potential confounding effects of the delivery method on the animal.

METHODS

Intraperitoneal and subcutaneous methods of systemic cannabis administration were tested in rat models. Subcutaneous delivery via needle injection and continuous osmotic pump release were evaluated using propylene glycol or Kolliphor solvents. In addition, the use of a needle injection and a propylene glycol solvent for intraperitoneal (IP) administration was investigated. Skin histopathological changes were evaluated following a trial of subcutaneous injections of cannabinoids utilizing propylene glycol solvent.

DISCUSSION

Although IP delivery of cannabinoids with propylene glycol as solvent is a viable method and is preferable to oral treatment in order to reduce gastrointestinal tract degradation, it has substantial feasibility limitations. We conclude that subcutaneous delivery utilizing osmotic pumps with Kolliphor as a solvent provides viable and consistent route of administration for long-term systemic cannabinoid delivery in the preclinical context.

Aqueous cannabidiol β-cyclodextrin complexed polymeric micelle nasal spray to attenuate in vitro and ex-vivo SARS-CoV-2-induced cytokine storms

Cannabidiol (CBD) has a number of biological effects by acting on the cannabinoid receptors CB₁ and CB₂. CBD may be involved in anti-inflammatory processes via CB₁ and CB₂ receptors, resulting in a decrease of pro-inflammatory cytokines. However, CBD's poor aqueous solubility is a major issue in pharmaceutical applications. The aim of the present study was to develop and evaluate a CBD nasal spray solution. A water-soluble CBD was prepared by complexation with β-cyclodextrin (β-CD) at a stoichiometric ratio of 1:1 and forming polymeric micelles using poloxamer 407. The mixture was then lyophilized and characterized using FT-IR, DSC, and TGA. CBD-β-CD complex-polymeric micelles were formulated for nasal spray drug delivery. The physicochemical properties of the CBD-β-CD complex-polymeric micelle nasal spray solution (CBD-β-CDPM-NS) were assessed. The results showed that the CBD content in the CBD-β-CD complex polymeric micelle powder was 102.1 ± 0.5%. The CBD-β-CDPM-NS was a clear colorless isotonic solution. The particle size, zeta potential, pH value, and viscosity were 111.9 ± 0.7 nm, 0.8 ± 0.1 mV, 6.02 ± 0.02, and 12.04 ± 2.64 cP, respectively. This formulation was stable over six months at ambient temperature. The CBD from CBD-β-CDPM-NS rapidly released to 100% within 1 min. Ex-vivo permeation studies of CBD-β-CDPM-NS through porcine nasal mucosa revealed a permeation rate of 4.8 μg/cm²/min, which indicated that CBD was effective in penetrating nasal epithelial cells. CBD-β-CDPM-NS was tested for its efficacy and safety in terms of cytokine production from nasal immune cells and toxicity to nasal epithelial cells. The CBD-β-CDPM-NS was not toxic to nasal epithelial at the concentration of CBD equivalent to 3.125-50 μg/mL. When the formulation was subjected to bioactivity testing against monocyte-like macrophage cells, it proved that the CBD-β-CDPM-NS has the potential to inhibit inflammatory cytokines. CBD-β-CDPM-NS demonstrated the formulation's ability to reduce the cytokine produced by S-RBD stimulation in ex vivo porcine nasal mucosa in both preventative and therapeutic modes.

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.

Cannabis Pharmacogenomics: A Path to Personalized Medicine

Cannabis and related compounds have created significant research interest as a promising therapy in many disorders. However, the individual therapeutic effects of cannabinoids and the incidence of side effects are still difficult to determine. Pharmacogenomics may provide the answers to many questions and concerns regarding the cannabis/cannabinoid treatment and help us to understand the variability in individual responses and associated risks. Pharmacogenomics research has made meaningful progress in identifying genetic variations that play a critical role in interpatient variability in response to cannabis. This review classifies the current knowledge of pharmacogenomics associated with medical marijuana and related compounds and can assist in improving the outcomes of cannabinoid therapy and to minimize the adverse effects of cannabis use. Specific examples of pharmacogenomics informing pharmacotherapy as a path to personalized medicine are discussed.

Topical cannabidiol is well tolerated in individuals with a history of elite physical performance and chronic lower extremity pain

INTRODUCTION

Cannabidiol (CBD) is a potential therapeutic for pain management. Yet, there exists a dearth of studies of its tolerability and efficacy, especially in special populations. Former elite athletes are a special population both susceptible to chronic pain and also highly trained and attuned to assess medication tolerability concerns. The purpose of the present open-label pilot study was to assess the tolerability of CBD in this population.

MATERIALS AND METHODS

Retrospective analysis was conducted in deidentified data from 20 individuals who were all previously professional athletes in US/American football, track and field, or basketball, with careers ranging from 4 to 10 years. Participants received topical CBD (10 mg twice daily by controlled dispenser) for chronic pain resulting from acute lower extremity injuries. Assessments of tolerability and secondary analyses of pain, pain-related disability, and activities of daily living were collected by self-report over the 6-week study period. Data were analyzed by descriptive statistics, pairwise t-test, and linear regression.

RESULTS

Seventy percent of participants completed the study. Of the individuals who completed the study, 50% reported minor adverse effects, none of which required medical attention, and 50% did not report any adverse effects. The mostly commonly reported effects were skin dryness (43% of study completers) and skin rash (21% of study completers), which rapidly resolved. There was a significant improvement in self-reported pain levels (intake mean 3.5 ± 0.29; exit mean 1.7 ± 0.23; P < 0.001) and pain-related disability, including family and home responsibilities, life support activities, occupational activities, recreational activities, self-care, sexual function, and social activities (all P < 0.001).

DISCUSSION

To the best of our knowledge, this is the first study to assess CBD treatment in elite athletes, who are disproportionally susceptible to disabling injuries. Topical administration of CBD was tolerated well by this population and resulted in only minor adverse effects. As elite athletes are trained and attuned to assess their own bodies due to their professional lives, this population is likely to detect tolerability concerns. However, this study was limited to a convenience sample and self-reported data. These pilot findings warrant further study of topical CBD in randomized and controlled studies of elite athletes.

Measurement of Δ9THC and metabolites in the brain and peripheral tissues after intranasal instillation of a nanoformulation

BACKGROUND

Comparative bioavailability of cannabinoids following their administration by dosing routes has been studied previously, but there are no quantitative reports of distribution of Δ⁹THC, nor its metabolites, across various brain regions following intranasal (i.n.) administration. The aim of the present study was to determine the time course of Δ⁹THC transport from nose to brain and to quantify the distribution of Δ⁹THC and its metabolites in four brain regions.

