Current trends on cannabidiol delivery systems: where are we and where are we going?

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.

Enhancing transmucosal delivery of CBD through nanoemulsion: in vitro and in vivo studies

Cannabidiol (CBD) has gained significant attention as a complementary and alternative medicine due to its promising therapeutic properties. However, CBD faces obstacles when administered orally due to its poor solubility in water, leading to limited absorption into the bloodstream and low and variable bioavailability. Therefore, the development of innovative delivery approaches that can enhance CBD's bioavailability, facilitate administration, and promote patient adherence is crucial. We propose a new approach for buccal delivery of CBD based on a self-assembling nanoemulsion (NE) made of a mixture of surfactants (Tween 80 and Labrasol) and medium chain triglycerides (MCTs). The NE formulation showed properties suitable for buccal administration, including appropriate size, CBD content, and surface properties, and, if compared to a CBD-MCT solution, it exhibited better control of administered doses, faster dissolution in buccal medium, and enhanced stability. The CBD-NE effectively released its active load within 5 h, remained stable even when diluted in simulated buccal fluids, and could be easily administered through a commercially available spray, providing consistent and reproducible doses of NE with optimized properties. In vitro permeation studies demonstrated that the CBD-NE facilitated swift and consistent permeation through the buccal mucosa, resulting in a higher concentration in the acceptor compartment compared to CBD-MCT. Furthermore, the in vivo study in mice showed that a single buccal administration of CBD-NE led to a quicker onset of action than a CBD solution in MCT, while maintaining the same plasma levels over time and leading to typically higher plasma concentrations compared to those usually achieved through oral administration. In conclusion, our CBD-NE represents a promising alternative formulation strategy for buccal CBD administration, overcoming the challenges associated with conventional formulations such as variable bioavailability and low control of administered doses.

Combining the potential of 3D printed buccal films and nanostructured lipid carriers for personalised cannabidiol delivery

Cannabidiol (CBD) has been recognized for its numerous therapeutic benefits, such as neuroprotection, anti-inflammatory effects, and cardioprotection. However, CBD has some limitations, including unpredictable pharmacokinetics and low oral bioavailability. To overcome the challenges associated with CBD delivery, we employed Design of Experiments (DoE), lipid carriers, and 3D printing techniques to optimize and develop buccal film loaded with CBD-NLCs. Three-factor Box-Behnken Design was carried out to optimise the NLCs and analyse the effect of independent factors on dependent factors. The emulsification-ultrasonication technique was used to prepare the NLCs. A pressure-assisted micro-syringe printing technique was used to produce the films. The produced films were studied for physicochemical, and mechanical properties, release profiles, and predicted in vivo performance. The observed particle size of the NLCs ranged from 12.17 to 84.91 nm whereas the PDI varied from 0.099 to 0.298. Lipid and sonication time positively affected the particle size whereas the surfactant concentration was inversely related. CBD was incorporated into the optimal formulation and the observed particle size, PDI, and zeta potential for the CBD-NLCs were 94.2 ± 0.47 nm, 0.11 ± 0.01 and - 11.8 ± 0.52 mV. Hydroxyethyl cellulose (HEC)-based gel containing the CBD-NLCs was prepared and used as a feed for 3D printing. The CBD-NLCs film demonstrated a slow and sustained in vitro release profile (84. 11 ± 7.02% in 6 h). The predicted AUC0-10 h, Cmax, and Tmax were 201.5 µg·h/L, 0.74 µg/L, and 1.28 h for a film with 0.4 mg of CBD, respectively. The finding demonstrates that a buccal film of CBD-NLCs can be fabricated using 3D printing.

