The Transdermal Delivery of Therapeutic Cannabinoids

Cannabis: Zone Aspects of Raw Plant Components in Sport-A Narrative Review

Objectives/Background: The Cannabis genus contain a mixture of cannabinoids and other minor components which have been studied so far. In this narrative review, we highlight the main aspects of the polarized discussion between abuse and toxicity versus the benefits of the compounds found in the Cannabis sativa plant. Methods: We investigated databases such as PubMed, Google Scholar, Web of Science and World Anti-doping Agency (WADA) documents for scientific publications that can elucidate the heated discussion related to the negative aspects of addiction, organ damage and improved sports performance and the medical benefits, particularly in athletes, of some compounds that are promising as nutrients. Results: Scientific arguments bring forward the harmful effects of cannabinoids, ethical and legislative aspects of their usage as doping substances in sports. We present the synthesis and metabolism of the main cannabis compounds along with identification methods for routine anti-doping tests. Numerous other studies attest to the beneficial effects, which could bring a therapeutic advantage to athletes in case of injuries. These benefits recommend Cannabis sativa compounds as nutrients, as well as potential pharmacological agents. Conclusions and Future Perspectives: From the perspective of both athletes and illegal use investigators in sport, there are many interpretations, presented and discussed in this review. Despite many recent studies on cannabis species, there is very little research on the beneficial effects in active athletes, especially on large groups compared to placebo. These studies may complete the current vision of this topic and clarify the hypotheses launched as discussions in this review.

Cannabinoids in Chronic Pain Management: A Review of the History, Efficacy, Applications, and Risks

Background/Objectives: Chronic pain remains a pervasive and challenging public health issue, often resistant to conventional treatments such as opioids, which carry substantial risks of dependency and adverse effects. Cannabinoids, bioactive compounds derived from the Cannabis sativa plant and their synthetic analogs, have emerged as a potential alternative for pain management, leveraging their interaction with the endocannabinoid system to modulate pain and inflammation. Methods: The current, evolving literature regarding the history, efficacy, applications, and safety of cannabinoids in the treatment of chronic pain was reviewed and summarized to provide the most current review of cannabinoids. Results: Evidence suggests that cannabinoids provide moderate efficacy in managing neuropathic pain, fibromyalgia, cancer-related pain, and multiple sclerosis-related spasticity. Patient-reported outcomes further indicate widespread perceptions of cannabinoids as a safer alternative to opioids, with potential opioid-sparing effects. However, the quality of existing evidence is limited by small sample sizes and methodological inconsistencies. Regulatory barriers, including the classification of cannabis as a Schedule I substance in the United States, continue to hinder robust research and clinical integration. Moreover, the risks associated with cannabinoids, such as psychiatric effects, addiction potential, and drug interactions, necessitate cautious application. Conclusions: Cannabinoids represent a promising, albeit complex, alternative for chronic pain management, particularly given the limitations and risks of traditional therapies such as opioids. However, significant deficiencies remain in the research. While smaller trials and systematic reviews indicate therapeutic potential, the quality of evidence is often low due to limited sample sizes, short study durations, and methodological inconsistencies. Large-scale, randomized controlled trials with long-term follow-up are urgently needed to confirm efficacy and safety across diverse patient populations and pain etiologies.

Protective effects of cannabinoid receptor 2 on annulus fibrosus degeneration by upregulating autophagy via AKT-mTOR-p70S6K signal pathway

As an important pathological process, annulus fibrosus (AF) degeneration contributes greatly to intervertebral disc degeneration (IVDD). Moreover, extracellular matrix (ECM) degradation and AF cell (AFC) autophagy are of utmost importance. The involvement of cannabinoid receptor type 2 (CB2) in the pathological mechanisms underlying different diseases has been demonstrated dueto its capacity toregulateautophagy. The objective of this study was to explore the impact of CB2-induced autophagy on AF degeneration and its underlying mechanism. First, the expression of CB2 in human degenerative AF tissues decreased with increasing degeneration degree, whereas its expression in rat AFCs increased in a concentration- and time-dependent manner following H2O2 intervention. Activation of CB2 increased collagen Ⅰ and Ⅱ expression while decreasing MMP3 and MMP13 expression. In addition, p62 expression decreased, whereas beclin-1 and LC3-Ⅱ/LC3-Ⅰ expression increased after JWH133 intervention. After CB2 activation, the addition of 3-MA impeded the synthesis of collagen Ⅰ and Ⅱ while preserving the elevated levels of MMP3 and MMP13. The activation of CB2 greatly suppressed the protein levels of the AKT/mTOR/p70S6K signaling pathway. In vivo, the JWH133 group exhibited elevated disk height index (DHI) and MRI signals, along with a comparatively intact structure of the intervertebral disc in contrast to the vehicle group. In general, CB2 activation could modulate apoptosis and autophagy in rat AFCs, thereby mitigating the advancement of IVDD. Moreover, the AKT/mTOR/p70S6K signaling pathway plays a role in the development of AF degeneration through the regulation of autophagy. The findings suggest that CB2 is a potentially effective therapeutic target for IVDD.