METHODS

Δ⁹THC was formulated as a lipophilic nano-emulsion and instilled i.n. to three groups of adult mice and euthanized after 2, 4, and 8 h. Brains were dissected into 4 regions. Sensitive analytical methods (HPLC-MS) were utilized to quantify levels of Δ⁹THC and metabolites in brain regions and peripheral tissues. Data was expressed as mean concentrations (± SEM) of Δ⁹THC and metabolites in brain regions, blood, plasma, urine, and liver. Two-way analysis of variance was performed followed by post hoc multiple comparisons.

RESULTS

Peak concentrations of Δ⁹THC were reached at 2 h in the brain (15.9 ng/mg), blood (4.54 μg/mL), and plasma (4.56 μg /mL). The percentage of administered dose of Δ⁹THC transported to the brain (5.9%) was greater than in blood (1.7%), plasma (1.6%), urine (0.4%), and liver (0.1%). Concentrations of Δ⁹THC and its THC-COOH metabolite in the liver reached their highest levels at 8 h.

DISCUSSION

The present study is the first to report the uptake and distribution across brain regions of Δ⁹THC and its principal metabolites following i.n. administration. The systemic bioavailability (absorption into the blood) of intranasal Δ⁹THC was 1.7% of the administered dose, much lower than that reported by others after oral ingestion (7-10%) and inhalation (20-35%), but those prior studies did not measure the transport of Δ⁹THC into brain regions. Others have reported Δ⁹THC in the whole brain following i.n. instillation in a different species (rats) to be twice (5.9%) that following i.p. injections, while metabolites of Δ⁹THC in rat brain were lower after i.n. administration.

CONCLUSIONS

The intranasal route of a Δ⁹THC nanoformulation is an effective way to deliver cannabinoids to the brain, especially in those who cannot take the medication orally. Going forward, a metered dosing nasal spray will provide accurate and consistent doses.

Examining the Systemic Bioavailability of Cannabidiol and Tetrahydrocannabinol from a Novel Transdermal Delivery System in Healthy Adults: A Single-Arm, Open-Label, Exploratory Study

INTRODUCTION

Transdermal cannabinoids may provide better safety and bioavailability profiles compared with other routes of administration. This single-arm, open-label study investigated a novel topical transdermal delivery system on the pharmacokinetics of cannabidiol (CBD) and tetrahydrocannabinol (THC).

METHODS

Participants were 39.5 ± 7.37 years old and healthy, based on a review by the Medical Director. Blood was collected pre-dose and 10, 20, 30, and 45 min, and 1, 1.5, 2, 2.5, 3, 4, 5, 6, 8, and 12 h after topical application of 100 mg CBD:100 mg THC. Psychoactive effects were assessed prior to each timepoint. Area-under-the-curve (AUC_0-12 h), maximum concentration (C_max), time to maximum concentration (T_max), area-under-the-curve to infinity (AUC_I), terminal elimination rate constant (λ), terminal half-life (t½), and absorption rate constant (k_a) were measured individually for CBD and THC. Safety was assessed by clinical chemistry, hematology, and adverse events.

RESULTS

AUC_0-12 h for CBD and THC was 3329.8 ± 3252.1 and 2093.4 ± 2090.6 pg/mL/h, with C_max of 576.52 ± 1016.18 and 346.57 ± 776.85 pg/mL, respectively. T_max for CBD and THC was 8 h, ranging from 2.5 h to 12 h and 10 min to 12 h, respectively. AUC_I for CBD and THC was 6609.2 ± 7056.4 and 3721.0 ± 3251.7 pg/mL/h, with t_1/2 of 5.68 ± 1.5 and 5.38 ± 1.25 h, respectively. CBD was absorbed at a faster rate compared with THC (123.36 ± 530.97 versus 71.5 ± 1142.19 h^-1) but with similar λ (0.12 ± 0.029 versus 0.13 ± 0.03 h^-1). No psychoactive effects were reported. Transdermal cannabinoid delivery was safe and well tolerated in the population studied.

CONCLUSION

To our knowledge, this is the first pharmacokinetic study in humans that demonstrated CBD and THC entering systemic circulation via transdermal administration . This study represents an important contribution to understanding the pharmacokinetics of transdermal cannabinoids.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier-NCT05121506 (November 16, 2021).

A reliable quantitative method for determining CBD content and release from transdermal patches in Franz cells

INTRODUCTION

There are several cannabidiol (CBD) transdermal patches available on the market. However, none are FDA-approved. Furthermore, not much evidence has been published about CBD release and skin permeation from such patches, so the effectiveness and reliability remain unclear.

OBJECTIVES

We aimed to develop a method to determine the in vitro release and skin permeation of CBD from transdermal patches using Franz cell diffusion in combination with quantitative ¹ H-NMR (qNMR).

MATERIALS AND METHODS

The study was conducted on CBD patches with known CBD content and six different commercially available or market-ready CBD patches using a Franz cell with a Strat-M™ membrane and with samples taken directly from the transdermal patch for qNMR analysis.

RESULTS

The use of qNMR yielded an average recovery of 100% ± 7% when samples with known CBD content were tested. Results from the testing of six commercially available patches indicated that five out of six patches did not contain the CBD amount stated by the manufacturer according to a ± 10% variance margin, of which four patches were under-labeled and one was over-labeled. The release rate of patches was determined, and significant differences between the patches were shown. Maximum release of CBD was calculated to occur after 39 to 70 h.

CONCLUSION

The established method was proven to be a reliable means of determining the quantity and release of CBD from transdermal patches and can be used to verify CBD content and release rate in transdermal patches.

Cannabidiol in clinical and preclinical anxiety research. A systematic review into concentration-effect relations using the IB-de-risk tool

BACKGROUND

Preclinical research suggests that cannabidiol (CBD) may have therapeutic potential in pathological anxiety. Dosing guidelines to inform future human studies are however lacking.

AIM

We aimed to predict the therapeutic window for anxiety-reducing effects of CBD in humans based on preclinical models.

