Periodic Reporting for period 1 - CBDHIGHBIO (Strategies to modulate the bioavailability of cannabinoids in edible products: in vitro tests, cytotoxicity, and pre-clinical assessment to generate reliable data for regulatory agencies)
Reporting period: 2022-10-17 to 2025-05-16
The cannabidiol (CBD) - an active compound found in Cannabis plants -has been gaining a lot of attention due to its potential terapeutic effects. However, despite ease-of-administration, the oral ingestion of CBD has low bioavailability. In pharmaceutics, bioavailability represents the portion of a drug that is actually able to have an active effect after being introduced into the body. The low CBD bioavailability is mainly attributed to two factors: i) it has a poor capacity of being solubilized in water, and ii) it is highly degraded in liver as a consequence of the hepatic metabolism. These factors combined gives to CBD a bioavailability of aproximately 12-20%. Moreover, the CBD absorption is patient-dependent, which makes hard the prediction of the effects of CBD after oral ingestion. The improvement of CBD bioavailability may minimize the variability of CBD absorption by the body providing substantial advantages in provinding predictable effects for the consumers.
A promising approach to enhance the oral bioavailability of CBD is its incorporation into lipid-based delivery systems. Lipids can enhance the oral bioavailability of poorly water-soluble compounds, such as CBD, via the improvement in solubilization in the intestinal milieu. Another interesting approach to enhance the oral bioavailability of CBD involves its incorporation into formulations that contain substances able to inhibit the cannabinoids-metabolizing enzymes, thereby preventing the CBD to be degraded by the hepatic metabolism. The substances that present this ability of inhibiting the metabolizing enzymes in the liver are called bioenhancers.
Thus, a strategy that combines the use of lipid-based formulations to improve the water solubility of CBD with the inhibition of the activity of enzymes responsible for the degradation of CBD in the liver can substantially increase the CBD bioavailability. In this sense, the main objectives of the CBDHIGHBIO project are to modulate the CBD bioavailability using lipid-based formulations combined with the addition of bioenhancers to inhibit the hepatic metabolism of CBD. We hypothesize that the combination between CBD and bioenhancers can substantially improve the CBD bioavailability. The increased bioavailability can decrease the patient-dependency of CBD absorption enabling the establishment of more accurate and predictable effects on consumers, at lower doses.
A promising approach to enhance the oral bioavailability of CBD is its incorporation into lipid-based delivery systems. Lipids can enhance the oral bioavailability of poorly water-soluble compounds, such as CBD, via the improvement in solubilization in the intestinal milieu. Another interesting approach to enhance the oral bioavailability of CBD involves its incorporation into formulations that contain substances able to inhibit the cannabinoids-metabolizing enzymes, thereby preventing the CBD to be degraded by the hepatic metabolism. The substances that present this ability of inhibiting the metabolizing enzymes in the liver are called bioenhancers.
Thus, a strategy that combines the use of lipid-based formulations to improve the water solubility of CBD with the inhibition of the activity of enzymes responsible for the degradation of CBD in the liver can substantially increase the CBD bioavailability. In this sense, the main objectives of the CBDHIGHBIO project are to modulate the CBD bioavailability using lipid-based formulations combined with the addition of bioenhancers to inhibit the hepatic metabolism of CBD. We hypothesize that the combination between CBD and bioenhancers can substantially improve the CBD bioavailability. The increased bioavailability can decrease the patient-dependency of CBD absorption enabling the establishment of more accurate and predictable effects on consumers, at lower doses.
The scientific activities of the CBDHIGHBIO project were organized in three work packages (WP). The WP1 was dedicated to the production and characterization of a nanostructured lipid-carrier (NLC), which is a nanoscale lipid-based formulation produced from the mixture between liquid and solid lipids in the presence of an emulsifier. This NLC was loaded with CBD and bioenhancer piperine (PIP). The produced NLC is an efficient carrier for CBD and PIP, since it presented excellent physical-chemical characteristics over a storage time confirming the potential of this formulation to deliver CBD by oral ingestion. Additionally, in the WP1, the NLCs loaded with CBD and PIP were subjected to in vitro digestion that provided preliminary information about the ability of the NLC to increase the CBD bioacessibility after oral ingestion. The activities of WP1 also included the evaluation of effect of different forms of CBD (isolate CBD as crystals or and CBD-rich extract) on the characteristics of NLC. The results demonstrated that NLC was able to efficiently carry both forms of CBD.
The WP2 was dedicated to evaluating the cytotoxicity potential of the compounds used to produce the NLC and the different forms of CBD using in vitro models of Caco-2 cell lines. The results demonstrated CBD present a cytotoxic potential against the Caco-2 cells at a certain concentration, but when CBD was incorporated into the NLC, its cytotoxicity potential was mitigated.
Finally, in the WP3 the promising NLC loaded with CBD and PIP were subjected to a pharmacokinetic study using mice models. This is an important step of the study because it enabled proving that the strategies adopted (incorporation of CBD into NLC and combine it with the bioenhancer PIP) to increase the CBD bioavailability were effective. The results demonstrated that the concentration of CBD in the mice plasma was almost 3 times higher when it was ingested in the form of a CBD-PIP-loaded NLC in comparison with the CBD ingested alone.
The WP2 was dedicated to evaluating the cytotoxicity potential of the compounds used to produce the NLC and the different forms of CBD using in vitro models of Caco-2 cell lines. The results demonstrated CBD present a cytotoxic potential against the Caco-2 cells at a certain concentration, but when CBD was incorporated into the NLC, its cytotoxicity potential was mitigated.
Finally, in the WP3 the promising NLC loaded with CBD and PIP were subjected to a pharmacokinetic study using mice models. This is an important step of the study because it enabled proving that the strategies adopted (incorporation of CBD into NLC and combine it with the bioenhancer PIP) to increase the CBD bioavailability were effective. The results demonstrated that the concentration of CBD in the mice plasma was almost 3 times higher when it was ingested in the form of a CBD-PIP-loaded NLC in comparison with the CBD ingested alone.
This project successfully demonstrated the potential of nanostructured lipid carriers (NLCs) formulated exclusively with food-grade ingredients - representing a significant advancement in a field that traditionally relies on pharmaceutical-grade components for nanoscale delivery systems. The innovative dual-strategy approach to enhance CBD bioavailability yielded remarkable results, confirming our hypothesis that entrapping CBD within a NLC matrix alongside piperine (PIP) as a bioenhancer substantially increases CBD plasma concentration.
Our findings establish the technological viability of NLCs as efficient delivery systems for CBD. These optimized CBD-loaded NLCs are now ready for integration into food matrices to evaluate their performance within complex food systems. To further elucidate CBD metabolism following oral administration, additional studies are necessary to: I) confirm piperine's specific role in inhibiting CYP450 enzymes, and ii) determine the precise mechanisms by which NLCs effectively redirect CBD absorption toward the lymphatic system.
These next-phase investigations will provide crucial insights into optimizing oral CBD delivery systems and expand the practical applications of this promising technology.
Our findings establish the technological viability of NLCs as efficient delivery systems for CBD. These optimized CBD-loaded NLCs are now ready for integration into food matrices to evaluate their performance within complex food systems. To further elucidate CBD metabolism following oral administration, additional studies are necessary to: I) confirm piperine's specific role in inhibiting CYP450 enzymes, and ii) determine the precise mechanisms by which NLCs effectively redirect CBD absorption toward the lymphatic system.
These next-phase investigations will provide crucial insights into optimizing oral CBD delivery systems and expand the practical applications of this promising technology.