Formation of Nano-emulsions by the Dilution of Gels: Solvent and Temperature

Abstract Low-energy emulsification method was used to prepare oil-in-water(O/W) nano-emulsions by diluting the system of water/PEG hydrogenated castor oil/(caprylic/capric triglyceride) with water. Most of the composition in terms of phase diagram of the system showed isotropic gel-like appearance. The influence of different procedures on the properties of O/W nano-emulsions prepared by dilution of gels has been studied. The dilution procedures were consisted of adding water stepwise into gels and vice-versa. We obtained fine nano-emulsions less than 200 nm, and the size of droplets of nanoemulsions with the same water and surfactant ratio was gradually increased by increasing the concentration of oil. The size of droplets of nano-emulsions showed a similar pattern between the two diluting procedures. The nano-emulsions with less than 200 nm diameter were stable. We also investigated the system of (water/glycerin)/PEG hydrogenated castor oil/(caprylic/capric triglyceride).