Structural analysis and cytotoxicity of host-guest inclusion complexes of cannabidiol with three native cyclodextrins

Development and characterization of pectin-based composite film incorporated with cannabidiol/2,6-di-O-methyl-β-cyclodextrin inclusion complex for food packaging

To reduce environmental pollution and improve human health, developing green active food packaging materials is very necessary. In this study, a novel antioxidant and antibacterial composite film was produced by incorporating inclusion complex (CDIC) of cannabidiol (CBD) with 2,6-di-O-methyl-β-cyclodextrin (DM-β-CD) into pectin. The pectin films loaded with CBD and hemp leaf water extract (HLE) were prepared for comparison. Comprehensive characterizations showed CBD was encapsulated by DM-β-CD and CDIC was evenly dispersed into pectin matrix, forming the compact and intact film. The composite films showed good mechanical properties and biodegradability. CDIC film showed the highest transparency and smoothness (Rrms/Rmax: 2.6/16.8 nm). The addition of bioactives reduced the water-binding capacity and CDIC film had the strongest hydrophobicity. Besides, DM-β-CD encapsulation improved the thermal stability of CBD in CDIC film. Benefiting from encapsulation and excellent bioactivities of CBD, CDIC film showed excellent antioxidant capacity and antibacterial activity, effectively inhibiting colony growth and maintaining the strawberry color in strawberry preservation. This work could provide a novel eco-friendly candidate for food packaging material and expand the use of CBD in food industry.

Spray freeze dried cannabidiol with dipalmitoylphosphatidylcholine (DPPC) for inhalation and solubility enhancement

Pulmonary delivery is an efficient route of administration to deliver cannabidiol (CBD) due to the high bioavailability and fast onset of action. The major formulation challenge is the poor aqueous solubility of CBD. This study aimed to produce inhalable CBD powders with enhanced solubility and characterise their solid-state properties. CBD was spray freeze dried with mannitol or trehalose dihydrate with and without dipalmitoylphosphatidylcholine (DPPC). All four powders had acceptable yields at > 70 % with porous and spherical particles. The two crystalline mannitol powders contained less residual solvent than both amorphous trehalose ones. The addition of DPPC did not affect the crystallinity and residual solvent level of the powders. Instead, DPPC made the particles more porous, decreased the particle size from 19-23 µm to 11-13 µm, and increased CBD solubility from 0.36 µg/mL to over 2 µg/mL. The two DPPC powders were dispersed from a low resistance RS01 inhaler, showing acceptable aerosol performance with emitted fractions at 91-93 % and fine particle fractions < 5 µm at 34-43 %. These formulations can be used as a platform to deliver CBD and other cannabinoids by inhalation.

Unveiling the synergy: a combined experimental and theoretical study of β-cyclodextrin with melatonin

Melatonin (MT) is a vital hormone controlling biorhythms, and optimizing its release in the human body is crucial. To address MT's unfavorable pharmacokinetics, we explored the inclusion complexes of MT with β-cyclodextrin (β-CD). Nano spray drying was applied to efficiently synthesize these complexes in three molar ratios (MT : β-CD = 1 : 1, 2 : 1, and 1 : 2), reducing reagent use and expediting inclusion. The complex powders were characterized through thermal analyses (TGA and DSC), Fourier transform infrared spectroscopy (FTIR), and in vitro MT release measurements via high-performance liquid chromatography (HPLC). In parallel, computational studies were conducted, examining the stability of MT : β-CD complexes by means of unbiased semi-empirical conformational searches refined by DFT, which produced a distribution of MT : β-CD binding enthalpies. Computational findings highlighted that these complexes are stabilized by specific hydrogen bonds and non-specific dispersive forces, with stronger binding in the 1 : 1 complex, which was corroborated by in vitro release data. Furthermore, the alignment between simulated and experimental FTIR spectra demonstrated the quality of both the structural model and computational methodology, which was crucial to enhance our comprehension of optimizing MT's release for therapeutic applications.

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.