Safety assessment of female sexual hygiene product containing cannabidiol in new zealand white rabbit and clinical trial

Cannabis is an herb known for its significant pharmacological effects. This study evaluated the safety of a female sexual hygiene product containing cannabidiol on the skin of experimental animals and humans. Irritation symptoms were tested using three female New Zealand white rabbits. In human trials, irritation and sensitivity symptoms were assessed in 30 healthy female volunteers. The results from the animal study indicated that body weight and clinical symptoms remained normal, with only slight irritation noted in the primary irritation index of the skin (PII = 0.6). In human trials, transepidermal water loss was observed during the induction phase but decreased over time. No abnormalities were found during the induction phase; however, irritation occurred during the challenge phase, which resolved after 8 h. It was concluded that the rinse-off product caused slight irritation when applied for more than 4 h in animals and 24 h in humans, which differs from its intended use of immediate rinse-off, where no irritation was observed.

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.

Cannabinoid Analgesia in Postoperative Pain Management: From Molecular Mechanisms to Clinical Reality

Postoperative pain (POP) is a challenging clinical phenomenon that affects the majority of surgical patients and demands effective management to mitigate adverse outcomes such as persistent pain. The primary goal of POP management is to alleviate suffering and facilitate a seamless return to normal function for the patient. Despite compelling evidence of its drawbacks, opioid analgesia remains the basis of POP treatment. Novel therapeutic approaches rely on multimodal analgesia, integrating different pharmacological strategies to optimize efficacy while minimizing adverse effects. The recognition of the imperative role of the endocannabinoid system in pain regulation has prompted the investigation of cannabinoid compounds as a new therapeutic avenue. Cannabinoids may serve as adjuvants, enhancing the analgesic effects of other drugs and potentially replacing or at least reducing the dependence on other long-term analgesics in pain management. This narrative review succinctly summarizes pertinent information on the molecular mechanisms, clinical therapeutic benefits, and considerations associated with the plausible use of various cannabinoid compounds in treating POP. According to the available evidence, cannabinoid compounds modulate specific molecular mechanisms intimately involved in POP. However, only two of the eleven clinical trials that evaluated the efficacy of different cannabinoid interventions showed positive results.

Analgesic and Anti-Inflammatory Effects of 1% Topical Cannabidiol Gel in Animal Models

Introduction: Cannabidiol (CBD), a phytocannabinoid isolated from cannabis plants, is an interesting candidate for studying its anti-inflammatory effects, especially in the pre-clinical and animal models. Its anti-inflammatory effects, such as reduction of edema and arthritis, have been demonstrated in animal models. However, topical CBD administration requires further evaluation of CBD dosage and efficacy in animal models and clinical settings. Methods: This in vivo study investigated the anti-inflammatory effects of topical CBD administration in an animal model. Scientific experiments, including the formalin test, writhing test, carrageenan-induced edema, histopathological examination, and detection of various proinflammatory mediators, were performed. Results: The anti-inflammatory effects in vivo after inflammation induction, represented by decreased times of paw licking, degree of paw edema, and decreased writhing response, showed that 1% of tropical CBD use had significantly comparable or better anti-inflammatory effects when compared with tropical diclofenac, an anti-inflammatory agent. Moreover, the anti-inflammatory effects were significant compared with the placebo. In addition, the histopathological examination showed that topical CBD drastically reduced leukocyte infiltration and the degree of inflammation. This study also showed that the levels of various proinflammatory mediators in the plasma of mice treated with topical CBD did not differ from those treated with diclofenac. Conclusions: The topical administration of 1% CBD gel is a potentially effective candidate for an anti-inflammatory agent. Candidate for an anti-inflammatory agent.

