Sodium lauroyl sarcosinate

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Sodium lauroyl sarcosinate is a widely used ingredient in cosmetics, personal care, and skincare formulations. Depending on its function, it may serve as a moisturizer, preservative, emulsifier, or active ingredient to enhance the overall effectiveness and performance of a product.

Sodium lauroyl sarcosinate (INCI), also known as sarcosyl, is an anionic surfactant derived from sarcosine used as a foaming and cleansing agent in shampoo, shaving foam, toothpaste, and foam wash products.

Sodium lauroyl sarcosinate
Names
IUPAC name
Sodium N-(Dodecanoyl)-N-methylglycinate
Systematic IUPAC name
Sodium (N-methyldodecanamido)acetate
Identifiers
3D model (JSmol)
ECHA InfoCard 100.004.801 Edit this at Wikidata
UNII
  • InChI=1S/C15H29NO3.Na/c1-3-4-5-6-7-8-9-10-11-12-14(17)16(2)13-15(18)19;/h3-13H2,1-2H3,(H,18,19);/q;+1/p-1
  • CCCCCCCCCCCC(=O)N(C)CC(=O)[O-].[Na+]
Properties
C15H28NNaO3
Molar mass 293.383 g·mol−1
Melting point 140 °C (284 °F; 413 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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This surfactant is amphiphilic due to the hydrophobic 12-carbon chain (lauroyl) and the hydrophilic carboxylate. Since the nitrogen atom is in an amide linkage, the nitrogen is not pH active and is neutrally charged in all aqueous solutions regardless of pH. The carboxylate has a pKa of about 3.6 and is therefore negatively charged in solutions of pH greater than about 5.5.

pH-sensitive vesicles can be prepared using this surfactant with another cationic or water-insoluble amphiphiles such as 1-decanol.

Addition of an mixture of equal parts of sodium lauroyl sarcosinate and the non-ionic surfactant sorbitan monolaurate (S20) to a buffered water:ethanol solution led to the formation of micelle-like aggregates, even though neither surfactant formed micelles when present alone. Such aggregates can help carry other small molecules, such as drugs, through the skin.

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