Anthelmintic Effect of Cannabidiol against Echinococcus granulosus sensu stricto

Cystic echinococcosis is a global parasitic zoonosis caused by infection with the larval stage of Echinococcus granulosus sensu lato. Cystic echinococcosis affects more than 1 million people worldwide, causing important economic costs in terms of management and livestock associated losses. Albendazole is the main drug used in treating human cystic echinococcosis. In spite of this, its low aqueous solubility, poor absorption, and consequently erratic bioavailability are the cause of its chemotherapeutic failures. Based on the described problem, new treatment alternatives urgently need to be developed. The aim of the present research was to study the in vitro and in vivo efficacy of cannabidiol (CBD), the second most abundant component of the Cannabis sativa plant, was demonstrated against E. granulosus sensu stricto. CBD (50 µg/mL) caused a decrease in protoscoleces viability of 80 % after 24 h of treatment which was consistent with the observed tegumental alterations. Detachment of the germinal layer was observed in 50 ± 10% of cysts treated with 50 µg/mL of CBD during 24 h. In the clinical efficacy study, all treatments reduced the weight of cysts recovered from mice compared with the control group. However, this reduction was only significant with ABZ suspension and the CBD + ABZ combination. As we could observe by the SEM study, the co-administration of CBD with ABZ suspension caused greater ultrastructural alteration of the germinal layer in comparison with that provoked with the monotherapy. Further in vivo research will be conducted by changing the dose and frequency of CBD and CBD + ABZ treatments and new available CBD delivery systems will also be assayed to improve bioavailability in vivo.

Targeting the Endocannabinoid System Present in the Glioblastoma Tumour Microenvironment as a Potential Anti-Cancer Strategy

The highly aggressive and invasive glioblastoma (GBM) tumour is the most malignant lesion among adult-type diffuse gliomas, representing the most common primary brain tumour in the neuro-oncology practice of adults. With a poor overall prognosis and strong resistance to treatment, this nervous system tumour requires new innovative treatment. GBM is a polymorphic tumour consisting of an array of stromal cells and various malignant cells contributing to tumour initiation, progression, and treatment response. Cannabinoids possess anti-cancer potencies against glioma cell lines and in animal models. To improve existing treatment, cannabinoids as functionalised ligands on nanocarriers were investigated as potential anti-cancer agents. The GBM tumour microenvironment is a multifaceted system consisting of resident or recruited immune cells, extracellular matrix components, tissue-resident cells, and soluble factors. The immune microenvironment accounts for a substantial volume of GBM tumours. The barriers to the treatment of glioblastoma with cannabinoids, such as crossing the blood-brain barrier and psychoactive and off-target side effects, can be alleviated with the use of nanocarrier drug delivery systems and functionalised ligands for improved specificity and targeting of pharmacological receptors and anti-cancer signalling pathways. This review has shown the presence of endocannabinoid receptors in the tumour microenvironment, which can be used as a potential unique target for specific drug delivery. Existing cannabinoid agents, studied previously, show anti-cancer potencies via signalling pathways associated with the hallmarks of cancer. The results of the review can be used to provide guidance in the design of future drug therapy for glioblastoma tumours.

Cannabidiol - Help and hype in targeting mucosal diseases

Cannabidiol (CBD) is one of the most commonly utilised phytocannabinoids due to its non-psychoactive and multiple potential therapeutic properties and its non-selective pharmacology. Recent studies have demonstrated efficacy of CBD in some types of drug resistant epilepsies in combination with other therapies; comparative efficacy to other agents or placebo has been hoped for anxiety, chronic pain, and inflammatory disorders based on animal data. Although CBD products are generally treated as a restricted substance, these are being eased, partially in response to significant growth in CBD product usage and increased production but more due to emerging evidence about its safety and pharmacological properties. Currently, only one CBD product (Epidiolex®) has been approved by the Australian Therapeutic Goods Administration and US Food and Drug Administration. CBD has demonstrated promise in alleviating gut and lung diseases in vitro; however, its physicochemical properties pose a significant barrier to achieving pharmacological effects in in vivo and clinical trials. Improving CBD formulations and delivery methods using technologies including self-emulsifying emulsion, nano and micro particles could overcome these shortfalls and improve its efficacy. This review focuses on the therapeutic potential of CBD in gastrointestinal and lung diseases from the available in vitro, in vivo, and clinical research. We report on identified research gaps and obstacles in the development of CBD-based therapeutics, including novel delivery methods.

