Vegetable oils composition affects the intestinal lymphatic transport and systemic bioavailability of co-administered lipophilic drug cannabidiol

Pharmacokinetics of cannabidiol, (-)-trans-Δ9-tetrahydrocannabinol, and their oxidative metabolites after intravenous and oral administration of a cannabidiol-dominant full-spectrum hemp product to beagle dogs

Introduction

This study investigated the pharmacokinetics, safety, and tolerability of a full-spectrum CBD-dominant oil formulated in medium-chain triglycerides (MCT oil) after a single intravenous (IV) administration, a single oral (PO) administration, and multiple oral administrations of CBD at a dose of 2.2 mg/kg in adult male and female beagle dogs.

Methods

The CBD-dominant extract was administered to adult, intact beagle dogs (male n = 4, female n = 2) once intravenously, once orally, and every 12 h orally for 21 days at a dose of 2.2 mg CBD/kg body weight (BW). Blood samples were collected at predetermined times to measure concentrations of serum CBD, 7-hydroxy-CBD (7-OH-CBD), 7-nor-7-carboxy-CBD (7-COOH-CBD), Δ9-tetrahydrocannabinol (Δ9-THC), 11-hydroxy-THC (11-OH-THC), and 11-carboxy-THC (11-COOH-THC). Serum CBD and Δ9-THC concentrations were analyzed to estimate various pharmacokinetic parameters. Selected physical, behavioral, hematologic, and blood chemical measurements were obtained before and during single and repeated dose administrations.

Results

Pharmacokinetics of CBD after IV administration indicated a median (range) systemic clearance (CL) of 7.06 (6.14-10.5) mL/min/kg, a steady-state volume of distribution (Vss) of 2.13 (1.10-2.85) L/kg, and a half-life of 291 (183-508) min. The median (range) extent of systemic availability of CBD after a single oral dose was 31.2 (17.7-35.7)%. Pharmacokinetics of Δ9-THC after IV administration were characterized by a CL of 8.85 (6.88-14.4) mL/min/kg, Vss of 1.98 (1.30-2.30) L/kg, and a half-life of 169 (139-476) min. The extent of systemic availability of Δ9-THC after PO administration was 40.9 (20.5-46.2)%. The test article was well tolerated in all dogs during the study. Although serum alkaline phosphatase concentrations increased during the repeated PO dose study, they remained within normal limits.

Discussion

Both CBD and Δ9-THC were rapidly cleared after IV administration and exhibited extensive volumes of distribution. Comparison of clearance to serum hepatic blood flow estimated the hepatic extraction ratio and extent of first pass metabolism after PO administration, which was confirmed by analyzing the single PO dose pharmacokinetic data. The AUC0-∞ for 7-OH-CBD after single IV compared to single PO dose was not different, suggesting complete absorption of CBD from the formulation in MCT oil when administered with canned dog food.

Population pharmacokinetics of cannabidiol and the impact of food and formulation on systemic exposure in children with drug-resistant developmental and epileptic encephalopathies

OBJECTIVE

Identifying factors influencing cannabidiol (CBD) exposure can optimize treatment efficacy and safety. We aimed to describe the population pharmacokinetics of CBD in children with drug-resistant developmental and epileptic encephalopathies (DEEs) and assess the influence of environmental, pharmacological, and clinical characteristics on CBD systemic exposure.

METHODS

Data from two pharmacokinetic studies of patients aged 2-18 years with DEEs were included (N = 48 patients). Serial blood samples were collected during maintenance treatment, before and after the morning dose, and up to 6 h after a dose of a purified CBD oil formulation, with or without a normocaloric breakfast. CBD plasma concentrations were also available following administration of a CBD-enriched formulation. Samples were quantified using a validated liquid chromatography/tandem mass spectrometry assay. A CBD population pharmacokinetic model was developed using nonlinear mixed-effects modeling. The effects of formulation, concomitant food intake, and demographic, clinical, and pharmacological factors on CBD pharmacokinetics were evaluated. Simulated maximum plasma concentration (Cmax) and area under the concentration-time curve between 0 and 12 h (AUC0-12) were calculated.

RESULTS

A one-compartment model with transit compartments and first-order elimination best described CBD pharmacokinetics. Mean values for CBD apparent clearance (CL/F) and volume of distribution (V/F) were 143.5 L/h and 1892.4 L, respectively. Weight was allometrically scaled for V/F and CL/F, sex was associated with V/F, and both formulation and food condition were associated with F (relative bioavailability). CBD Cmax increased by 41% and AUC0-12 by 45% when CBD was administered with food compared to fasting. Dose-normalized AUC0-12 was approximately 50% lower with CBD-enriched oil compared to purified CBD.

