This document discusses surfactants, their classification and applications in cosmetics and cosmeceuticals. Surfactants are amphipathic molecules with a hydrophilic head and hydrophobic tail that lower surface tension. They are classified as anionic, cationic, non-ionic or amphoteric based on the nature of the hydrophilic group. Common applications include use as emulsifying agents, for foaming and cleansing purposes like in shampoos, and as wetting agents. Anionic, cationic, non-ionic and amphoteric surfactants are used for different purposes depending on their properties like detergency and foaming ability or mildness.

1. S U R F A C T A N T S -
C L A S S I F I C A T I O N A N D
A P P L I C A T I O N I N C O S M E T I C S
A N D C O S M E C E U T I C A L S
P r e s e n t e d B y
S u j i t h a M a r y
M P h a r m
S t J o s e p h C o l l e g e O f P h a r m a c y
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2. SURFACTANTS
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3. DEFINITION:
• A Surface active agent (surfactants) is a substance which lowers the
surface tension of the medium in which it is dissolved ,and /or the
interfacial tension with other phases.
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4. INTRODUCTION
• All surface active agents have a structural feature in common : they are all
amphipathic molecule : that is , the molecule has two distinct parts –a
hydrophobic unit and a hydrophilic unit.
• A surfactant molecule is composed of a hydrophilic head and a hydrophobic tail.
The head can be an anionic, a cationic, a zwitterion, or a non-ionic group while
the tail is a nonpolar hydrocarbon chain.
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5. CLASSIFICATION OF
SURFACTANTS
According to the nature of the hydrophilic group surfactants are classified as:
• Anionic
• Cationic
• Non ionic
• Ampholytic
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7. ANIONIC SURFACTANTS
• Those surfactants in which surface active ion is negatively charged in solution,
are anionic surfactants.
• Anionic groups may be directly connected to hydrophobic part or these may be
connected through ester , ether, amide , or amidine links.
Eg; Sodium dodecyl sulphate
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8. a. surfactants having anionic groups connected directly to the hydrophobic unit.
Eg:fatty acid soaps, alkyl sulphonates , alkyl sulphates, alkyl aryl sulphonates,alkyl
phosphates.
b. Surfactants having anionic groups connected through ester links
Eg: monoglyceride sulphates, dialkyl sulphosuccinate, polyethylene glycol ester,
sulphates isoethionates .
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9. c. Surfactants having anionic groups connected through ether links.
Eg; alkyl ether sulphates ,phenol ether sulphates, alkyl ether carboxylates
d. Surfactants having anionic groups connected through amide links.
eg; alkalonamide sulphates, taurines, sarcosinates.
e. Surfactants having anionic groups connected through amidine links .
eg:imidazole sulphates.
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10. CATIONIC SURFACTANTS
• Those surfactants in which surface active ion is positively charged in solution, are cationic
surfactants.
Eg; Cetyl trimethylammonium bromide (CTAB)
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11. Nitrogenous Surfactants
• Quarternary ammonium salts in which nitrogen is directly attached to the
hydrophobic part.
Eg; alkyl trimethhyl ammonium salts, dialkyl dimethyl ammonium salts, alkyl
dimethhyl benzyl ammonium salts, ethoxylated alkyl-dimethhyl ammonium salts.
• Surfactants in which the cationic group separated from the hydrophobic group.
Eg; Quarternized amides of ethylene diamine, Quarternized amides of
polyethylenediamine.
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12. • Surfactants in which cationic group is located in a heterocyclic ring.
eg; Alkyl pyridinium salts , alkyl morpholinium salts, alkyl imidazolinium salts
• Dicationic surfactants
eg; Quarternised diamine salts .
 Non nitrogenous surfactants
Eg; sulphonium salts , phosphonium salts.
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13. NON IONIC SURFACTANTS
Hydrophilic part of the molecule is made up of multiple uncharged
polar groups.
Eg; Hydroxyl groups or ether linkages in ethylene oxide chains
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14. • Three types
1. Alkanolamines. eg.fatty acid alkanolamine, fatty acid dialkanolamine
2. Polyethylene glycol derivatives.
Eg. Alkyl polyglycol ether, alkyl aryl polyglycol ethers, thioethers
3.Polyethylenimine derivatives.
Eg. Alkylpolyethyleneimine, polyethyleneimine amides
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15. AMPHOTERIC (ZWITTER-IONIC)
SURFACTANTS
Able to form a surface active ion with both positive and negative charges.
eg; Lecithin
• three types
1.Alkylamino acids . eg. Alkyl β aminopropionates, betaines
2. Acylaminoacids . eg. Acyl β amino propionates, acyl peptides
3. Alkylimidazolines
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16. APPLICATIONS OF SURFACTANTS
1. EMULSIFICATION PURPOSES:
• Many cosmetics are emulsions in which surfactants have been used as the
emulsifying agents.
• Three types of surfactants usually used as emulsifying agents: anionic,
cationic and non anionic.