METHODS

We conducted two systematic searches in PubMed and Embase up to August 2021, into pharmacokinetic (PK) and pharmacodynamic (PD) data of systemic CBD exposure in humans and animals, which includes anxiety-reducing and potential side effects. Risk of bias was assessed with SYRCLE's RoB tool and Cochrane RoB 2.0. A control group was an inclusion criterion in outcome studies. In human outcome studies, randomisation was required. We excluded studies that co-administered other substances. We used the IB-de-risk tool for a translational integration of outcomes.

RESULTS

We synthesised data from 87 studies. For most observations (70.3%), CBD had no effect on anxiety outcomes. There was no identifiable relation between anxiety outcomes and drug levels across species. In all species (humans, mice, rats), anxiety-reducing effects seemed to be clustered in certain concentration ranges, which differed between species.

DISCUSSION

A straightforward dosing recommendation was not possible, given variable concentration-effect relations across species, and no consistent linear effect of CBD on anxiety reduction. Currently, these results raise questions about the broad use as a drug for anxiety. Meta-analytic studies are needed to quantitatively investigate drug efficacy, including aspects of anxiety symptomatology. Acute and (sub)chronic dosing studies with integrated PK and PD outcomes are required for substantiated dose recommendations.

In Vitro Release, Mucosal Permeation and Deposition of Cannabidiol from Liquisolid Systems: The Influence of Liquid Vehicles

This work investigated the influence of liquid vehicles on the release, mucosal permeation and deposition of cannabidiol (CBD) from liquisolid systems. Various vehicles, including EtOH, nonvolatile low- and semi-polar solvents, and liquid surfactants, were investigated. The CBD solution was converted into free-flowing powder using carrier (microcrystalline cellulose) and coating materials (colloidal silica). A physical mixture of the CBD and carrier–coating materials was prepared as a control. The non-crystalline state of CBD in the liquisolid systems was confirmed using XRD, FTIR and SEM studies. The CBD liquisolid powder prepared with volatile and nonvolatile solvents had a better CBD release performance than the CBD formed as the surfactant-based and control powders. The liquisolid systems provided the CBD permeation flux through porcine esophageal mucosa ranging from 0.68 ± 0.11 to 13.68 ± 0.74 µg·cm⁻²·h⁻¹, with the CBD deposition levels of 0.74 ± 0.04 to 2.62 ± 0.30 μg/mg for the dry mucosa. Diethylene glycol monoethyl ether showed significant CBD permeation enhancement (2.1 folds) without an increase in mucosal deposition, while the surfactants retarded the permeation (6.7–9.0 folds) and deposition (1.5–3.2 folds) significantly. In conclusion, besides the drug release, liquid vehicles significantly influence mucosal permeation and deposition, either enhanced or suppressed, in liquisolid systems. Special attention must be paid to the selection and screening of suitable liquid vehicles for liquisolid systems designed for transmucosal applications.

Enhancement of transdermal permeation of cannabinoids and their pharmacodynamic evaluation in rats

The objective of the present study was to enhance the transdermal permeation of cannabinoids: cannabidiol (CBD), cannabigerol (CBG) and tetrahydrocannabivarin (THCV) using chemical permeation enhancer approach and evaluate them for their anti-inflammatory effect in vivo in a paw edema model in rats. Cannabinoids gel formulations were developed using FDA approved inactive ingredients: lactic acid (LA), polyethylene glycol-400 (PEG-400), N-methyl-2 pyrrolidone (NMP), dimethyl sulfoxide (DMSO). In vitro skin permeation testing (IVPT) showed flux of ∼ 13.25 μg/cm²/h for CBD, ∼9.38 μg/cm²/h for CBG and ∼ 51.74 μg/cm²/h for THCV. Additionally, IVPT study showed cumulative drug permeation of 610.96 ± 88.92 μg/cm², 432.09 ± 35.59 μg/cm² and 2384.44 ± 42.22 μg/cm² from CBD, CBG and THCV gel formulations respectively. Further, effect of excipients on cannabinoid permeation showed that, formulation containing lactic acid, NMP and DMSO showed significantly (p < 0.0001) enhanced flux of cannabinoids as compared to formulation without LA, NMP and DMSO. In vivo studies showed that paw edema was significantly (p < 0.0001) reduced in the groups containing CBD, CBG, THCV as compared to control and placebo formulation. In conclusion, flux of CBD, CBG and THCV was significantly enhanced using chemical permeation enhancers approach which helped in reducing rat paw edema.

Mucosal Delivery of Cannabidiol: Influence of Vehicles and Enhancers

In this study, the mucosal permeation and deposition of cannabidiol (CBD) with neat and binary vehicles were investigated. Permeation experiments were performed using static diffusion cells coupled with fresh porcine esophageal mucosa. The CBD-vehicle solutions were applied at a fixed dose (~5 mg/cm²), and the corresponding permeation parameters were calculated. In neat vehicles, the permeation flux (J_ss) ranged from 0.89 ± 0.15 to 179.81 ± 23.46 µg·cm^-2·h^-1, while the CBD deposition ranged from 11.5 ± 1.8 to 538.3 ± 105.3 μg·cm^-2. Propylene glycol (PG) and diethylene glycol monoethyl ether (DEGEE) yielded the highest permeability (P_s) and CBD deposition, while medium-chain triglycerides (MCT) yielded the lowest P_s and deposition. This was due to the difference in apparent partition coefficient (K), which is related to the solubility of CBD in the vehicle. The PG:DEGEE binary vehicle boosted J_ss (1.5-1.6 fold) and deposition (2.0-2.7 folds) significantly, compared to neat DEGEE. The combination of DEGEE with MCT dramatically enhanced J_ss (11-44 fold) and deposition (1.6-4.7 fold). The addition of lipophilic enhancers, laurocapram, and oleic acid, to PG:DEGEE and DEGEE:MCT vehicles significantly reduced J_ss (0.3-0.7 fold) and deposition (0.4-0.8 fold) while nerolidol had no effect. These permeation reductions were found to be related to modification of the K and/or diffusivity values. This study provides useful basic information for the development of CBD formulations intended for transmucosal delivery.

