Surfactant skin irritation

Surfactant Skin irritation (in vivo on human) Collagen swelling (mL/g) (in vitro)... 

Emulsions of fatty- and petroleum-based substances, both oils and waxes, of the o/w type are made by using blends of sorbitan fatty esters and their poly(oxyethylene) derivatives. Mixtures of poly(oxyethylene(20)) sorbitan monostearate (Polysorbate 60) and sorbitan monostearate are typical examples of blends used for lotions and creams. Both sorbitan fatty acid esters and their poly(oxyethylene) derivatives are particularly advantageous in cosmetic uses because of their very low skin irritant properties. Sorbitan fatty ester emulsifiers for w/o emulsions of mineral oil are used in hair preparations of both the lotion and cream type. Poly(oxyethylene(20)) sorbitan monolaurate is useflil in shampoo formulations (see Hairpreparations). Poly(oxyethylene) sorbitan surfactants are also used for solubilization of essential oils in the preparation of colognes and after-shave lotions. 

The study of skin irritation is probably still more complex than that of eye irritation. Surfactants interact with epidermal tissues, proteins, and enzymes causing local effects. Singer and Pittz [369], Cooper and Berner [370], and Schwuger and Bartnik [371] presented excellent explanations and reviews on these interactions. 

One of the longest known synthetically prepared surfactants are the fatty alcohol sulfates, which were prepared on technical scale before 1940. Along with their ethoxylated counterparts, the fatty alcohol ether sulfates, which appeared on the stage shortly after, their use in toiletries is very popular but they can also be found in products for textile industry and auxiliaries in emulsion polymerization. With the exception of soaps, the mentioned anionic surfactants all have a sulfur-containing functional group. Denying the differences between these, their skin irritancy potential is remarkably high. 

Comparative primary skin irritation scores of surfactant solutions (15% active content) show various types of sulfosuccinates as being the least irritant materials, well below sodium laureth-3 sulfate. It was also shown that an increase in degree of ethoxylation reduces skin and eye irritation, leading to laureth-3 (lauryl alcohol with 3 mol ethylene oxide) as the ideal organic raw material [17]. The results are given in Fig. 9 for eye irritation and in Fig. 10 for skin irritation. 

In Fig. 11 results are given for sulfosuccinate surfactants of different molecular structure tested according to the Draize skin irritation procedure. The test method defines test scores verbally as described in Table 21. The data in Fig. 11 prove the nonirritant character of sulfosuccinates tested at 10% concentration. Similar results were found for another group of sulfosuccinates [103]... 

The skin condition reflects the skin irritation elicited by a surfactant when applied. Skin surface appraisal is hence a means for assessing product mildness. 

Sulfosuccinates are not only less irritating to skin and mucus membranes than other surfactants, but it was also found that they reduce skin irritation of other surfactants used in skin and hair care products. In particular, the effect on sodium lauryl ether sulfate was found to be most pronounced [103]. Figure 14 shows the mollifying effect of disodium oleic acid monoethanol amide sulfo-succinate when blended with anionic surfactant at a total concentration of 15%. 

The development of monoalkyl phosphate as a low-skin-irritating anionic surfactant is accented in a review with 30 references on monoalkyl phosphate salts, including surface-active properties, cutaneous effects, and applications to paste- and liquid-type skin cleansers, and also on phosphorylation reactions from the viewpoint of industrial production [26]. The preparation and industrial applications of phosphate esters as anionic surfactants were discussed [27]. 

