2. • Introduction To Surfactant .
• Classification .
• Selection Of Surfactant .
• How Do Cosmetic Surfactants Work ?
• Application Of Surfactant .
• Reference .
2
CONTENT :
3. 3
Introduction To Surfactant .
• Definition:
Surfactants are compounds that lower the surface tension (or interfacial tension)
between two liquids, between a gas and a liquid, or between a liquid and a solid.
• Composition:
Surfactants are usually organic compounds that are amphiphilic , meaning they contain
both hydrophobic groups (their tails) and hydrophilic groups (their heads).
Typically tail is long alkyl chain, and head is polar or hydrophilic groups . Therefore
they are soluble in both organic solvents and water.
5. 5
Type : Amphoteric Surfactant .
• Definition:
Amphoteric surfactants are those which can have both a negative charge and a
positive charge, depending on the pH . These materials are also referred to as
zwitterionic materials .
• Example:
cocamidopropyl betaine, cocoamphopropionate, and sodium lauraminopropionate .
• Amphoterics are used because they have good detergency and are less irritating
than the anionics .
• They also can help thicken a formula and have a positive effect on foam, as they
make the bubbles smaller and feel creamier.
• The main drawback to using them is that they are significantly more expensive
6. 6
Type : Anionic Surfactant .
• Definition:
Anionic surfactant are negatively charged surfactant ions .
• Example :
sodium lauryl sulfate , ammonium lauryl sulfate (ALS), sulfosuccinates, alkyl
benzene sulfanate, acyl methyl taurates, acyl sarcocinates, propyl peptide
condensates, monoglyceride sulfates and fatty glycerol, ether sulfanates.
• Anionics are used primarily as the main detergent in cosmetics because they are
good at removing dirt and oil.
• They produce pleasing amounts of foam. They are relatively inexpensive.
• Their primary drawback is that they can be irritating
• This is why they are often blended with amphoteric surfactants.
7. 7
Type : Cationic Surfactant .
• Definition:
These are positively charged surfactant molecules.
• Example :
Quaternary ammonium salts, cetrimonium bromide (CTAB), cetylpyridinium
chloride (CPC), benzalkonium chloride (BAC), benzethonium chloride (BZT).
• They are not used for cleansing formulas because they don’t clean, rinse, or
foam .
• They are more irritating.
• cationics are great for conditioning.
• When a cation is put on hair or skin, the positive portion of the molecule is
attracted to the negatively charged damaged site creating an electrostatic
bond. While water rinses most things away, the cationic surfactant remains
8. 8
Type : Nonionic
• Definition :
Nonionic surfactants are molecules that do not have a charge.
• Example :
Fatty alcohol – cetyl alcohol , steryl alcohol . Ethers – brij , octyl glucoside .
Ester – glyceryl laurate , span .
• They are good foam enhancers (when used with anionics) and can reduce
irritation
• They also can thicken systems and provide a conditioning effect.
• Additionally, they are very good for solubilizing fragrances and other natural
oils in formulating.
• Gentle cleansers such as baby shampoos are based on nonionics.
• Nonionics do not work as well as anionics in shampoos.
12. 12
How Do Cosmetic Surfactants Work ?
• When surfactants are put into solutions, the molecules have a tendency to
line up in a certain way depending on the solution composition, the
concentration of the surfactant, and the temperature.
• In a water solution with extremely low surfactant concentrations, the
molecules tend to bounce around randomly without forming structures. But
at the Critical Micelle Concentration (CMC)
• They arrange themselves in spherical structures called micelles. On the
outer layer of the spheres are the hydrophilic parts of the surfactant
molecule and on the inner layer are the lipophilic parts.
• It’s a bit like a cream filled donut.
13. 13
Application Of Surfactant .
• Cleansing Surfactants :
• The useful thing about micelles is that they can help suspend oil in water.
• When a small amount of oily materials is put into an aqueous solution of
surfactants, it will migrate into the center portion of the micelle.
• So, when you put a surfactant solution on a surface like hair or skin, the oil that
is there will be drawn away from the surface and into the micelles. When the
surfactant solution is rinsed away, the surface is clean
• Foaming :
• Foam is another characteristic of surfactant solutions so you’ll need
surfactants if you want your product to foam.
• Essentially, foam is the entrapment of air in liquids and the alignment of
the surfactant molecules helps keep the foam stable.
• It should be noted that foam itself is not related to the ability of a product
to clean. But consumers expect cleansing products to foam so as a
cosmetic formulator, you’ll have to add foaming surfactants
14. 14
Application Of Surfactant .
• Emulsification :
• While cleansing cosmetics remove oils, many cosmetic products are design to
add oily materials to the skin and hair.
• These ingredients usually can’t be applied directly because they have
undesirable aesthetic characteristics in their concentrated form.
• For this reason, cosmetic chemists create emulsions using surfactants.
• Solubilization :
• The problem with most emulsions is that they usually create opaque
products.
• However, there are times when a cosmetic chemist wants a clear
formula but still wants to blend an oil in a mostly water formula.
• Fortunately, there are surfactants that have the ability to create particles
so small that light passes through them and the solutions remain clear.
• Molecules that do this are solubilizing surfactants.
15. 15
Application Of Surfactant .
• Conditioning:
• Since surfactants often contain an “oily” part on their molecule, they have
conditioning properties that can improve the feel and look of the surfaces of
skin and hair.
• For them to work this way, the surfactants have to be left behind and also be
non-irritating.
• This can be achieved through a leave-on cosmetic product or by using
surfactants that can bond to surfaces through an electrostatic charge .
• Surfactants in mouth washes:
• Mainly for two purposes, mouthwashes may be employed such as cosmetic and
therapeutic.
• Cosmetic mouthwashes can be synthesized to decrease lousy smell by the
application of flavoring and / or antimicrobial agents.
• While therapeutic mouth rinses may be synthesized to decrease gingivitis,
plaque, stomatitis, and dental caries.
• Surfactants are employed as they assist in the debris’ exclusion via delivering
foaming action and in the flavors’ solubilization.
16. 16
Application Of Surfactant .
• Surfactants in microbiology:
• Surface active agents such as quaternary ammonium compounds are those
compounds which have antibacterial activity in themselves
17. 17
Reference :
• Suhail .m , kumar. A , khan a. , et.al Surfactants and their Role in
Pharmaceutical Product Development: An overview (2019) , researchgate .
https://www.researchgate.net/publication/337756082_Surfactants_and_thei
r_Role_in_Pharmaceutical_Product_Development_An_overview
• Romanowski. P . An introduction to cosmetic technology ( 2015) , AOCS
https://www.aocs.org/stay-informed/inform-magazine/featured-articles/an-
introduction-to-cosmetic-technology-april-2015?SSO=True
• Nwokolo . G . Basics and Potential Applications of Surfactants – A Cosmetic
Science Perspective (2018) Researchgate .
https://www.researchgate.net/publication/329246583_Basics_and_Potential
_Applications_of_Surfactants_-_A_Cosmetic_Science_Perspective