Development and Evaluation of Cannabidiol Orodispersible Tablets Using a 23-Factorial Design

Orodispersible tablets (ODTs) are pharmaceutical formulations used to obtain fast therapeutic effects, usually recommended for geriatric and pediatric patients due to their improved compliance, bioavailability, ease of administration, and good palatability. This study aimed to develop ODTs with cannabidiol (CBD) phytocannabinoid extracted from Cannabis sativa used in the treatment of Lennox–Gastaut and Dravet syndromes. The tablets were obtained using an eccentric tableting machine and 9 mm punches. To develop CBD ODTs, the following parameters were varied: the Poloxamer 407 concentration (0 and 10%), the type of co-processed excipient (Prosolv^® ODT G2—PODTG2 and Prosolv^® EasyTab sp—PETsp), and the type of superdisintegrant (Croscarmellose—CCS, and Soy Polysaccharides—Emcosoy^®—EMCS), resulting in eleven formulations (O1–O11). The following dependent parameters were evaluated: friability, disintegration time, crushing strength, and the CBD dissolution at 1, 3, 5, 10, 15, and 30 min. The dependent parameters were verified according to European Pharmacopoeia (Ph. Eur.) requirements. All the tablets obtained were in accordance with quality requirements in terms of friability (less than 1%), and disintegration time (less than 180 s). The crushing strength was between 19 N and 80 N. Regarding the dissolution test, only four formulations exhibited an amount of CBD released higher than 80% at 30 min. Taking into consideration the results obtained and using the Modde 13.1 software, an optimal formulation was developed (O12), which respected the quality criteria chosen (friability 0.23%, crushing strength of 37 N, a disintegration time of 27 s, and the target amount of CBD released in 30 min of 99.3 ± 6%).

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.

Cannabinoid Content and Label Accuracy of Hemp-Derived Topical Products Available Online and at National Retail Stores

IMPORTANCE

Products containing cannabinoids such as cannabidiol (CBD) have proliferated since 2018, when the Agriculture Improvement Act removed hemp (ie, cannabis containing <0.3% Δ9-tetrahydrocannabinol [THC]) from the US controlled substances list. Topical cannabinoid products can be purchased nationwide at retail stores and over the internet, yet research on these products is scarce.

OBJECTIVE

To evaluate the cannabinoid content (ie, CBD and THC) and label accuracy of topical cannabinoid products and to quantify their therapeutic and nontherapeutic claims.

DESIGN, SETTING, AND PARTICIPANTS

Product inclusion criteria included designation as hemp products, intended for topical or transdermal application, and purported to contain cannabinoids (eg, CBD). All unique products available at each retail store were purchased. Online products were identified via Google using relevant keywords (eg, hemp or CBD topical). Various products (eg, lotions and patches) were purchased from retail stores (eg, pharmacies, grocery stores, and cosmetic or beauty stores) in Baltimore, Maryland, and online. Data analysis was performed from March to June 2022.

MAIN OUTCOMES AND MEASURES

Labeled and actual total amounts of CBD and THC, measured via gas chromatography-mass spectrometry. Therapeutic and nontherapeutic claims and references to the US Food and Drug Administration were quantified.

RESULTS

A total of 105 products were purchased, 45 from retail locations and 60 online. Of the 89 products that listed a total amount of CBD on the label, 18% (16 products) were overlabeled (ie, contained >10% less CBD than advertised), 58% (52 products) were underlabeled (ie, contained >10% more CBD than advertised), and 24% (21 products) were accurately labeled. The median (range) percentage deviation between the actual total amount of CBD and the labeled amount was 21% (-75% to 93%) for in-store products and 10% (-96% to 121%) for online products, indicating that products contained more CBD than advertised overall. THC was detected in 37 of 105 products (35%), although all contained less than 0.3% THC. Among the 37 THC-containing products, 4 (11%) were labeled as THC free, 14 (38%) indicated they contained less than 0.3% THC, and 19 (51%) did not reference THC on the label. Overall, 28% of products (29 products) made therapeutic claims, 14% (15 products) made cosmetic claims, and only 47% (49 products) noted that they were not Food and Drug Administration approved.

CONCLUSIONS AND RELEVANCE

In a case series of topical cannabinoid products purchased online and at popular retail stores, products were often inaccurately labeled for CBD and many contained THC. These findings suggest that clinical studies are needed to determine whether topical cannabinoid products with THC can produce psychoactive effects or positive drug tests for cannabis.

Pharmacokinetics of Cannabidiol Following Intranasal, Intrarectal, and Oral Administration in Healthy Dogs

The therapeutic potential of cannabidiol (CBD), a non-psychtropic component of the Cannabis sativa plant, is substantiated more and more. We aimed to determine the pharmacokinetic behavior of CBD after a single dose via intranasal (IN) and intrarectal (IR) administration in six healthy Beagle dogs age 3–8 years old, and compare to the oral administration route (PO). Standardized dosages applied for IN, IR and PO were 20, 100, and 100 mg, respectively. Each dog underwent the same protocol but received CBD through a different administration route. CBD plasma concentrations were determined by ultra-high performance liquid chromatography-tandem mass spectrometry before and at fixed time points after administration. Non-compartmental analysis was performed on the plasma concentration-time profiles. Plasma CBD concentrations after IR administration were below the limit of quantification. The mean area under the curve (AUC) after IN and PO CBD administration was 61 and 1,376 ng/mL*h, respectively. The maximal plasma CBD concentration (C_max) after IN and PO CBD administration was 28 and 217 ng/mL reached after 0.5 and 3.5 h (T_max), respectively. Significant differences between IN and PO administration were found in the T_max (p = 0.04). Higher AUC and C_max were achieved with 100 mg PO compared to 20 mg IN, but no significant differences were found when AUC (p = 0.09) and C_max (p = 0.44) were normalized to 1 mg dosages. IN administration of CBD resulted in faster absorption when compared to PO administration. However, PO remains the most favorable route for CBD delivery due to its more feasible administration. The IR administration route is not advised for clinical application.

A Systematic Review on Cannabinoids for Neuropathic Pain Administered by Routes Other than Oral or Inhalation

The use of cannabis and cannabinoid products for the treatment of neuropathic pain is a growing area of research. This type of pain has a high prevalence, limited response to available therapies and high social and economic costs. Systemic cannabinoid-based therapies have shown some unwanted side effects. Alternative routes of administration in the treatment of neuropathic pain may provide better acceptance for the treatment of multiple pathologies associated with neuropathic pain. To examine the efficacy, tolerability, and safety of cannabinoids (individualized formulations, phytocannabinoids, and synthetics) administered by routes other than oral or inhalation compared to placebo and/or conventional medications in the management of neuropathic pain. This systematic review of the literature reveals a lack of clinical research investigating cannabis by routes other than oral and inhalation as a potential treatment for neuropathic pain and highlights the need for further investigation with well-designed clinical trials. There is a significant lack of evidence indicating that cannabinoids administered by routes other than oral or inhaled may be an effective alternative, with better tolerance and safety in the treatment of neuropathic pain. Higher quality, long-term, randomized controlled trials are needed to examine whether cannabinoids administered by routes other than inhalation and oral routes may have a role in the treatment of neuropathic pain.

