Cosmetic preparations, preservative

Nonfood preservative appHcations of sodium and potassium benzoate are found in pharmaceutical and cosmetic preparations, such as toothpastes and powders, tobacco, pastes and glue, as well as starch and latex (36,37). 

Uses Preparation of sodium and butyl benzoates, benzoyl chloride, phenol, caprolactum, and esters for perfume and flavor industry plasticizers manufacture of alkyl resins preservative for food, fats, and fatty oils seasoning tobacco dentifrices standard in analytical chemistry antifungal agent synthetic resins and coatings pharmaceutical and cosmetic preparations plasticizer manufacturing (to modify resins such as polyvinyl chloride, polyvinyl acetate, phenol-formaldehyde). 

Preservatives are added to various dosage forms and cosmetic preparations to prevent microbial contamination. In parenteral and ophthalmic preparations, preservatives arc used to maintain. sterility in the event of accidental contamination during use. An ideal prc.scrvative would be effective at low concentrations against all possible microorganisms, be nontoxic and compatible with other constituents of the preparation, and be stable for the. shelf life of the preparation. The ideal pre.servative dues not exi.st. but there is quite a bit of experience with some of them. In srnne ca.ses. combinations of preservative agents arc used to approximate a mixture of ideal features. 

Use Additive in antidandruff preparations, preservation of cosmetics, metalworking fluids, inhibition of bacterial and fungal growth on fabric. 

When added to hair-care cosmetic preparations, chitosan interacts with keratin forming a uniform and elastic film which is more stable to high humidity than those usually formed with synthetic polymers. Moreover, it reduces the electrostatic charges, so that the hair does not stand on end, preserving the hair do. The hair treated with chitosan formulations has less tendency to adhere and is more easily brushed than with traditional fixers [204]. 

The second group consists of preservatives (see Sect 23.8), used to guarantee the microbiological quality of the product throughout its shelf life. For example esters of hydroxy-benzoic acid, quaternary ammonium substances and sorbic acid are widely used in pharmaceutical and cosmetic preparations. Other preservatives that are used include phenol, chlorhexidine, benzoic acid and benzyl alcohol. 

A great advantage of PEGs in all cosmetic applications is that they provide no nutrient for microorganisms and are not sensitive to oxidation. Consequently, such formulations have no tendency to go bad. PEGs are virtually free from bacteria when manufactured. Other sensitive components in cosmetic preparations must, if necessary, be protected by antioxidants or preservatives. 

Several micro-organisms can survive and propagate on unpreserved cosmetic products. Preservatives are routinely added to all preparations that can support microbial growth. The choice of a preservative for a given product is difficult. Anhydrous preparations and products containing high levels of ethanol or t-propanol may not require the addition of preservatives. 

At the concentrations at which organic mercurials such as phenylmercuric nitrate, thiomersal, etc., are used as preservatives in pharmaceutical and cosmetic preparations microbiological methods of assay are frequently more reliable than are chemical ones. Either the plate-diffusion or the tube-dilution technique, as described on pp. 814 to 826 for the assay of antibiotics, can be used. The former is probably the method of choice although the latter is the more sensitive, being able to detect the organic... 

Ozonides that are prepared by means of the reaction between ozone and olefins do not cause inflammatory processes in skin and are not decomposed by catalase. Ozonides participate as an oxidizing agent without liberating peroxide groups, which might oxidize cells. About 1000 subcutaneous injections of castor-oil ozonides have been made without tissue response [311]. A 4% solution of the ozonide of sorbic acid in ethyl diglycol (ozonide SV) is used in cosmetics to preserve face creams and... 

Salts of neodecanoic acid have been used in the preparation of supported catalysts, such as silver neodecanoate for the preparation of ethylene oxide catalysts (119), and the nickel soap in the preparation of a hydrogenation catalyst (120). Metal neodecanoates, such as magnesium, lead, calcium, and zinc, are used to improve the adherence of plasticized poly(vinyl butyral) sheet to safety glass in car windshields (121). Platinum complexes using neodecanoic acid have been studied for antitumor activity (122). Neodecanoic acid and its esters are used in cosmetics as emoUients, emulsifiers, and solubilizers (77,123,124). Zinc or copper salts of neoacids are used as preservatives for wood (125). 

Decorative eye cosmetic products have been reported to be subject to pathogenic microbial contamination. Regulatory agencies in several countries, therefore, permit the use of mercury-containing preservatives in eye makeups. The infections reported were to a large extent caused by contamination during use, and the introduction of self-sterilising preparations seems warranted. 

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). 

Ethanol (CH3CH2OH) is widely used as a disinfectant and antiseptic. The presence of water is essential for activity, hence 100% ethanol is ineffective. Concentrations between 60 and 95% are bactericidal but a 70% solution is usually employed for the disinfection of skin, clean instruments or surfaces. At higher concentrations, e.g. 90%, ethanol is also active against most viruses, including TUV. Ethanol is also a popular choice in pharmaceutical preparations and cosmetic products as a solvent and preservative. 

