CHAPTER 7: Nanoemulsions

A nanoemulsion is an emulsion with droplet size of 100 nm or less. The emulsifiers used in nanoemulsions include non-ionic emulsifiers such as polysorbates and sucrose esters, Zwitterionic emulsifiers such as lecithin, and food polymeric emulsifiers such as starch sodium octenyl succinate (OSA - starch). Recently some new emulsifiers have been used to make nanoemulsion like Quillaja saponin and d-α-tocopheryl polyethylene glycol succinate (Vitamin E TPGS). To optimize the formulation and process of nanoemulsion, it is important to understand the properties of emulsifiers such as their hydrophilic-lipophilic balance (HLB) values, critical packing parameters (CPP), and microemulsion phase diagram. There are two approaches in preparing nanoemulsion: top-down or high energy shearing device, and bottom-up or low energy emulsification methods.