Cannabidiol and epilepsy in Brazil: a current review

BACKGROUND

Cannabidiol (CBD) has become a promising therapeutic option in the treatment of epilepsy. Recent studies provide robust evidence that CBD is effective and safe. Limitations in current knowledge and regulatory issues still limit CBD use. CBD use regarding epilepsy types still lacks clear guidelines.

OBJECTIVE

To critically review the main current pharmacological features and clinical issues regarding CBD use in epilepsy, to provide current regulatory background regarding CBD use in Brazil, and to suggest a practical CBD therapeutic guide in Brazil.

METHODS

Non-systematic literature review (up to February 2022) of current concepts of CBD and epilepsy, including the authors' personal experience.

RESULTS

Five pivotal trials have led to CBD approval as an adjunctive treatment for Dravet and Lennox-Gastaut syndromes, and for the tuberous sclerosis complex. Efficacy of CBD in other drug-resistant epilepsies remains not completely understood. CBD adverse event profile and drug interactions are better understood. CBD is well tolerated. In Brazil, CBD is not classified as a medication, but as a product subject to a distinct regulatory legislation. CBD is still not offered by the National Brazilian health system, but can be purchased in authorized pharmacies or imported under prescription and signed informed consent.

CONCLUSION

CBD is a recognized novel treatment for epilepsy. Future well-designed studies and public health strategies are needed to offer widespread access to CBD, and to improve the quality of life of people living with epilepsy in Brazil.

New idea to promote the clinical applications of stem cells or their extracellular vesicles in central nervous system disorders: combining with intranasal delivery

The clinical translation of stem cells and their extracellular vesicles (EVs)-based therapy for central nervous system (CNS) diseases is booming. Nevertheless, the insufficient CNS delivery and retention together with the invasiveness of current administration routes prevent stem cells or EVs from fully exerting their clinical therapeutic potential. Intranasal (IN) delivery is a possible strategy to solve problems as IN route could circumvent the brain‒blood barrier non-invasively and fit repeated dosage regimens. Herein, we gave an overview of studies and clinical trials involved with IN route and discussed the possibility of employing IN delivery to solve problems in stem cells or EVs-based therapy. We reviewed relevant researches that combining stem cells or EVs-based therapy with IN administration and analyzed benefits brought by IN route. Finally, we proposed possible suggestions to facilitate the development of IN delivery of stem cells or EVs.

The Transdermal Delivery of Therapeutic Cannabinoids

Recently, several studies have indicated an increased interest in the scientific community regarding the application of Cannabis sativa plants, and their extracts, for medicinal purposes. This plant of enormous medicinal potential has been legalised in an increasing number of countries globally. Due to the recent changes in therapeutic and recreational legislation, cannabis and cannabinoids are now frequently permitted for use in clinical settings. However, with their highly lipophilic features and very low aqueous solubility, cannabinoids are prone to degradation, specifically in solution, as they are light-, temperature-, and auto-oxidation-sensitive. Thus, plant-derived cannabinoids have been developed for oral, nasal-inhalation, intranasal, mucosal (sublingual and buccal), transcutaneous (transdermal), local (topical), and parenteral deliveries. Among these administrations routes, topical and transdermal products usually have a higher bioavailability rate with a prolonged steady-state plasma concentration. Additionally, these administrations have the potential to eliminate the psychotropic impacts of the drug by its diffusion into a nonreactive, dead stratum corneum. This modality avoids oral administration and, thus, the first-pass metabolism, leading to constant cannabinoid plasma levels. This review article investigates the practicality of delivering therapeutic cannabinoids via skin in accordance with existing literature.

In vitro percutaneous absorption studies of cannabidiol using human skin: Exploring the effect of drug concentration, chemical enhancers, and essential oils

Cannabidiol, a non-psychoactive constituent of cannabis, has garnered much attention after United States Food and Drug Administration approved Epidiolex® for oral use. Although therapeutic effect of cannabidiol after systemic absorption has been investigated extensively, its therapeutic potential in treating skin disorders after local delivery still needs further exploration. Our study has investigated the effect of cannabidiol concentration, chemical enhancers, and essential oils on percutaneous absorption of cannabidiol. In vitro permeation tests were conducted on human skin. The 24 h study results suggest no significant difference in amount of drug absorbed into skin, between 5% (242.41 ± 12.17 µg/cm²) and 10% (232.79 ± 20.82 cm²) cannabidiol solutions. However, 1% delivered (23.02 ± 4.74 µg/cm²) significantly lower amount of drug into skin than 5% and 10%. Transcutol and isopropyl myristate did not enhance delivery of cannabidiol. However, oleic acid was found to be useful as chemical enhancer. Oleic acid (43.07 ± 10.11 µg/cm²) had significantly higher cannabidiol delivery into skin than the group without oleic acid (10.98 ± 3.40 µg/cm²) after a 4 h in vitro permeation study. Essential oils at concentrations tested had lower total cannabidiol delivery when compared to control. This study's findings will help guide future research on the pharmacological effect of percutaneously delivered cannabidiol on inflammatory skin disorders.

Medicinal Cannabis Pharmacokinetics and Potential Methods of Delivery

The evidence of cannabis exhibiting polypharmacological properties has been accumulating for the past few decades, particularly for its analgesic and anti-inflammatory abilities. However, inconsistent dosage forms and erratic absorption levels prevent medicinal cannabis products from becoming mainstream recommendations for pain management. Current cannabis products fail to address the undesirable characteristics associated with cannabinoids such as low solubility, poor bioavailability, and lack of specificity, all of which contribute to low therapeutic effect. In this narrative view, the pharmacokinetics of cannabis products and possible methods of drug delivery, in the form of carrier systems, will be explored. The incorporation of cannabinoids into carrier systems provides an opportunity to improve absorption levels, increase bioavailability and reduce adverse events allowing for a greater therapeutic effect.

