Cannabidiol (CBD) has shown promise in treating conditions such as epilepsy, multiple sclerosis, and anxiety, but its effectiveness is limited by poor water solubility and low absorption in the body.
In a recent study published in the International Journal of Molecular Sciences, researchers from the University of South Australia explored an innovative way to enhance the bioavailability of CBD by forming a phospholipid complex.
By improving CBD’s dissolution, stability, and permeability, they believe that this method could unlock its full therapeutic potential.
The study tested different formulations to find the optimal phospholipid combination, resulting in a complex that significantly outperforms pure CBD in solubility and absorption.
Study: Optimising Cannabidiol Delivery: Improving Water Solubility and Permeability Through Phospholipid Complexation. Image Credit: Nuva Frames/Shutterstock.com
Therapeutic Properties Of Cannabidiol
Cannabidiol is a non-psychoactive compound derived from cannabis that has gained widespread attention for its potential to treat neurological disorders, chronic pain, and inflammation.
Despite its medical benefits, its poor solubility in water and instability in the gastrointestinal tract limit its absorption, leading to inconsistent effects.
Traditional oil-based formulations offer slight improvements but still suffer from low bioavailability, variable absorption, and rapid degradation. Researchers have explored alternative methods, such as self-emulsifying drug delivery systems and synthetic CBD formulations, but no solution has provided a substantial increase in bioavailability.
Phospholipid complexation (PLC), which leverages lipid molecules to improve drug solubility and absorption, has emerged as a promising approach. This method has previously enhanced the bioavailability of other poorly soluble drugs, such as quercetin and silybin.
Building on this success, the present study investigated whether PLC can overcome CBD’s limitations in absorption and bioavailability and provide a more effective and stable oral delivery system.
About The Study
To develop this improved CBD formulation, the researchers designed a phospholipid complex (CBD-PLC) using a solvent evaporation method. They screened different phospholipid candidates to identify the most effective type for enhancing solubility and absorption.
They then optimized the ratio of CBD to phospholipid, resulting in nano-sized particles (194.3 nm) with improved water compatibility. The study employed multiple analytical techniques to characterize the CBD-PLC formulation.
Differential scanning calorimetry and Fourier transform infrared spectroscopy was used to confirm successful complex formation, while scanning electron microscopy was employed to verify the complex’s uniform, spherical particle morphology.
Additionally, lipophilicity tests were also used to measure the oil/water partition coefficient to determine the water solubility of the complex.
For permeability assessment, the researchers conducted in vitro studies using Caco-2 cell monolayers, a widely accepted model for intestinal absorption.
Additionally, dissolution tests in simulated gastrointestinal fluids were also undertaken to determine whether a significantly faster and greater release of CBD from the complex could be observed.
Furthermore, stability studies were conducted over 12 months at various temperatures. The CBD-PLC formulation was found to remain stable at 4 °C and 25 °C but showed some degradation at 40 °C, suggesting that cooler storage conditions are preferable for maintaining potency.
Major Inferences
The study found that the phospholipid complexation significantly improved the solubility, permeability, and stability of CBD. Compared to pure CBD, CBD-PLC exhibited a 32.7% higher permeability coefficient at 30 µM concentration and nearly doubled absorption at 40 µM.
The phospholipid formulation also enhanced the water solubility of CBD, with dissolution tests showing a 67.1% release at 3 hours, compared to only 7.2% for a physical mixture and 0% for pure CBD.
Additionally, cellular uptake studies using the Caco-2 monolayer model confirmed that CBD-PLC crossed the intestinal barrier more efficiently than pure CBD, further demonstrating its potential for improved bioavailability.
The stability tests also revealed that CBD-PLC maintained its properties under standard storage conditions (4 °C and 25 °C), but slight degradation occurred at 40 °C, emphasizing the importance of proper storage.
One limitation of the study was that the complex was tested in vitro, meaning further research, including in vivo testing, is necessary to confirm these findings in human subjects. Additionally, while the phospholipid complex improved CBD’s absorption, the exact mechanism of enhanced bioavailability requires further investigation.
These results suggested that phospholipid-based delivery systems could revolutionize oral CBD formulations, making treatments more effective and reliable for conditions such as epilepsy, chronic pain, and neurodegenerative diseases. The improved bioavailability may also allow for lower doses, reducing costs and potential side effects.
Conclusions
In summary, the study provided strong evidence that phospholipid complexation is a promising strategy to enhance the effectiveness of oral CBD.
By significantly improving solubility, absorption, and stability, this method could lead to more consistent and potent CBD treatments.
Although further research, including in vivo testing, is needed, these findings pave the way for developing better pharmaceutical formulations, ultimately making CBD-based therapies more accessible and effective for a wide range of medical conditions.