SIGNIFICANCE

In the present study, we described the effects of food and formulation on CBD exposure in children with DEEs. Increased CBD exposure with food intake and significant changes in drug exposure when switching between CBD formulations should be considered in patient management.

Rapeseed oleosomes facilitate intestinal lymphatic delivery and oral bioavailability of cannabidiol

Due to high lipophilicity and extensive first-pass metabolic loss, cannabidiol (CBD) has low oral bioavailability. Co-administration of CBD and long-chain lipids facilitates the intestinal lymphatic delivery, resulting in higher systemic bioavailability, as well as high levels of the drug within the intestinal lymphatic system. However, despite previous attempts with various lipid-based formulations, the oral bioavailability of CBD is still limited. In this work, we have developed a novel formulation of CBD based on natural rapeseed oleosomes. In vivo studies in rats demonstrated that oral administration of CBD-loaded rapeseed oleosomes leads to substantially higher oral bioavailability and intestinal lymphatic targeting of CBD in comparison with rapeseed oil or artificial emulsion made of rapeseed oil and lecithin. In vitro mechanistic assessments, including in vitro lipolysis and peroxide value determination suggest that the lower oxidative state of the oil in oleosomes in comparison to crude oil or artificial emulsion is likely to be the main factor responsible for the superior performance of the CBD-loaded rapeseed oleosomes in vivo. Although further investigation will be needed, the data suggest that natural seeds-derived oleosomes can be used as a promising lipid-based drug delivery platform promoting the bioavailability and lymphatic delivery of lipophilic drugs.

Novel Lipid Formulation Increases Absorption of Oral Cannabidiol (CBD)

Background: Cannabidiol (CBD) is an approved treatment for childhood epilepsies and a candidate treatment for several other CNS disorders. However, it has poor oral bioavailability. We investigated the effect of a novel lipid formulation on its absorption in humans and on its tissue distribution in mice. Methods: In a double-blind crossover study in fasting healthy volunteers, we compared the pharmacokinetics of a single dose of 1000 mg of CBD in the lipid formulation and in a powder formulation (ClinicalTrials.gov: NCT05032807). In a second study, male CD1 mice were administered CBD in either the lipid formulation or dissolved in water, via oral gavage (n = 1 per timepoint). The tissue distribution of CBD was assessed using matrix-assisted laser desorption/ionization mass spectrometric imaging. Results: Plasma exposure (AUC0-48) of CBD was nine times greater for the lipid formulation than the powder formulation (611.1 ng·h/mL [coefficient of variation {CV%}: 104.6] and 66.8 ng·h/mL [CV%: 50.7], respectively). With the powder formulation, the AUC0-48 was related to the concentration of specific gastrointestinal bacteria and bile acids. These associations were attenuated with the lipid formulation. In the animal study, after treatment with the lipid formulation, measurable concentrations of CBD were identified in all organs. For the aqueous formulation, tissue concentrations of CBD were below the limit of quantification. Conclusions: Administering oral CBD in a lipid formulation was associated with an increase in its gastrointestinal absorption, as well as an attenuation of the relationship between its absorption and features of the gut microbiome.

Understanding lymphatic drug delivery through chylomicron blockade: A retrospective and prospective analysis

Scientists have developed and employed various models to investigate intestinal lymphatic uptake. One approach involves using specific blocking agents to influence the chylomicron-mediated lymphatic absorption of drugs. Currently utilized models include pluronic L-81, puromycin, vinca alkaloids, colchicine, and cycloheximide. This review offers a thorough analysis of the diverse models utilized, evaluating existing reports while delineating the gaps in current research. It also explores pharmacokinetic related aspects of intestinal lymphatic uptake pathway and its blockage through the discussed models. Pluronic L-81 has a reversible effect, minimal toxicity, and unique mode of action. Yet, it lacks clinical reports on chylomicron pathway blockage, likely due to low concentrations used. Puromycin and vinca alkaloids, though documented for toxicity, lack information on their application in drug intestinal lymphatic uptake. Other vinca alkaloids show promise in affecting triglyceride profiles and represent possible agents to test as blockers. Colchicine and cycloheximide, widely used in pharmaceutical development, have demonstrated efficacy, with cycloheximide preferred for lower toxicity. However, further investigation into effective and toxic doses of colchicine in humans is needed to understand its clinical impact. The review additionally followed the complete journey of oral lymphatic targeting drugs from intake to excretion, provided a pharmacokinetic equation considering the intestinal lymphatic pathway for assessing bioavailability. Moreover, the possible application of urinary data as a non-invasive way to measure the uptake of drugs through intestinal lymphatics was illustrated, and the likelihood of drug interactions when specific blockers are employed in human subjects was underscored.

