The Effect of Cannabidiol on Performance and Post-Load Recovery among Healthy and Physically Active Individuals: A Systematic Review.

Athlete performance and post-load recovery can be considered one of the most important and actively discussed topics in professional sport. One substance aimed at improving performance is cannabidiol (CBD), which has been actively gaining popularity with several studies published in recent years. The PubMed, Scopus, and Cochrane Library databases were searched from inception to April 2024 according to PRISMA recommendations to identify studies on the effects of CBD on exercise capacity and post-load recovery. An initial search identified 901 publications, of which seven fully met the inclusion criteria. Current evidence supports a limited beneficial effect of CBD on a number of physiological parameters, such as VO2, mean power, and relative mean power. At the same time, there were limited data on the beneficial effects of CBD on strength parameters (including vertical jump, counter movement jump, one repetition max bench press, and barbell back squat) and post-load recovery. Notably, most of the studies included in the analysis were conducted between 2021 and 2024, indicating a growing interest among researchers in the use of CBD in healthy, physically active individuals. Further studies are needed to assess the safety of different CBD administration protocols in professional athletes.

Pharmacological and physiological effects of cannabidiol: a dose escalation, placebo washout study protocol.

BACKGROUND: Cannabinoids such as cannabidiol (CBD) exhibit anti-inflammatory properties and have the potential to act as a therapeutic following mild traumatic brain injury. There is limited evidence available on the pharmacological, physiological and psychological effects of escalating CBD dosages in a healthy, male, university athlete population. Furthermore, no dosing regimen for CBD is available with implications of improving physiological function. This study will develop an optimal CBD dose based on the pharmacokinetic data in contact-sport athletes. The physiological and psychological data will be correlated to the pharmacokinetic data to understand the mechanism(s) associated with an escalating CBD dose. METHODS/DESIGN: Forty participants will receive escalating doses of CBD ranging from 5 mg CBD/kg/day to 30 mg CBD/kg/day. The CBD dose is escalated every two weeks in increments of 5 mg CBD/kg/day. Participants will provide blood for pharmacological assessments at each of the 10 visits. Participants will complete a physiological assessment at each of the visits, including assessments of cerebral hemodynamics, blood pressure, electrocardiogram, seismocardiogram, transcranial magnetic stimulation, and salivary analysis for genomic sequencing. Finally, participants will complete a psychological assessment consisting of sleep, anxiety, and pain-related questionnaires. DISCUSSION: This study will develop of an optimal CBD dose based on pharmacological, physiological, and psychological properties for future use during contact sport seasons to understand if CBD can help to reduce the frequency of mild traumatic injuries and enhance recovery. TRIAL REGISTRATION: Clinicaltrials.gov: NCT06204003.

Inter-strain variability in responses to a single administration of the cannabidiol-rich cannabis extract in mice.

Cannabidiol (CBD) has gained widespread popularity; however, its pharmacological and toxicological profiles in the context of human genetic diversity remain largely unexplored. Here, we investigated the variability in metabolism and toxicity of CBD-rich cannabis extract (CRCE) in genetically diverse mouse models: C57BL/6J, B6C3F1/J, and NZO/HlLtJ strains. Mice received a single dose of CRCE containing 57.9% CBD at dosages of 0, 246, 738, and 2460 mg/kg of CBD. At 24 h after treatment, no appreciable histomorphological changes were detected in the liver. Plasma bilirubin levels increased markedly in all strains at the highest CBD dose. Mice in all treatment groups displayed significant but distinct increases in ALT and AST levels. While B6C3F1/J and NZO/HlLtJ mice had negligible plasma CBD levels at 738 mg/kg, C57BL/6J mice exhibited levels exceeding 7000 ng/mL. At 2460 mg/kg, high CBD concentrations were found in B6C3F1/J and C57BL/6J mice, but markedly lower levels were seen in NZO/HlLtJ mice. Gene expression profiling showed significant increases in Cyp2b10 across all strains but varying responses in Cyp1a1 expression, indicating strain-specific CYP dysregulation. Genetically diverse mice exhibited differential pharmacological and toxicological responses to CRCE, suggesting a high potential for inter-individual variability in the pharmacology and toxicology of CBD in humans.

