Emulsifying

Such components help to combine water and oils in one formula, which themselves quickly exfoliate. Due to this, the product remains homogeneous, spreads more easily over the skin or hair and retains a pleasant, stable texture — from a light lotion to a dense cream. In fact, they work at the boundary of two phases and hold the mixture in the form of an emulsion, so the product does not break down into watery and oily parts during storage and use. This is especially important for creams, milks, conditioners and cleansers, where the comfort of application directly depends on the structure of the formula. (fda.gov)

For the skin, such ingredients are important primarily indirectly: they do not so much take care of themselves as ensure a uniform supply of softening, moisturizing and protective components in each application. In hair products, they help to make the texture smoother and more uniform, so that the composition is better distributed along the length and does not feel uneven. In cosmetic databases, this function also affects the appearance of the product, its density, slip, and the overall stability of the formula. Typical examples include Glyceryl Stearate, which is described in cosmetic databases as an emulsifying component, and Polysorbate 20, known as a nonionic surfactant used as an emulsifier and solubilizer. (pubchem.ncbi.nlm.nih.gov )

It is thanks to such substances that the cream does not "sweat" with drops of water, and the serum with the oil part does not require constant shaking. At the same time, the specific properties depend on the type of emulsifier and the entire formula system: some are better suited for dense nutritious textures, others for lighter, fluid products. Therefore, the presence of this function in the composition usually indicates that the ingredient is involved not only in creating a convenient consistency, but also in maintaining the quality of the product throughout its entire life. (pubchem.ncbi.nlm.nih.gov)