Development and pharmacokinetic evaluation of a self-nanoemulsifying drug delivery system for the oral delivery of cannabidiol

The number of lipophilic drug candidates in pharmaceutical discovery pipelines has increased in recent years. These drugs often possess physicochemical properties that result in poor oral bioavailability, and their clinical potential may be limited without adequate formulation strategies. Cannabidiol (CBD) is an excellent example of a highly lipophilic compound with poor oral bioavailability, due to low water solubility and extensive first-pass metabolism. An approach that may overcome these limitations is formulation of the drug in self-nanoemulsifying drug delivery systems (SNEDDS). Herein, CBD-SNEDDS formulations were prepared and evaluated in vitro. Promising formulations (F2, F4) were administered to healthy female Sprague-Dawley rats via oral gavage (20 mg/kg CBD). Resulting pharmacokinetic parameters of CBD were compared to those obtained following administration of CBD in two oil-based formulations: a medium-chain triglyceride oil vehicle (MCT-CBD), and a sesame oil-based formulation similar in composition to an FDA-approved formulation of CBD, Epidiolex® (SO-CBD). Compared to MCT-CBD, administration of the SNEDDS formulations led to more rapid absorption of CBD (median T_max values: 0.5 h (F2), 1 h (F4), 6 h (MCT-CBD)). Administration of F2 and F4 formulations also improved the systemic exposure to CBD by 2.2 and 2.8-fold compared to MCT-CBD; however, no improvement was found compared to SO-CBD.

Cannabidiol Produces Distinct U-Shaped Dose-Response Effects on Cocaine-Induced Conditioned Place Preference and Associated Recruitment of Prelimbic Neurons in Male Rats

Background

Cannabidiol (CBD) has received attention for the treatment of substance use disorders. In preclinical models of relapse, CBD attenuates drug seeking across several drugs of abuse, including cocaine. However, in these models CBD has not been consistently effective. This inconsistency in CBD effects may be related to presently insufficient information on the full spectrum of CBD dose effects on drug-related behaviors.

Methods

We address this issue by establishing a full dose-response profile of CBD’s actions using expression of cocaine-induced conditioned place preference as a model for drug-motivated behavior in male rats and by concurrently identifying dose-dependent effects of CBD on underlying neuronal activation and distinct neuronal phenotypes showing dose-dependent activation changes. Additionally, we established CBD levels in plasma and brain samples.

Results

CBD produced linear increases in CBD brain/plasma concentrations but suppressed conditioned place preference in a distinct U-shaped manner. In parallel with its behavioral effects, CBD produced U-shaped suppressant effects on neuronal activation in the prelimbic but not infralimbic cortex or nucleus accumbens core and shell. RNAscope in situ hybridization identified suppression of glutamatergic and GABAergic (gamma-aminobutyric acidergic) signaling in the prelimbic cortex as a possible cellular mechanism for the attenuation of cocaine-induced conditioned place preference by CBD.

Conclusions

The findings extend previous evidence on the potential of CBD in preventing drug-motivated behavior. However, CBD’s dose-response profile may have important dosing implications for future clinical applications and may contribute to the understanding of discrepant CBD effects on drug seeking reported in the literature.

Plant-Derived Compounds as Promising Therapeutics for Vitiligo

Vitiligo is the most common depigmenting disorder characterized by white patches in the skin. The pathogenetic origin of vitiligo revolves around autoimmune destruction of melanocytes in which, for instance, oxidative stress is responsible for melanocyte molecular, organelle dysfunction and melanocyte specific antigen exposure as well as melanocyte cell death and thus serves as an important contributor for vitiligo progression. In recent years, natural products have shown a wide range of pharmacological bioactivities against many skin diseases, and this review focuses on the effects and mechanisms of natural compounds against vitiligo models. It is showed that some natural compounds such as flavonoids, phenols, glycosides and coumarins have a protective role in melanocytes and thereby arrest the depigmentation, and, additionally, Nrf2/HO-1, MAPK, JAK/STAT, cAMP/PKA, and Wnt/β-catenin signaling pathways were reported to be implicated in these protective effects. This review discusses the great potential of plant derived natural products as anti-vitiligo agents, as well as the future directions to explore.

Topical Cannabinoids for Treating Chemotherapy-Induced Neuropathy: A Case Series

BACKGROUND

Chemotherapy-induced peripheral neuropathy is a common and often severe side effect from many chemotherapeutic agents, with limited treatment options. There is no literature on the use of topical cannabinoids for chemotherapy-induced neuropathy.

CASE PRESENTATIONS

The current manuscript presents a case series of patients presenting in oncology clinics at Sutter Health, CA and Mayo Clinic, Rochester, MN from April 2019 to December 2020 with chemotherapy-induced peripheral neuropathy who used topical creams containing the cannabinoids delta-nine-tetrahydrocannabinol (THC) and/or cannabidiol (CBD).

CONCLUSIONS

This case series suggests that topical cannabinoids may be helpful for patients with chemotherapy-induced peripheral neuropathy. This paper also discusses the potential mechanisms of action by which topical cannabinoids might alleviate established CIPN symptoms. A randomized placebo-controlled trial using a standardized product is planned to study the actual efficacy of such treatment.

Plasma and joint tissue pharmacokinetics of two doses of oral cannabidiol oil in guinea pigs (Cavia porcellus)

Cannabidiol (CBD) has gained widespread popularity as a treatment for osteoarthritis (OA) in pets; however, there is minimal scientific evidence regarding safe and effective dosing. This study determined plasma and tissue pharmacokinetics after oral CBD oil suspension administration in Hartley guinea pigs (Cavia porcellus), which spontaneously develop OA at 3 months of age. Ten, 5-month-old, male guinea pigs were randomly assigned to receive 25 (n = 5) or 50 mg/kg (n = 5) CBD oil once orally. Blood samples were collected at 0, 0.25, 0.5, 1, 2, 4, 8, 12, and 24 h timepoints. Open-field enclosure monitoring revealed no adverse effects. After euthanasia, stifle cartilage and infrapatellar fat pads were collected to quantitate CBD. CBD concentrations were determined using a validated liquid chromatography-mass spectrometry method, and pharmacokinetic parameters were calculated using noncompartmental analysis. The area under the plasma concentration-versus-time curve was 379.5 and 873.7 h*ng/mL, maximum plasma concentration was 42 and 96.8 ng/mL, time to maximum plasma concentration was 1.6 and 4.8 h, and terminal phase half-life was 8.1 and 10.8 h for the 25 and 50 mg/kg doses, respectively. CBD was detected in joint tissues of all animals. Further studies, including work in female guinea pigs, are needed to determine the efficacy of CBD for OA.