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 Use of Compounds Derived from Cannabis sativa in the Treatment of Epilepsy, Painful Conditions, and Neuropsychiatric and Neurodegenerative Disorders

Neurological disorders present a wide range of symptoms and challenges in diagnosis and treatment. Cannabis sativa, with its diverse chemical composition, offers potential therapeutic benefits due to its anticonvulsive, analgesic, anti-inflammatory, and neuroprotective properties. Beyond cannabinoids, cannabis contains terpenes and polyphenols, which synergistically enhance its pharmacological effects. Various administration routes, including vaporization, oral ingestion, sublingual, and rectal, provide flexibility in treatment delivery. This review shows the therapeutic efficacy of cannabis in managing neurological disorders such as epilepsy, neurodegenerative diseases, neurodevelopmental disorders, psychiatric disorders, and painful pathologies. Drawing from surveys, patient studies, and clinical trials, it highlights the potential of cannabis in alleviating symptoms, slowing disease progression, and improving overall quality of life for patients. Understanding the diverse therapeutic mechanisms of cannabis can open up possibilities for using this plant for individual patient needs.

Development and Characterization of a Microemulsion Containing a Cannabidiol Oil and a Hydrophilic Extract from Sambucus ebulus for Topical Administration

Cannabidiol (CBD) is a safe and non-psychotropic phytocannabinoid with a wide range of potential therapeutic anti-inflamatory and antioxidant activities. Due to its lipophilicity, it is normally available dissolved in oily phases. The main aim of this work was to develop and characterize a new formulation of a microemulsion with potential anti-inflammatory and antioxidant activity for the topical treatment of inflammatory skin disorders. The microemulsion system was composed of a 20% CBD oil, which served as the hydrophobic phase; Labrasol/Plurol Oleique (1:1), which served as surfactant and cosurfactant (S/CoS), respectively; and an aqueous vegetal extract obtained from Sambucus ebulus L. (S. ebulus) ripe fruits, which has potential anti-oxidant and anti-inflammatory activity and which served as the aqueous phase. A pseudo-ternary phase diagram was generated, leading to the selection of an optimal proportion of 62% (S/CoS), 27% CBD oil and 11% water and, after its reproducibility was tested, the aqueous phases were replaced by the vegetal hydrophilic extract. The defined systems were characterized in terms of conductivity, droplet size (by laser scattering), compatibility of components (by differential scanning calorimetry) and rheological properties (using a rotational rheometer). The designed microemulsion showed good stability and slight pseudo-plastic behavior. The release properties of CBD from the oil phase and caffeic acid from the aqueous phase of the microemulsion were studied via in vitro diffusion experiments using flow-through diffusion cells and were compared to those of a CBD oil and a microemulsion containing only CBD as an active substance. It was found that the inclusion of the original oil in microemulsions did not result in a significant modification of the release of CBD, suggesting the possibility of including hydrophilic active compounds in the formulation and establishing an interesting strategy for the development of future formulations.

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.

Cannabinoids in the treatment of glioblastoma

Glioblastoma (GBM) is the most prevalent primary malignant tumor of the nervous system. While the treatment of other neoplasms is increasingly more efficacious the median survival rate of GBM patients remains low and equals about 14 months. Due to this fact, there are intensive efforts to find drugs that would help combat GBM. Nowadays cannabinoids are becoming more and more important in the field of cancer and not only because of their properties of antiemetic drugs during chemotherapy. These compounds may have a direct cytotoxic effect on cancer cells. Studies indicate GBM has disturbances in the endocannabinoid system-changes in cannabinoid metabolism as well as in the cannabinoid receptor expression. The GBM cells show expression of cannabinoid receptors 1 and 2 (CB1R and CB2R), which mediate various actions of cannabinoids. Through these receptors, cannabinoids inhibit the proliferation and invasion of GBM cells, along with changing their morphology. Cannabinoids also induce an intrinsic pathway of apoptosis in the tumor. Hence the use of cannabinoids in the treatment of GBM may be beneficial to the patients. So far, studies focusing on using cannabinoids in GBM therapy are mainly preclinical and involve cell lines and mice. The results are promising and show cannabinoids inhibit GBM growth. Several clinical studies are also being carried out. The preliminary results show good tolerance of cannabinoids and prolonged survival after administration of these drugs. In this review, we describe the impact of cannabinoids on GBM and glioma cells in vitro and in animal studies. We also provide overview of clinical trials on using cannabinoids in the treatment of GBM.

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.

