Process for the preparation of water-in-oil and oil-in-water nanoemulsions

Abstract

Process for the preparation of a water-in-oil or oil-in¬water nanoemulsion wherein the dispersed phase is distrib¬uted in the dispersing phase in the form of droplets having a diameter ranging from 1 to 500 nm, comprising: 1) the preparation of a homogeneous water / oil blend (I) characterized by an interface tension lower than 1 mN / m, comprising water in an amount of 30 to 70% by weight, at least two surface-active agents having a different HLB, se-lected from non-ionic, anionic, polymeric surface-active agents, said surface-active agents being present in such a quantity as to make the blend homogeneous; 2) the dilution of the blend (I) in a dispersing phase consisting of oil or water with the addition of a surface-active agent, selected from non-ionic, anionic, polymeric surface-active agents, the quantity of the dispersing phase and surface-active agent being such as to obtain a nanoe-mulsion having a HLB different from that of the blend (I).