Poly(ethylene glycol)-b-poly(epsilon-caprolactone) nanoparticles as a platform for the improved oral delivery of cannabidiol

Cannabidiol (CBD), a non-psychoactive constituent of Cannabis, has proven neuroprotective, anti-inflammatory and antioxidant properties though his therapeutic use, especially by the oral route, is still challenged by the poor aqueous solubility that results in low oral bioavailability. In this work, we investigate the encapsulation of CBD within nanoparticles of a highly hydrophobic poly(ethylene glycol)-b-poly(epsilon-caprolactone) block copolymer produced by a simple and reproducible nanoprecipitation method. The encapsulation efficiency is ~ 100% and the CBD loading 11% w/w (high performance liquid chromatography). CBD-loaded nanoparticles show a monomodal size distribution with sizes of up to 100 nm (dynamic light scattering), a spherical morphology, and the absence of CBD crystals (high resolution-scanning electron microscopy and cryogenic-transmission electron microscopy) which is in line with a very efficient nanoencapsulation. Then, the CBD release profile from the nanoparticles is assessed under gastric- and intestine-like conditions. At pH 1.2, only 10% of the payload is released after 1 h. Conversely, at pH 6.8, a release of 80% is recorded after 2 h. Finally, the oral pharmacokinetics is investigated in rats and compared to a free CBD suspension. CBD-loaded nanoparticles lead to a statistically significant ~ 20-fold increase of the maximum drug concentration in plasma (Cmax) and a shortening of the time to the Cmax (tmax) from 4 to 0.3 h, indicating a more complete and faster absorption than in free form. Moreover, the area-under-the-curve (AUC), a measure of oral bioavailability, increased by 14 times. Overall results highlight the promise of this simple, reproducible, and scalable nanotechnology strategy to improve the oral performance of CBD with respect to common oily formulations and/or lipid-based drug delivery systems associated with systemic adverse effects.

Current Challenges and Opportunities for Improved Cannabidiol Solubility

Cannabidiol (CBD), derived from the cannabis plant, has gained significant attention due to its potential therapeutic benefits. However, one of the challenges associated with CBD administration is its low bioavailability, which refers to the fraction of an administered dose that reaches systemic circulation. This limitation necessitates the exploration of various approaches to enhance the bioavailability of CBD, thus helping to maximize its therapeutic potential. A variety of approaches are now emerging, including nanoemulsion-based systems, lipid-based formulations, prodrugs, nanocarriers, and alternative routes of administration, which hold promise for improving the bioavailability of CBD and pave the way for novel formulations that maximize the therapeutic potential of CBD in various medical conditions. This opinion piece presents the current understanding surrounding CBD bioavailability and considers strategies aimed at improving both its absorption and its bioavailability.

Cannabidiol nanoemulsion for eye treatment - Anti-inflammatory, wound healing activity and its bioavailability using in vitro human corneal substitute

Cannabidiol (CBD) is the non-psychoactive component of the plant Cannabis sativa (L.) that has great anti-inflammatory benefits and wound healing effects. However, its high lipophilicity, chemical instability, and extensive metabolism impair its bioavailability and clinical use. Here, we report on the preparation of a human cornea substitute in vitro and validate this substitute for the evaluation of drug penetration. CBD nanoemulsion was developed and evaluated for stability and biological activity. The physicochemical properties of CBD nanoemulsion were maintained during storage for 90 days under room conditions. In the scratch assay, nanoformulation showed significantly ameliorated wound closure rates compared to the control and pure CBD. Due to the lower cytotoxicity of nanoformulated CBD, a higher anti-inflammatory activity was demonstrated. Neither nanoemulsion nor pure CBD can penetrate the cornea after the four-hour apical treatment. For nanoemulsion, 94 % of the initial amount of CBD remained in the apical compartment while only 54 % of the original amount of pure CBD was detected in the apical medium, and 7 % in the cornea, the rest was most likely metabolized. In summary, the nanoemulsion developed in this study enhanced the stability and biological activity of CBD.

