Synthesis, Characterization and Stress-Testing of a Novel Quillaja Saponin Stabilized Oil-in-Water Phytocannabinoid Nanoemulsion

This study describes the design, optimization, and stress-testing of a novel phytocannabinoid nanoemulsion generated using high-pressure homogenization. QNaturale®, a plant-derived commercial emulsifier containing quillaja saponin, was used to stabilize the lipid phase droplets in water. Optimization studies revealed that after 10 homogenization cycles at a pressure of 30,000 psi in the presence of 10 wt% QNaturale® (1.5 wt% quillaja saponin), average nanoemulsion droplet diameters were ca.

120 nm and average droplet surface zeta-potentials were ca. -30 mV for a lipid phase comprising 16.6 wt% CBD-enriched cannabis extract and 83.4 wt% carrier (soybean) oil. The optimized nanoemulsion proved to be stable to droplet agglomeration and phase separation upon storage under ambient conditions for 6 weeks, as well as under a variety of physical stressors such as heat, cold, dilution, and

carbonation. pH values under 2 and moderately high salt concentrations (> 100 mM), however, destabilized 0the CD_CBD nanoemulsion, eventually leading to phase separation. Cannabis potency, determined by HPLC, was detrimentally affected by any changes in the nanoemulsion phase stability. Quillaja saponin stabilized cannabidiol (CBD)-enriched nanoemulsions are stable, robust systems even at low emulsifier concentrations, and are therefore significant from both a scientific as well as a commercial perspective.