CBD-Loaded Nanostructured Lipid Carriers: Optimization, Characterization, and Stability

Cannabidiol (CBD) has demonstrated its potential to enhance depression treatment through various biological pathways. However, the application potential of CBD is significantly impeded by its polymorphic nature, limited water solubility, and hepatic first-pass metabolism. To improve chemical stability and water solubility, nanostructured lipid carriers loaded with CBD (CBD-NLCs) were developed using a hot-melt emulsification method and optimized by response surface methodology (RSM). The process parameters were optimized using a four-factor and three-level Box-Behnken experimental design consisting of 29 experiments. The CBD-NLCs were formulated and characterized, demonstrating desirable properties, including a mean particle size of 54.33 nm, a PDI value of 0.118, a zeta potential of -29.7 mV, and an impressive encapsulation efficiency rate of 87.58%. The nanoparticles were found to possess an approximately spherical shape, as revealed by scanning and transmission electron microscopy. The stability studies have demonstrated that CBD-NLCs effectively mitigated the photodegradation of CBD and exhibited a stable behavior for 42 days when stored. The CBD-NLCs displayed a biphasic release profile characterized by an initial burst release (over 50% of CBD released within 20 min) followed by a subsequent gradual and sustained release, aligned with first-order kinetics and Fickian diffusion. These findings demonstrate the potential suitability of this formulation as a carrier for CBD in food fortification and pharmaceutical applications.