Physical Properties of Oily Gels and Their Application in Cosmetics

Abstract

Oily gels are commonly used to make stick and paste cosmetics and their physical properties are important for product performance and stability. Oil gelling agents for cosmetics are broadly classified into waxes, e.g. hydrocarbons and wax esters, and organo-gelling agents, e.g. sugar fatty acid esters and hydroxystearic acid. In this paper, the gelation mechanisms of various gelling agents are systemically explained and the relationship between the physical properties of gels and the performance of cosmetics, such as stick hardness, application feeling and coating gloss, are clarified. The composition of plant wax (the mixture of candelilla wax and behenyl behenate) having a gelling performance equivalent to that of petroleum waxes, which were developed on the basis of crystal control technology, is also described. Furthermore, the physical properties of gel films which are formed by the application of gels to skin or lip are analyzed by a quartz crystal microbalance sensor and then the relationship between the type of gelling agents and the performances such as gloss, sustainability, and feeling of the films is explained.