Dose-dependent effects of oral cannabidiol and delta-9-tetrahydrocannabinol on serum anandamide and related N-acylethanolamines in healthy volunteers.

BACKGROUND: The mental health benefits of cannabidiol (CBD) are promising but can be inconsistent, in part due to challenges in defining an individual's effective dosage. In schizophrenia, alterations in anandamide (AEA) concentrations, an endocannabinoid (eCB) agonist of the eCB system, reflect positively on treatment with CBD. Here, we expanded this assessment to include eCBs alongside AEA congeners, comparing phytocannabinoids and dosage in a clinical setting. METHODS: Liquid chromatography-tandem mass spectrometry quantified changes in serum levels of AEA, 2-arachidonoylglycerol (2-AG), alongside AEA-related compounds oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), which were attained from two independent, parallel-designed, clinical trials investigating single, oral CBD (600 or 800 mg), delta-9-tetrahydrocannabinol (Δ9-THC, 10 or 20 mg) and combination administration (CBD|800 mg+Δ9-THC|20 mg) in healthy volunteers (HVs, n=75). Concentrations were measured at baseline (t=0), 65 and 160 min post administration. RESULTS: CBD-led increases in AEA (1.6-fold), OEA and PEA (1.4-fold) were observed following a single 800 mg (pcorr<0.05) but not 600 mg dosage. Declining AEA was observed with Δ9-THC at 10 mg (-1.3-fold) and 20 mg (-1.4-fold) but restored to baseline levels by 160 min. CBD+Δ9-THC yielded the highest increases in AEA (2.1-fold), OEA (1.9-fold) and PEA (1.8-fold) without reaching a maximal response. CONCLUSION: CBD-administered effects towards AEA, OEA and PEA are consistent with phase II trials reporting clinical improvement for acute schizophrenia (CBD≥800 mg). Including Δ9-THC appears to enhance the CBD-induced response towards AEA and its congeners. Our results warrant further investigations into the potential of these lipid-derived mediators as metabolic measures for CBD dose prescription and co-cannabinoid administration.

A randomized, double-blind, placebo-controlled trial to evaluate the effect of nabiximols oromucosal spray on clinical measures of spasticity in patients with multiple sclerosis.

BACKGROUND: Spasticity is a common and potentially debilitating symptom of multiple sclerosis (MS) with a highly variable presentation. Understanding, quantifying, and managing MS-associated spasticity (MSS) is a challenge for research and in clinical practice. The tetrahydrocannabinol:cannabidiol oromucosal spray nabiximols has demonstrated beneficial effects in the treatment of MSS in clinical studies as well as real-world observational studies, and is approved for the treatment of MSS in 29 countries globally. Most randomized studies evaluated the efficacy of nabiximols using the change in average daily spasticity scores reported by patients using the spasticity Numeric Rating Scale as a primary endpoint. This study, RELEASE MSS1 (NCT04657666), was conducted using a prespecified primary endpoint of change in spastic muscle tone (Modified Ashworth Scale Lower Limb Muscle Tone-6 [MAS LLMT-6]) to corroborate the efficacy of nabiximols as adjunctive therapy observed with the patient-measured spasticity Numeric Rating Scale primary endpoint in the previous pivotal studies. METHODS: This was a phase 3, multicenter, randomized, double-blind, placebo-controlled, 2-treatment, 2-period, crossover trial. Because of the prevalence and functional impact of lower limb spasticity on the individual patient's overall experience of MS spasticity, the MAS LLMT-6 was derived from the clinician-rated MAS. The MAS LLMT-6 is the average transformed MAS score of 6 muscle groups (knee flexors, knee extensors, and ankle plantar flexors; all assessed bilaterally). Secondary measures included MAS LLMT-4 scores, defined as the average of the 4 individual MAS-transformed scores of knee flexors and knee extensors bilaterally. Patients had a diagnosis of MS and an untransformed MAS score of at least 2 in ≥2 of 6 LLMT-6 muscle groups despite current treatment with ≥1 of the following oral antispasticity agents: baclofen, tizanidine, or dantrolene. Eligible participants were randomly assigned to 1 of 2 treatment sequences. Each treatment sequence consisted of two treatment periods, each consisting of a 14-day dose titration phase followed by a 7-day dose maintenance phase. RESULTS: Of 68 patients enrolled, 33 were assigned to nabiximols followed by placebo and 35 were assigned to placebo followed by nabiximols. Least squares mean changes in MAS LLMT-6 scores from baseline to day 21 were -0.23 for nabiximols and -0.26 for placebo; the least squares mean treatment difference in MAS LLMT-6 scores for nabiximols versus placebo was 0.04, which was not statistically significant (P = 0.7152). Mean changes in MAS LLMT-4 scores from baseline to day 21 also were not significantly different between the nabiximols and placebo groups. Safety results in this study were consistent with the known safety profile of nabiximols in patients with MSS. CONCLUSION: Despite the established efficacy of nabiximols in MSS observed using patient-reported measures, the primary endpoint was not met in this study. The findings from this study reflect and emphasize some of the challenges in the evaluation and treatment of MS spasticity. CLINICAL TRIAL REGISTRATION NUMBER (CLINICALTRIALS.GOV): : NCT04657666.