Gagliardi, L., De Orsi, D Manna, L, Tonelli, D. Simultaneous determination of antioxidants and preservatives in cosmetics and pharmaceutical preparations by reversed phase HPLC./. Liquid Chromatogr. Rel. Technol. 1997, 20, 1979-1808. 

The results are consistent with the beeswax that was used in the preparation of the cosmetics preserved in the unguentaria, while the other lipids are most likely the residue of... 

Cosmetics are preparations (except so and detergents) for the preservation and beauty of the body. In the rich countries domesticated animals also have their cosmetics, such as creams based on a>3-polyunsaturated fetty acids, for strengthening and repair of feet and noses of hounds and pointers. 

Glycerol is used (l) in the manufacture of high explosives, e.g,. glyceryl trinitrate ( nitroglycerin ), which is the main component of dynamite. (2) in antifreeze solutions, especially for automobile radiators. (3) to maintain a moisi condition in fruits and tobacco, (4) in cosmetics and skin preparations, and (5) to prepare glycerol phosphoric acid, used in medicine, and "boroglyceride" used as, a preservative. See Table l... 

In addition, new technology is available, which uses the gel-state PC matrix for stabilizing a formulation containing not only metabolites but also emollients free of surfactants, perfumes, and preservatives. This new technology is used for the preparation of Physiogel AI (Stiefel Laboratories), a new cosmetic product in the market in several European countries. Physiogel AI contains the following metabolites ... 

Substances that are intentionally added to food and do not contain any nutritional value are termed food additives. These are added to, or used in the preparation of, food as preservatives or to change its texture, consistency, taste, colour, alkalinity, or acidity. There are several types of food additives, details of which are given below. In Europe food additives are given an E number (see Table 8 for examples), while different code numbers are used in the USA. These numbers appear on the packaging. It has been estimated that there are well over 3,000 different additives, most of which are used purely for cosmetic purposes, and relatively few of which are employed as preservatives or in processing. 

Ethanol and aqueous ethanol solutions of various concentrations (see Sections 8 and 17) are widely used in pharmaceutical formulations and cosmetics see Table 1. Although ethanol is primarily used as a solvent, it is also employed in solutions as an antimicrobial preservative. Topical ethanol solutions are also used as penetration enhancers " and as disinfectants. Ethanol has also been used in transdermal preparations in combination with Labrasol as a 7)... 

Benzyl alcohol is an antimicrobial preservative used in cosmetics, foods, and a wide range of pharmaceutical formulations, including oral and parenteral preparations, at concentrations up to 2.0% v/v. In cosmetics, concentrations up to 3.0% v/v may be used as a preservative. Concentrations of 5% v/v or more are employed as a solubilizer, while a 10% v/v solution is used as a disinfectant. 

Cetylpyridinium chloride is a quaternary ammonium cationic surfactant, used in pharmaceutical and cosmetic formulations as an antimicrobial preservative see Section 10. It is used therapeutically as an antiseptic agent used alone or in combination with other drugs for oral and throat care used in nonparenteral formulations licensed in the UK and used in oral and inhalation preparations at concentrations of 0.02-1.5 mg (see Section 16). 

Chlorobutanol is primarily used in ophthalmic or parenteral dosage forms as an antimicrobial preservative at concentrations up to 0.5% w/v see Section 10. It is commonly used as an antibacterial agent for epinephrine solutions, posterior pituitary extract solutions, and ophthalmic preparations intended for the treatment of miosis. It is especially useful as an antibacterial agent in nonaqueous formulations. Chlorobutanol is also used as a preservative in cosmetics [see Section 16) as a plasticizer for cellulose esters and ethers and has been used therapeutically as a mild sedative and local analgesic. 

Chlorocresol is used as an antimicrobial preservative in cosmetics and pharmaceutical formulations. It is generally used in concentrations up to 0.2% in a variety of preparations except those intended for oral administration or that contact mucous membrane. Chlorocresol is effective against bacteria, spores, molds, and yeasts it is most active in acidic media. Preservative efficacy may be reduced in the presence of some other excipients, particularly nonionic surfactants, see Sections 10 and 12. 

Methylparaben and other parabens are widely used as antimicrobial preservatives in cosmetics and oral and topical pharmaceutical formulations. Although parabens have also been used as preservatives in injections and ophthalmic preparations, they are now generally regarded as being unsuitable for these types of formulations owing to the irritant potential of the parabens. These experiences may depend on... 

Phenylmercuric acetate is no longer permitted to be used as a pesticide in the USA. It is, however, included in the FDA Inactive Ingredients Guide (ophthalmic preparations), and is also included in nonparenteral medicines licensed in the UK. In France, a maximum concentration of 0.01% is permitted for use in pharmaceuticals. The use of phenylmercuric acetate in cosmetics is restricted in the UK see Phenylmercuric Nitrate. Included in the Canadian List of Acceptable Non-medicinal Ingredients (however, there must be no other suitable preservatives available). 

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