Rationalizing a prospective coupling effect of cannabinoids with the current pharmacotherapy for melanoma treatment

Melanoma is one of the leading fatal forms of cancer, yet from a treatment perspective, we have minimal control over its reoccurrence and resistance to current pharmacotherapies. The endocannabinoid system (ECS) has recently been accepted as a multifaceted homeostatic regulator, influencing various physiological processes across different biological compartments, including the skin. This review presents an overview of the pathophysiology of melanoma, current pharmacotherapy used for treatment, and the challenges associated with the different pharmacological approaches. Furthermore, it highlights the utility of cannabinoids as an additive remedy for melanoma by restoring the balance between downregulated immunomodulatory pathways and elevated inflammatory cytokines during chronic skin conditions as one of the suggested critical approaches in treating this immunogenic tumor. This article is categorized under: Cancer > Molecular and Cellular Physiology.

Human Data on Pharmacokinetic Interactions of Cannabinoids: A Narrative Review

Concomitant use of cannabinoids with other drugs may result in pharmacokinetic drug-drug interactions, mainly due to the mechanism involving Phase I and Phase II enzymes and/or efflux transporters. Cannabinoids are not only substrates but also inhibitors or inducers of some of these enzymes and/or transporters. This narrative review aims to provide the available information reported in the literature regarding human data on the pharmacokinetic interactions of cannabinoids with other medications. A search on Pubmed/Medline, Google Scholar, and Cochrane Library was performed. Some studies were identified with Google search. Additional articles of interest were obtained through cross-referencing of published literature. All original research papers discussing interactions between cannabinoids, used for medical or recreational/adult-use purposes, and other medications in humans were included. Thirty-two studies with medicinal or recreational/adult-use cannabis were identified (seventeen case reports/series, thirteen clinical trials, and two retrospective analyses). In three of these studies, a bidirectional pharmacokinetic drug-drug interaction was reported. In the rest of the studies, cannabinoids were the perpetrators, as in most of them, concentrations of cannabinoids were not measured. In light of the widespread use of prescribed and non-prescribed cannabinoids with other medications, pharmacokinetic interactions are likely to occur. Physicians should be aware of these potential interactions and closely monitor drug levels and/or responses. The existing literature regarding pharmacokinetic interactions is limited, and for some drugs, studies have relatively small cohorts or are only case reports. Therefore, there is a need for high-quality pharmacological studies on cannabinoid-drug interactions.

Spray-Dried Powder Containing Cannabigerol: A New Extemporaneous Emulgel for Topical Administration

Cannabigerol (CBG), a cannabinoid from Cannabis sativa L., recently attracted noteworthy attention for its dermatological applications, mainly due to its anti-inflammatory, antioxidant, and antimicrobial effectiveness similar to those of cannabidiol (CBD). In this work, based on results from studies of in vitro permeation through biomimetic membranes performed with CBG and CBD in the presence and in the absence of a randomly substituted methyl-β-cyclodextrin (MβCD), a new CBG extemporaneous emulgel (oil-in-gel emulsion) formulation was developed by spray-drying. The powder (SDE) can be easily reconstituted with purified water, leading to a product with chemical-physical and technological characteristics that are comparable to those of the starting emulgels (E). Thermogravimetric analysis (TGA), attenuated total reflection-Fourier transformed infrared spectroscopy (ATR-FTIR), x-ray powder diffraction (XRPD), and high-performance liquid chromatography (HPLC) analyses demonstrated that the spray-drying treatment did not alter the chemical properties of CBG. This product can represent a metered-dosage form for the localized treatment of cutaneous afflictions such as acne and psoriasis.

Self-report methodology for quantifying standardized cannabis consumption in milligrams delta-9-tetrahydrocannabinol

