Mucoadhesive nanostructured lipid carriers as a cannabidiol nasal delivery system for the treatment of neuropathic pain

Chitosan-coated nanostructured lipid carriers for intranasal delivery of sinapic acid in Aβ1-42 induced C57BL/6 mice for Alzheimer's disease treatment

Sinapic acid (SA) is a plant-derived antioxidant that exhibits neuroprotective activity. However, its poor bioavailability in the brain limits its therapeutic application in treating Alzheimer's disease (AD). Therefore, the present study hypothesizes that coating nanostructured lipid carriers (NLCs) with a biological macromolecule like chitosan (CH-SA-NLCs) could enhance the delivery of SA for AD treatment. The CH-SA-NLCs were spherical with sizes below 200 nm, confirmed by AFM, SEM, and TEM and achieved a sustained drug release of 76.5 % in pH 6.5 simulated nasal fluid over 24 h. Moreover, the histopathology study confirmed the safety of CH-SA-NLCs, validating its suitability for intranasal administration. Not only the in vitro sustained drug release closely correlated with in vivo pharmacokinetics of CH-SA-NLCs (i.n.), demonstrating a 1.7-fold increase in SA's half-life compared to plain SA (i.v.) in plasma but also CH-SA-NLCs (i.n.) achieved a superior AUC0-∞ of 7676.32 ± 2738.55 ng/g*h with a 2.6-fold improved drug targeting efficiency of SA in the brain of BALB/c mice. These improvements resulted in significant neuroprotective effects and decreased oxidative stress and inflammatory levels in Aβ1-42-induced mice. Overall, the study highlights safe and effective intranasal delivery of SA via chitosan-coated nanocarrier as a promising AD treatment strategy.

Enhancing ocular drug delivery: development and in vivo evaluation of mucoadhesive nanostructured lipid carriers for terbinafine

This study investigated incorporating Terbinafine Hydrochloride (TH) into chitosan-coated nanostructured lipid carrier (NLCs) to improve ocular treatment for fungal keratitis. Solubility studies were conducted to determine the most suitable lipids for NLCs formulation. TH-loaded NLCs were prepared via emulsification followed by ultrasonication. The impact of various lipids and surfactants on the formulation was investigated. The optimal formulation (TH-NLC10) was coated with chitosan (0.5% w/v), resulting in the coated TH-NLC10-CS 0.05% formulation. This formulation was evaluated for physicochemical properties, morphology, in-vitro release, mucoadhesion, permeation, and in vivo efficacy in treating ocular fungal keratitis in rabbits. Results revealed variations in lipids and surfactants significantly affected particle size. All prepared TH-NLCs formulations within the nanometer range. Physicochemical characterizations of the coated TH-NLC10-CS 0.05% showed 88.37 ± 2.41 nm size, 20.2 ± 1.4 mV zeta potential, 93.3 ± 1.5% w/w entrapment efficiency, and spherical morphology. TH-NLC10-CS 0.05% exhibited sustained TH release (66.65 ± 4.3% over 8 h) and strong mucoadhesion as indicated by a decrease in zeta potential from +20.2 ± 1.4 mV to +2.9 ± 0.7 mV. TH-NLC10-CS 0.05% demonstrated a 2.4-fold increase in TH permeation compared to plain TH, along with effective in vivo antifungal activity. This study confirms that mucoadhesive NLCs with TH are promising for the treatment of ocular fungal keratitis.

Formulation and Evaluation of Solid Self-Nanoemulsifying Drug Delivery System of Cannabidiol for Enhanced Solubility and Bioavailability

Background/Objectives: This study aims to develop a solid self-nanoemulsifying drug delivery system (SNEDDS) to enhance the solubility and oral bioavailability of cannabidiol (CBD). Methods: According to the solubility of CBD and pseudo-ternary phase diagrams of the different ingredients, an oil (medium-chain triglyceride, MCT), mixed surfactants (Labrasol, Tween 80), and a co-surfactant (Transcutol) were selected for the SNEDDS. CBD-loaded SNEDDS formulations were prepared and characterized. The optimal SNEDDS was converted into solid SNEDDS powders via solid carrier adsorption and spray drying techniques. Various evaluations including flowability, drug release, self-emulsifying capacity, X-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), morphology, and pharmacokinetic characteristics were conducted. Subsequently, the solid powders with fillers, disintegrants, and lubricants were added to the capsules for accelerated stability testing. Results: The investigations showed that the two S-SNEDDS formulations improved the CBD's solubility and in vitro drug release, with good storage stability. The pharmacokinetic data of Sprague Dawley rats indicated that a single oral dose of L-SNEDDS and spray drying SNEDDS led to a quicker absorption and a higher Cmax of CBD compared to the two oil-based controls (CBD-sesame oil (similar to Epidiolex®) and CBD-MCT), which is favorable for the application of CBD products. Conclusions: SNEDDS is a prospective strategy for enhancing the solubility and oral bioavailability of CBD, and solid SNEDDS offers flexibility for developing more CBD-loaded solid formulations. Moreover, SNEDDS provides new concepts and methods for other poorly water-soluble drugs.

Cannabis constituents for chronic neuropathic pain; reconciling the clinical and animal evidence

Chronic neuropathic pain is a debilitating pain syndrome caused by damage to the nervous system that is poorly served by current medications. Given these problems, clinical studies have pursued extracts of the plant Cannabis sativa as alternative treatments for this condition. The vast majority of these studies have examined cannabinoids which contain the psychoactive constituent delta-9-tetrahydrocannabinol (THC). While there have been some positive findings, meta-analyses of this clinical work indicates that this effectiveness is limited and hampered by side-effects. This review focuses on how recent preclinical studies have predicted the clinical limitations of THC-containing cannabis extracts, and importantly, point to how they might be improved. This work highlights the importance of targeting channels and receptors other than cannabinoid CB1 receptors which mediate many of the side-effects of cannabis.

Preparation and characterization of bionics Oleosomes with high loading efficiency: The enhancement of hydrophobic space and the effect of cholesterol

Liposomes (LIP) loaded with natural active ingredients have significant potential in the food industry. However, their low loading efficiency (LE) hampers the advancement of liposomal products. To improve the loading capacity of functional compounds, bionic oleosomes (BOLE) with a monolayer of phospholipid membranes and a glyceryl tricaprylate/caprate (GTCC) oil core have first been engineered by high-pressure homogenization. TEM revealed that the core of BOLE consists of GTCC instead of water, thereby extending the hydrophobic space. Steady-state fluorescence and active loading experiments confirmed that cholesterol (CH) detached from the phospholipid membrane and entered the oil core, where it repelled cannabidiol (CBD). Based on the extending hydrophobic space, CBD-BOLE was prepared and its LE was 3.13 times higher than CBD-LIP. The CBD-phospholipid ratio (CPR) of CBD-BOLE significantly improved at least 7.8 times. Meanwhile, the free radical scavenging activity of CBD was increased and cytotoxicity was reduced.