Stability, biofunctional, and antimicrobial characteristics of cannabidiol isolate for the design of topical formulations

Cannabidiol (CBD) is a high-value natural compound of Cannabis Sativa plant. It is a non-psychotropic phytocannabinoid, attracting significant attention as a multifunctional active ingredient for topical applications. Although it is demonstrated that CBD can be used for specific dermatological ailments, reliable data on functionalities are limited. The present study aimed to investigate the structural stability, biofunctionality, and antimicrobial characteristics of CBD isolate to assist in the design of various topical formulations. The stability of CBD in solid and solubilized states was assessed to establish storage and formulation conditions. The performance of CBD solubilized in organic and aqueous media was evaluated for free radical scavenging, tyrosinase, and collagenase enzyme inhibition, which showed good prospects for the ingredient. The antimicrobial activity of solubilized CBD was evaluated against Gram-negative (E. coli, P. aeruginosa), Gram-positive bacterial strains (S. aureus, S. epidermidis, C. acnes), and fungal strains (C. albicans, M. furfur) using agar well diffusion and broth microdilution methods. Due to the presence of surfactants in CBD aqueous solution, it displayed a lack of antimicrobial activity against all the tested microorganisms. CBD solubilized in an organic medium showed no activity against Gram-negative bacterial strains but higher activity against tested Gram-positive bacterial and fungal strains.

In Vitro Wound Healing Potential of a Fibroin Film Incorporating a Cannabidiol/2-Hydroxypropyl-β-cyclodextrin Complex

This study aimed to develop a film dressing prepared by incorporating a complex of cannabidiol and 2-hydroxypropyl-β-cyclodextrin (CBD/HP-β-CD) into a fibroin-based film and to investigate its wound healing capabilities. The fibroin from silkworm cocoons exhibited a total protein content of 96.34 ± 0.14% w/w and a molecular weight range of 25 to 245 kDa. Fourier-transform infrared spectroscopy (FTIR) revealed the presence of characteristic amide peaks (I, II, and III) in the isolated fibroin. The CBD/HP-β-CD complex, prepared with a molar ratio of 1:2 (CBD to HP-β-CD), had 81.5 ± 1.2% w/w CBD content, as determined by high-performance liquid chromatography (HPLC). X-ray diffraction (XRD) and FTIR analyses demonstrated successful encapsulation of CBD's hydrophobic aromatic rings by HP-β-CD. Blending the fibroin solution with the CBD/HP-β-CD complex produced a transparent, slightly yellowish film. Mechanical testing revealed a tensile strength of 48.67 ± 2.57 MPa and a % elongation at a break of 1.71 ± 0.21%. XRD and FTIR analyses showed distinctive crystalline and chemical structures of the film. In subsequent in vitro experiments with normal human dermal fibroblasts, the film demonstrated potential for wound healing. An increase in cell division (G2/M phase) was observed compared to the fibroin film without the CBD/HP-β-CD complex. Additionally, fibroblasts treated with the film exhibited enhanced cell migration in a scratch assay and increased expression of vascular endothelial growth factor protein compared to the control group. Overall, these findings underscore the film's potential for enhancing wound healing outcomes.

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

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

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.

Comparative study of encapsulated cannabidiol ternary solid dispersions prepared by different techniques: The application of a novel technique jet milling

Jet milling is a common technique in ultrafine powder preparation field. It has never been used to design delivery systems. Cannabidiol (CBD) is an important cannabinoid of hemp but poor aqueous solubility limited its applications. In this study, solid dispersion (SD) technique was combined with cyclodextrin complexation technique, and jet milling was used for the first time to prepare SDs for improving CBD solubility. Different characterizations demonstrated that the dispersion effect and complexation structure of CBD SD3 prepared by jet milling were comparable to that of CBD SD2 prepared by spray drying (a common solution-based method), and were better than that of CBD SD1 prepared by cogrinding. The water solubility of CBD was increased to 20.902 μg/mL (909-fold) in CBD SD3. Besides, the antioxidant activity and cytotoxicity to tumor cells of CBD were enhanced by dispersion. This work indicated that jet milling, as a new technique with low cost and excellent applicability, could be further developed for the delivery of food functional factors or bioactive molecules.

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

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

Cannabidiol-Loaded Nanocarriers and Their Therapeutic Applications

Cannabidiol (CBD), one of the most promising constituents isolated from Cannabis sativa, exhibits diverse pharmacological actions. However, the applications of CBD are restricted mainly due to its poor oral bioavailability. Therefore, researchers are focusing on the development of novel strategies for the effective delivery of CBD with improved oral bioavailability. In this context, researchers have designed nanocarriers to overcome limitations associated with CBD. The CBD-loaded nanocarriers assist in improving the therapeutic efficacy, targetability, and controlled biodistribution of CBD with negligible toxicity for treating various disease conditions. In this review, we have summarized and discussed various molecular targets, targeting mechanisms and types of nanocarrier-based delivery systems associated with CBD for the effective management of various disease conditions. This strategic information will help researchers in the establishment of novel nanotechnology interventions for targeting CBD.

