ABSTRACT
Solubilization is a term denoting the tendency of a substance to dissolve in the dispersed part in a colloidal system. The emphasis on the dispersed part is essential: dissolving a water soluble substance in the continuous part of a colloidal system, such as a salt in the aqueous part of an oil-in-water (o/w) microemulsion, is not solubilization, but dissolving an oil-soluble compound in the oil droplets in the same microemulsion is. To a large extent cosmetic preparations are colloidal structures, and solubilization is essential for product esthetics and performance. As a consequence, the number of solubilized systems is very high, and in this chapter no attempt is made to cover many of these systems. The chapter is instead organized around a few illustrative systems for which the fundamental factors are analyzed.