pH-Sensitive Tacrolimus loaded nanostructured lipid carriers for the treatment of inflammatory bowel disease

Inflammatory Bowel Disease is the chronic tissue inflammation of the lower part of the Gastrointestinal tract (GIT). Conventional therapeutic approaches face numerous challenges, often making the delivery system inadequate for treating the disease. This study aimed to integrate a pH-sensitive polymer and nanostructured lipid carriers (NLCs) to develop a hybrid nanocarrier system. Tacrolimus-loaded NLCs coated with Eudragit® FS100 (TAC-NLCs/E FS100) nanoparticles were prepared via double emulsion technique followed by an aqueous enteric coating technique. Various parameters, such as particle size, entrapment efficiency, and zeta potential were optimized using Design Expert software®. Cetyltrimethyl ammonium bromide (CTAB) was used as a cationic surfactant which induces a positive charge on the nanoparticles. These cationic NLCs can adhere to the mucosal surface, thereby enabling prolonged retention. In vitro drug release was assessed, and the results demonstrated that drug release was retarded at pH 1.2 corresponding to upper GIT pH and maximum drug was released at pH 7.4 (colonic pH). Moreover, we evaluated TAC-NLCs/E FS100 nanoparticles in murine colitis models to gauge the efficacy of both coated and uncoated NLCs formulation. The TAC-NLCs/E FS100 showed a pronounced reduction in induced colitis, as evident from the restoration of morphological features, improved histopathological scores, antioxidant levels, and decreased the levels of proinflammatory cytokines. Thus, pH-sensitive TAC-NLCs/EFS 100 are attributed to the enhanced localization and targeted delivery at the specific site.

Cannabinoids-Multifunctional Compounds, Applications and Challenges-Mini Review

Cannabinoids represent a highly researched group of plant-derived ingredients. The substantial investment of funds from state and commercial sources has facilitated a significant increase in knowledge about these ingredients. Cannabinoids can be classified into three principal categories: plant-derived phytocannabinoids, synthetic cannabinoids and endogenous cannabinoids, along with the enzymes responsible for their synthesis and degradation. All of these compounds interact biologically with type 1 (CB1) and/or type 2 (CB2) cannabinoid receptors. A substantial body of evidence from in vitro and in vivo studies has demonstrated that cannabinoids and inhibitors of endocannabinoid degradation possess anti-inflammatory, antioxidant, antitumour and antifibrotic properties with beneficial effects. This review, which spans the period from 1940 to 2024, offers an overview of the potential therapeutic applications of natural and synthetic cannabinoids. The development of these substances is essential for the global market of do-it-yourself drugs to fully exploit the promising therapeutic properties of cannabinoids.

CBD-Loaded Nanostructured Lipid Carriers: Optimization, Characterization, and Stability

Cannabidiol (CBD) has demonstrated its potential to enhance depression treatment through various biological pathways. However, the application potential of CBD is significantly impeded by its polymorphic nature, limited water solubility, and hepatic first-pass metabolism. To improve chemical stability and water solubility, nanostructured lipid carriers loaded with CBD (CBD-NLCs) were developed using a hot-melt emulsification method and optimized by response surface methodology (RSM). The process parameters were optimized using a four-factor and three-level Box-Behnken experimental design consisting of 29 experiments. The CBD-NLCs were formulated and characterized, demonstrating desirable properties, including a mean particle size of 54.33 nm, a PDI value of 0.118, a zeta potential of -29.7 mV, and an impressive encapsulation efficiency rate of 87.58%. The nanoparticles were found to possess an approximately spherical shape, as revealed by scanning and transmission electron microscopy. The stability studies have demonstrated that CBD-NLCs effectively mitigated the photodegradation of CBD and exhibited a stable behavior for 42 days when stored. The CBD-NLCs displayed a biphasic release profile characterized by an initial burst release (over 50% of CBD released within 20 min) followed by a subsequent gradual and sustained release, aligned with first-order kinetics and Fickian diffusion. These findings demonstrate the potential suitability of this formulation as a carrier for CBD in food fortification and pharmaceutical applications.

Cannabidiol and neurodegeneration: From molecular mechanisms to clinical benefits

Neurodegenerative disorders (NDs) such as Alzheimer's disease, Parkinson's disease, Huntington's disease, multiple sclerosis, and amyotrophic lateral sclerosis are severe and life-threatening conditions in which significant damage of functional neurons occurs to produce psycho-motor malfunctions. NDs are an important cause of death in the elderly population worldwide. These disorders are commonly associated with the progression of age, oxidative stress, and environmental pollutants, which are the major etiological factors. Abnormal aggregation of specific proteins such as α-synuclein, amyloid-β, huntingtin, and tau, and accumulation of the associated oligomers in neurons are the hallmark pathological features of NDs. Existing therapeutic options for NDs are only symptomatic relief and do not address root-causing factors, such as protein aggregation, oxidative stress, and neuroinflammation. Cannabidiol (CBD) is a non-psychotic natural cannabinoid obtained from Cannabis sativa that possesses multiple pharmacological actions, including antioxidant, anti-inflammatory, and neuroprotective effects in various NDs and other neurological disorders both in vitro and in vivo. CBD has gained attention as a promising drug candidate for the management of neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease, by inhibiting protein aggregation, free radicals, and neuroinflammation. In parallel, CBD has shown positive results in other neurological disorders, such as epilepsy, depression, schizophrenia, and anxiety, as well as adjuvant treatment with existing standard therapeutic agents. Hence, the present review focuses on exploring the possible molecular mechanisms in controlling various neurological disorders as well as the clinical applications of CBD in NDs including epilepsy, depression and anxiety. In this way, the current review will serve as a standalone reference for the researchers working in this area.

Bioactive Properties and In Vitro Digestive Release of Cannabidiol (CBD) from Tailored Composites Based on Carbon Materials

The use of carriers to improve cannabidiol (CBD) bioavailability during digestion is at the forefront of research. The main objective of this research was to evaluate CBD bioactivity and develop CBD composites based on tailored carbon support to improve availability under digestive conditions. The antioxidant capacity of CBD was evaluated using spectrophotometric methods, and anti-proliferative assays were carried out using human colon carcinoma cells (SW480). Twenty-four composites of CBD + carbon supports were developed, and CBD desorption tests were carried out under simulated digestive conditions. The antioxidant capacity of CBD was comparable to and superior to Butylhydrox-ytoluene (BHT), a commercial antioxidant. CBD reflected an IC-50 of 10,000 mg/L against SW480 cancer cells. CBD in biological systems can increase the shelf life of lipid and protein foods by 7 and 470 days, respectively. Finally, acid carbons showed major CBD adsorption related to electrostatic interactions, but basic carbons showed better delivery properties related to electrostatic repulsion. A tailored composite was achieved with a CBD load of 27 mg/g with the capacity to deliver 1.1 mg, 21.8 mg, and 4 mg to the mouth, stomach, and duodenum during 18 h, respectively. This is a pioneering study since the carriers were intelligently developed to improve CBD release.