Solid-State Formation of a Potential Melphalan Delivery Nanosystem Based on β-Cyclodextrin and Silver Nanoparticles

Melphalan (Mel) is an antineoplastic widely used in cancer and other diseases. Its low solubility, rapid hydrolysis, and non-specificity limit its therapeutic performance. To overcome these disadvantages, Mel was included in β-cyclodextrin (βCD), which is a macromolecule that increases its aqueous solubility and stability, among other properties. Additionally, the βCD-Mel complex has been used as a substrate to deposit silver nanoparticles (AgNPs) through magnetron sputtering, forming the βCD-Mel-AgNPs crystalline system. Different techniques showed that the complex (stoichiometric ratio 1:1) has a loading capacity of 27%, an association constant of 625 M^-1, and a degree of solubilization of 0.034. Added to this, Mel is partially included, exposing the NH₂ and COOH groups that stabilize AgNPs in the solid state, with an average size of 15 ± 3 nm. Its dissolution results in a colloidal solution of AgNPs covered by multiple layers of the βCD-Mel complex, with a hydrodynamic diameter of 116 nm, a PDI of 0.4, and a surface charge of 19 mV. The in vitro permeability assays show that the effective permeability of Mel increased using βCD and AgNPs. This novel nanosystem based on βCD and AgNPs is a promising candidate as a Mel nanocarrier for cancer therapy.

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.

Structural Investigation of Beta-Cyclodextrin Complexes with Cannabidiol and Delta-9-Tetrahydrocannabinol in 1:1 and 2:1 Host-Guest Stoichiometry: Molecular Docking and Density Functional Calculations

The complexation of β-cyclodextrin (β-CD) with cannabidiol (CBD) and Δ⁹-tetrahydrocannabinol (THC) was investigated using molecular docking and M062X/6-31G(d,p) calculations. The calculations suggested two possible complex formations of 1:1 and 2:1 host-guest molecular ratio of β-CD with CBD and THC. The preferred orientation of all complexes in this study exhibited the hydrogen bonding between hydroxy-substituted benzene ring of CBD and THC with the β-CD's secondary hydroxy groups at the wide rim. The calculated complexation energies indicate that formation of the 2:1 complexes (-83.53 to -135.36 kcal/mol) was more energetically favorable and chemically stable than the 1:1 complexes (-30.00 to -34.92 kcal/mol). However, the deformation energies of the host and the guest components in the 2:1 complexes (37.47-96.91 kcal/mol) are much higher than those in the 1:1 complexes (3.49-8.69 kcal/mol), which means the formation processes of the 2:1 complexes are more difficult due to the rigidity of the dimeric β-CDs. Therefore, the inclusion complexes of β-CD with CBD and THC are more likely to be in 1:1 host-guest ratio than in 2:1 molecular ratio. The results of this study supported the experimental results that the complexation constant of 1:1 β-CD/CBD (Ks = 300 M^-1) is greater than that of 2:1 β-CDs/CBD (Kss = 0.833 M^-1). Altogether, this study introduced the fitting parameters that could indicate the stability of the molecular fits in complex formation of each stoichiometry host-guest ratio, which are important for the assessment of the inclusion mechanisms as well as the relationships of reactants and products in chemical reactions.

Biophysical Studies and In Vitro Effects of Tumor Cell Lines of Cannabidiol and Its Cyclodextrin Inclusion Complexes

Phytocannabinoids possess anticancer properties, as established in vitro and in vivo. However, they are characterized by high lipophilicity. To improve the properties of cannabidiol (CBD), such as solubility, stability, and bioavailability, CBD inclusion complexes with cyclodextrins (CDs) might be employed, offering targeted, faster, and prolonged CBD release. The aim of the present study is to investigate the in vitro effects of CBD and its inclusion complexes in randomly methylated β-CD (RM-β-CD) and 2-hyroxypropyl-β-CD (HP-β-CD). The enhanced solubility of CBD upon complexation with CDs was examined by phase solubility study, and the structure of the inclusion complexes of CBD in 2,6-di-O-methyl-β-CD (DM-β-CD) and 2,3,6-tri-O-methyl-β-CD (TM-β-CD) was determined by X-ray crystallography. The structural investigation was complemented by molecular dynamics simulations. The cytotoxicity of CBD and its complexes with RM-β-CD and HP-β-CD was tested on two cell lines, the A172 glioblastoma and TE671 rhabdomyosarcoma cell lines. Methylated β-CDs exhibited the best inclusion ability for CBD. A dose-dependent effect of CBD on both cancer cell lines and improved efficacy of the CBD–CDs complexes were verified. Thus, cannabinoids may be considered in future clinical trials beyond their palliative use as possible inhibitors of cancer growth.