Alterations to sphingolipid metabolism from antipsychotic administration in healthy volunteers are restored following the use of cannabidiol.

Randomized clinical trials substantiate cannabidiol (CBD) as a next-generation antipsychotic, effective in alleviating positive and negative symptoms associated with psychosis, while minimising the adverse effects seen with established treatments. Although the mechanisms remain debated, CBD is known to induce drug-responsive changes in lipid-based retrograde neurotransmitters. Lipid aberrations are also frequently observed with antipsychotics, which may contribute to their efficacy or increase the risk of undesirables, including metabolic dysfunction, obesity and dyslipidaemia. Our study investigated CBD's impact following lipid responses triggered by interaction with second-generation antipsychotics (SGA) in a randomized phase I safety study. Untargeted mass spectrometry assessed the lipidomic profiles of human sera, collected from 38 healthy volunteers. Serum samples were obtained prior to commencement of any medication (t = 0), 3 days after consecutive administration of one of the five, placebo-controlled, treatment arms designed to achieve steady-state concentrations of each SGA (amisulpride, 150 mg/day; quetiapine, 300 mg/day; olanzapine 10 mg/day; risperidone, 3 mg/day), and after six successive days of SGA treatment combined with CBD (800 mg/day). Receiver operating characteristics (ROC) refined 3712 features to a putative list of 15 lipids significantly altered (AUC > 0.7), classified into sphingolipids (53 %), glycerolipids (27 %) and glycerophospholipids (20 %). Targeted mass spectrometry confirmed reduced sphingomyelin and ceramide levels with antipsychotics, which mapped along their catabolic pathway and were restored by CBD. These sphingolipids inversely correlated with body weight after olanzapine, quetiapine, and risperidone treatment, where CBD appears to have arrested or attenuated these effects. Herein, we propose CBD may alleviate aberrant sphingolipid metabolism and that further investigation into sphingolipids as markers for monitoring side effects of SGAs and efficacy of CBD is warranted.

Does a broad-spectrum cannabidiol supplement improve performance in a 10-min cycle ergometer performance-test?

Cannabidiol (CBD) is a non-intoxicating phytocannabinoid which has been proposed to possess anti-inflammatory and analgesic properties. Given the potential for perceptions of pain to limit exercise performance, the aim of the present study was to investigate if 3 weeks of daily CBD supplementation (150 mg day-1) improved performance in a 10-min performance-trial on a cycle ergometer. In a randomized, double-blind and placebo-controlled study, 22 healthy participants (n = 11 male and n = 11 female) completed two 10-min performance trials on a WattBike cycle ergometer interspersed with a 3-week supplementation period. Supplementation involved either 150 mg day-1 oral CBD or 150 mg day-1 of a visually identical placebo (PLA). During trials, ratings of perceived exertion (RPE [6-20]), heart rate (HR) and blood lactate (BLa) were collected every 2 min. Mean power (W) was also taken throughout the exercise at each time point. All data were analyzed using two-way ANOVAs. There were no significant differences (P > 0.05) between CBD or PLA groups for mean power (W) during the 10-min performance trial. There were also no significant differences (P > 0.05) in any of the physiological or perceptual parameters (HR, BLa and RPE) between conditions. Three weeks supplementation of a broad-spectrum CBD supplement did not improve performance via any change in RPE during a 10-min time trial on a cycle ergometer, and as such, this evidence does not support the claim that broad-spectrum CBD supplements could be performance-enhancing in this exercise modality.

