Cyclodextrin and Cosmetics
Cyclodextrins (CDs) is a cyclic oligosaccharide formed by a 4-glycosidic bond, which usually contains 6,7,8 d-pyrano glucose units, which are known as alpha, beta, games-cyclodextrins, and their chemical structural models.See figure 1.They were discovered by Villiers in 1891 as a white crystalline compound, which can be produced by a cyclodextrin glycosyltransferase produced by bacillus cereus.
The CDSS have a cone-shaped cylindrical structure, the inner side of the cavity is hydrophobic, the lateral water is hydrophilic, and there is a local chiral space.Its cavity can accommodate a variety of organic and inorganic small molecules to form inclusion, so that the nature of the object molecules can be greatly changed.For example, increase the solubility of insoluble substances, volatile substances can better against the degradation of light and heat, the sublimation of material and reduce volatility, incompatible compounds to form the physical isolation, chromatography can be separated, useless stench smell and taste can be hide, at the same time also can control the release of the fragrant aroma.Therefore, cyclodextrin can be used as a new functional material to improve the defects of cosmetics.
Cyclodextrin and Skin.
Cosmetics act on the skin mostly through the process of skin absorption, and the functional components of the functional components depend on the efficacy of cosmetics.For example, sunscreen substances generally act on the cuticle of the skin to enhance the skin's ability to reflect, scatter and absorb uv rays, thereby reducing the irritation of ultraviolet radiation to the skin in the sun.Skin whitening agents, anti-aging agents and antioxidants are commonly used in the epidermal basal layer or dermis.It is worth noting that the barrier action of the cuticle of the skin can hinder the process of skin absorption by the cosmetics, thus reducing the cosmetic effect.Therefore, increasing the permeability of cuticle is the key to improve the performance of cosmetics.Although the cuticle is tightly structured, it is not monolithic and can significantly improve the permeability through proper treatment.Now enhanced cosmetics transdermal absorption ability of the commonly used method is by adding the osmosis promoter (such as unsaturated fatty acids, unsaturated fatty alcohols, etc.), the change in the stratum corneum lipids order, make cell fully power increase, promote the chances of cosmetics through stratum corneum.
As a new kind of cosmetic ingredient, cyclodextrin can not only act on the surface of the cuticle, but also can substitute the osmotic stimulant to participate in the reaction.According to the principle of similar phase dissolution, the surface hydrophilic cyclodextrins are difficult to penetrate the stratum corneum formed by lipids.Therefore, cyclodextrin can be added to the cosmetic formulation that ACTS on the surface of the cuticle.At the same time, on the basis of the theory of hydrate and seepage theory, cyclodextrin due to its extremely easily soluble in water, when the stratum corneum cells in the state of hydration, cells themselves will occur, resulting in a decline in structure compactness and cyclodextrin corneous layer distribution coefficient will increase as the result of a skin layer diffusion rate is increased, so that it is easily through the skin cutin layer.In addition, cyclodextrin can also extract the oil from the biofilm to make the material have the ability to absorb through the skin.