An Ultrafast Ultrahigh-Performance Liquid Chromatography Coupled With Tandem Mass Spectrometry Method for Cannabidiol Monitoring in Pediatric Refractory Epilepsy

BACKGROUND

Cannabidiol (CBD) is a nonpsychoactive natural product that has been increasingly used as a promising new drug for the management of neurological conditions such as refractory epilepsy. Development of rapid and sensitive methods to quantitate CBD is essential to evaluate its pharmacokinetics in humans, particularly in children. The objective of this work was to develop and validate an ultrafast ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) method for CBD quantitation that is capable of detecting major CBD and tetrahydrocannabinol (THC) metabolites in the plasma of pediatric refractory epilepsy patients.

METHODS

Eight-point CBD calibration curves were prepared using 60 µL of plasma from healthy volunteers. Samples were analyzed in a Shimadzu Nexera X2 UHPLC system, which was coupled to a Sciex QTRAP 6500 mass spectrometer. Chromatography was optimized in acetonitrile (ACN)/water with a 70%-90% gradient of ACN in 2 minutes. Multiple reaction monitoring transitions of major CBD and THC metabolites were optimized in patient plasma.

RESULTS

The optimized UHPLC-MS/MS method was validated for the linear range (1-300 ng/mL) of CBD (r2 = 0.996). The limit of quantification and limit of detection were 0.26 and 0.86 ng/mL, respectively. Accuracy and precision met the acceptable validation limits. CBD recovery and matrix effects were 83.9 ± 13.9% and 117.4 ± 4.5%, respectively. The method was successfully applied to quantify CBD and detect the major CBD and THC metabolites in clinical samples. 7-COOH-CBD was the most intensely detected metabolite followed by glucuronide conjugates.

CONCLUSIONS

A simple and sensitive method for rapidly monitoring CBD and identifying relevant metabolites was developed. Its applicability in samples from children treated for epilepsy was demonstrated, making it an excellent alternative for performing pharmacokinetic studies.

Development and optimisation of biopharmaceutical properties of a new microemulgel of cannabidiol for locally-acting dermatological delivery

Cannabidiol (CBD) is a pleiotropic phytocannabinoid, recently investigated to treat many skin diseases. This study aimed to develop a CBD-loaded O/A microemulsion (CBD-ME) formulated as microemulgel (CBD-MEgel), suitable for local administration. The developed CBD-ME consisted of Solutol HS 15 (20%, surfactant), Transcutol P (9%, cosolvent), isopropyl myristate (5%, oil phase), water (66%) and 1% w/w CBD. Globules had polydispersity index less than 0.23 ± 0.02 and size of 35 ± 2 nm; these values did not change after loading CBD and gelling the formulation with Sepigel 305 obtaining a clear and homogeneous formulation with a pH of 6.56 ± 0.20, suitable for cutaneous application. Viscosity properties were investigated by the rotational digital viscometer, at both 21 ± 2 °C and 35 ± 2 °C. Viscosities of CBD-MEgel were 439,000 ± 4,243 mPa·s and 391,000 ± 1,414 mPa·s respectively. The release studies displayed that 90 ± 24 μg/cm² of CBD were released in 24 h. The CBD permeability, evaluated using Franz diffusion cells and rabbit ear skin, was 3 ± 1 μg/cm². Skin-PAMPA^TM gave a CBD effective permeability of (1.67 ± 0.16) ·10^-7 cm/s and an absorbed dose of 115.30 ± 16.99 µg/cm² after 24 h. Lastly, physical and chemical stability of both CBD-ME and CBD-MEgel were evaluated over a period of 3 months, showing optimal shelf-life at the storage conditions.

Cannabinoid Formulations and Delivery Systems: Current and Future Options to Treat Pain

The field of Cannabis sativa L. research for medical purposes has been rapidly advancing in recent decades and a growing body of evidence suggests that phytocannabinoids are beneficial for a range of conditions. At the same time impressing development has been observed for formulations and delivery systems expanding the potential use of cannabinoids as an effective medical therapy. The objective of this review is to present the most recent results from pharmaceutical companies and research groups investigating methods to improve cannabinoid bioavailability and to clearly establish its therapeutic efficacy, dose ranges, safety and also improve the patient compliance. Particular focus is the application of cannabinoids in pain treatment, describing the principal cannabinoids employed, the most promising delivery systems for each administration routes and updating the clinical evaluations. To offer the reader a wider view, this review discusses the formulation starting from galenic preparation up to nanotechnology approaches, showing advantages, limits, requirements needed. Furthermore, the most recent clinical data and meta-analysis for cannabinoids used in different pain management are summarized, evaluating their real effectiveness, in order also to spare opioids and improve patients' quality of life. Promising evidence for pain treatments and for other important pathologies are also reviewed as likely future directions for cannabinoids formulations.

Safety and Tolerability of Transdermal Cannabidiol Gel in Children With Developmental and Epileptic Encephalopathies: A Nonrandomized Controlled Trial

IMPORTANCE

Developmental and epileptic encephalopathies (DEEs) are the most severe group of drug-resistant epilepsies. Alternatives to oral therapies are urgently needed to reduce seizures and improve developmental outcomes and comorbidities in this medically complex population.

OBJECTIVE

To assess the safety and tolerability of cannabidiol (CBD) transdermal gel in children with DEEs and to evaluate seizure frequency, sleep, and quality of life.

DESIGN, SETTING, AND PARTICIPANTS

This nonrandomized controlled trial was conducted in 2 centers in Australia and New Zealand from April 2018 to July 2019. Children and adolescents aged 3 to 18 years with DEEs who were receiving a stable regimen of 1 to 4 antiseizure medications were eligible for this study. After 1-month baseline and titration periods, patients entered a 5.5-month flexible-dosing maintenance period for a total of 6.5 months of treatment. Data were analyzed throughout the 6.5-month treatment period.

INTERVENTIONS

Twice-daily applications of CBD transdermal gel at doses of 125 to 500 mg for 6.5 months.

MAIN OUTCOMES AND MEASURES

Safety and tolerability assessments included adverse events (AEs) and examination of skin. The outcome for seizures was the median percentage change from baseline in monthly (28-day) seizure frequency of focal impaired awareness seizures (FIAS) and tonic-clonic seizures (TCS) over 6.5 months.