Medicinal cannabis tea contains variable doses of cannabinoids and no terpenes.

Tea is a recommended way of administration of prescribed cannabis plant products in Denmark. We aimed to investigate the cannabinoid and terpene doses contained in different teas. We analysed tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), and terpene concentrations in three repeated preparations of each type of tea, and in plant material. In standard tea, concentrations of THC were [median (min-max)] 9.5 (2.3-15), 19 (13-34), and 36 (26-57) µg/mL for products with a labelled content of 6.3%, 14%, and 22% total THC (THC + THCA), respectively. The CBD concentration in tea from a product labelled with 8% total CBD (CBD + CBDA) was 7.5 (1.9-10) µg/mL. Based on this, the recommended starting amount of 0.2 L of the different teas would contain between 0.46 and 11.3 mg THC, and 0.38 to 2.0 mg CBD. Adding creamer before, but not after boiling, increased the THC and CBD concentration 2.3-4.4 and 2.1-fold, respectively. Terpenes were detected in plant material, but not in tea. The study elucidates THC and CBD doses in different teas, which may assist the clinician's choice of cannabis product. Moreover, it underscores the need for caution as administration as tea can result in exposure to different doses, even when the same cannabis product is used.

In situ forming PLA and PLGA implants for the parenteral administration of Cannabidiol.

Cannabidiol (CBD) is the main non-psychotropic cannabinoid. It has attracted a great deal of interest in the treatment of several diseases such as inflammatory disorders and cancer. Despite its promising clinical interest, its administration is very challenging. In situ forming implants (ISFIs) could be a simple and cheap strategy to administer CBD while obtaining a prolonged effect with a single administration. This work aims to design, develop, and characterize for the first time ISFIs for the parenteral administration of CBD with potential application in cancer disease. Formulations made of PLGA-502, PLGA-502H, and PLA-202 in NMP or DMSO and PLA-203 in DMSO at a polymer concentration of 0.25 mg/µL and loaded with CBD at a drug: polymer ratio of 2.5:100 and 5:100 (w/w) were developed. The formulations prepared with NMP exhibited a faster drug release. CBD implants elaborated with PLGA-502 and DMSO with the highest CBD: polymer ratio showed the most suitable drug release for one month. This formulation was successfully formed in ovo onto the chorioallantoic chick membrane without exhibiting signs of toxicity and exhibited a superior antiangiogenic activity than CBD in solution administered at the same doses. Consequently, implants made of PLGA-502 and DMSO represent a promising strategy to effectively administer CBD subcutaneously as combination therapy in cancer disease.

Enhanced brain-targeting and efficacy of cannabidiol via RVG-Exo/CBD nanodelivery system.

This study introduces an innovative brain-targeted drug delivery system, RVG-Exo/CBD, utilizing rabies virus glycoprotein (RVG)-engineered exosomes for encapsulating cannabidiol (CBD). The novel delivery system was meticulously characterized, confirming the maintenance of exosomal integrity, size, and successful drug encapsulation with a high drug loading rate of 83.0 %. Evaluation of the RVG-Exo/CBD's brain-targeting capability demonstrated superior distribution and retention in brain tissue compared to unmodified exosomes, primarily validated through in vivo fluorescence imaging. The efficacy of this delivery system was assessed using a behavioral sensitization model in mice, where RVG-Exo/CBD notably suppressed methamphetamine-induced hyperactivity more effectively than CBD alone, indicating a reduction in effective dose and enhanced bioavailability. Overall, the RVG-Exo/CBD system emerges as a promising strategy for enhancing the therapeutic efficacy and safety of CBD, particularly for neurological applications, highlighting its potential for addressing the limitations associated with traditional CBD administration in clinical settings.