Enhancing cannabidiol bioaccessibility using ionic liquid as emulsifier to produce nanosystems: Characterization of structures, cytotoxicity assessment, and in vitro digestion

The emulsifying potential of a biocompatible ionic liquid (IL) to produce lipid-based nanosystems developed to enhance the bioaccessibility of cannabidiol (CBD) was investigated. The IL (cholinium oleate) was evaluated at concentrations of 1 % and 2 % to produce nanoemulsions (NE-IL) and nanostructured lipid carriers (NLC-IL) loaded with CBD. The IL concentration of 1 % demonstrated to be sufficient to produce both NE-IL and NLC-IL with excellent stability properties, entrapment efficiency superior to 99 %, and CBD retention rate of 100 % during the storage period evaluated (i.e. 28 days at 25 °C). The in vitro digestion evaluation demonstrated that the NLC-IL provided a higher stability to the CBD, while the NE-IL improved the CBD bioaccessibility, which was mainly related to the composition of the lipid matrices used to obtain each nanosystem. Finally, it was observed that the CBD cytotoxicity was reduced when the compound was entrapped into both nanosystems.

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

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

CB65 and novel CB65 liposomal system suppress MG63 and Saos-2 osteosarcoma cell growth in vitro

Curable approaches for primary osteosarcoma are inadequate and urge investigation of novel therapeutic formulations. Cannabinoid ligands exert antiproliferative and apoptotic effect on osteosarcoma cells via cannabinoid 2 (CB2) or transient receptor potential vanilloid type (TRPV1) receptors. In this study, we confirmed CB2 receptor expression in MG63 and Saos-2 osteosarcoma cells by qRT-PCR and flow cytometry (FCM), then reported the reduction effect of synthetic specific CB2 receptor agonist CB65 on the proliferation of osteosarcoma cells by WST-1 (water-soluble tetrazolium-1) and RTCA (real-time impedance-based proliferation). CB65 revealed an IC50 (inhibitory concentration) for MG63 and Saos-2 cells as 1.11 × 10-11 and 4.95 × 10-11 M, respectively. The specific antiproliferative effect of CB65 on osteosarcoma cells was inhibited by CB2 antagonist AM630. CB65 induced late apoptosis of MG63 and Saos-2 cells at 24 and 48 h, respectively by FCM when applied submaximal concentration. A novel CB65 liposomal system was generated by a thin film hydration method with optimal particle size (141.7 ± 0.6 nm), polydispersity index (0.451 ± 0.026), and zeta potential (-10.9 ± 0.3 mV) values. The encapsulation efficiency (EE%) of the CB65-loaded liposomal formulation was 51.12%. The CB65 and CB65-loaded liposomal formulation releasing IC50 of CB65 reduced proliferation by RTCA and invasion by scratch assay and induced late apoptosis of MG63 and Saos-2 cells, by FCM. Our results demonstrate the CB2 receptor-mediated antiproliferative and apoptotic effect of a new liposomal CB65 delivery system on osteosarcoma cells that can be used as a targeted and intelligent tool for bone tumors to ameliorate pediatric bone cancers following in vivo validation.

Development and characterization of nanostructured lipid carriers for cannabidiol delivery

This study evaluated the physicochemical characteristics of nanostructured lipid carriers (NLCs) as a potential vehicle for cannabidiol (CBD), a lipophilic molecule with great potential to promote health benefits. NLCs were produced using hemp seed oil and fully-hydrogenated soybean oil at different proportions. The emulsifiers evaluated were soybean lecithin (SL), Tween 80 (T80) and a mixture of SL:T80 (50:50). CBD was tested in the form of CBD-rich extract or isolate CBD, to verify if it affects the NLCs characteristics. Based on particle size and polydispersity, SL was considered the most suitable emulsifier to produce the NLCs. All lipid proportions evaluated had no remarkable effect on the physicochemical characteristics of NLCs, resulting in CBD-loaded NLCs with particle size below 250 nm, high CBD entrapment efficiency and CBD retention rate of 100% for 30 days, demonstrating that NLCs are a suitable vehicle for both CBD-rich extract or isolate CBD.

Formulation and In Vitro-Ex vivo Evaluation of Cannabidiol and Cannabidiol-Valine-Hemisuccinate Loaded Lipid-Based Nanoformulations for Ocular Applications

The goal of this investigation is to develop stable ophthalmic nanoformulations containing cannabidiol (CBD) and its analog cannabidiol-valine-hemisuccinate (CBD-VHS) for improved ocular delivery. Two nanoformulations, nanoemulsion (NE) and nanomicelles (NMC), were developed and evaluated for physicochemical characteristics, drug-excipient compatibility, sterilization, thermal analysis, surface morphology, ex-vivo transcorneal permeation, corneal deposition, and stability. The saturation solubility studies revealed that among the surfactants tested, Cremophor EL had the highest solubilizing capacity for CBD (23.3 ± 0.1 mg/mL) and CBD-VHS (11.2 ± 0.2 mg/mL). The globule size for the lead CBD formulations (NE and NMC) ranged between 205 and 270 nm while CBD-VHS-NMC formulation had a particle size of about 78 nm. The sterilized formulations, except for CBD-VHS-NMC at 40 °C, were stable for three months of storage (last time point tested). Release, in terms of CBD, in the in-vitro release/diffusion studies over 18 h, were faster from the CBD-VHS nanomicelles (38 %) compared to that from the CBD nanoemulsion (16 %) and nanomicelles (33 %). Transcorneal permeation studies revealed improvement in CBD permeability and flux with both formulations; however, a greater improvement was observed with the NMC formulation compared to the NE formulation. In conclusion, the nanoformulations prepared could serve as efficient topical ocular drug delivery platforms for CBD and its analog.

Nanosuspension-Loaded Dissolving Microneedle Patches for Enhanced Transdermal Delivery of a Highly Lipophilic Cannabidiol

Purpose

Transdermal Drug Delivery System (TDDS) offers a promising alternative for delivering poorly soluble drugs, challenged by the stratum corneum's barrier effect, which restricts the pool of drug candidates suitable for TDDS. This study aims to establish a delivery platform specifically for highly lipophilic drugs requiring high doses (log P > 5, dose > 10 mg/kg/d), to improve their intradermal delivery and enhance solubility.

Methods

Cannabidiol (CBD, log P = 5.91) served as the model drug. A CBD nanosuspension (CBD-NS) was prepared using a bottom-up method. The particle size, polydispersity index (PDI), zeta potential, and concentration of the CBD-NS were characterized. Subsequently, CBD-NS was incorporated into dissolving microneedles (DMNs) through a one-step manufacturing process. The intradermal dissolution abilities, physicochemical properties, mechanical strength, insertion depth, and release behavior of the DMNs were evaluated. Sprague-Dawley (SD) rats were utilized to assess the efficacy of the DMN patch in treating knee synovitis and to analyze its skin permeation kinetics and pharmacokinetic performance.