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

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

DG, Sun L, Banjara B, Mosley-Kellum K, Dinh TC, Singh M. Cannabidiol-Loaded Extracellular Vesicles from Human Umbilical Cord Mesenchymal Stem Cells Alleviate Paclitaxel-Induced Peripheral Neuropathy

In cancer patients, chronic paclitaxel (PTX) treatment causes excruciating pain, limiting its use in cancer chemotherapy. The neuroprotective potential of synthetic cannabidiol (CBD) and CBD formulated in extracellular vesicles (CBD-EVs) isolated from human umbilical cord derived mesenchymal stem cells was investigated in C57BL/6J mice with PTX-induced neuropathic pain (PIPN). The particle size of EVs and CBD-EVs, surface roughness, nanomechanical properties, stability, and release studies were all investigated. To develop neuropathy in mice, PTX (8 mg/kg, i.p.) was administered every other day (four doses). In terms of decreasing mechanical and thermal hypersensitivity, CBD-EVs treatment was superior to EVs treatment or CBD treatment alone (p < 0.001). CBD and CBD-EVs significantly reduced mitochondrial dysfunction in dorsal root ganglions and spinal homogenates of PTX-treated animals by modulating the AMPK pathway (p < 0.001). Studies inhibiting the AMPK and 5HT1A receptors found that CBD did not influence the neurobehavioral or mitochondrial function of PIPN. Based on these results, we hypothesize that CBD and CBD-EVs mitigated PIPN by modulating AMPK and mitochondrial function.

Curcumin-infused xerogel-based nutraceutical development and its 4D shape-shifting behavior

Cereal-based functional foods with shape-changing (four-dimensional [4D]) properties is a novel approach in the current scenario. The main objective of the research is to develop a bioactive compound incorporated in flat two-dimensional xerogel and its hydromorphic three-dimensional shape transformation. The spray-dried curcumin at three different concentrations was incorporated with hydrogel (wheat-barley flour 8%), and flat xerogel was formed by sessile drop drying at 30°C and 78% relative humidity. The top smooth and rough bottom surface of xerogel provided anisotropic swelling properties during the shape transformation. The antimicrobial and antioxidant properties of xerogel were examined, and the retention of curcumin during the shape transformation was also examined during the research. The porous structure of barley-wheat xerogel has enhanced the incorporation of water-insoluble bioactive components like curcumin. The diffusion properties of curcumin xerogel provided an antimicrobial effect against gram-negative pathogenic bacteria. The optimum temperature (70°C) during the shape-shifting provides the retention of bioavailability and functional properties of curcumin. The work describes the opportunities for developing xerogel incorporated with more bioactive and functional components and study its stability and hydromorphic 4D shape-changing behavior. PRACTICAL APPLICATION: Xerogel is a good carrier for different bioactive components. The development of curcumin-infused biodegrade, non-toxic, and cereal-based xerogel provide an excellent opportunity for the delivery of curcumin in a cost-effective way. The shape-changing easily consumable forms of xerogel will attract more consumers, and it retains the bioavailability of infused compounds during processing.

Development of cannabidiol nanoemulsion for direct nose to brain delivery: Statistical optimization, in vitro and in vivo evaluation

