All cosmetics are made up of several systems, the most typical of which is the emulsion. The emulsion consists of an aqueous phase, an oil phase and an emulsifier.
However, water and oil are naturally mutually exclusive. Without a means, they cannot be allowed to coexist peacefully. Therefore, it is necessary to introduce a third component: a component that helps the water phase and the oil phase to “hand in hand”. That is, a surfactant or an emulsifier.
These three are mixed together and can’t form the texture we want. It may be very thin, just like milk, it is very easy to flow. At this time, the fourth major category will be introduced, called thickening ingredients, such as cellulose, algin, and xanthan. Typically this is a colloid that provides the necessary viscosity and spreadability.
The above four components constitute the skeleton and foundation of a cosmetic, which we call a matrix, or a carrier.
Applying only oil and water to the face is not enough. We also need to repair, calm, whiten, anti-allergic, anti-oxidant, anti-aging and so on. These must introduce the fifth major category of ingredients, which can be said to be all-encompassing, called “active ingredients” or “efficiency raw materials.” For example, everyone is familiar with nicotinamide, vitamin E, retinol and so on.
Finally, the product has a validity period of 2-3 years, and it must be ensured that the product is not mildewed, does not rot, and does not deteriorate. At this point, another type of ingredient is introduced: the antiseptic stability class, which includes both preservatives, such as parabens, and some antioxidants to avoid rancidity such as oils and fats.
The above is a typical product form. On this basis, it can be increased or decreased. For example, if you are doing gel, spray or face film, you don’t have to use oil phase. For compound essential oils, the water phase is not necessarily required, as they may be self-contained and do not require the addition of preservatives.
The matrix component can sometimes also be the active ingredient. Such as:
- Glycerin and sodium hyaluronate are active ingredients with moisturizing function, but they are also one of the components of the aqueous phase. They can even be thickened with sodium hyaluronate.
- Oil phase matrices, such as petrolatum, also act as a moisturizing agent. Helps promote skin barrier repair, so functionally, it is also an active ingredient.