For the cream base is not enough just to mix oil and water.It is clear that such a mixture would be unstable and rapidly exfoliate.emulsifiers - To ensure the stability of the emulsion, special substances are used.They are dependent on the stability, uniformity and consistency of the creams.
emulsifier molecule has an elongated shape, its one pole binds water, and another - fats.The nature of the emulsifier used depends on the type of the resulting emulsion ( "water in oil" or "oil in water").
as emulsifiers in cosmetics are used:
- various surfactants (surface active agents) - cationic, anionic, amphoteric, nonionic
- natural emulsifiers of vegetable and animal origin
- synthetic and semi-synthetic polymers - Carbopol, methylcellulose, carboxymethylcelluloseetc.
-. silicone-based emulsifiers."A clear sign of improper use of emulsifiers -. Water or oil, which poured from a jar just bought a cream"
The strongest and most inexpensive emulsifiers are surface-active substances (SAS) detergency.T
When applied to the skin surfactant layered lipid barrier of the skin.The bad news is that they can penetrate deep enough into the skin until the cells of the germinal layer of the epidermis.It is also disappointing that they destroy the cell membrane lipid.
Yet in the surfactant's ability to destroy the lipid barrier of the skin has its advantages.The fact that most active ingredients are water soluble and can not independently penetrate the epidermal barrier.Properly chosen and balanced surfactant systems increase the permeability of the stratum corneum for active ingredients that would otherwise remain on the skin surface.
Synthetic emulsifying and structure-forming components are complex and obscure names:. Monostearate of glycerol stearate, distilled monoglycerides, etc. However, these "non-natural" ingredients have to accept, because without them it is simply impossible to make a cream.
Stearin, for example, it is acceptable for the skin - because stearic acid is found in the composition of fats, allocated by the sebaceous glands of man.
artificial emulsifiers produce and based on ethylene oxide.These include, in particular, macrogol, and polysorbate.
as emulsifiers for the emulsion "water in oil" is used monoglitserinovy ether.For
creams type "oil in water" is used emulsifiers potassium, sodium, ammonium and triethanolamine soaps of fatty acids (stearic, oleic and others.).
Available also emulsifiers containing phosphate esters, - emulsifying wax.Sophisticated
derivatives of sugars and glycerin - a new generation of emulsifiers such as glycerol fatty acid ester and polyglycerol ester of fatty acids.The chemical composition they are as close to the animal and vegetable fats, which are commonly used in food.In addition, these new emulsifiers are made in the image and likeness of the natural substances contained in the skin.
Natural structure-forming materials are well compatible with the skin.It waxes (beeswax, jojoba wax, kandelily), hydrocolloids (agar, pectin, gelatin, cholesterol), chitosan, lanolin, lecithin and so forth. For example, the wax is very polezen as forms on the skin surface film that protects it from harmful influencesenvironment and prevents dehydration.
However the emulsifying ability of natural substances is weaker than that of the surfactant.In addition, cosmetics based on them is a more expensive, it should be remembered that all consumers.
Now try to find a practical application of the information received.How to determine the quality of cosmetics in terms of the emulsifiers used in it?
• Cheap cosmetics contain a lot of detergent (synthetic surfactants), which are the cheapest and easiest way to stabilize emulsions.
• A clear sign of improper use of emulsifiers - water or oil, which poured from a jar just bought a cream.
• Emulsifiers should not react with other components to cause irritation to the skin, exhibit toxic effects, have an unpleasant odor.