Results

The CBD-NS, stabilized with Tween 80, exhibited a particle size of 166.83 ± 3.33 nm, a PDI of 0.21 ± 0.07, and a concentration of 46.11 ± 0.52 mg/mL. The DMN loaded with CBD-NS demonstrated favorable intradermal dissolution and mechanical properties. It effectively increased the delivery of CBD into the skin, extended the action's duration in vivo, and enhanced bioavailability. CBD-NS DMN exhibited superior therapeutic efficacy and safety in a rat model of knee synovitis, significantly inhibiting TNF-α and IL-1β compared with the methotrexate subcutaneous injection method.

Conclusion

NS technology effectively enhances the solubility of the poorly soluble drug CBD, while DMN facilitates penetration, extends the duration of action in vivo, and improves bioavailability. Furthermore, CBD has shown promising therapeutic outcomes in treating knee synovitis. This innovative drug delivery system is expected to offer a more efficient solution for the administration of highly lipophilic drugs akin to CBD, thereby facilitating high-dose administration.

Cannabidiol-Loaded Solid Lipid Nanoparticles Ameliorate the Inhibition of Proinflammatory Cytokines and Free Radicals in an In Vitro Inflammation-Induced Cell Model

Cannabidiol (CBD) is a non-psychoactive compound derived from Cannabis sativa. It has demonstrated promising effects in combating inflammation and holds potential as a treatment for the progression of chronic inflammation. However, the clinical application of CBD is limited due to its poor solubility and bioavailability. This study introduces an effective method for preparing CBD-loaded solid lipid nanoparticles (CBD-SLNs) using a combination of low-energy hot homogenization and ultrasonication. We enhanced this process by employing statistical optimization with response surface methodology (RSM). The optimized CBD-SLN formulation utilizes glyceryl monostearate as the primary lipid component of the nanocarrier. The CBD-SLN formulation is screened as a potential tool for managing chronic inflammation. Stable, uniformly dispersed spherical nanoparticles with a size of 123 nm, a surface charge of -32.1 mV, an encapsulation efficiency of 95.16%, and a drug loading of 2.36% were obtained. The CBD-SLNs exhibited sustained release properties, ensuring prolonged and controlled CBD delivery, which could potentially amplify its therapeutic effects. Additionally, we observed that CBD-SLNs significantly reduced both reactive oxygen and nitrogen species and proinflammatory cytokines in chondrocyte and macrophage cell lines, with these inhibitory effects being more pronounced than those of free CBD. In conclusion, CBD-SLNs demonstrated superiority over free CBD, highlighting its potential as an effective delivery system for CBD.

Cannabinoids and endocannabinoids as therapeutics for nervous system disorders: preclinical models and clinical studies

Cannabinoids are lipophilic substances derived from Cannabis sativa that can exert a variety of effects in the human body. They have been studied in cellular and animal models as well as in human clinical trials for their therapeutic benefits in several human diseases. Some of these include central nervous system (CNS) diseases and dysfunctions such as forms of epilepsy, multiple sclerosis, Parkinson's disease, pain and neuropsychiatric disorders. In addition, the endogenously produced cannabinoid lipids, endocannabinoids, are critical for normal CNS function, and if controlled or modified, may represent an additional therapeutic avenue for CNS diseases. This review discusses in vitro cellular, ex vivo tissue and in vivo animal model studies on cannabinoids and their utility as therapeutics in multiple CNS pathologies. In addition, the review provides an overview on the use of cannabinoids in human clinical trials for a variety of CNS diseases. Cannabinoids and endocannabinoids hold promise for use as disease modifiers and therapeutic agents for the prevention or treatment of neurodegenerative diseases and neurological disorders.

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.

Recent Advances in Intranasal Administration for Brain-Targeting Delivery: A Comprehensive Review of Lipid-Based Nanoparticles and Stimuli-Responsive Gel Formulations

Addressing disorders related to the central nervous system (CNS) remains a complex challenge because of the presence of the blood-brain barrier (BBB), which restricts the entry of external substances into the brain tissue. Consequently, finding ways to overcome the limited therapeutic effect imposed by the BBB has become a central goal in advancing delivery systems targeted to the brain. In this context, the intranasal route has emerged as a promising solution for delivering treatments directly from the nose to the brain through the olfactory and trigeminal nerve pathways and thus, bypassing the BBB. The use of lipid-based nanoparticles, including nano/microemulsions, liposomes, solid lipid nanoparticles, and nanostructured lipid carriers, has shown promise in enhancing the efficiency of nose-to-brain delivery. These nanoparticles facilitate drug absorption from the nasal membrane. Additionally, the in situ gel (ISG) system has gained attention owing to its ability to extend the retention time of administered formulations within the nasal cavity. When combined with lipid-based nanoparticles, the ISG system creates a synergistic effect, further enhancing the overall effectiveness of brain-targeted delivery strategies. This comprehensive review provides a thorough investigation of intranasal administration. It delves into the strengths and limitations of this specific delivery route by considering the anatomical complexities and influential factors that play a role during dosing. Furthermore, this study introduces strategic approaches for incorporating nanoparticles and ISG delivery within the framework of intranasal applications. Finally, the review provides recent information on approved products and the clinical trial status of products related to intranasal administration, along with the inclusion of quality-by-design-related insights.

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.

Nanocarriers for Cannabinoid Delivery: Enhancing Therapeutic Potential

Medical cannabis has potential therapeutic benefits in managing pain, anxiety, depression, and neurological and movement disorders. Phytocannabinoids derived from the cannabis plant are responsible for their pharmacological and therapeutic properties. However, the complexity of cannabis components, especially cannabinoids, poses a challenge to effective medicinal administration. Even with the increasing acceptance of cannabis-based medicines, achieving consistent bioavailability and targeted distribution remains difficult. Conventional administration methods are plagued by solubility and absorption problems requiring innovative solutions. After conducting a thorough review of research papers and patents, it has become evident that nanotechnology holds great promise as a solution. The comprehensive review of 36 research papers has yielded valuable insights, with 7 papers reporting enhanced bioavailability, while others have focused on improvements in release, solubility, and stability. Additionally, 19 patents have been analyzed, of which 7 specifically claim enhanced bioavailability, while the remaining patents describe various formulation methods. These patents outline effective techniques for encapsulating cannabis using nanocarriers, effectively addressing solubility and controlled release. Studies on the delivery of cannabis using nanocarriers focus on improving bioavailability, prolonging release, and targeting specific areas. This synthesis highlights the potential of nanotechnology to enhance cannabis therapies and pave the way for innovative interventions and precision medicine.

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.

