A New Preparing Method for Fine O/W Emulsions by D Phase Emulsification and Their Application to Cosmetic Industry

Abstract

A new emulsification technique for producing fine O/W emulsions, D phase emulsification, has been developed and elucidated the emulsification mechanism by using phase diagrams. The process of D phase emulsification begins with the formation of isotropic surfacatant solution, followed by formation of an oil-in-surfactant (O/D) gel emulsion by dispersion of oil in the surfactant solution, and finally formation of an O/W emulsion by the addition of an aqueous phase to the gel emision. The characteristics of D phase emulsification are as follows : (1) it is easy to produce submicron O/W emulsion in many types of oils and surfactants, (2) strict HLB adjustment is not necessary, (3) it is possible to reduce the emulsifier content. This emulsification method has been applied to develop new types of cosmetics.