In Vitro Predictive Model for Intestinal Lymphatic Uptake: Exploration of Additional Enhancers and Inhibitors

Drug absorption via chylomicrons holds significant implications for both pharmacokinetics and pharmacodynamics. However, a mechanistic understanding of predicting in vivo intestinal lymphatic uptake remains largely unexplored. This study aimed to delve into the intestinal lymphatic uptake of drugs, investigating both enhancement and inhibition using various excipients through our previously established in vitro model. It also examined the applicability of the model by assessing the lymphatic uptake enhancement of a lymphotropic formulation with linoleoyl polyoxyl-6 glycerides using the same model. The model successfully differentiated among olive, sesame, and peanut oils in terms of lymphatic uptake. However, it did not distinguish between oils containing long-chain fatty acids and coconut oil. Coconut oil, known for its abundance of medium-chain fatty acids, outperformed other oils. This heightened uptake was attributed to the superior emulsification of this oil in artificial chylomicron media due to its high content of medium-chain fatty acids. Additionally, the enhanced uptake of the tested formulation with linoleoyl polyoxyl-6 glycerides underscored the practical applicability of this model in formulation optimization. Moreover, data suggested that increasing the zeta potential of Intralipid® using sodium lauryl sulfate (SLS) and decreasing it using (+/-) chloroquine led to enhanced and reduced uptake in the in vitro model, respectively. These findings indicate the potential influence of the zeta potential on intestinal lymphatic uptake in this model, though further research is needed to explore the possible translation of this mechanism in vivo.

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.

The Chimera of TPGS and Nanoscale Lipid Carriers as Lymphatic Drug Delivery Vehicles to Fight Metastatic Cancers

The lymphatic system (LS) plays a crucial role in fluid balance, transportation of macromolecules, and immune response. Moreover, LS is a channel for microbial invasion and cancer metastasis. Particularly, solid tumors, including lung, breast, melanoma, and prostate cancers, are metastasized across highways of LS. Subsequently, the fabrication of chimeric lymphatic drug delivery systems (LDDS) is a promising strategy to fight cancer metastasis and control microbial pandemics. In this regard, LDDS, in terms of PEG-nanoscaled lipid carriers, elicited a revolution during the COVID-19 pandemic as cargoes for mRNA vaccines. The drug delivered by the lymphatic pathway escapes first-pass metabolism and enhances the drug's bioavailability. Ample approaches, including synthesis of prodrugs, trigging of chylomicron biosynthesis, and fabrication of nanocarriers, facilitate lymphatic drug delivery. Specifically, nanoscales lipid cargoes have the propensity to lymphatic trafficking. Interestingly, TPGSengineered nanoscale lipid cargoes enhance lymphatic trafficking, increase tissue permeation, and, specifically, uptake. Moreover, they overcome biological barriers, control biodistribution, and enhance organelles localization. Most anticancer agents are non-specific, have low bioavailability, and induced drug resistance. Therefore, TPGS-engineered nanoscale lipid chimeras improve the therapeutic impact of anticancer agents. This review highlights lymphatic cancer metastasis, nanoscales lipid cargoes as LDDS, and their influence on lymphatic trafficking, besides the methods of LDD studies.

Development of lipophilic ester prodrugs of dolutegravir for intestinal lymphatic transport

The establishment of latent cellular and anatomical viral reservoirs is a major obstacle to achieving a cure for people infected by HIV. Mesenteric lymph nodes (MLNs) are one of the most important anatomical reservoirs of HIV. Suboptimal levels of antiretroviral (ARVs) drugs in these difficult-to-penetrate viral reservoirs is one of the limitations of current antiretroviral therapy (ART) regimens. This study aimed to design and assess highly lipophilic ester prodrugs of dolutegravir (DTG) formulated with long-chain triglyceride (LCT) for delivery of DTG to the viral reservoir in mesenteric lymph and MLNs. A number of alkyl ester prodrugs of DTG were designed based on the predicted affinity to chylomicrons (CM), and the six most promising prodrugs were selected and synthesised. The synthesised prodrugs were further assessed for their intestinal lymphatic transport potential and biotransformation in biorelevant media in vitro and ex vivo. DTG and the most promising prodrug (prodrug 5) were then assessed in pharmacokinetic and biodistribution studies in rats. Although oral administration of 5 mg/kg of unmodified DTG (an allometrically scaled dose from humans) with or without lipids achieved concentrations above protein binding-adjusted IC90 (PA-IC90) (64 ng/mL) in most tissues, the drug was not selectively targeted to MLNs. The combination of lipophilic ester prodrug and LCT-based formulation approach improved the targeting selectivity of DTG to MLNs 4.8-fold compared to unmodified DTG. However, systemic exposure to DTG was limited, most likely due to poor intestinal absorption of the prodrug following oral administration. In vitro lipolysis showed a good correlation between micellar solubilisation of the prodrug and systemic exposure to DTG in rats in vivo. Thus, it is prudent to include in vitro lipolysis in the early assessment of orally administered drugs and prodrugs in lipidic formulations, even when intestinal lymphatic transport is involved in the absorption pathway. Further studies are needed to clarify the underlying mechanisms of low systemic bioavailability of DTG following oral administration of the prodrug and potential ways to overcome this limitation.

