Sodium lauroyl sarcosinate (
INCI The International Nomenclature of Cosmetic Ingredients, abbreviated INCI, are the unique identifiers for cosmetic ingredients such as waxes, oils, pigments, and other chemicals that are assigned in accordance with rules established by the Personal C ...
), also known as sarcosyl, is an
anionic 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 a ...
derived from
sarcosine used as a foaming and cleansing agent in
shampoo
Shampoo () is a hair care product, typically in the form of a viscous liquid, that is used for cleaning hair. Less commonly, shampoo is available in solid bar format. Shampoo is used by applying it to wet hair, massaging the product into the s ...
,
shaving foam
Shaving cream or shave cream is a category of cream cosmetics used for shaving preparation. The purpose of shaving cream is to soften the hair by providing lubrication.
Different types of shaving creams include aerosol shaving cream (also kno ...
, toothpaste, and foam wash products.
This surfactant is
amphiphilic
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 ...
due to the
hydrophobic
In chemistry, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water (known as a hydrophobe). In contrast, hydrophiles are attracted to water.
Hydrophobic molecules tend to be nonpolar and, t ...
12-carbon chain (
lauroyl) and the
hydrophilic
A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press.
In contrast, hydrophobes are no ...
carboxylate
In organic chemistry, a carboxylate is the conjugate base of a carboxylic acid, (or ). It is an ion with negative charge.
Carboxylate salts are salts that have the general formula , where M is a metal and ''n'' is 1, 2,...; ''carboxylat ...
. Since the nitrogen atom is in an
amide
In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula , where R, R', and R″ represent organic groups or hydrogen atoms. The amide group is called a peptide bond when it is ...
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
Vesicle may refer to:
; In cellular biology or chemistry
* Vesicle (biology and chemistry), a supramolecular assembly of lipid molecules, like a cell membrane
* Synaptic vesicle
; In human embryology
* Vesicle (embryology), bulge-like features o ...
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 conven ...
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
Sorbitan monolaurate is a mixture of esters formed from the fatty acid lauric acid and polyols derived from sorbitol, including sorbitan and isosorbide. As a food additive, it is designated with the E number E493.
See also
* Sorbitan monostearat ...
(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
Within the fields of molecular biology and pharmacology, a small molecule or micromolecule is a low molecular weight (≤ 1000 daltons) organic compound that may regulate a biological process, with a size on the order of 1 nm. Many drugs are ...
, 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
Arm & Hammer is a brand of baking soda-based consumer products marketed by Church & Dwight, a major American manufacturer of household products. The logo of the brand depicts the ancient symbol of a muscular arm holding a hammer inside a red c ...
Baking Soda Toothpaste, a Church & Dwight product, where it is used as a
surfactant.
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