The skin stratum corneum contains 10% to 20% moisture. […]
The skin stratum corneum contains 10% to 20% moisture. The skin is delicate and elastic, and the skin is in the best condition. When the moisture in the stratum corneum is less than 10%, the skin will appear dry, wrinkle or even desquamation. Moisturizing cosmetics is a kind of cosmetics for the purpose of maintaining moderate moisture in the outer layer of skin. In moisturizing cosmetics, the moisturizing agent to play the role of moisturizing mainly have the following categories of substances.
(1) oils and fats
This kind of moisturizer is not absorbed by the skin. It can form oil film on the surface of the skin to prevent the evaporation of the water of the cuticle and play a close and moisturizing effect. The representative raw material is Vaseline, but its greasy is strong, so many other oils and fats, such as olive oil and almond oil, are used.
(2) hygroscopic components
Such moisturizers are small molecules of alcohols, acids, amines and other organic compounds, which can absorb moisture from the surrounding environment and improve the moisture content of the stratum corneum. Such as amino acid, glycerin, sodium pyrrolidone carboxylic acid, lactic acid and lactate. This moisturizer is only suitable for the season with high relative humidity and southern area. It is not suitable for the dry winter in the north, but it can be solved by combining with the oil moisturizer.
(3) hydrophilic components
This kind of moisturizing agent for polymer hydrophilic compounds, water swelling to form a spatial network structure, combining free water in the net, to combine free water so that water is not easy evaporation, play a moisturizing effect, is a kind of advanced moisturizing ingredients, the use of a wide range, suitable for all kinds of skin, a variety of climatic conditions. The raw material is hyaluronic acid (also known as hyaluronic acid). It is a kind of sticky polysaccharide, which has a strong and mild moisturizing effect. It is a very excellent moisturizer.
(4) the natural barrier of the prosthetic cuticle is the natural barrier of the human body. If the barrier function is reduced, the amount of water lost in the skin is increased. Add moisturizing substances to moisturize products, improve the barrier function of stratum corneum, and reduce the amount of water lost through skin to achieve moisturizing effect. Such as ceramide, vitamin E and so on.