Application of Oil-in-Water Cannabidiol Emulsion for the Treatment of Rheumatoid Arthritis

Predicting lymphatic transport potential using graph transformer based on limited historical data from in vivo studies

The lymphatic system hosts a large number of therapeutic targets that can be used to modulate a wide range of diseases including cancers, autoimmune and inflammatory disorders, infectious diseases and metabolic syndrome; however, drug access to the lymphatic system is often challenging. Over the past decades significant efforts have been made to promote drug transport to the lymphatics through medicinal chemistry approaches, and a number of promising progresses are emerging. Nevertheless, so far it remains difficult to clearly delineate the mechanism of lymphatic drug transport and to map the design criteria for lymphotropic drug molecules, and the attempts to synthesize lymph-directing drug candidates or drug derivatives are largely in an experience-driven, trial and error basis. Furthermore, complex experimental procedures required for the study of lymphatic drug transport have limited data accumulation in the field, and this in turn hampers mechanistic studies and understanding of drug design criteria. Our current study aims to 1) review and summarize published work that assessed lymphatic drug transport by both direct measurement (e.g. determination of drug concentrations in lymph fluid) or indirect measurement (e.g. imaging methods or by comparing the changes of pharmacokinetics profile in the absence and presence of lymphatic transport blocker); 2) to analyze lymphatic drug transport data of 185 drugs according to experimental models and conditions, followed by dataset regrouping according to the extent of lymphatic transport; 3) to establish different Artificial Intelligence (AI) models including Graph Convolutional Network (GCN), Graph Attention Network (GAT) and Graph Transformer (GT) to predict the potential of drug transport via the lymphatics following oral administration, during which process data augmentation approaches were employed to compensate for the limited data. The results demonstrated that our model can enhance data and lymphatic drug transport prediction by correlating in vivo data with the chemical structure of drugs (represented by Simplified Molecular Input Line Entry System, SMILES). Additionally, we analyzed the relationship between the extent of lymphatic transport and a number of physicochemical parameters (including LogP, LogD7.4 and molecular weight) of drugs with reported lymphatic absorption data. The results demonstrate that the capability of lymphatic transport does not appear to be determined by any single parameter alone.

Cannabidiol (CBD): A Systematic Review of Clinical and Preclinical Evidence in the Treatment of Pain

Background/Objectives: Cannabis sativa L. is a plant that has been used for thousands of years for its industrial and medicinal properties. In recent years, there has been a rise in the study of this plant due to its bioactive compounds for pharmaceutical applications. Particularly, cannabidiol has demonstrated analgesic and non-psychoactive properties. The objective of this systematic review is to update and to gather the clinical and preclinical evidence on CBD in pain treatment. Methods: This study was performed following the PRISMA guidelines and using the following search terms "((cannabidiol) NOT (THC)) NOT (tetrahydrocannabinol)) AND (pain treatment)" in PubMed and Web of Science, with the following inclusion criteria: CBD pain treatment without THC in monotherapy, including both clinical and preclinical trials. From the initial sample of more than 500 articles, a total of 40 studies were selected, eliminating duplicate studies from the databases and considering the inclusion and exclusion criteria. On one hand, clinical trials were analyzed using CBD products without THC used in monotherapy, assigning a Jadad score to evaluate the quality/bias of the trials; on the other hand, the main preclinical trials were analyzed, grouping the results into in vivo and in vitro trials. Results: Based on the review conducted, there is sufficient clinical and preclinical evidence of CBD in pain treatment, so CBD could be an effective and safe treatment in reducing pain due to its analgesic and anti-inflammatory properties. These effects appear to be primarily mediated by the activation of TRPV-1, 5HT-1A, and CB1, with emerging therapeutic relevance in the management of osteoarthritis and chronic pain. Conclusions: Although clinical and preclinical research show promising results, clinical evidence is limited, and more studies should be performed in the future with isolated CBD.

Oxytocin and Vasopressin Gene Expression in the Brain as Potential Biomarkers for Cannabidiol Therapeutic Efficacy

Over the last several years, there has been increased interest in cannabidiol (CBD) to treat various ailments such as pain, anxiety, insomnia, and inflammation. The potential for CBD as an anti-inflammatory therapy has come, in part, from its demonstrated ability to suppress neuroinflammation in autoimmune diseases, such as the mouse model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE). The increased use of CBD strongly suggests that more research is necessary to elucidate its safety and efficacy and determine the mechanisms by which it acts. Thus, we conducted two separate studies. In the first, RNA sequencing (RNA-Seq) analysis of brains of female mice undergoing EAE in the presence and absence of CBD was conducted to identify potential genes that mediated its neuroprotective effects when efficacious. In the second, we assessed some of the same genes in male and female mice treated with CBD in the absence of an immune stimulus. Together, these data showed that CBD modestly increased oxytocin (Oxt) and arginine vasopressin (vasopressin, Avp) gene expression in the brains of mice, regardless of whether there was active inflammation. Overall, these data suggest that Oxt and Avp might act as biomarkers for CBD exposure.

