Cosmetically important compounds

There are several functional aspects of the compounds to be considered in the cosmetic applications. The primary requisite is its biocompatibility with the skin or hair. The compound should be safe and does not elicit any adverse immunological response. As performance of the compound is related to its structure and physiochemical properties, a proper downstream processing is required to purify the compounds with the intact structure and functional properties. Once a compound shows a promising skin/ hair care activities, a cosmetic formulation could be designed and its safety is checked by animal testing or human skin equivalent testing. At times, volunteer studies have also been performed to check the effectiveness and side effects of the cosmetic formulation. Different functional properties of cosmetically important compounds are discussed below. 

Ethylene oxide also has a number of other important industrial uses, although the quantity used for such purposes is small compared to the uses mentioned above. For example, it is used as a rocket propellant because of its tendency to decompose easily with the release of large amounts of energy. It is also used as a sterilizing medium, particularly for the sterilization of surgical instruments and consumer products, such as spices and cosmetics. The compound is also used as a demulsifier in the petroleum industry. A demulsifier is a material that aids in the separation of the components of complex mixtures, like those handled in the processing of petroleum. Ethylene oxide is also used as a fumigant, which is a gas used to kill insects and other pests. 

One of the most important methods to synthesize organic silicon compotmds is the addition of hydrosilanes to double bonds. Production of plasticizers, adhesives, and cosmetic formulation compounds are examples of industrial hydrosilylation products. The most widely used catalyst is hexachloroplatinic add, H2PtClj (Speier s catalyst). The method described by Behr et al. [18-20] uses a biphasic liquid-liquid system imder mild conditions at ambient pressure and short reaction times. 

Such findings are in agreement with other works that compare different extraction methods [38-39]. Overall, SFE affords richer extracts, with higher number of separated compounds the use of EtOH as co-solvent increases the antioxidant potential of the extract, if compared with pure CO2 extraction, due to the increase in solvent polarity the supercritical fluid is able to extract important compounds not detected in conventional extracts, such as oleic acid and phytol, used in cosmetic products. 

Applications. The most ubiquitous use of infrared spectrometry is chemical identification. It has long been an important tool for studying newly synthesi2ed compounds in the research lab, but industrial identification uses cover an even wider range. In many industries ir spectrometry is used to assay feedstocks (qv). In the flavors (see Flavors and spices), fragrances (see Perfumes), and cosmetics (qv) industries, it can be used not only for gross identification of feedstocks, but for determining specific sources. The spectra of essential oils (see Oils, essential), essences, and other natural products vary with the season and source. Adulteration and dilution can also be identified. 

Perfumes, Flavors, Cosmetics, and Soap. Many naturally occurring esters in essential oils and some synthetic esters are important fragrance and flavor compounds (61,62). They are used in perfumes, flavors, cosmetics, soaps, detergents, and air fresheners. Benzyl, butyl, ethyl, methyl, and phenyl esters of benzoic acid are used as flavors, perfumes, and food preservatives. Glyceryl 4-aminobenzoate [136-44-7] and 2-ethyUiexyl 4-dimethylaminobenzoate [21245-02-3] are used in cosmetic sunscreen preparations. Alkyl esters of 4-hydroxybenzoic acid, called parabens, have been used under various names for fungus infections of the skin, and as preservatives in lotions and creams (101). Soap and cosmetic fragrances use large amounts of amyl and benzyl saHcylate. Benzyl saHcylate [118-58-1] is also used in deodorant sprays. 2-Ethylhexyl saHcylate [118-60-5] and 2-ethylhexyl 4-methoxycinnamate [5466-77-3] are used in sunscreen formulations (102). 

Chlorinated polyether is formulated particularly for products requiring, good chemical resistance. Other materials exhibiting good chemical resistance include all of the fluorocarbon plastics, ethylpentenes, polyolefins, certain phenolics, and diallyl phtha-late compounds. Additives such as fillers, plasticizers, stabilizers, colorants, and type catalysts can decrease the chemical resistance of unfilled plastics. Certain chemicals in cosmetics will affect plastics, and tests are necessary in most cases with new formulations. Temperature condition is also very important to include in the evaluation. Careful tests must be made under actual use conditions in final selection studies. 

Zinc oxide is the most important zinc compound. The principal industrial use of zinc oxide is as a catalyst to shorten the time of vulcanization in the production of mbber. The compound also is used as a white pigment in paints, cosmetics, and photocopy paper, hi everyday life, ZnO is also a common sunscreen. 

Compound 1 is used as a solvent in the food, paint, resin/plastics, soap and woodpulp/paper industries, and as a plasticizer. Compound 2 is used as an intermediate for the manufacture of hydraulic fluid additives and cosmetics. Sulphonal (2 2-his(ethylsulphonyl)-propane), another important sulphone, is a colourless solid, stable to acids and alkalis, with hypnotic properties. 

A practical method of modification of polysaccharides by clean oxidation using H2O2 as oxidant and cheap iron phthalocyanine as catalyst has been developed. Since no acids, bases or buffers and no chlorinated compounds were used, a pure product can be recovered without additional treatment. Importantly, this flexible method provides materials with a wide range of DScho and DScooh just by an appropriate choice of the reaction conditions. Oxidized polysaccharides thus obtained possess various, tailormade hydrophihc/hydrophobic properties which have been tested successfully in cosmetic and other apphcations. 

In contrast to a variety of oxidizable compounds, only a few examples for the detection of strong oxidants with transition metal hexacyanoferrates were shown. Among them, hydrogen peroxide is discussed in the following section. Except for H202, the reduction of carbon dioxide [91] and persulfate [92] by Prussian blue-modified electrode was shown. The detection of the latter is important in cosmetics. It should be noted that the reduction of Prussian blue to Prussian white occurs at the lowest redox potential as can be found in transition metal hexacyanoferrates. 

In this context the integration of HPLC in the SMB concept has shown a tremendous potential for the development of separation process which are efficient and versatile as well as economically sound. The first separations of pharmaceutical compounds using HPLC-SMB technology were performed in the early 1990s [6 - 8]. Other areas of application, e. g., the fine chemicals, cosmetics and perfume industries have since followed suit [9]. Most importantly and as a reaction to the needs of these new areas of application, SMB systems smaller than the huge SMB-plants adapted to the needs of the petrochemical industry, are now commercially available. 

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