Sodium hyaluronate is an inherent component in the human body. It is a kind of glucuronic acid. It has no specificity. It widely exists in the placenta, amniotic fluid, lens, articular cartilage, skin dermis and other tissues and organs. It is distributed in the cytoplasm and intercellular substance, and acts as a lubricant and nourisher to the cells and organelles contained therein.

At the same time, it provides a microenvironment for cell metabolism. It is a gel made of a human body's natural hyaluronic acid and other drugs that promote cell regeneration and wrinkle reduction , and is used by injection.

Moisturizing effect is the most important function of sodium hyaluronate in cosmetics . Compared with other humectants, the relative humidity of the surrounding environment has little effect on its moisturizing property. Moisturizers commonly used in cosmetics include glycerin , propylene glycol , sorbitol , polyethylene glycol, sodium lactate , and sodium pyrrolidone carboxylate .

HA is the main component of human interstitial cells, vitreous body, joint synovial fluid and other connective tissues . It has the characteristics of retaining water in the body, maintaining extracellular space, regulating osmotic pressure, lubricating, and promoting cell repair. As a carrier of ophthalmic drugs, it prolongs the residence time of drugs on the ocular surface by increasing the viscosity of eye drops, improves the bioavailability of drugs, and reduces the irritation of drugs to the eyes.

Auxiliary therapy can be directly injected into the joint cavity as a lubricant for the treatment of arthritis [1]. The moisturizing effect of sodium hyaluronate in skin tissue is one of its most important physiological functions. Sufficient moisture makes the skin smooth and delicate. HA has the highest moisture absorption at low relative humidity (33%), and the lowest moisture absorption at high relative humidity (75%), which is suitable for the skin's moisturizing needs for cosmetics in different seasons and environmental humidity, without greasy feeling and blockage Pore ​​feel.

wrinkle resistance

The moisture level of the skin is closely related to the content of hyaluronic acid. With age, the content of hyaluronic acid in the skin decreases, which weakens the water retention function of the skin and produces wrinkles. Sodium hyaluronate aqueous solution has strong viscoelasticity and lubricity, and when applied on the surface of the skin, it can form a moisturizing and breathable film to keep the skin moisturized and shiny. Small molecule hyaluronic acid can penetrate into the dermis , promote blood microcirculation , help the skin absorb nutrients, and play a role in beauty and anti-wrinkle health care.

Film-forming and lubricating properties belong to high-molecular polymers. When applied, the lubricating feeling is obvious and the hand feels good. The macromolecules form a breathable film on the skin surface, making the skin smooth and moist, blocking the invasion of foreign bacteria and dust, etc., and the small molecules are transparent. Sodium acid can penetrate into the dermis, slightly dilate capillaries, increase blood circulation, improve intermediate metabolism , promote skin nutrient absorption, and achieve the effect of lubrication and fullness.

Sunscreen and skin damage repair function on the skin surface can eliminate active oxygen free radicals produced by ultraviolet rays in the sun, protect the skin from ultraviolet rays, and also promote skin regeneration in injured parts by promoting the proliferation and differentiation of epidermal cells.

moisturizing effect

Experiments have shown that sodium hyaluronate has the highest moisture absorption at low relative humidity (33%) and the lowest moisture absorption at high relative humidity (75%) compared with these humectants . This unique property is adapting to the skin's requirements for moisturizing cosmetics in different seasons and under different environmental humidity, such as dry winter and humid summer. The moisturizing property of sodium hyaluronate is related to its quality, the higher the quality, the better the moisturizing performance. Sodium hyaluronate is rarely used alone as a moisturizer, and is often used in combination with other moisturizers.

Nutrition

Sodium hyaluronate is an inherent biological substance of the skin, and exogenous sodium hyaluronate is a supplement to the skin's endogenous sodium hyaluronate. Sodium hyaluronate with a small quality can penetrate into the epidermis of the skin to promote the supply of skin nutrients and the excretion of waste , thereby preventing skin aging and playing a role in beautifying and nourishing the skin. Skin care is more important than other makeup, and it has become the modern people's awareness of beauty care.

Repair and prevent skin damage

Photoburn or sunburn caused by sun exposure, such as skin reddening, blackening, peeling, etc., is mainly caused by the ultraviolet rays in the sun. Sodium hyaluronate can promote the regeneration of injured skin by promoting the proliferation and differentiation of epidermal cells and scavenging oxygen free radicals . It also has a certain preventive effect when used in advance. Its mechanism of action is different from that of UV absorbers commonly used in sunscreens . Therefore, in sunscreen skin care products, HA and UV absorbers are used together to have a synergistic effect, which can simultaneously reduce the penetration of ultraviolet rays and the damage caused by a small amount of ultraviolet rays that pass through. Repair skin damage and play a double protective role [2].

The combined use of sodium hyaluronate, egf and heparin can accelerate the regeneration of epidermal cells, making the skin tender, smooth and elastic. When the skin suffers from mild burns, applying water-based cosmetics containing sodium hyaluronate on the surface can relieve pain and accelerate the healing of the injured skin.

Lubricity and Film Formation

Sodium hyaluronate is a high-molecular polymer with strong lubricating and film-forming properties. The skin care products containing sodium hyaluronate have obvious lubricating feeling and good hand feeling when applied. After being applied to the skin, a thin film can be formed on the surface of the skin, making the skin feel smooth and moist, and protecting the skin. Hair care products containing sodium hyaluronate can form a thin film on the surface of the hair, which has the functions of moisturizing , lubricating, hair care, and eliminating static electricity, making the hair easy to comb, elegant and natural.

thickening

Sodium hyaluronate has a high viscosity in aqueous solution , and its 1% aqueous solution is in the form of a gel, which can thicken and stabilize when added to cosmetics .