Optimising Cannabidiol Delivery: Improving Water Solubility and Permeability Through Phospholipid Complexation

Cannabidiol (CBD) has demonstrated therapeutic potential in treating epilepsy, multiple sclerosis, Alzheimer's, Parkinson's, and Crohn's diseases. Despite its promising effects and analgesic, anti-inflammatory, and anxiolytic properties, oral CBD's full potential is hindered by poor water solubility (0.7-10 μg/mL), low permeability, and chemical instability. This study aimed to enhance CBD's dissolution, stability, and gastrointestinal (GI) permeability by forming a CBD-phospholipid complex (CBD-PLC). We hypothesised that CBD-PLC would enhance CBD's hydrophilicity, thus improving GI barrier permeability. This study involved screening an optimal phospholipid (PL) using a Design of Experiments (DoE) approach to prepare CBD-PLC with nanosized droplets (194.3 nm). Dissolution studies revealed significantly enhanced release rates for CBD-PLC-44.7% at 2 h and 67.1% at 3 h-compared to 0% for pure CBD and 7.2% for a physical mixture (PM). Cellular uptake studies showed that at 30 µM, CBD-PLC exhibited 32.7% higher apparent permeability coefficients (P_app), nearly doubling at 40 µM compared to pure CBD. Cytotoxicity tests confirmed safety over 24 h, while 12-month stability tests demonstrated consistent performance under varied conditions. The results indicate that CBD-PLC improves CBD's solubility, permeability, and stability, offering a promising strategy to address the limitations of oral CBD delivery systems.