preparation and application of nano emulsion in the last decade(2000_2010)

Abstract

Emulsion is a system containing two immiscible phases: a dispersed phase and a continuous phase. Components needed to prepare an emulsion are oil, water, surfactant and energy. The nature of surfactant determines the type of emulsion (oil-in-water (O/W) or water-in-oil (W/O)). Nano-emulsion is an emulsion with 20–200 nm droplet size. The required Energy to form nano-emulsion can be obtained from a mechanical device (high energy emulsification) or from the chemical potential of the components (low energy emulsification). High energy emulsification consists of high pressure homogenization (HPH), ultrasonication and microfluidization and low energy emulsification consists of phase inversion temperature (PIT), phase inversion composition (PIC) and solvent diffusion. O/W nano-emulsions have been studied more than W/O nano-emulsions and preparation of nano-emulsion with high energy emulsification is more reported than low energy emulsification. Small droplet size of nano-emulsion enhances emulsion stability; therefore nano-emulsion has various applications in the industrial field, such as personal care and cosmetics as well as health care, food and agrochemicals. Pharmacy and cosmetics are fields where more direct applications of nano-emulsions are proposed.