In situ hydrogel containing diazepam-loaded nanostructured lipid carriers (DZP-NLC) for nose-to-brain delivery: development, characterization and deposition studies in a 3D-printed human nasal cavity model

The nasal route has been investigated as a promising alternative for drug delivery to the central nervous system, avoiding passage through the blood-brain barrier and improving bioavailability. In this sense, it is necessary to develop and test the effectiveness of new formulations proposed for the management of neurological disorders. Thereby, the aim of this work was to develop and characterize an ion sensitive in situ hydrogel containing diazepam-loaded nanostructured lipid carriers (DZP-NLC) for nasal delivery in the treatment of epilepsy. Physical characterization of the developed formulations was performed and included the evaluation of rheological features, particle size, polydispersity index (PDI) and zeta potential (ZP) of an in situ hydrogel containing DZP-NLC. Afterwards, in vitro drug release, in vitro mucoadhesion and biocompatibility studies with RPMI 2650 nasal cells were performed. The in situ hydrogel containing DZP-NLC was aerosolized with a nasal spray device specifically designed for nose-to-brain delivery (VP7 multidose spray pump with a 232 N2B actuator) and characterized for droplet size distribution and spray cone angle. Finally, the deposition pattern of this hydrogel was evaluated in a 3D-printed human nasal cavity model. The developed in situ hydrogel containing DZP-NLC presented adequate characteristics for nasal administration, including good gelling ability, mucoadhesiveness and prolonged drug release. In addition, after inclusion in the hydrogel net, the particle size (81.79 ± 0.53 nm), PDI (0.21 ± 0.10) and ZP (-30.90 ± 0.10 mV), of the DZP-NLC remained appropriate for nose-to-brain delivery. Upon aerosolization in a nasal spray device, a suitable spray cone angle (22.5 ± 0.2°) and adequate droplet size distribution (Dv (90) of 317.77 ± 44.12 µm) were observed. Biocompatibility studies have shown that the developed formulation is safe towards RPMI 2650 cells in concentrations up to 100 μg/mL. Deposition studies on a 3D-printed human nasal cavity model revealed that the best nasal deposition profile was obtained upon formulation administration without airflow and at an angle from horizontal plane of 75°, resulting in 47% of administered dose deposited in the olfactory region and 89% recovery. The results of this study suggested that the intranasal administration of the developed in situ hydrogel containing DZP-NLC could be a promising alternative to the conventional treatments for epilepsy.

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.

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.

Dimeric ferulic acid conjugate as a prodrug for brain targeting after nasal administration of loaded solid lipid microparticles

OBJECTIVE

Ferulic acid (Fer) displays antioxidant/anti-inflammatory properties useful against neurodegenerative diseases. To increase Fer uptake and its central nervous system residence time, a dimeric prodrug, optimizing the Fer loading on nasally administrable solid lipid microparticles (SLMs), was developed.

METHODS

The prodrug was synthesized as Fer dimeric conjugate methylated on the carboxylic moiety. Prodrug antioxidant/anti-inflammatory properties and ability to release Fer in physiologic environments were evaluated. Tristearin or stearic acid SLMs were obtained by hot emulsion technique. In vivo pharmacokinetics were quantified by HPLC.

RESULTS

The prodrug was able to release Fer in physiologic environments (whole blood and brain homogenates) and induce in vitro antioxidant/anti-inflammatory effects. Its half-life in rats was 18.0 ± 1.9 min. Stearic acid SLMs, exhibiting the highest prodrug loading and dissolution rate, were selected for nasal administration to rats (1 mg/kg dose), allowing to obtain high prodrug bioavailability and prolonged residence in the cerebrospinal fluid, showing AUC (Area Under Concentration) values (108.5 ± 3.9 μg∙mL-1∙min) up to 30 times over those of Fer free drug, after its intravenous/nasal administration (3.3 ± 0.3/5.16 ± 0.20 μg∙mL-1∙min, respectively) at the same dose. Chitosan presence further improved the prodrug brain uptake.

CONCLUSIONS

Nasal administration of prodrug-loaded SLMs can be proposed as a noninvasive approach for neurodegenerative disease therapy.

Cannabinoid-Based Ocular Therapies and Formulations

The interest in the pharmacological applications of cannabinoids is largely increasing in a wide range of medical areas. Recently, research on its potential role in eye conditions, many of which are chronic and/or disabling and in need of new alternative treatments, has intensified. However, due to cannabinoids’ unfavorable physicochemical properties and adverse systemic effects, along with ocular biological barriers to local drug administration, drug delivery systems are needed. Hence, this review focused on the following: (i) identifying eye disease conditions potentially subject to treatment with cannabinoids and their pharmacological role, with emphasis on glaucoma, uveitis, diabetic retinopathy, keratitis and the prevention of Pseudomonas aeruginosa infections; (ii) reviewing the physicochemical properties of formulations that must be controlled and/or optimized for successful ocular administration; (iii) analyzing works evaluating cannabinoid-based formulations for ocular administration, with emphasis on results and limitations; and (iv) identifying alternative cannabinoid-based formulations that could potentially be useful for ocular administration strategies. Finally, an overview of the current advances and limitations in the field, the technological challenges to overcome and the prospective further developments, is provided.

An update of nano-based drug delivery systems for cannabinoids: Biopharmaceutical aspects & therapeutic applications

Nanotechnology has been widely used to improve stability, efficacy, release control and biopharmaceutical aspects of natural and synthetic cannabinoids. In this review, the main types of cannabinoid-based nanoparticles (NPs) reported so far are addressed, taking into account the advantages and disadvantages of each system. Formulation, preclinical and clinical studies performed with colloidal carriers were individually analyzed. Lipid-based nanocarriers have been recognized for their high biocompatibility and ability to improve both solubility and bioavailability. Δ⁹-tetrahydrocannabinol-loaded lipid systems designed to treat glaucoma, for example, showed superior in vivo efficacy in comparison to market formulations. The analyzed studies have shown that product performance can be modulated by varying particle size and composition. In the case of self-nano-emulsifying drug delivery systems, the reduced particle size shortens the time to reach high plasma concentrations while the incorporation of metabolism inhibitors extends the plasma circulation time. The use of long alkyl chain lipids in NP formulations, in turn, is strategized to achieve intestinal lymphatic absorption. Polymer NPs have been prioritized when a sustained or site-specific cannabinoid release is desirable (e.g., CNS-affecting diseases/cancer). The functionalization of the surface of polymer NPs makes their action even more selective whereas surface charge modulation is highlighted to provide mucoadhesion. The present study identified promising systems for targeted applications, making the process of optimizing new formulations more effective and faster. Although NPs have shown a promising role in the treatment of several difficult-to-treat diseases, more translational studies should be performed to confirm the benefits reported here.

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.

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.