Formulation Development and Evaluation of Cannabidiol Hot-Melt Extruded Solid Self-Emulsifying Drug Delivery System for Oral Applications.

Cannabidiol (CBD) is a highly lipophilic compound with poor oral bioavailability, due to poor aqueous solubility and extensive pre-systemic metabolism. The aim of this study was to explore the potential of employing Hot Melt Extrusion (HME) technology for the continuous production of Self Emulsifying Drug Delivery Systems (SEDDS) to improve the solubility and in vitro dissolution performance of CBD. Accordingly, different placebos were processed through HME in order to obtain a lead CBD loaded solid SEDDS. Two SEDDS were prepared with sesame oil, Poloxamer 188, Gelucire®59/14, PEO N80 and Soluplus®. Moreover, Vitamin E was added as an antioxidant. The SEDDS formulations demonstrated emulsification times of 9.19 and 9.30 min for F1 and F2 respectively. The formed emulsions showed smaller droplet size ranging from 150-400 nm that could improve lymphatic uptake of CBD and reduce first pass metabolism. Both formulations showed significantly faster in vitro dissolution rate (90% for F1 and 83% for F2) compared to 14% for the pure CBD within the first hour, giving an enhanced release profile. The formulations were tested for stability over a 60-day time period at 4°C, 25°C, and 40°C. Formulation F1 was stable over the 60-day time-period at 4°C. Therefore, the continuous HME technology could replace conventional methods for processing SEDDS and improve the oral delivery of CBD for better therapeutic outcomes.

High-loading cannabidiol powders for inhalation.

Limited attempts have been made previously to develop high-loading CBD inhalable powders, which are essential for high dose delivery. Therefore, this study aimed to develop and characterise inhalable powders with ≥ 95 % w/w CBD by wet ball milling. The effects of magnesium stearate (2 % and 5 %) and inhaler resistance (low-resistance and high-resistance RS01 inhalers) on aerosol performance were also compared. Wet ball milling produced CBD powders with > 50 % production yield. The milled particles showed irregular shapes. The powders were crystalline with minimal amorphous content, low residual solvent level (<1%), and low moisture sorption (<4%). Magnesium stearate improved both the emitted and fine particle fractions. The aerodynamic particle size distribution of the formulations differed between the low-resistance and high-resistance RS01 inhalers. The latter decreased throat deposition but increased inhaler retention. The dissolution profiles showed that all three formulations released CBD steadily and plateaued at 30 min. The best scenario was CBD with 5 % magnesium stearate dispersed from the high resistance RS01 inhaler, showing the highest FPF with the lowest throat deposition. This combination may be tested in vivo in the future to investigate its pharmacokinetic profile.

Enhanced oral bioavailability and in vitro evaluation of cannabidiol camel milk-derived exosome formulation in resistant MDA-MB-231 and MDA-MB-468 breast cancer cells.

The potential of camel milk-derived exosomes (CMDE) to enhance the bioavailability of Cannabidiol (CBD) was investigated. CBD-CMDE formulation was prepared using an established procedure and its particle size was 138.4 ± 4.37 nm, and CBD entrapment efficiency of 56.56 ± 4.26 %. In-vitro release studies showed release of 78.27 ± 5.37 % and 46.42 ± 4.75 % CBD from CMDE and control CBD formulation respectively in pH 6.8 at 24 hr. The apparent permeability (Papp) of CBD-CMDE was found to be enhanced by 3.95-fold with Papp of 22.9*10-6 ± 0.34 cm/sec as compared to control CBD formulation with Papp of 5.8*10-6 ± 0.65 cm/sec in MDCK cells. CBD-CMDE was found to be more potent than CBD in 2D cytotoxicity assay with IC50 values of 3.6 ± 0.54 µM, 3.88 ± 0.54 µM and 7.53 ± 0.59 µM, 7.53 ± 0.59 µM against Doxorubicin (DOX) resistant MDA-MB-231 and Rapamycin (RM) resistant MDA-MB-468 breast cancer cells respectively. Moreover, 3D spheroids assay results demonstrated CBD-CMDE with IC50 values of 14 ± 0.85 µM, 15 ± 0.07 µM as compared to CBD alone with IC50 values of 25 ± 0.93 µM, 34.7 ± 0.08 µM in MDA-MB-231 DOX RT cells and MDA-MB-468 RM RT cells respectively. In-vivo PK studies showed enhanced bioavailability of CBD from CBD-exosomes with AUC(0-24h) of 1350.56 ± 187.50 h.ng/mL as compared to CBD control formulation with AUC(0-24h) of 351.95 ± 39.10 h.ng/mL with a single oral dose of 12 mg/kg. The data indicate that CMDE significantly improved the oral bioavailability of CBD. Overall, CMDE can be used to enhance the oral absorption of poorly bioavailable APIs.

