Surfactants in Personal Care and Cosmetics

Since cosmetic products come in thorough contact with various organs and tissues of the human body, a most important consideration for choosing ingredients to be used in these formulations is their medical safety. Many cosmetic preparations are left on the skin after application for indefinite periods. Therefore, the ingredients used must not cause any allergy, sensitization or irritation, and they must be free of any impurities that have toxic effects. 

Applied Surfactants Principles and Applications. Tharwat F. Tadros Copyright 2005 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 3-527-30629-3 

The following subsections summarise some of the most commonly used formulations in cosmetics. 

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I 7 2 Surfactants in Personal Care and Cosmetics Tab. 12.1. Characteristics of skin creams. 

Mixtures of surfactants and polymers are very common in many industrial formulations. With many suspension and emulsion systems stabilized with surfactants, polymers are added for several reasons, e.g. as suspending agents ( thickeners ) to prevent sedimentation or creaming of these systems. In many other systems, such as in personal care and cosmetics, water-soluble polymers are added to enhance the function of the system, e.g. in shampoos, hair sprays, lotions and creams. The interaction between surfactants and water-soluble polymers furnishes synergistic effects, e.g. enhancing the surface activity, stabilizing foams and emulsions, etc. It is, therefore important to study systematically the interaction between surfactants and water-soluble polymers. 

For applications in personal care and cosmetics, a wider range of surfactants can be used provided these molecules satisfy some essential criteria such as lack of skin irritation, lack of toxicity on application and safety to the environment (biodegradability of the molecule is essential in this case). 

Surfactants in Personal Care Products and Decorative Cosmetics, Third Edition, edited by Linda D. Rhein, Mitchell Schlossman, Anthony O Lenick,... 

Surfactants in Personal Care Products and Decorative Cosmetics,... 

Many mixtures of surfactants, especially ionic with nonionic, exhibit surface properties significantly better than do those obtained with either component alone. Such synergistic effects greatly improve many technological applications in areas such as emulsion formulations, emulsion polymerization, surface tension reduction, coating operations, personal care and cosmetics products, pharmaceuticals, and petroleum recovery, to name only a few. The use of mixed surfactant systems should always be considered as a method for obtaining optimal performance in any practical surfactant application. 

Different analytes are determined by using electrochemical techniques such as differential pulse voltammetry (e.g., metal ions and chlorhexidine in oral care products, glycolic acid in creams, dyes in lipsticks) or potentiometry (e.g., inorganic compounds and anionic and cationic surfactants in personal care products). Modified carbon electrodes and biosensors have been developed to determine some cosmetic ingredients by techniques such as voltammetry or potentiometry. 

Barson DC, Using consumer research in the development and restaging of personal care products. In Surfactant in Personal Care Products and Decorative Cosmetics, Surfactant Science Series, Vol. 135 (Eds. Rhein LD, Scholssman M, O Lenick and Somasundaran P), Marcel Dekker, New York, 2007, pp. 95-105. 

Amphoteric polysaccharides are those polyglycans capable of carrying both cationic and anionic charges on the same chain. The term amphoteric derives from the Greek am-photeros, which means both. There are very few naturally occurring amphoteric polysaccharides most of those used cosmetically are seminatural derivatives. Amphoteric polysaccharides are relatively unknown and underutilized in cosmetics although the use of amphoteric surfactants in personal care is quite common. 

AES (C12-C14/15 2-3 EO) can be considered as the most efficient anionic surfactant in terms of superior detergency power, good tolerance for water hardness, mildness on hands and fibres. The application therefore is wide from household to personal care and cosmetic products. Unfortunately, sulphated alcohol ether sulphates show a limited stability to hydrolysis at high temperatures, and this restricts their use in heavy... 

Chapters 12 to 15 deal with some specific applications of surfactants in the following industries personal care and cosmetics, pharmaceuticals, agrochemicals and the food industry. These chapters have been written to illustrate the applications of surfactants, but in some cases the basic phenomena involved are briefly described with reference to the more fundamental chapters. This applied part of the book demonstrates that an understanding of the basic principles should enable the formulation scientist to arrive at the optimum composition using a rational approach. It should also accelerate the development of the formulation and in some cases enable a prediction of the long-term physical stability. 

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