Solubilizer: Definition, Properties and Cosmetic Applications

What Is a Solubilizer?

A solubilizer is a surfactant or surfactant-like ingredient used to help disperse and incorporate substances that have limited water solubility into a water-based formulation.

Unlike an emulsifier, which is generally used to create and stabilise an emulsion containing a significant oil phase, a solubilizer is typically used for small amounts of oil-soluble ingredients.

How Do Solubilizers Work?

Solubilizers can form organised structures, such as micelles, that can accommodate oil-soluble materials within an aqueous phase. This allows ingredients such as fragrances, essential oils and certain oil-soluble active ingredients to be incorporated into otherwise water-based products.

The amount of solubilizer required depends on the type and concentration of the material being solubilized and the characteristics of the formulation.

Solubilizers in Cosmetic Products

Solubilizers are commonly used in:

• Micellar waters
• Facial toners
• Facial mists
• Body sprays
• Eau de toilette and other water-based fragrance products
• Clear cleansing products

Common cosmetic solubilizers include Polysorbates, PEG-based surfactants and certain non-ionic surfactants.

Solubilizer vs. Emulsifier

A solubilizer is generally used to incorporate relatively small quantities of oil-soluble materials into an aqueous system, often while maintaining a clear or nearly clear appearance.

An emulsifier is used to create and stabilise an emulsion containing two immiscible phases, such as oil and water. The distinction depends on the formulation and the amount and type of oil phase involved.