The effects of a brand-specific, hemp-derived cannabidiol product on physiological, biochemical, and psychometric outcomes in healthy adults: a double-blind, randomized clinical trial.

BACKGROUND: Cannabidiol (CBD) is a non-psychoactive phyto-cannabinoid derived from the Cannabis sativa plant. CBD exhibits various interactions at receptor sites, prompting the research of its potential anti-inflammatory, immunomodulatory, psychological, and pain-relieving effects. This study aimed to investigate the physiological, biochemical, and psychometric effects of a brand-specific, hemp-derived CBD product in healthy adults over a 12-week observation period. METHODS: 54 healthy males and females (age = 25 ± 7y; BMI = 24.82 ± 3.25 kg/m2) recruited from a large Southeastern University completed the study. Participants arrived at the laboratory after > 8 h of fasting, and > 48 h without alcohol consumption and vigorous exercise. Following baseline measurements (height, weight, blood pressure, electrocardiogram (ECG), and blood work), participants were stratified by sex and randomized to either CBD or placebo groups. Products were administered double-blinded, with both given in liquid form containing medium-chain triglyceride oil, while the CBD product specifically contained 50 mg/mL of CBD. Participants were instructed to consume 1 mL of their product twice daily and were given enough product to last until their next laboratory visit. Data were collected at baseline and on days 30 ± 3, 60 ± 3, and 90 ± 3. Blood was drawn for analysis of immune and inflammatory biomarkers. Chronic pain among participants was calculated using urine samples according to the foundational pain index (FPI). Self-reported psychometric questionnaires were utilized (Cohen's Perceived Stress Scale, Pittsburgh Sleep Quality Index, Profile of Mood States,10-item Likert scale for perceived pain) to assess stress, sleep quality, mood state, and body discomfort. To determine overall wellbeing, participants completed a daily survey indicating if they missed work or school due to illness. Change from baseline was calculated for each measure, and mixed effects models were used to determine differences between groups over time while adjusting for baseline values (α = 0.05). Data are presented as mean ± standard deviation. RESULTS: There were no Group-by-Time interactions or Group or Time main effects for immune or inflammatory biomarkers (p > 0.05). Analyses revealed no Group-by-Time interactions or main effects observed for perceived stress, sleep quality, overall mood disturbance, and all the profile of mood state subscales (p > 0.05), except "vigor-activity." A Time main effect was found for the sub-score for "vigor-activity" (p = 0.007; Pre CBD = 19.5 ± 5.2, Post CBD = 17.3 ± 5.3; Pre PL = 19.0 ± 5.7, Post PL = 17.9 ± 7.1), which decreased from Visit 3 to Visit 4 (p = 0.025) and from Visit 3 to Visit 5 (p = 0.014). There was a Group main effect for FPI (p = 0.028; Pre CBD = 11.9 ± 14.4, Post CBD = 8.8 ± 10.9; Pre PL = 9.0 ± 14.2, Post PL = 12.9 ± 11.5), indicating that the placebo group had greater increases in pain over the intervention compared to the CBD group. No significant differences were found between groups in the incidence and prevalence of "colds or flus" (p > 0.05). DISCUSSION: CBD was safe and well tolerated in healthy adults. These findings show pain was lower in the CBD group, suggesting a potentially positive effect for consumption of CBD. "Vigor-activity" decreased across the intervention, which may be a confounding effect of the academic semester. While the dosage chosen was safe, more research may be warranted using higher doses as these may be needed to observe further therapeutic effects in healthy populations.