Cannabidiol-Loaded Nanostructured Lipid Carriers (NLCs) for Dermal Delivery: Enhancement of Photostability, Cell Viability, and Anti-Inflammatory Activity

The aim of this study was to encapsulate cannabidiol (CBD) extract in nanostructured lipid carriers (NLCs) to improve the chemical stability and anti-inflammatory activity of CBD for dermal delivery. CBD-loaded NLCs (CBD-NLCs) were prepared using cetyl palmitate (CP) as a solid lipid and stabilized with Tego^® Care 450 (TG450) or poloxamer 188 (P188) by high-pressure homogenization (HPH). The CBD extract was loaded at 1% w/w. Three different oils were employed to produce CBD-NLCs, including Transcutol^® P, medium-chain triglycerides (MCT), and oleic acid (OA). CBD-NLCs were successfully prepared with an entrapment efficiency (E.E.) of 100%. All formulations showed particle sizes between 160 and 200 nm with PDIs less than 0.10. The type of surfactant and oil used affected the particle sizes, zeta potential, and crystallinity of the CBD-NLCs. CBD-NLCs stabilized with TG450 showed higher crystallinity after production and storage at 30 °C for 30 days as compared to those with P188. Encapsulation of the CBD extract in NLCs enhanced its chemical stability after exposure to simulated sunlight (1000 kJ/m²) compared to that of the CBD extract in ethanolic solution. The CBD-NLCs prepared from MCT and OA showed slower CBD release compared with that from Transcutol^® P, and the kinetic data for release of CBD from CBD-NLCs followed Higuchi's release model with a high coefficient of determination (>0.95). The extent of CBD permeation through Strat-M^® depended on the oil type. The cytotoxicity of the CBD extract on HaCaT and HDF cells was reduced by encapsulation in the NLCs. The anti-inflammatory activity of the CBD extract in RAW264.7 cell macrophages was enhanced by encapsulation in CBD-NLCs prepared from MCT and OA.

The Effect of Chinese Agarwood Essential Oil with Cyclodextrin Inclusion against PCPA-Induced Insomnia Rats

OBJECTIVE

To study the extraction process of agarwood active ingredients (AA) and investigate the safety and effectiveness of AA in the treatment of insomnia rats by nasal administration.

METHOD

A β-cyclodextrin (β-CD) inclusion compound (a-β-CD) was prepared from agarwood essential oil (AEO), and the preparation process was optimized and characterized. The safety of AA in nasal mucosa was evaluated through Bufo gargarizans maxillary mucosa and rat nasal mucosa models. Insomnia animal models were replicated by injecting p-chlorophenylalanine (PCPA), conducting behavioral tests, and detecting the expression levels of monoamine neurotransmitters (NE and 5-HT) and amino acids (GABA/Glu) in the rat hypothalamus.

RESULTS

The optimum inclusion process conditions of β-CD were as follows: the feeding ratio was 0.35:1.40 (g:g), the inclusion temperature was 45 °C, the inclusion time was 2 h, and the ICY% and IEO% were 53.78 ± 2.33% and 62.51 ± 3.21%, respectively. The inclusion ratio, temperature, and time are the three factors that have significant effects on the ICY% and IEO% of a-β-CD. AA presented little damage to the nasal mucosa. AA increased the sleep rate, shortened the sleep latency, and prolonged the sleep time of the rats. The behavioral test results showed that AA could ameliorate depression in insomnia rats to a certain extent. The effect on the expression of monoamine neurotransmitters and amino acids in the hypothalamus of rats showed that AA could significantly reduce NE levels and increase the 5-HT level and GABA/Glu ratio in the hypothalamus of insomnia rats.

CONCLUSION

The preparation of a-β-CD from AEO can reduce its irritation, improve its stability, increase its curative effect, and facilitate its storage and transport. AA have certain therapeutic effects on insomnia. The mechanism of their effect on rat sleep may involve regulating the expression levels of monoamine neurotransmitters and amino acids in the hypothalamus.

Recent Advances in Intranasal Liposomes for Drug, Gene, and Vaccine Delivery

Liposomes are safe, biocompatible, and biodegradable spherical nanosized vesicles produced from cholesterol and phospholipids. Recently, liposomes have been widely administered intranasally for systemic and brain delivery. From the nasal cavity, liposome-encapsulated drugs and genes enter the systemic circulation primarily via absorption in the respiratory region, whereas they can be directly transported to the brain via the olfactory pathway. Liposomes can protect drugs and genes from enzymatic degradation, increase drug absorption across the nasal epithelium, and prolong the residence time in the nasal cavity. Intranasal liposomes are also a potential approach for vaccine delivery. Liposomes can be used as a platform to load antigens and as vaccine adjuvants to induce a robust immune response. With the recent interest in intranasal liposome formulations, this review discusses various aspects of liposomes that make them suitable for intranasal administration. We have summarized the latest advancements and applications of liposomes and evaluated their performance in the systemic and brain delivery of drugs and genes administered intranasally. We have also reviewed recent advances in intranasal liposome vaccine development and proposed perspectives on the future of intranasal liposomes.

Formulation of Nanomicelles Loaded with Cannabidiol as a Platform for Neuroprotective Therapy

The present study is focused on the development of cannabidiol-loaded polymeric nanomicelles as a drug delivery system with neuroprotective effects. Cannabidiol was loaded in Pluronic micelles (Pluronic P123 or its combination with Pluronic F127) possessing an average diameter smaller than 50 nm and high encapsulation efficiency for the hydrophobic drug (80% and 84%, respectively). The successful encapsulation and transformation of cannabidiol in amorphous phase were observed by IR spectroscopy and X-ray diffraction, respectively. Studies with neuroblastoma cells (SH-SY5Y and Neuro-2a) showed that the pure cannabidiol caused a dose-dependent reduction of cell viability, whereas its loading into the micelles decreased cytotoxicity. Further, neuroprotective effects of pure and micellar cannabidiol were examined in a model of H₂O₂-induced oxidative stress in both neuroblastoma cells. The pre-treatment of cell lines with cannabidiol loaded into the mixed Pluronic P123/F127 micelles exerted significantly stronger protection against the oxidative stress compared to pure cannabidiol and cannabidiol in single Pluronic P123 micelles. Interestingly, the empty mixed P123/F127 micelles demonstrated protective activity against the oxidative stress. In conclusion, the study revealed the opportunity to formulate a new drug delivery system of cannabidiol, in particular nanosized micellar aqueous dispersion, that could be considered as a perspective platform for cannabidiol application in neurodegenerative diseases.

