University of South Australia scientists have developed a new solution to improve the effectiveness of cannabidiol (CBD) in treating epilepsy, multiple sclerosis and other neurodegenerative diseases.
While widely prescribed for its analgesic, anti-inflammatory and neuroprotective properties, CBD’s clinical applications have been limited by its poor water solubility and absorption in the human body.
By developing a phospholipid complex – a class of lipids (fats) that contain phosphorus – researchers at the university have increased the solubility of CBD by up to six times and improved its absorption in the gastrointestinal tract.
Lead researcher Professor Sanjay Garg said the breakthrough, reported in the International Journal of Molecular Sciences, means patients could experience more consistent and effective results with lower doses of oral CBD medications.
Currently, only a small fraction of orally ingested CBD reaches the bloodstream, limiting its therapeutic effects, Professor Garg said.
“For this reason, a number of different formulations have been explored, including the production of synthetic CBD, self-emulsifying delivery systems, and encapsulating CBD in gelatine matrix pellets, but all of them have only resulted in minor improvements in bioavailability,” he added.
The research team identified the optimal phospholipid composition to form nanosized CBD-PLC particles. Compared to pure CBD, the phospholipid complex improved dissolution rates from 0% to 67.1% within three hours, demonstrating a significant enhancement in drug release.
In cellular uptake studies, CBD-PLC exhibited 32.7% higher permeability than unmodified CBD, ensuring greater absorption through the intestinal wall.
The team also found the new delivery system to be more stable than traditional CBD formulations, which degrade over time when exposed to heat, light or oxygen, reducing their potency and shelf life.
Testing over 12 months showed CBD-PLC retained its performance under varied storage conditions, making it a more reliable option for pharmaceutical applications, according to the researchers.
The study’s first author, UniSA PhD candidate Thabata Muta, said the discovery has significant implications for the future of CBD-based therapeutics.
“Improved bioavailability means lower doses can achieve the same therapeutic effect, potentially reducing side effects and making treatment more cost effective,” she said.
The research team believes the innovation could be applied beyond CBD, providing a blueprint for enhancing the absorption of other poorly water-soluble drugs.
It is now exploring opportunities for commercialisation and clinical trials to validate the new formulation.
The study was supported by a PhD scholarship jointly funded by the University of South Australia, MedTEC Pharma, and the SA Government’s Industry Doctoral Training Centre program.