Transdermal Delivery of Cannabidiol for the Management of Acute Inflammatory Pain: A Comprehensive Review of the Literature.

The emerging field of nanotechnology has paved the way for revolutionary advancements in drug delivery systems, with nanosystems emerging as a promising avenue for enhancing the therapeutic potential and the stability of various bioactive compounds. Among these, cannabidiol (CBD), the non-psychotropic compound of the Cannabis sativa plant, has gained attention for its therapeutic properties. Consequently, researchers have devoted significant efforts to unlock the full potential of CBD's clinical benefits, where various nanosystems and excipients have emerged to overcome challenges associated with its bioavailability, stability, and controlled release for its transdermal application. Therefore, this comprehensive review aims to explain CBD's role in managing acute inflammatory pain and offers an overview of the state of the art of existing delivery systems and excipients for CBD. To summarize this review, a summary of the cannabinoids and therapeutical targets of CBD will be discussed, followed by its conventional modes of administration. The transdermal route of administration and the current topical and transdermal delivery systems will also be reviewed. This review will conclude with an overview of in vivo techniques that allow the evaluation of the anti-inflammatory and analgesic potentials of these systems.

The effect of cannabinoids on single-level lumbar arthrodesis outcomes in a rat model.

BACKGROUND CONTEXT: The opioid epidemic is a public health crisis affecting spine care and pain management. Medical marijuana is a potential nonopioid analgesic yet to be studied in the surgical setting since its effects on bone healing are not fully understood. Studies have demonstrated analgesic and potentially osteoinductive properties of cannabinoids with endocannabinoid receptor expression in bone tissue. PURPOSE: We hypothesize that tetrahydrocannabinol (THC) and cannabidiol (CBD) will not decrease bone healing in spinal fusion. STUDY DESIGN: Seventy-eight adult Sprague-Dawley rats were used for this study. Utilizing allogenic bone grafts (6 donor rats), posterolateral inter-transverse lumbar fusion at the L4-L5 level was performed. The animals were equally divided into four treatment groups, each receiving 0.1 ml intraperitoneal injections weekly as follows: placebo (saline), 5 mg/kg THC, 5 mg/kg CBD, and a combination of 5 mg/kg THC and 5mg/kg CBD (Combo). METHODS: Callus tissue was harvested 2- and 8-weeks postsurgery for qPCR assessment to quantify changes in the expression of osteogenic genes. Manual palpation was done to assess the strength of the L4-L5 arthrodesis on all rats. µCT image-based callus analysis and histology were performed. One-way ANOVA followed by post hoc comparisons was performed. RESULTS: µCT demonstrated no significant differences. Treatment groups had slightly increased bone volume and density compared to control. qPCR at 2 weeks indicated downregulated RANKL/OPG ratios skewing towards osteogenesis in the CBD group, with the THC and CBD+THC groups demonstrating a downward trend (p>.05). ALPL, BMP4, and SOST were significantly higher in the CBD group, with CTNNB1 and RUNX2 also showing an upregulating trend. The CBD group showed elevation in Col1A1 and MMP13. Data at eight weeks showed ALPL, RUNX2, BMP4, and SOST were downregulated for all treatment groups. In the CBD+THC group, RANK, RANKL, and OPG were downregulated. OPG downregulation reached significance for the THC and CBD+THC group compared to saline. Interestingly, the RANKL/OPG ratio showed upregulation in the CBD and CBD+THC groups. RANKL showed upregulation in the CBD group. At 2 and 8 weeks, the CBD treatment group showed superior histological progression, increasing between time points. CONCLUSION: This study demonstrates that CBD and THC have no adverse effect on bone healing and the rate of spinal fusion in rats. Osteogenic factors were upregulated in the CBD-treated groups at 2 weeks, which indicates a potential for bone regeneration. In this group, compared to control, the RANKL/OPG ratio at the early healing phase demonstrates the inhibition of osteoclast differentiation, enhancing bone formation. Interestingly, it shows promoted osteoclast differentiation at the later healing phase, enhancing bone remodeling. This aligns with the physiological expectation of a lower ratio in the early phases and a higher ratio in the later remodeling phases. CLINICAL SIGNIFICANCE: CBD and THC showed no inhibitory effects on bone healing in a spinal fusion model. Moreover, histologic and gene expression analysis demonstrated that CBD may, in fact, enhance bone healing. Further research is needed to confirm the safe usage of THC and CBD in the postoperative setting following spinal fusions.