Background: There is currently no format-independent method to determine delta-9-tetrahydrocannabinol (THC) in milligrams for self-report studies.Objectives: Validate self-report method for quantifying mg THC from commercially available cannabis products using product labeling, which includes both net weight and product potency.Methods: 53 adult cannabis users (24 M, 29F), 21-39 years of age (M = 28.38, SD = 4.15), were instructed to report daily use via a weekly survey for two consecutive weeks, provide product label photographs, abstain from use for 24 h, submit a urine sample and complete the Cannabis Use Disorder Identification Test - Revised (CUDIT-R) and the Marijuana Craving Questionnaire - Short Form (MCQ-SF). Milligrams of THC were determined by multiplying quantity of product used by its THC concentration. Urine was analyzed for the urine metabolite 11-nor-carboxy-THC (THC-COOH) via liquid chromatography mass spectroscopy. THC and THC-COOH values were log10 transformed prior to correlational analyses.Results: Median daily THC consumption was 102.53 mg (M = 203.68, SD = 268.13). Thirty-three (62%) of the 53 participants reported using two or more formats over the 2-week period. There was a significant positive correlation between log10 THC-COOH and log10 THC mg (r(41) = .59, p < .001), log10 THC mg and MCQ-SF score (r(41) = .59, p < .001), and log10 THC mg dose and CUDIT-R score, (r(41) = .39, p = .010).Conclusion: Our label-based methodology provides consumption information across all modalities of cannabis use in standard units that can be combined across products for calculation of dose. It is a viable and valid method for quantifying mg of THC consumed and can be utilized in any region where cannabis is legal, and labeling is regulated.

Topical Cannabidiol and the Progression Rate of Delayed Onset Muscle Soreness

This study investigated the efficacy of topical cannabidiol (CBD) ointment in reducing localized inflammation, minimizing performance detriments, and attenuating soreness associated with delayed onset muscle soreness (DOMS). In a double blind randomized control trial, upper-arm circumferences, maximal voluntary isometric contractions (MVICs) for elbow flexion at 90° and 30° for college-aged participants (n = 21, age 20.8 ± 1.9 years) were assessed at baseline. Participants then performed a DOMS-inducing protocol for the biceps brachii. Topical CBD ointment and placebo (P) ointment were randomly assigned and applied 30 minutes, 24, 48 and 72 hours post the DOMS protocol. The baseline parameters and a visual analog scale (VAS) to assess perceived soreness were assessed 24, 48 and 72 hours post DOMS protocol. A 4x2 repeated measures factorial ANOVA (P < 0.05) analyzed both within and between subject differences. No changes were statistically significant on any days between conditions: Upper-arm circumferences in the CBD arm (7.1 ± 5.8 cm) and in the P arm (7.3 ± 5.8 cm). MVICs were reduced at both the 90° and 30° positions (-5.9 ± 9.0 Nm (90°)); (-4.8 ± 6.5 Nm (30°)) and the P arm (-5.0 ± 10.0 Nm (90°)); (-4.6 ± 5.3 Nm (30°)). Soreness increased in both the CBD arm (6.1 ± 2.1) and the P arm (5.5 ± 2.6) over time. Topical CBD therefore did not alter any parameters vs the P treatment, thus the use of topical CBD does not attenuate the effects of DOMS.

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.

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.

Cannabidiol (CBD) for the treatment of subcutaneous treprostinil (Remodulin®) site pain: a case report

Background

Pulmonary arterial hypertension occurs as a result of vascular remodeling and dysregulation of endothelial cells that narrows small pulmonary arteries and raises precapillary pressures. Pulmonary arterial hypertension is a rare and progressive disease characterized by dyspnea, chest pain, and syncope. Parenteral treprostinil is indicated for the treatment of pulmonary arterial hypertension to diminish symptoms associated with exercise. Up to 92% of patients treated with treprostinil via subcutaneous delivery experienced infusion site pain and approximately 23% discontinued treatment due to site pain. Cannabidiol salve may have analgesic and anti-inflammatory properties and could be an additional option for patients with infusion site pain.

Case report

Two patients with pulmonary arterial hypertension were treated with cannabidiol salve. Both patients reported a reduction in infusion site pain without the need for narcotics.

Conclusion

These two cases suggest that cannabidiol salve may help to minimize redness and alleviate pain at the infusion site. Additional studies are required to test the effectiveness of cannabidiol in a larger group of patients with infusion site pain.

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.

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.

Nanoformulations as a strategy to overcome the delivery limitations of cannabinoids

Medical cannabis has received significant interest in recent years due to its promising benefits in the management of pain, anxiety, depression and neurological and movement disorders. Specifically, the major phytocannabinoids derived from the cannabis plant such as (-) trans-Δ⁹ -tetrahydrocannabinol (THC) and cannabidiol (CBD), have been shown to be responsible for the pharmacological and therapeutic properties. Recently, these phytocannabinoids have also attracted special attention in cancer treatment due to their well-known palliative benefits in chemotherapy-induced nausea, vomiting, pain and loss of appetite along with their anticancer activities. Despite the enormous pharmacological benefits, the low aqueous solubility, high instability (susceptibility to extensive first pass metabolism) and poor systemic bioavailability restrict their utilization at clinical perspective. Therefore, drug delivery strategies based on nanotechnology are emerging to improve pharmacokinetic profile and bioavailability of cannabinoids as well as enhance their targeted delivery. Here, we critically review the nano-formulation systems engineered for overcoming the delivery limitations of native phytocannabinoids including polymeric and lipid-based nanoparticles (lipid nano capsules (LNCs), nanostructured lipid carriers (NLCs), nanoemulsions (NE) and self-emulsifying drug delivery systems (SEDDS)), ethosomes and cyclodextrins as well as their therapeutic applications.

