Surfactant - hydrotrope

Ingredients with this function help to increase the solubility of substances that do not mix well with water, and thus make the formula more homogeneous and stable. In cosmetics, they are especially useful in shampoos, shower gels, cleansers and micellar formulas: they help to retain perfumes, essential oils, preservatives and some of the assets in a clear or uniform solution. Due to this, the product does not become cloudy, does not delaminate and is more easily distributed over the skin or hair. In international cosmetic reference books, hydrotrope is distinguished as a separate functional category of ingredients, and professional reviews of CIR describe such substances as auxiliary components for water systems and detergent formulas. (cosmeticsinfo.org)

For skin and hair, such components usually work indirectly: they do not take care of themselves as noticeably as emollients or moisturizers, but they improve the consumer properties of the product. The texture becomes lighter and more fluid, the foam is more stable, and the cleaning systems are technologically more convenient. This is especially important in flushable products, where it is necessary to combine water, surfactants and fat-soluble additives without loss of transparency and effectiveness. Typical examples are Sodium Xylenesulfonate and Sodium Cumenesulfonate: CIR classifies xylene and cumenesulfonates as hydrotropes and indicates that they are used as cosmetic ingredients in various formulas. (cir-safety.org)

Most often, such substances are administered in small quantities as technological assistants. They allow you to make cleansers more stable during storage and more pleasant to use, without weighing down the hair and without leaving a pronounced film on the skin. At the same time, the final effect always depends on the entire formula: hydrotrop improves the performance of the system as a whole, but does not replace the main cleansing, softening or conditioning components. (cir-safety.org)