Evaluation of the efficacy, safety, and pharmacokinetics of nanodispersible cannabidiol oral solution (150 mg/mL) versus placebo in mild to moderate anxiety subjects: A double blind multicenter randomized clinical trial.

BACKGROUND: Anxiety disorders, an increasingly prevalent global mental health illness, affected approximately 301 million individuals worldwide in 2019. There is an unmet need for the treatment of anxiety disorders, as current therapies are associated with limited response rates, residual symptoms, and adverse effects. OBJECTIVES: To evaluate the efficacy, safety, and pharmacokinetics of nanodispersible cannabidiol (CBD) oral solution versus placebo for the treatment of mild to moderate anxiety disorders. METHODS: This phase 3 prospective, randomized, double blind, parallel group, placebo-controlled, 15-week cohort study took place at multiple sites across India. Eligible participants were randomly assigned to one of the two treatment arms (CBD or placebo) in a 1:1 ratio. RESULTS: 178 participants were randomized to receive CBD (n=89) or placebo (n=89). The study met both primary (GAD-7 and HAM-A scores) and secondary outcomes (CGI-I, CGI-S, PHQ-9 and PSQI scores). The GAD-7 score difference between the end of treatment and baseline for the CBD versus the placebo was -7.02 (S.E: 0.25, 95% CI -7.52; -6.52), p<0.0001. Similarly, the HAM-A score difference at the end of treatment compared to baseline for the CBD versus the placebo was -11.9 (S.E: 0.33, 95% CI -12.6; -11.3), p<0.0001. CONCLUSIONS: Nanodispersible CBD was therapeutically safe with no serious adverse events, well tolerated, and effective for the treatment of mild to moderate anxiety disorders, as well as associated depression and sleep quality disturbances. These results pave way for probable prospective use of nanodispersible CBD formulation for various psychiatry disorders alone or in conjunction with other drugs.

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).

Infant formula as a solid lipid dose form for enhancement of the oral bioavailability of cannabidiol for paediatric patients.

Cannabinoids can save paediatric patients from harmful psychological conditions caused by epilepsy. However, the limited aqueous solubility of the drug presents a limitation to oral absorption and bioavailability. Previous studies have shown the enhancement of oral bioavailability for poorly water-soluble drugs using milk or milk-based products like infant formula as a novel lipid-based formulation, due to digestion of the lipids to enhance drug solubility that is particularly well suited to infants and in low economy settings. Therefore, this study has investigated the in vitro solubilisation enhancement of cannabidiol (CBD) in milk-based products during digestion using synchrotron small angle X-ray scattering, followed by pharmacokinetic studies to determine the relative oral bioavailability. The in vitro results, coupled with in vivo data, demonstrate a two-fold increase in the oral bioavailability of CBD in bovine milk as well as infant formula. The results of this study indicate the potential for infant formula to be considered as a novel formulation approach for CBD. Further study is encouraged for more drugs with infant formula to strengthen the correlation between the solubilisation of drug and their oral bioavailability.

RETRACTED: Left hemisphere lateralization of the limbic system and frontoparietal network (FPN) correlates with positive and negative symptom improvement following cannabidiol (CBD) administration in psychosis and ultra-high risk (UHR) populations: A voxel-wise meta-analysis.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the authors when they discovered and reported to the editors that articles containing population samples drawn from similar cohorts of healthy participants without psychosis were erroneously included in the psychosis subgroup of the meta-analysis. This error in the systematic review processes ultimately affects the findings in the meta-analysis. The authors deeply apologize for this error.