Enhanced Stability and Oral Bioavailability of Cannabidiol in Zein and Whey Protein Composite Nanoparticles by a Modified Anti-Solvent Approach

Wide applications of cannabidiol (CBD) in the food and pharmaceutical industries are limited due to its low bioavailability, sensitivity to environmental pressures and low water solubility. Zein nanoparticles were stabilized by whey protein (WP) for the delivery of cannabidiol (CBD) using a modified anti-solvent approach. Particle size, surface charge, encapsulation efficiency, and re-dispersibility of nanoparticles were influenced by the zein to WP ratio. Under optimized conditions at 1:4, zein–WP nanoparticles were fabricated with CBD (200 μg/mL) and further characterized. WP absorbed on zein surface via hydrogen bond, hydrophobic forces, and electrostatic attraction. The zein–WP nanoparticles showed excellent storage stability (4 °C, dark) and effectively protected CBD degradation against heat and UV light. In vivo pharmacokinetic study demonstrated that CBD in zein–WP nanoparticles displayed 2-times and 1.75-fold enhancement in maximum concentration (C max) and the area under curve (AUC) as compared to free-form CBD. The data indicated the feasibility of developing zein–WP based nanoparticles for the encapsulation, protection, and delivery of CBD.

Cannabidiol/hydroxypropyl-β-cyclodextrin inclusion complex: structure analysis, release behavior, permeability, and bioactivity under in vitro digestion

The inclusion complex of CBD greatly improved its release performance and bioactivity.

Self-Assembly System Based on Cyclodextrin for Targeted Delivery of Cannabidiol

Cannabidiol (CBD) is one specific kind of the cannabinoid in Cannabis sativa L with a wide range of pharmacological activities. However, the poor water solubility and specificity of CBD limits its application in pharmaceutical field. For solving these problems, in this work, we successfully prepared a targeted carrier by grafting biotin (BIO) onto ethylenediamine-β-Cyclodextrin (EN-CD) in a single step to generate a functionalized supramolecule, named BIO-CD. Subsequently, an amantadine-conjugated cannabinoids (AD-CBD) was prepared and self-assembled with the BIO-CD. A series of methods were used to characterize the inclusion behavior and physicochemical properties of AD-CBD and BIO-CD. The results showed that AD-CBD entered the cavity of BIO-CD and formed a 1:1 host-guest inclusion complex. MTT assay and confocal laser scanning microscopy (CLSM) revealed that the targeting effect and anticancer activity of AD-CBD/BIO-CD inclusion complex against three human cancer cell lines were higher than BIO-CD, AD-CBD and free CBD. Moreover, the inclusion complex could release drugs under weakly acidic conditions. These results demonstrated that AD-CBD/BIO-CD inclusion complex possess excellent targeted and anticancer activity, which is hopeful to be applied in clinic as a new therapeutic approach.

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

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

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

INTRODUCTION

Cannabidiol (CBD), a phytocannabinoid from Cannabis sativa, has several therapeutic properties. However, its high lipophilicity, metabolization, and instability impair its bioavailability and translational use in clinical settings. Several advanced drug delivery systems (ADDSs) have been evaluated as CBD carriers to overcome these drawbacks. These systems can improve the CBD dissolution profile, protect it against metabolization, and produce a site-specific release, increasing its bioavailability and making CBD administration clinically effective.

AREAS COVERED

This review summarizes scientific reports on cannabidiol advanced delivery systems (CBD-ADSs) that have been (i) developed, and (ii) applied therapeutically; reports published in the main scientific databases until January 2020 were included. Studies without experimental data and/or published in languages other than English were excluded. Moreover, pharmaceutical technology tools in CBD therapeutic use have been discussed, emphasizing the clinical translation of CBD carrier use.