The development of monoalkyl phosphate as a low skin irritating anionic surfactant is accented in a review with 30 references on monoalkyl phosphate salts, including surface-active properties, cutaneous effects, and applications to paste and liquid-type skin cleansers, and also phosphorylation reactions from the viewpoint of industrial production [26]. Amine salts of acrylate ester polymers, which are physiologically acceptable and useful as surfactants, are prepared by transesterification of alkyl acrylate polymers with 4-morpholinethanol or the alkanolamines and fatty alcohols or alkoxylated alkylphenols, and neutralizing with carboxylic or phosphoric acid. The polymer salt was used as an emulsifying agent for oils and waxes [70]. Preparation of pharmaceutical liposomes with surfactants derived from phosphoric acid is described in [279]. Lipid bilayer vesicles comprise an anionic or zwitterionic surfactant which when dispersed in H20 at a temperature above the phase transition temperature is in a micellar phase and a second lipid which is a single-chain fatty acid, fatty acid ester, or fatty alcohol which is in an emulsion phase, and cholesterol or a derivative. 

As the central function of a shampoo is to cleanse the hair, the primary ingredient of a shampoo is a detergent (also known as a surfactant). Many shampoos, particularly those targeted for babies and children, claim to cause no eye irritation or sting. A no-tears formulation achieves this claim by carefully adjusting the nature of the surfactants. In particular, the identity and concentration of surfactants with an ionic or charged portion are controlled to minimize both eye and skin irritation. 

Glyphosate is a significant eye and skin irritant. It has caused lethal outcomes, although it is far less potent than the bipyridyl herbicides. Although the pure chemical seems to have little persistence and lower toxicity than other herbicides, the commercial formulations of glyphosate often contain surfactants and other active compounds that complicate the toxicity of the product. No specific treatment is available for glyphosate toxicity. 

Synthetic surfactants are commonly used in shampoos, sometimes for reasons of cost and sometimes for performance. Non-ideal mixing in micelles can result when the repulsions between different surfactant head-groups are not uniform, such as when an anionic sulfonate is mixed with a non-ionic ethoxylate or when an anionic is mixed with a betaine. This causes the cmc of the mixture to be smaller than would be the case for ideal mixing, or for either surfactant alone. Such a reduction in cmc can be used to reduce the surfactant monomer concentration in a shampoo. This is an advantage since reducing the monomer concentration reduces the amount of eye and skin irritation experienced when the shampoo is used [904], Other synthetics offer other benefits. For example, some silicone surfactants can not only function as emulsifiers in hair and skin care products, but also act to improve feel, gloss, sheen, emolliency, conditioning and foam stabilization [905]. 

Sulfosuccinate Half Esters. To meet the demand for surfactants having low toxicity, especially low skin irritation, Nippon Shokubai commercialized a series of sulfosuccinate half esters of SAE, SOFTANOL-MES series, by it s own technology(32, 33, 34). 

Loden, M., Barany, E., Mandahl, P., and Wessman, C., The influence of urea-treatment on skin susceptibility to surfactant-induced irritation. A placebo-controlled and randomized study, Exogenous Dermatol., 1, 3, 2004. 

Paye, M. and Morrison, B.M. Non-visible skin irritation. Proceedings of the 4th world surfactant congress, Barcelona 3, 42-51 (1996). 

Hall-Manning, T.J., Holland, G.H., Rennie, G., Revell, P, Hines, J., Barratt, M.D., and Basketter, D.A. The skin irritation potential of mixed surfactant mixtures. Food Chem. Toxicol. 1998 36 233-238. 

SAFETY PROFILE Moderately toxic by ingestion and intravenous routes. Experimental reproductive effects. Human mutation data reported. An eye and human skin irritant. Many glycol ethers cause dangerous human reproductive effects. When heated to decomposition it emits toxic fumes of NO. A surfactant. See also GLYCOL ETHERS. 

Localized tissue irritation can be seen from the intramuscular (IM) route. This is especially an issue when the formulation pH differs from the pH of the surrounding tissue or when precipitation of poorly soluble drugs occurs. Incorrect administration of IM injections is probably the most important factor that causes local adverse effects. Local skin irritation can also be seen with transdermal delivery systems due to the alcohols, nonionic surfactants, and adhesives. 

CAS 119823-35-7. TM for a surfactant. Hazard Moderately toxic by ingestion and skin contact. A severe skin irritant. 

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