Lipid nanoparticles strategies to modify pharmacokinetics of central nervous system targeting drugs: Crossing or circumventing the blood-brain barrier (BBB) to manage neurological disorders

The main limitation to the success of central nervous system (CNS) therapies lies in the difficulty for drugs to cross the blood-brain barrier (BBB) and reach the brain. Regarding its structure and enzymatic complexity, crossing the BBB is a challenge, although several alternatives have been identified. For instance, the use of drugs encapsulated in lipid nanoparticles has been described as one of the most efficient approaches to bypass the BBB, as they allow the passage of drugs through this barrier, improving brain bioavailability. In particular, solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) have been a focus of research related to drug delivery to the brain. These systems provide protection of lipophilic drugs, improved delivery and bioavailability, having a major impact on treatments outcomes. In addition, the use of lipid nanoparticles administered via routes that transport drugs directly into the brain seems a promising solution to avoid the difficulties in crossing the BBB. For instance, the nose-to-brain route has gained considerable interest, as it has shown efficacy in 3D human nasal models and in animal models. This review addresses the state of the art on the use of lipid nanoparticles to modify the pharmacokinetics of drugs employed in the management of neurological disorders. A description of the structural components of the BBB, the role of the neurovascular unit and limitations for drugs to entry into the CNS is first addressed, along with the developments to increase drug delivery to the brain, with a special focus on lipid nanoparticles. In addition, the obstacle of BBB complexity in the creation of new effective drugs for the treatment of the most prevalent neurological disorders is also addressed. Finally, the proposed strategies for lipid nanoparticles to reach the CNS, crossing or circumventing the BBB, are described. Although promising results have been reported, especially with the nose-to-brain route, they are still ongoing to assess its real efficacy in vivo in the management of neurological disorders.

Promising Nanocarriers to Enhance Solubility and Bioavailability of Cannabidiol for a Plethora of Therapeutic Opportunities

In recent years, the interest in cannabidiol (CBD) has increased because of the lack of psychoactive properties. However, CBD has low solubility and bioavailability, variable pharmacokinetics profiles, poor stability, and a pronounced presystemic metabolism. CBD nanoformulations include nanosuspensions, polymeric micelles and nanoparticles, hybrid nanoparticles jelled in cross-linked chitosan, and numerous nanosized lipid formulations, including nanostructured lipid carriers, vesicles, SNEEDS, nanoemulsions, and microemulsions. Nanoformulations have resulted in high CBD solubility, encapsulation efficiency, and stability, and sustained CBD release. Some studies assessed the increased C_max and AUC and decreased T_max. A rational evaluation of the studies reported in this review evidences how some of them are very preliminary and should be completed before performing clinical trials. Almost all the developed nanoparticles have simple architectures, are well-known and safe nanocarriers, or are even simple nanosuspensions. In addition, the conventional routes of administration are generally investigated. As a consequence, many of these studies are almost ready for forthcoming clinical translations. Some of the developed nanosystems are very promising for a plethora of therapeutic opportunities because of the versatility in terms of the release, the crossing of physiological barriers, and the number of possible routes of administration.

Cannabidiol-loaded injectable chitosan-based hydrogels promote spinal cord injury repair by enhancing mitochondrial biogenesis

The treatment of traumatic spinal cord injury (SCI) remains challenging as the neuron regeneration is impaired by irregular cavity and apoptosis. An injectable in situ gelling hydrogel is therefore developed for the local delivery of cannabidiol (CBD) through a novel method based on polyelectrolyte (PEC) interaction of sodium carboxymethylcellulose (CMC) and chitosan (CS). It can be injected into the spinal cord cavity with a 26-gauge syringe before gelation, and gelled after 110 ± 10 s. Of note, the in-situ forming hydrogel has mechanical properties similar to spinal cord. Moreover, the CBD-loaded hydrogels sustain delivery of CBD for up to 72 h, resulting in reducing apoptosis in SCI by enhancing mitochondrial biogenesis. Importantly, the CBD-loaded hydrogels raise neurogenesis more than pure hydrogels both in vivo and in vitro, further achieving significant recovery of motor and urinary function in SCI rats. Thus, it suggested that CMC/CS/CBD hydrogels could be used as promising biomaterials for tissue engineering and SCI.

Fabrication and Preliminary In Vitro Evaluation of 3D-Printed Alginate Films with Cannabidiol (CBD) and Cannabigerol (CBG) Nanoparticles for Potential Wound-Healing Applications

In this study, drug carrier nanoparticles comprised of Pluronic-F127 and cannabidiol (CBD) or cannabigerol (CBG) were developed, and their wound healing action was studied. They were further incorporated in 3D printed films based on sodium alginate. The prepared films were characterized morphologically and physicochemically and used to evaluate the drug release profiles of the nanoparticles. Additional studies on their water loss rate, water retention capacity, and 3D-printing shape fidelity were performed. Nanoparticles were characterized physicochemically and for their drug loading performance. They were further assessed for their cytotoxicity (MTT Assay) and wound healing action (Cell Scratch Assay). The in vitro wound-healing study showed that the nanoparticles successfully enhanced wound healing in the first 6 h of application, but in the following 6 h they had an adverse effect. MTT assay studies revealed that in the first 24 h, a concentration of 0.1 mg/mL nanoparticles resulted in satisfactory cell viability, whereas CBG nanoparticles were safe even at 48 h. However, in higher concentrations and after a threshold of 24 h, the cell viability was significantly decreased. The results also presented mono-disperse nano-sized particles with diameters smaller than 200 nm with excellent release profiles and enhanced thermal stability. Their entrapment efficiency and drug loading properties were higher than 97%. The release profiles of the active pharmaceutical ingredients from the films revealed a complete release within 24 h. The fabricated 3D-printed films hold promise for wound healing applications; however, more studies are needed to further elucidate their mechanism of action.

Compritol-Based Nanostrucutured Lipid Carriers (NLCs) for Augmentation of Zolmitriptan Bioavailability via the Transdermal Route: In Vitro Optimization, Ex Vivo Permeation, In Vivo Pharmacokinetic Study

Migraine is a severe neurovascular disease manifested mainly as unilateral throbbing headaches. Triptans are agonists for serotonin receptors. Zolmitriptan (ZMP) is a biopharmaceutics classification system (BCS) class III medication with an absolute oral bioavailability of less than 40%. As a result, our research intended to increase ZMP bioavailability by developing transdermal nanostructured lipid carriers (NLCs). NLCs were prepared utilizing a combination of hot melt emulsification and high-speed stirring in a 3² full factorial design. The studied variables were liquid lipid type (X₁) and surfactant type (X₂). The developed NLCs were evaluated in terms of particle size (Y₁, nm), polydispersity index (Y₂, PDI), zeta potential (Y₃, mV), entrapment efficacy (Y₄, %) and amount released after 6 h (Q6h, Y₅, %). At 1% Mygliol as liquid lipid component and 1% Span 20 as surfactant, the optimized formula (NLC9) showed a minimum particle size (138 ± 7.07 nm), minimum polydispersity index (0.39 ± 0.001), acceptable zeta potential (−22.1 ± 0.80), maximum entrapment efficiency (73 ± 0.10%) and maximum amount released after 6 h (83.22 ± 0.10%). The optimized formula was then incorporated into gel preparation (HPMC) to improve the system stability and ease of application. Then, the pharmacokinetic study was conducted on rabbits in a cross-over design. The calculated parameters showed a higher area under the curve (AUC_0–24, AUC_0–∞ (ng·h/mL)) of the developed ZMP-NLCs loaded gel, with a 1.76-fold increase in bioavailability in comparison to the orally administered marketed product (Zomig^®). A histopathological examination revealed the safety of the developed nanoparticles. The declared results highlight the potential of utilizing the proposed NLCs for the transdermal delivery of ZMP to improve the drug bioavailability.