ANIONICS:
• Widely used for emulsification purposes especially in the formulation of
hand creams and lotions.
eg. Fatty acid soaps, polyol fatty acid monoesters containing fatty acid soaps,
sulphuric esters etc.
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17. CATIONICS:
• Not widely used as emulsifying agents in cosmetics.
• Following properties should be kept in mind:
i . These are substantive to proteins at acid pH
ii. These tend to produce emulsions with acid pH
iii. They have germicidal properties if not inactivated by anionics or
incompatible materials.
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18. NON-IONICS:
• Compatible with large number of cosmetics because they do not ionise in
solutions.Therefore they are compatible with both anionic and cationic
surfactants.
Eg: Polyoxyethylene fatty alcohol ethers (eg; polyoxyethylene lauryl alcohol)
polyoxyethylene fatty acid esters (eg; polyoxyethylene stearate)
polyoxyethylene sorbitan fatty acid esters ( eg; polyoxy ethylene sorbitan
monostearate )
Sorbitan fatty acid ester ( eg; sorbitol monostearate)
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19. NATURAL SURFACTANTS
They also used in cosmetics for the emulsifying properties such as lanoline, cholesterol,
saponins. Today they largely replaced by synthetic detergents. However lecithin which
is a phospholipid is still being used today in the preparation of milky lotion and
creams.Lecithin is obtained from egg yolk and soya bean.
2.FOAMING AND CLEANSING PURPOSE
For this purpose , surfactants are used mostly in shampoo, in which the principle
ingredients are surfactants. For foaming and cleansing , anionics, cationic , non-ionic
and amphoteric surfactants are used.
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20. ANIONIC SURFACTANTS
• This is the most widely used type of surfactant for laundering, dishwashing
liquids and shampoos because of its excellent cleaning properties.
• In shampoo the anions such as alkaline sulphonates and alkaline benzene
sulphonate and fatty acids soaps are not used.
• α- olefinic sulphonates, alkyl sulphate are very popularly used in shampoo for
detergency and foaming properties.
• Sulphosuccinates are known for the mild effects and less irritant to eyes and used
in mild shampoo as auxillary surfactants. Methyl taurides, and acyl peptides may
be used.
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21. CATIONIC SURFACTANTS
• They are not good foaming agents or detergents.
• They are also irritant to eyes and interact with protiens, thus they cause dirt re-deposition on
hair shaft.
• They can be used as additives for germicidal properties upto 5% in shampoo.
Eg:- alkyltrimethyl ammonium, sterile dimethyl benzyl ammonium, cetyl pyridinium salts.
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22. NON-IONIC SURFACTANTS:
• They are good detergents and can be used as principle surfactants.
• Polyglyceryl ethers have good detergency and foaming properties.
• They are mild in nature and do not irritate the eye mucosa.
• Other non-ionics such as fatty acid alkanolamide are not used as detergents but
produce conditioning effects.
• Few other non-ionics used for other purposes for increasing the stability and
viscosity.
Eg:- pluronics, sorbitol esters, ethoxylated fatty alcohols.
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23. AMPHOTERIC SURFACTANTS
• Mainly used in mild shampoos such as baby shampoo because of their mildness to
skin and eye.
• They are known to have conditioning properties.
Eg:- n-alkyl amino acids and betaines and imidazoline derivatives.
• N-alkyl amino acids are best foaming agents used in mildly alkaline pH.
• Betaines are cationic in acidic pH and anionic in alkaline pH.
• They are stable over a wide range of pH(2-12).
• They are also compatible with cationics, anionics, and non-ionics.
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24. 3.WETTING AGENTS:
• All surfactants have good wetting properties.
• For the purpose of enhancing wetting, the short chain alkyl aryl sulphonates, alkyl
ethyl sulphates are often used for improving wetting properties.
4. SOLUBILISATION:
• Surfactants when used above CMC are known to have solubilising properties.
• For incorporating perfumes in cosmetics or certain additives which requires
solubilisation.
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COMMONLY USED SURFACTANTS :
Sodium lauryl sulphate (can be derived from coconuts) Produces High Foam; easy
to thicken. Strong Anionic Surfactant; can cause irritation .
Disodium lauryl sulphosuccinate (derived from coconuts),Foaming agent, Mild
Anionic Surfactant; gentle on the skin.
Decyl Polyglucoside (vegetable derived, used in baby shampoos for its gentleness)
Cetearyl alcohol (derived from coconut oil) Amphoteric Surfactant
Decyl Glucoside (derived from sugar)
Glyceryl Cocoate (derived from vegetables)

26. CONCLUSION
• The classification is usually based on characteristics from the hydrophilic part.
• Surfactants are widely used in the detergent industry, lubrication, softening
finishes, sewage sludge, herbicide dispersions, and petroleum Industry.
• The properties provide the use of surfactants in wettability modification ,
detergency , foaming ,cleansing and in emulsification purposes.
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27. REFERENCE
• Sharma PP.Cosmetics- Formulation , manufacturing and quality control.5th ed,
2014, P:94-103
• Harry’s cosmeticology p;633-640.
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