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.
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
PKA may refer to:
* Professionally known as:
** Pen name
** Stage persona
* p''K''a, the symbol for the acid dissociation constant at logarithmic scale
* Protein kinase A, a class of cAMP-dependent enzymes
* Pi Kappa Alpha, the North-American so ...
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
cation
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...
ic or water-insoluble
amphiphile
An amphiphile (from the Greek αμφις amphis, both, and φιλíα philia, love, friendship), or amphipath, is a chemical compound possessing both hydrophilic (''water-loving'', polar) and lipophilic (''fat-loving'') properties. Such a compoun ...
s such as
1-decanol
1-Decanol is a straight chain fatty alcohol with ten carbon atoms and the molecular formula C10H21OH. It is a colorless to light yellow viscous liquid that is insoluble in water and has an aromatic odor. The interfacial tension against water at 2 ...
.
Addition of an mixture of equal parts of sodium lauroyl sarcosinate and the non-ionic surfactant
sorbitan monolaurate (S20) to water 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.
In culture
Sodium lauroyl sarcosinate was sold as a special ingredient called "Gardol" in
Colgate "Dental Cream", as
toothpaste was then called, during the 1950s
through the mid-1960s in the US
and the mid-1970s in France.
Its current use as a preventive
dentifrice is in
Arm & Hammer Baking Soda Toothpaste, a Church & Dwight product, where it is used as a
surfactant
Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming ...
.
References
{{Reflist
External links
"Occupational Allergic Contact Dermatitis From Sodium Lauroyl Sarcosinate in Liquid Soap,"Zemtsov, Alexander MD, MSC; Fett, Deborah MD, ''Dermatitis'', June 2005, Volume 16, Issue 2, p. 97
Cosmetics chemicals
Household chemicals
Organic sodium salts
Anionic surfactants