Sodium Stearoyl Lactylate
- Sodium Stearoyl Lactylate
Sodium stearoyl lactylate is an anionic emulsifier that has a characteristic odor and appears as a brittle solid or white or yellowish powder. The compound is insoluble in water and soluble in ethanol. Sodium stearoyl lactylate is a food additive, acting as an emulsifying agent in food products. In food products, it also functions as an emulsifier, stabilizer, surface active agent, texturizer, and dough strengthener. In addition to the food industry, sodium stearoyl lactylate is an effective emulsifying agent in the cosmetic and health industry. The compound is found in eye creams, biocides, antibacterial products, foundations, concealers, softeners, conditioners, skin conditioning agents, and hand or body lotions. (“Sodium stearoyl-2-lactylate
Sodium stearoyl lactylate is a plant-derived compound formed from sodium salts of stearoyl lactylic acids combined with sodium salts of associated acids. The compound is manufactured via a reaction between stearic acid and lactic acid with subsequent conversion to sodium salts. Distillation is employed to eliminate excess water. Both stearic acid and lactic acid are naturally occurring substances. (Hasenhuettl, 2019; Norn, 2014; “Sodium stearoyl lactylate,”) The compound may also contain free fatty acids such as stearic acid and palmitic acid, free lactic acid, unneutralized palmitoyl lactylic acid, and unneutralized stearoyl lactylic acid. (Lamb et al., 2010)
Sodium stearoyl lactylate is an emulsifying and surfactant agent. It works by interacting with the starches and proteins owing to its anionic nature. (“CIR Ingredient Status Report,” 2019)
- Skin Benefits of Sodium Stearoyl Lactylate
- Sodium Stearoyl Lactylate as a Surfactant in Soap
The chemical and physical nature of the surfactant plays a key role in the effectiveness of soaps and handwashes in removing microbes from the skin surface. Surfactants facilitate the production of micelles that make oily debris easily solubilized in water, enabling the removal of oily debris during the wash. Sodium stearoyl lactylate has a hydrophilic-lipophilic balance (HLB) of 10. This compound forms a barrier on the skin and prevents the superficial layers of the layers from being removed while washing with the soap. As opposed to another anionic surfactant, sodium lauryl sulphate, which causes skin damage at greater concentrations, sodium stearoyl lactylate does not cause skin damage. (Jensen et al., 2017)
- Sodium Stearoyl Lactylate and Improvement in Skin Elasticity
Lactylates are effective skin elasticity enhancing agents that improve the elasticity of the outer layer of skin, the stratum corneum. Flexible, soft, and supple skin is the major cosmetic goal among the male and female populations. Such skin reflects the normal functioning and structure of the epidermis of the skin. Following exposure to different adverse climate conditions, the stratum corneum of the skin may become hard, flaky, and inelastic. The skin may lose its moisture owing to excessive contact with solvents and detergents. The addition of sodium stearoyl lactylate to the creams and lotions imparts opacity, body, and lubricity to these skincare products. The softening action of these products is further promoted by the absorption of sodium stearoyl lactylate into the skin. This compound improves and restores the texture of the skin by reducing the scaling and dryness of the skin. (Hagan, 1995)
- Skin Barrier
Anionic surfactant, sodium stearoyl lactylate, enhances the polarity of the skin. However, this compound does not extraction of lipids from the skin surface. The surfactant mixes with the lipid matrix of the stratum corneum and stimulates fluidity of the lipid chains. The compound is retained on the skin surface while elevating the polar component of the skin. The organization of the lipid matrix affects the barrier function and permeability of the skin, with subsequent influence on the moisturization and hydration of the skin. (Lemery et al., 2015)
- Safety Profile
Ionic surfactants, whether anionic or cationic, tend to be toxic when they are soluble in water. As compared to cationic surfactants, anionic surfactants such as sodium stearyl lactylate are less irritant. These surfactants have lower acute and chronic toxic effects and do not elicit significant dermal and ocular irritation. The compound does not alter the viability of the skin cells and does not stimulate the release of interleukin 1-alpha (IL-1α). However, the compound does not contribute to the release of higher levels of IL-8. (Lémery et al., 2015) The emulsifier, sodium stearoyl lactylate, is added to lotions and creams. Jensen et al. reported a case study that described the toxic dermatologic effects of Ostrich oil cream containing sodium stearoyl lactylate. In the study subject, this emulsifying agent elicits allergic contact dermatitis upon topical application of the relevant product. (Jensen & Andersen, 2005)
- Emulsifier Complex and LipidTAC Products
LipidTAC offers a wide range of products suitable for every skin type. The products nourish and restore the imbalances in the skin, improving the overall appearance of the skin. The LipidTAC emulsifier complex is derived from natural sources and does not contain any ethoxylated ingredients. The complex is a self-emulsifier for oil-in-water emulsions. The acyl lactylates of the emulsifier complex are responsible for conditioning skin and hair. The lactic and acyl component of fatty acids react together to produce anionic lactylates. The two constituents are natural moisturizing factors (NMF) present in the skin. Lactylates are excellent conditioners, enhancers, and stabilizers. The emulsification system is balanced and complete and is used in creams and lotions to provide a conditioned and soft feel to the skin. Raw materials used for the production of emulsifier complex are GMO-free. Glyceryl stearate, sodium stearoyl lactylates, and Cetearyl alcohol are the key constituents of the LipidTAC emulsifier complex. The initial two compounds are also added to edible formulations, however, Cetearyl alcohol is not food grade, hence, used in cosmetics only.
CIR Ingredient Status Report. (2019). https://online.personalcarecouncil.org/jsp/CIRList.jsp?id=9008
Hagan, D. B. (1995). Method for enhancing human skin elasticity by applying octanoyl lactylic acid thereto. In: Google Patents.
Hasenhuettl, G. L. (2019). Synthesis and commercial preparation of food emulsifiers. In Food emulsifiers and their applications (pp. 11-39). Springer.
Jensen, C. D., & Andersen, K. E. (2005). Allergic contact dermatitis from sodium stearoyl lactylate, an emulsifier commonly used in food products. Contact Dermatitis, 53(2), 116. https://doi.org/10.1111/j.0105-1873.2005.0650c.x
Jensen, D. A., Rogers, M. A., & Schaffner, D. W. (2017). Surfactant concentration and type affects the removal of Escherichia coli from pig skin during a simulated hand wash. Letters in applied microbiology, 65(4), 292-297.
Lamb, J., Hentz, K., Schmitt, D., Tran, N., Jonker, D., & Junker, K. (2010). A one-year oral toxicity study of sodium stearoyl lactylate (SSL) in rats. Food and chemical toxicology, 48(10), 2663-2669.
Lémery, E., Briançon, S., Chevalier, Y., Bordes, C., Oddos, T., Gohier, A., & Bolzinger, M.-A. (2015). Skin toxicity of surfactants: Structure/toxicity relationships. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 469, 166-179.
Lemery, E., Briançon, S., Chevalier, Y., Oddos, T., Gohier, A., Boyron, O., & Bolzinger, M.-A. (2015). Surfactants have multi-fold effects on skin barrier function. European Journal of Dermatology, 25(5), 424-435.
Norn, V. (2014). Emulsifiers in food technology. John Wiley & Sons.
Sodium stearoyl lactylate. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-172/subpart-I/section-172.846