EXPERT OPINION

Studies reporting CBD-ADS use for medicinal applications were reviewed and revealed multifaceted systems that can overcome the physicochemical drawbacks of CBD and improve its biological activities. Therefore, researchers concluded that the developed CBD-ADS can be used as an alternative to traditional formulations because they show comparable or superior effectiveness in treatment protocols. Although several criteria remain to be met, our findings emphasize the potential of CBD-ADSs for translational therapeutics, particularly for neurological-disorders.

Development of Water-Soluble Electrospun Fibers for the Oral Delivery of Cannabinoids

Cannabidiol (CBD) and cannabigerol (CBG) are two active pharmaceutical ingredients, derived from cannabis plant. In the present study, CBD and CBG were formulated with polyvinyl(pyrrolidone) (PVP) and Eudragit L-100, using electrohydrodynamic atomization (electrospinning). The produced fibers were smooth and uniform in shape, with average fiber diameters in the range of 700-900 nm for PVP fibers and 1-5 μm for Eudragit L-100 fibers. The encapsulation efficiency for both CB and CBG was high (over 90%) for all formulations tested. Both in vitro release and disintegration tests of the formulations in simulated gastric fluids (SGF) and simulated intestinal fluids (SIF) indicated the rapid disintegration and dissolution of the fibers and the subsequent rapid release of the drugs. The study concluded that the electrospinning process is a fast and efficient method to produce drug-loaded fibers suitable for the per os administration of cannabinoids.

Cannabidiol aqueous solubility enhancement: Comparison of three amorphous formulations strategies using different type of polymers

Poor aqueous solubility of terpenophenolic compound Cannabidiol (CBD) is a major issue in the widespread use of this promising therapeutic polyphenol. Moreover, choosing the appropriate strategy to overcome this challenge is time-consuming and based on trial-error processes. The amorphous form of CBD provided higher aqueous solubility as well as faster dissolution rate in comparison with crystalline CBD. Nevertheless, amorphous forms of CBD tend to recrystallize. The aim of this study was to use three different strategies based on the stabilization of the amorphous form. Cyclodextrins (CH₃αCD, HPβCD and HPγCD.), mesoporous silicas (Silsol® and Syloid® AL-1FP) and water soluble polymers (Kollidon® VA64, Kollidon® 12PF and Soluplus®) were processed by using the following techniques: freeze-drying, spray-drying, subcritical carbon dioxide impregnation or hot-melt extrusion. All the obtained formulations provided complete amorphous CBD, although the drug loading depend highly of the excipients. CBD-cyclodextrin formulations, processed by freeze-drying or spray-drying, and CBD-mesoporous silica formulations, processed by subcritical CO₂ or by atmospheric impregnation, provided significant increase of aqueous solubility. While the use of Kollidon® 12PF did not provided significant increased solubility within 90 min, Kollidon® VA64 has been highlighted as the excipient that exhibits the highest increase of aqueous solubility of this study. Finally, all formulations, excepted CBD-ALFP formulations, showed adequate stability within at least two months.

Complexation with β-cyclodextrin enhances apoptosis-mediated cytotoxic effect of harman in chemoresistant BRAF-mutated melanoma cells

Harman, a natural β-carboline alkaloid, has recently gained considerable interest due to its anticancer properties. However, its physicochemical characteristics and poor oral bioavailability have been limiting factors for its pharmaceutical development. In this paper, we described the complexation of harman (HAR) with β-cyclodextrin (βCD) as a promising alternative to improve its solubility and consequently its cytotoxic effect in chemoresistant melanoma cells (A2058 cell line). Inclusion complexes (βCD-HAR) were prepared using a simple method and then characterized by FTIR, NMR and SEM techniques. Through in silico studies, the mechanism of complexation of HAR with βCD was elucidated in detail. Both HAR and βCD-HAR promoted cytotoxicity, apoptosis, cell cycle arrest and inhibition of cell migration in melanoma cells. Interestingly, complexation of HAR with βCD enhanced its pro-apoptotic effect by increasing of caspase-3 activity (p < 0.05), probably due to an improvement in HAR solubility. In addition, HAR and βCD-HAR sensitized A2058 cells to vemurafenib, dacarbazine and 5FU treatments, potentializing their cytotoxic activity. These findings suggest that complexation of HAR with natural polymers such as βCD can be useful to improve its bioavailability and antimelanoma activity.