Skin compatibility

Human skin compatibility has a high priority in manual dishwashing detergents. Recently, it was shown that there are some new possibilities to lower the Zein number by intelligent formulations. The Zein number is a common measure of the denaturation of protein under controlled conditions [84], A better... 

DLSS, DPMS, DSIS, and a blend containing SLAS and DCAD are the components to improve the formulations skin mildness, i.e., the skin compatibility of the other surfactants present. SLES/ALAS/SLAS, i.e., sodium lauryl ether sulfate, ammonium lauryl sulfate, sodium lauryl sulfate, are examples of high-foaming basic surfactants. 

While in the past mainly sodium lauryl sulfate was the surfactant of choice, recently more skin-compatible materials have taken its place. 

FIG. 14 Skin compatibility mollifying effect of DOMS. (From Ref. 103.)... 

They have many advantages, they are formaldehyde free, halogen free, demonstrate good thermal Figure 7 Phenoxyethanol stability and have good skin compatibility. However,... 

In the development of the protein-fatty acid condensates it was possible to combine the renewable resources fatty acids (from vegetable oil) and protein, which can be obtained from both animal waste (leather) as well as from many plants, to construct a surfactant structure with a hydrophobic (fatty acid) and a hydrophilic (protein) part (Fig. 4.12). This was carried out by reacting protein hydrolysate with fatty acid chloride under Schotten-Baumann conditions using water as solvent. Products are obtained that have an excellent skin compatibility and, additionally, a good cleaning effect (particularly on the skin) and, in combination with other surfactants, lead to an increase in performance. For instance, even small additions of the acylated protein hydrolysate improve the skin compatibility. An... 

Spreading value Sensory feeling Skin compatibility Stability Origin... 

W. F. Pittermann and M. Kietzmann. Bovine udder skin (BUS) Testing of skin compatibility and skin protection. ALTEX 23 65-71 (2006). 

Cosmetic Rinse off Preparations. In certain cosmetic products, tor example hair shampoos, it is not possible to use complexing agents because of the irritation of mucous membranes. Here a low sensitivity of surfactants to water hardness is a precondition for their application. Foam formation is generally considered to be a measure of shampoo quality (Table V). With increase in water hardness the foam volume of alkyl sulfates decreases very much, whereas with the corresponding alkyl ether sulfates this decrease is relatively small. For cosmetic applications, the good skin compatibility and low irritation to mucous membranes of alkyl ether sulfates is of high importance (37). 

Glucose octadienyl ether (DS = 2) is non-toxic with good skin compatibility [73]. The viscosity of derivative with moderate degree of substitution (DS = 1.5) reaches 2500 cPs at 25°C and potential applications as emulsifiers or defoamers are conceivable. 

Gotte, E., Skin compatibility of tensides measured by their capacity for dissolving zein, in Proceedings of 4th Int. Cong. Surface Active Substances, Brussels, pp. 83-90, 1964. 

Paye, M. and Cartiaux, Y. Squamometry a tool to move from exaggerated to more and more realistic application conditions for comparing human skin compatibility of surfactant-based products. Int. J. Cosmet. Sci. 21, 59-68 (1999). 

Walker, A.P., Basketter, D.A., Baverel, M., Diembeck, W., Matthies, W., Mougin, D., Paye, M., Rothlisburger, R., and Dupuis, J. Test guideline for assessment of skin compatibility of cosmetic finished products in man. Food Chem. Toxicol. 1996 34 551-560. 

With such materials, the perfumer s path of exploration is marked in advance. The perfumer must find out whether the new material possesses any significant positive differences compared to the familiar ones, differences that make the material worthy of being added to the standard repertoire these may be differences in odor qualities such as character, tenacity, or volume, or advantages in application characteristics such as stability, cost, or skin compatibility. 

Sulfation converts the hydroxyl group to a sulfate (—OSO2OH) with improved surfactant properties. Apart from soap, it is the earliest anionic surfactant (dating back to 1874) and is still used in textile processing, leather treatment, and as an additive for cutting oils and hydraulic fluids. The sulfated hydrogenated oil has the consistency of an ointment and gives adjustable viscosity to water-based formulations with excellent skin compatibility. 

Fatty Alcohol Ether Sulfates. Probably the most important derivatives of fatty alcohol in the C12-C14 and C12-C16 ranges are the fatty alcohol ether sulfates. They are produced by the sulfation of the fatty alcohol, containing 2-3 moles of ethylene oxide, with sulfur trioxide or chlorosulfonic acid and subsequently neutralized with caustic soda, ammonia, or an alkanolamine. The ether sulfates possess superior properties over the fatty alcohol sulfates. They have unlimited water solubility, are unaffected by water hardness, and possess superior skin compatibility. Accordingly, they are used in liquid shampoos and bath preparations. One characteristic of this material is its ability to increase its viscosity by the addition of an electrolyte such as salt (5). 

The development of cosmetic microemulsion cleansers with alkyl polyglycosides (APG) was described by Forster et al. [4]. This class of non-ionic surfactants has excellent environmental and skin compatibility. Cosmetic cleanser multicomponent systems are required to have good foaming and cleansing performance. Figure 8.3 shows a pseudo-ternary phase diagram of a five-component formulation. It consists of water, the oil dioctyl cyclohexane (DOCH), the non-ionic surfactant C12/14-APG, the anionic surfactant fatty alcohol ether sulphate (FAES) and the co-surfactant sorbitan monolaurate (SML). The phase diagram... 

Incompatibilities between the adhesive system and other formulation excipients may be circumvented by designs in which the adhesive is remote from the drug delivery area of the system (Figure 14.15d). Three critical considerations in system selection are adhesion to skin, compatibility with skin and physical/chemical stability of the total formulation and components. 

Devices are secured to the skin by use of a skin-compatible pressure-sensitive adhesive, usually based on silicones, acrylates or polyisobutylenes. These adhesives are evaluated by shear-testing and assessment of rheological parameters (Musolf 1987). Standard rheological tests include creep compliance (measurement of the ability of the adhesive to flow into... 

Fatty acid ethanolamides and isopropanolamides are solid or waxy products insoluble in water. Diethanolamides are usually pastes or liquids and show better dispersibility in water. In institutional and household formulations, shampoos, bath and shower preparations, fatty alkanolamides play the role of foam stabiliser, thickener, corrosion inhibitor, and ancillary agent that improves the skin compatibility of anionic surfactants. Undecylenic ethanolamide and undecylenic diethanolamide act as fungicides also [47]. Use of diethanolamine derivatives has legislative limitations today in some countries (but not its amides) because they are proved to be precursors of carcinogenic nitrosoamines. The probability of the nitrosoamine formation is assumed to increase in the presence of formaldehyde and formaldehyde-releasing preservatives [44-46]. 

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