The formation of oil/water (O/W) nano-emulsions suitable for cosmeceutical application was studied. Nano-emulsions were prepared by using phase inversion composition (PIC) method, one of the low-energy emulsification methods. The process consist of stepwise water addition to oil/surfactant mixture, at T = 25°C. Caprylic/capric triglycerides (GTCC), propylene glycol dicaprylate/dicaprate (PC) and oleic acid (OA) were applied as an oil phase. Polysorbate 80 was used as the surfactant. Kinetic stability of the nano-emulsions was analyzed by measuring droplet size as a function of time for different oil/surfactant ratio. The particles size distribution was analyzed by means DLS measurement technique (Dynamic Light Scattering), using Zetasizer Nano ZS (Malvern Instruments, UK). One of triterpenoic acid, practically non-water soluble substance was selected as an active and incorporated into the stable formulation. The obtained results proved that the nanoemulsion NE-T80-GTCC-20:80 based on caprylic/capric triglycerides with the oil/surfactant ratio O/S = 2 0:80 and the droplet size r = 25 nm was the most stable one and additionally showed the highest solubilisation capacity for the triterpene.
Formation and structure of slightly anionically charged nanoemulsions obtained by the phase inversion concentration (PIC) method