New Drug Delivery Systems Developed for Brain Targeting

The blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (B_CSF) are two of the most complex and sophisticated concierges that defend the central nervous system (CNS) by numerous mechanisms. While they maintain the neuro-ecological homeostasis through the regulated entry of essential biomolecules, their conservative nature challenges the entry of most of the drugs intended for CNS delivery. Targeted delivery challenges for a diverse spectrum of therapeutic agents/drugs (non-small molecules, small molecules, gene-based therapeutics, protein and peptides, antibodies) are diverse and demand specialized delivery and disease-targeting strategies. This review aims to capture the trends that have shaped the current brain targeting research scenario. This review discusses the physiological, neuropharmacological, and etiological factors that participate in the transportation of various drug delivery cargoes across the BBB/B_CSF and influence their therapeutic intracranial concentrations. Recent research works spanning various invasive, minimally invasive, and non-invasive brain- targeting approaches are discussed. While the pre-clinical outcomes from many of these approaches seem promising, further research is warranted to overcome the translational glitches that prevent their clinical use. Non-invasive approaches like intranasal administration, P-glycoprotein (P-gp) inhibition, pro-drugs, and carrier/targeted nanocarrier-aided delivery systems (alone or often in combination) hold positive clinical prospects for brain targeting if explored further in the right direction.

Development and characterization of cannabidiol-loaded alginate copper hydrogel for repairing open bone defects in vitro

The clinical treatment of open bone defects caused by accidental bone trauma, bone tumors, bone diseases and bone infections is challenging. In this study, we designed and fabricated a multifunctional alginate-based hydrogel that contains cannabidiol (CBD), SA@Cu/CBD hydrogel, for repairing open bone defects. The results of physicochemical characterization showed that the SA@Cu/CBD hydrogel was successfully prepared and showed a suitable swelling ratio, high thermal stability, and stable mechanical properties. In vitro evaluation of antibacterial activity indicated that more than 90% of S. aureus and E. coli were inhibited compared to the control group. The ALP activity assay showed that the ALP expression level of MC3T3-E1cells in SA@Cu/CBD hydrogel was approximately 2-fold higher than that in the control group on day 7 and 14. Additionally, compared to the control group, the level of mineralized deposits in SA@Cu/CBD hydrogel was also improved by about 2 times on day 14. The PCR results indicated the mRNA expression levels of osteogenic markers (ALP, Col1α1, OCN, and RUNX2 genes) and angiogenic markers (EGFL6 and VEGF genes) in SA@Cu/CBD hydrogel were significantly upregulated compared to that in the control group, and the mRNA expression levels of critical inflammatory cytokines (TNF-α and IL-1β) in the SA@Cu/CBD hydrogel were significantly down-regulated compared to that in SA@Cu hydrogel. Taken together, these results demonstrated that the SA@Cu/CBD hydrogel showed significantly anti-bacterial, anti-inflammation, angiogenic and osteogenic activities in vitro studies. Thus, SA@Cu/CBD hydrogels may be a promising candidate in repairing open bone defects.

Development of Stable Nano-Sized Transfersomes as a Rectal Colloid for Enhanced Delivery of Cannabidiol

Current cannabidiol (CBD) formulations are challenged with unpredictable release and absorption. Rational design of a rectal colloid delivery system can provide a practical alternative. In this study the inherent physiochemical properties of transferosomes were harnessed for the development of a nano-sized transfersomes to yield more stable release, absorption, and bioavailability of CBD as a rectal colloid. Transfersomes composed of soya lecithin, cholesterol, and polysorbate 80 were synthesized via thin film evaporation and characterized for size, entrapment efficiency (%), morphology, CBD release, ex vivo permeation, and physicochemical stability. The optimized formulation for rectal delivery entrapped up to 80.0 ± 0.077% of CBD with a hydrodynamic particle size of 130 nm, a PDI value of 0.285, and zeta potential of −15.97 mV. The morphological investigation via SEM and TEM revealed that the transfersomes were spherical and unilamellar vesicles coinciding with the enhanced ex vivo permeation across the excised rat colorectal membrane. Furthermore, transfersomes improved the stability of the encapsulated CBD for up to 6 months at room temperature and showed significant promise that the transfersomes promoted rectal tissue permeation with superior stability and afforded tunable release kinetics of CBD as a botanical therapeutic with inherent poor bioavailability.

Pharmacokinetics and Pharmacodynamics of Intranasal Solid Lipid Nanoparticles and Nanostructured Lipid Carriers for Nose-to-Brain Delivery

Nose-to-brain drug delivery has been of great interest for the treatment of many central nervous system (CNS) diseases and psychiatric disorders over past decades. Several nasally administered formulations have been developed to circumvent the blood-brain barrier and directly deliver drugs to the CNS through the olfactory and trigeminal pathways. However, the nasal mucosa's drug absorption is insufficient and the volume of the nasal cavity is small, which, in combination, make nose-to-brain drug delivery challenging. These problems could be minimized using formulations based on solid lipid nanoparticles (SLNs) or nanostructured lipid carriers (NLCs), which are effective nose-to-brain drug delivery systems that improve drug bioavailability by increasing drug solubility and permeation, extending drug action, and reducing enzymatic degradation. Various research groups have reported in vivo pharmacokinetics and pharmacodynamics of SLNs and NLCs nose-to-brain delivery systems. This review was undertaken to provide an overview of these studies and highlight research performed on SLN and NLC-based formulations aimed at improving the treatment of CNS diseases such neurodegenerative diseases, epilepsy, and schizophrenia. We discuss the efficacies and brain targeting efficiencies of these formulations based on considerations of their pharmacokinetic parameters and toxicities, point out some gaps in current knowledge, and propose future developmental targets.

Liposome Loaded Ion/Temperature Dual Responsive Gellan Gum Hydrogel as Potential Nasal-To-Brain Delivery System

Intranasal administration, which can bypass the blood-brain barrier (BBB), is widely recognized as a promising strategy for high-efficiency drug delivery to the brain. Herein, for the purpose of effectively delivering drugs to the brain via intranasal administration, glutathione (GSH)-modified gellan gum (GSH-GG) with ion/temperature dual responsive properties was synthesized and encapsulated on galanthamine hydrobromide (GH)-loaded liposomes (GH-Lipo) for effective GH delivery to the brain (GH-Lipo@GSH-GG). Our results demonstrated that GSH-GG greatly decreased the gelation temperature of GG from 44.0 °C to 22.1 °C without compromising its ion responsiveness. Moreover, GSH-GG had a good protection ability for GH-loaded liposomes without affecting its drug release. Most importantly, the finally obtained GH-Lipo@GSHGG showed acceptable targeted delivery of GH to the brain upon in vivo administration. Therefore, this formulation can be employed as a potential delivery system in nasal-to-brain delivery.