RESULTS

Of 48 patients (mean [SD] age, 10.5 [3.8] years; 26 [54%] boys), 29 (60%) had at least 1 treatment-related AE over 6.5 months; 44 of 46 treatment-related AEs (96%) were mild or moderate. Treatment-related AEs that occurred in at least 5% of patients were application-site dryness, application-site pain, and somnolence (each reported by 4 patients [8%]). The only treatment-related gastrointestinal AE was diarrhea, reported in a single patient. CBD treatment was associated with reductions in FIAS and TCS frequency. Analysis of the 33 patients with FIAS and TCS showed a median (interquartile range) monthly reduction in seizures of 58% (-5.3% to 81.8%) at 5 months and 43.5% (-23.8% to 57.5%) over the entire 6.5-month study period. Parents and caregivers noted improvements in social or interpersonal engagement and irritability (33 of 43 [77%] participants); alertness, energy, and sleep (23 of 43 [53%]); and cognition or concentration (20 of 43 [47%]).

CONCLUSIONS AND RELEVANCE

In this study, CBD transdermal gel was safe, well tolerated, and was associated with reductions in FIAS and TCS frequency and disease burden.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: ACTRN12618000516280.

Cannabinoids, the endocannabinoid system, and pain: a review of preclinical studies

ABSTRACT

This narrative review represents an output from the International Association for the Study of Pain's global task force on the use of cannabis, cannabinoids, and cannabis-based medicines for pain management, informed by our companion systematic review and meta-analysis of preclinical studies in this area. Our aims in this review are (1) to describe the value of studying cannabinoids and endogenous cannabinoid (endocannabinoid) system modulators in preclinical/animal models of pain; (2) to discuss both pain-related efficacy and additional pain-relevant effects (adverse and beneficial) of cannabinoids and endocannabinoid system modulators as they pertain to animal models of pathological or injury-related persistent pain; and (3) to identify important directions for future research. In service of these goals, this review (1) provides an overview of the endocannabinoid system and the pharmacology of cannabinoids and endocannabinoid system modulators, with specific relevance to animal models of pathological or injury-related persistent pain; (2) describes pharmacokinetics of cannabinoids in rodents and humans; and (3) highlights differences and discrepancies between preclinical and clinical studies in this area. Preclinical (rodent) models have advanced our understanding of the underlying sites and mechanisms of action of cannabinoids and the endocannabinoid system in suppressing nociceptive signaling and behaviors. We conclude that substantial evidence from animal models supports the contention that cannabinoids and endocannabinoid system modulators hold considerable promise for analgesic drug development, although the challenge of translating this knowledge into clinically useful medicines is not to be underestimated.

The Effects of Food on Cannabidiol Bioaccessibility

Cannabidiol (CBD) is a hydrophobic non-psychoactive compound with therapeutic characteristics. Animal and human studies have shown its poor oral bioavailability in vivo, and the impact of consuming lipid-soluble CBD with and without food on gut bioaccessibility has not been explored. The purpose of this research was to study the bioaccessibility of CBD after a three-phase upper digestion experiment with and without food, and to test lipase activity with different substrate concentrations. Our results showed that lipase enzyme activity and fatty acid absorption increased in the presence of bile salts, which may also contribute to an increase in CBD bioaccessibility. The food matrix used was a mixture of olive oil and baby food. Overall, the fed-state digestion revealed significantly higher micellarization efficiency for CBD (14.15 ± 0.6% for 10 mg and 22.67 ± 2.1% for 100 mg CBD ingested) than the fasted state digestion of CBD (0.65 ± 0.7% for 10 mg and 0.14 ± 0.1% for 100 mg CBD ingested). The increase in bioaccessibility of CBD with food could be explained by the fact that micelle formation from hydrolyzed lipids aid in bioaccessibility of hydrophobic molecules. In conclusion, the bioaccessibility of CBD depends on the food matrix and the presence of lipase and bile salts.

Transdermal Route: A Viable Option for Systemic Delivery of Antidepressants

The high rise in the population suffering from depression depicts the need for improved and highly effective treatment options for this condition. Efforts to develop existing drugs into user-friendly dosage forms with a number of advantages in major depressive states, including but not limited to: sustained drug release, reduced drug dosing frequency, improved tolerance and adherence, suitability for use in diverse populations and different treatment scenarios, as well as less central nervous system side effects are required. One such non-invasive drug delivery route that could provide the aforementioned benefits in the treatment of depression is the transdermal route. A number of conventional and emerging transdermal delivery strategies have been investigated for some potent antidepressants and results depict the potential of this route as a viable means for systemic delivery of therapeutically relevant doses of the tested agents, with Emsam®, the commercially available patch of selegiline, being an evidence for the same. The investigated approaches include the formulation of transdermal patches, use of vesicular drug carriers, pro-drug approach, microemulsification, chemical as well as physical enhancement technologies. This review provides a comprehensive account of the rationale, developments made till date, scope and future prospects of delivering antidepressants via the transdermal1 route of administration.

Untapped endocannabinoid pharmacological targets: Pipe dream or pipeline?

It has been established that the endogenous cannabinoid (endocannabinoid) system plays key modulatory roles in a wide variety of pathological conditions. The endocannabinoid system comprises both cannabinoid receptors, their endogenous ligands including 2-arachidonoylglycerol (2-AG), N-arachidonylethanolamine (anandamide, AEA), and enzymes that regulate the synthesis and degradation of endogenous ligands which include diacylglycerol lipase alpha (DAGL-α), diacylglycerol lipase beta (DAGL-β), fatty acid amide hydrolase (FAAH), monoacylglycerol lipase (MAGL), α/β hydrolase domain 6 (ABHD6). As the endocannabinoid system exerts considerable involvement in the regulation of homeostasis and disease, much effort has been made towards understanding endocannabinoid-related mechanisms of action at cellular, physiological, and pathological levels as well as harnessing the various components of the endocannabinoid system to produce novel therapeutics. However, drug discovery efforts within the cannabinoid field have been slower than anticipated to reach satisfactory clinical endpoints and raises an important question into the validity of developing novel ligands that therapeutically target the endocannabinoid system. To answer this, we will first examine evidence that supports the existence of an endocannabinoid system role within inflammatory diseases, neurodegeneration, pain, substance use disorders, mood disorders, as well as metabolic diseases. Next, this review will discuss recent clinical studies, within the last 5 years, of cannabinoid compounds in context to these diseases. We will also address some of the challenges and considerations within the cannabinoid field that may be important in the advancement of therapeutics into the clinic.