Real-World Evidence of Factors Affecting Cannabidiol Exposure in Children with Drug-Resistant Developmental and Epileptic Encephalopathies

The identification of factors that affect cannabidiol (CBD) systemic exposure may aid in optimizing treatment efficacy and safety in clinical practice. In this study, we aimed to correlate CBD plasma concentrations at a steady state to demographic, clinical, and pharmacological characteristics as well as seizure frequency after the administration of a purified CBD oil solution in a real-world setting of children with drug-resistant developmental and epileptic encephalopathies (DEEs). Patients receiving oral CBD pharmaceutical products at maintenance were enrolled. Venous blood samples were drawn before the CBD morning dose, 12 h apart from the last evening dose (C0 or CBD trough concentration). A linear mixed-effect analysis was implemented to assess the correlation between C0 and clinical, laboratory, pharmacological, and lifestyle factors. Fifteen females and seven males with a median age of 12.8 years (ranging between 4.7 and 17.2) were included. The median CBD dose was 8.8 mg/kg/day (ranging between 2.6 and 22.5), and the CBD C0 median (range) was 48.2 ng/mL (3.5-366.3). The multivariate model showed a 109.6% increase in CBD C0 in patients with concomitant levothyroxine (β = 0.74 ± 0.1649, p < 0.001), 56.8% with food (β = 0.45 ± 0.1550, p < 0.01), and 116.0% after intake of a ketogenic diet (β = 0.77 ± 0.3141, p < 0.05). All patients included were responders without evidence of an association between C0 and response status. In children with DEEs, systemic concentrations of CBD may be significantly increased when co-administered with levothyroxine, food, or a ketogenic diet.

Oral lipid-based formulations alter delivery of cannabidiol to different anatomical regions in the brain

Delivery to the brain is a challenging task due to its protection by the blood-brain barrier (BBB). Lipids and fatty acids are reported to affect the permeability of the BBB, although this has not been reported following oral administration. Cannabidiol (CBD) has high therapeutic potential in the brain, therefore, this work investigated CBD delivery to anatomical brain regions following oral administration in lipid-based and lipid-free vehicles. All formulations resulted in a short brain T_max (1 h) and brain-plasma ratios ≥ 3.5, with retention up to 18 h post administration. The highest CBD delivery was observed in the olfactory bulb and striatum, and the medulla pons and cerebellum the lowest. The lipid-free vehicle led to the highest levels of CBD in the whole brain. However, when each anatomical region was assessed individually, the long chain triglyceride-rich rapeseed oil formulation commonly showed optimal performance. The medium chain triglyceride-rich coconut oil formulation did not result in the highest CBD concentration in any brain region. Overall, differences in CBD delivery to the whole brain and various brain regions were observed following administration in different formulations, indicating that the oral formulation selection may be important for optimal delivery to specific regions of the brain.

Hypolipidemic effects of macadamia oil are related to AMPK activation and oxidative stress relief: In vitro and in vivo studies

Macadamia oil is rich in monounsaturated fatty acids, especially a high level of palmitoleic acid, which may have beneficial health effects by lowering blood lipid levels. In our study, the hypolipidemic effects of macadamia oil and its potential mechanisms of action were investigated using a combination of in vitro and in vivo assays. The results showed that macadamia oil significantly reduced lipid accumulation, and improved triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) levels in oleic acid-induced high-fat HepG2 cells. The macadamia oil treatment also exhibited antioxidant effects, as seen by its ability to reduce reactive oxygen species and malondialdehyde (MDA) levels, and increase superoxide dismutase (SOD) activity. The effects of 1000 μg/mL of macadamia oil were comparable to that of 4.19 μg/mL simvastatin. The results of qRT-PCR and western blotting analyses indicated that macadamia oil effectively inhibited hyperlipidemia by reducing the expression levels of SREBP-1c, PPAR-γ, ACC and FAS and by enhancing the expression levels of HO-1, NRF2 and γ-GCS, via AMPK activation and oxidative stress relief, respectively. In addition, different doses of macadamia oil were found to significantly improve liver lipid accumulation, reduce serum and liver TC, TG, and LDL-C levels, increase HDL-C levels, increase antioxidant enzyme (SOD, GSH-Px, and T-AOC) activity, and decrease the MDA content of mice on a high-fat diet. These results indicated that macadamia oil had a hypolipidemic effect and provide insights that might facilitate the development of functional food and dietary supplements.