Cannabidiol (CBD) is a prescribed drug for epilepsy but has low oral bioavailability and gastric instability. Because of the direct link between the nasal cavity and the central nervous system (CNS), intranasal administration of CBD as nanoemulsions which are the small sized lipid carriers seem to improve the bioavailability. CBD-NEs were made using Capryol 90, Tween 80, and Transcutol P as oil, surfactant, and co-surfactant, respectively, following aqueous titration approach. Then, using the Box-Behnken design, CBD-NE was statistically optimised for the selection of desirable excipient concentrations in order to create the optimal CBD-NE formulation. As independent variables in the statistical design, Capryol 90 (oil; coded as A), Tween 80 (surfactant; coded as B), and Transcutol P (co-surfactant; coded as C) were used. The dependent variables were droplet size (DS; coded as R1) and polydispersity index (PDI; coded as R2). The average DS, PDI, and the zeta potential of the optimized CBD-NEs were observed to be 88.73 ± 2.67 nm, 0.311 ± 0.015, and –2.71 ± 0.52 mV respectively. Pure CBD and lyophilized CBD-NE FT-IR spectra demonstrated no physicochemical interaction between excipients and the drug. Furthermore, differential scanning calorimetry and X-ray diffraction measurements revealed the amorphous CBD in the NE. As compared to pure CBD, the optimised CBD-NE showed considerably better in vitro drug release as well as ex vivo nasal permeability. The drug targeting efficiency and direct transport percentage of the optimised CBD-NEs were found to be 419.64 % and 76.17 %, respectively, in this research. Additionally, pharmacokinetic investigations after intranasal administration of CBD-NE revealed considerably higher drug concentrations in the brain with better brain targeting efficiency. As a result, the development of CBD-NE may be an excellent alternative for better intranasal delivery.

Improved Therapeutic Efficacy of CBD with Good Tolerance in the Treatment of Breast Cancer through Nanoencapsulation and in Combination with 20(S)-Protopanaxadiol (PPD)

Cannabidiol (CBD), a nonpsychoactive major component derived from Cannabis sativa, widely used in neurodegenerative diseases, has now been proven to have growth inhibitory effects on many tumor cell lines, including breast tumors. Meanwhile CBD can effectively alleviate cancer-associated pain, anxiety, and depression, especially tumor cachexia, thus it is very promising as an anti-tumor drug with unique advantages. 20(S)-Protopanaxadiol (PPD) derived from the best-known tonic Chinese herbal medicine Ginseng was designed to be co-loaded with CBD into liposomes to examine their synergistic tumor-inhibitory effect. The CBD-PPD co-loading liposomes (CP-liposomes) presented a mean particle size of 138.8 nm. Further glycosyl-modified CP-liposomes (GMCP-liposomes) were prepared by the incorporation of n-Dodecyl β-D-maltoside (Mal) into the liposomal bilayer with glucose residue anchored on the surface to act as a ligand targeting the GLUT1 receptor highly expressed on tumor cells. In vivo studies on murine breast tumor (4T1 cells)-bearing BALB/c mice demonstrated good dose dependent anti-tumor efficacy of CP-liposomes. A high tumor inhibition rate (TIR) of 82.2% was achieved with good tolerance. However, glycosylation modification failed to significantly enhance TIR of CP-liposomes. In summary, combined therapy with PPD proved to be a promising strategy for CBD to be developed into a novel antitumor drug, with characteristics of effectiveness, good tolerance, and the potential to overcome tumor cachexia.

Differential Interaction of Cannabidiol with Biomembranes Dependent on Cholesterol Concentration

Cannabidiol (CBD), the major nonpsychoactive component of plant-derived cannabinoids, has been reported to have a broad range of potential beneficial pharmacological effects on the central nervous system (CNS). In this study, the droplet interface bilayer, a model cell membrane, is used to examine the effects of CBD on passive water permeability, a fundamental membrane biophysical property. The presence of CBD decreases the water permeability of model lipid membranes composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and at low concentrations of cholesterol (Chol) (20 mol %) in DOPC, whereas when higher concentrations of Chol are present (33 mol %), CBD has an opposing effect, increasing water permeability. The diametric effect in water permeability change upon addition of CBD to Chol-low and Chol-high bilayers signifies a variant interaction of CBD, depending on the initial state of bilayer packing and fluidity. Additionally, differential scanning calorimetry studies provide evidence that there are selective changes in thermotropic behavior for CBD with DOPC and with DOPC/Chol membranes, respectively, supportive of these varying membrane interactions of CBD dependent upon cholesterol. The intriguing ability of CBD to sensitively respond to membrane Chol concentrations in modifying physical properties highlights the significant impact that CBD can have on heterogeneous biomembranes including those of the CNS, the neurons of which are enriched in Chol to a point where up to a quarter of the body's total Chol is in the brain, and defective brain Chol homeostasis is implicated in neurodegenerative diseases.