The antinociceptive activity and mechanism of action of cannabigerol

Cannabis has been used for centuries to treat pain. The antinociceptive activity of tetrahydrocannabinol (THC) or cannabidiol (CBD) has been widely studied. However, the antinociceptive effects of other cannabis components, such as cannabichromene (CBC) and cannabigerol (CBG), have rarely been revealed. The antinociceptive mechanism of CBG is not yet clear, so we investigated the antinociceptive effect of CBG on different pain models, and explored the mechanism of action of CBG to exert antinociceptive effects. In the current study, we compared the antinociceptive effects of CBC, CBD, and CBG on the carrageenan-induced inflammatory pain model in mice, and the results showed that CBG had a better antinociceptive effects through intraplantar administration. On this basis, we further investigated the antinociceptive effect of CBG on CIA-induced arthritis pain model and nerve pain model in mice, and found that CBG also relieved on both types of pain. Then, we explored the antinociceptive mechanism of CBG, which revealed that CBG can activate TRPV1 and desensitize it to block the transmission of pain signals. In addition, CBG can further activate CB2R, but not CB1R, to stimulate the release of β-endorphin, which greatly promotes the antinociceptive effect. Finally, the safety test results showed that CBG had no irritating effect on the rabbits' skin, and it did not induce significant biochemical and hematological changes in mice. Transdermal delivery results also indicated that CBG has certain transdermal properties. Overall, this study indicates that CBG is promising for developing a transdermal dosage for pain management.

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).

Effect of Lipid Vehicles on Solubility, Stability, and Topical Permeation of Delta-9-Tetrahydrocannabinol

Delta-9-tetrahydrocannabinol (THC) is one of the most effective antinociceptive agents used in the treatment of peripheral neuropathy. THC is highly lipophilic and susceptible to thermal and oxidative degradation. Identifying appropriate solvents in which THC is stable as well as adequately solubilized is crucial in developing topical dosage forms. Lipid solvent systems are of utmost utility and relevance for formulating highly lipophilic drugs. Hence, the objective of this project was to screen the solubility of THC in lipidic excipients, monitor THC content in the selected vehicles during stability, and study the influence of these excipients on permeation of THC across skin. The solubility of THC in liquid lipid excipients was in the range of 421 to 500 mg/g. The solubility of THC in solid lipid excipients was in the range of 250 to 750 mg/g. THC in its neat form was poorly stable, but when dissolved in lipid-based excipients, its stability improved significantly. THC in lipid excipients was more stable at 4 ± 3°C compared to samples stored at 25 ± 2°C. The antioxidants (butylated hydroxytoluene and ascorbyl palmitate) used in the excipients further improved the stability of THC. The results demonstrated that the liquid and solid lipid excipients used in the study could solubilize THC freely and mitigate the degradation of THC significantly. The binary combination of lipid excipients enhanced THC skin permeation and retention, demonstrating the potential for topical formulation development of THC.

Lipid-Drug Conjugates and Nanoparticles for the Cutaneous Delivery of Cannabidiol

Lipid nanoparticles are currently used to deliver drugs to specific sites in the body, known as targeted therapy. Conjugates of lipids and drugs to produce drug-enriched phospholipid micelles have been proposed to increase the lipophilic character of drugs to overcome biological barriers. However, their applicability at the topical level is still minimal. Phospholipid micelles are amphiphilic colloidal systems of nanometric dimensions, composed of a lipophilic nucleus and a hydrophilic outer surface. They are currently used successfully as pharmaceutical vehicles for poorly water-soluble drugs. These micelles have high in vitro and in vivo stability and high biocompatibility. This review discusses the use of lipid-drug conjugates as biocompatible carriers for cutaneous application. This work provides a metadata analysis of publications concerning the conjugation of cannabidiol with lipids as a suitable approach and as a new delivery system for this drug.