Ivacaftor pharmacokinetics and lymphatic transport after enteral administration in rats

Background: Ivacaftor is a modern drug used in the treatment of cystic fibrosis. It is highly lipophilic and exhibits a strong positive food effect. These characteristics can be potentially connected to a pronounced lymphatic transport after oral administration. Methods: A series of studies was conducted to describe the basic pharmacokinetic parameters of ivacaftor in jugular vein cannulated rats when dosed in two distinct formulations: an aqueous suspension and an oil solution. Additionally, an anesthetized mesenteric lymph duct cannulated rat model was studied to precisely assess the extent of lymphatic transport. Results: Mean ± SD ivacaftor oral bioavailability was 18.4 ± 3.2% and 16.2 ± 7.8%, respectively, when administered as an aqueous suspension and an oil solution. The relative contribution of the lymphatic transport to the overall bioavailability was 5.91 ± 1.61% and 4.35 ± 1.84%, respectively. Conclusion: Lymphatic transport plays only a minor role in the process of ivacaftor intestinal absorption, and other factors are, therefore, responsible for its pronounced positive food effect.

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.

Pharmacokinetics of Two Nanoemulsion Formulations of Δ8-Tetrahydrocannabinol in Rats

The use of Δ8-tetrahydrocannabinol (Δ8-THC) has increased in recent years. Given that the oral absorption of cannabinoids in oil formulations is typically slow and variable, nanoemulsions may be an improved delivery vehicle. Therefore, we characterized the pharmacokinetics (PK) in Sprague-Dawley rats following the administration of three different oral formulations containing 10 mg/kg Δ8-THC: a translucent liquid nanoemulsion, a reconstituted powder nanoemulsion, and a medium chain triglyceride (MCT) oil solution for comparison. Δ8-THC was also administered intravenously at 0.6 mg/kg. Plasma samples were quantified for Δ8-THC and two metabolites, 11-hydroxy-Δ8-THC (11-OH-Δ8-THC) and 11-carboxy-Δ8-THC (COOH-Δ8-THC). Non-compartmental PK parameters were calculated, and a PK model was developed based on pooled data. Despite a smaller median droplet size of the translucent liquid nanoemulsion (26.9 nm) compared to the reconstituted powder nanoemulsion (168 nm), the PK was similar for both. The median Tmax values of Δ8-THC for the nanoemulsions (0.667 and 1 h) were significantly shorter than the median Tmax of Δ8-THC in MCT oil (6 h). This resulted in an approximately 4-fold higher Δ8-THC exposure over the first 4 h for the nanoemulsions relative to the MCT oil solution. The active 11-OH-Δ8-THC metabolite followed a similar pattern to Δ8-THC. The non-compartmental bioavailability estimates of Δ8-THC for the nanoemulsions (11-16.5%) were lower than for the MCT oil solution (>21.5%). However, a model-based analysis indicated similar bioavailability for all three oral formulations. These results demonstrate favorable absorption properties of both nanoemulsions, despite the difference in droplet sizes, compared to an MCT oil formulation.

Effects of Cannabidiol in Inflammation: A Review of Pre-clinical and Clinical Findings

Cannabidiol (CBD) is the second most abundant component of the plant Cannabis sativa. Currently, CBD is approved for Lennox-Gastaut and Dravet syndrome and newly for tuberous sclerosis complex. However, based on the available data, CBD migth have a broad spectrum of potential therapeutic uses. Therefore, the aim of this review was to summarize the evidence on the effects of CBD on pain and inflammation of various causes. PubMed and Web of Science databases were searched until January 2023. The medical keyword term "cannabidiol" was combined with "pain", "arthritis", and "inflammation". Based on the initial search for these terms, 9, 5, and 5 relevant publications have been selected. Based on the available data, it is not possible to draw a clear conclusion about the effect of CBD to releave pain, because each study used a different route of administration or treatment regimen. The studies also differed in etiopathogenesis of pain (chronic, neuropathic, and possibly inflammatory pain), and in general included only small number of subjects. In case of anti-inflammatory qualities of CBD, its effect on the intestinal system is negligible. On the other hand, positive treatment results were observed in all publications dealing with the effect of CBD on arthritis.

Pathogenesis of Collagen-Induced Arthritis: Role of Immune Cells with Associated Cytokines and Antibodies, Comparison with Rheumatoid Arthritis

Collagen-induced arthritis is the most com-mon in vivo model of rheumatoid arthritis used for investigation of new potential therapies in preclinical research. Rheumatoid arthritis is a systemic inflammatory and autoimmune disease affecting joints, accompanied by significant extra-articular symptoms. The pathogenesis of rheumatoid arthritis and collagen-induced arthritis involves a so far properly unexplored network of immune cells, cytokines, antibodies and other factors. These agents trigger the autoimmune response leading to polyarthritis with cell infiltration, bone and cartilage degeneration and synovial cell proliferation. Our review covers the knowledge about cytokines present in the rat collagen-induced arthritis model and the factors affecting them. In addition, we provide a comparison with rheumatoid arthritis and a description of their important effects on the development of both diseases. We discuss the crucial roles of various immune cells (subtypes of T and B lymphocytes, dendritic cells, monocytes, macrophages), fibroblast-like synoviocy-tes, and their related cytokines (TNF-α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-17, IL-23, GM-CSF, TGF-β). Finally, we also focus on key antibodies (rheu-matoid factor, anti-citrullinated protein antibodies, anti-collagen II antibodies) and tissue-degrading enzymes (matrix metalloproteinases).