COSMETICS & COSMECEUTICALS
Building blocks for different
product formulations of
CLAASIFICATION OF SURFACTANTS
APPLICATION OF SURFACTANTS
CLASSIFICATION OF EMOLLIENTS
APPLICATION OF EMOLLIENTS
CLASSIFICATION OF REHOLOGIC ADDITIVES
ANTIMICROBIAL AGENTS USED AS PRESERVATIVES
FACTORS AFFECTING MICROBIAL AGENTS EFFICACY
Main building blocks for cosmetics
III. Rheological additives
IV. Antimicrobial used as preservatives
Surfactants are compounds that lower the
surface tension between two liquids,
between a gas and a liquid, or between a
liquid and a solid.
Surfactants may act as,
foaming agents, and
6 General structure of surfactant
CLASSIFICATION OF SURFACTANTS
Surfactants can be classified on the basis of
their physical properties , chemical structure
or on the basis of their uses.
Most logical classification of surfactants is on
the basis of the ionic behavior in aqueous
They are classified into four types :-
Those surface active agents in which
surface-active ion is negatively charged in
the solution , are anionic surfactants.
Anionic groups may be directly connected
to hydrophobic part or these may be
connected through ester , ether , amide or
On basis of that sub-classification can be
1. Surfactant having anionic groups
10 connected directly to the hydrophobic
GROUPS General formula
Fatty acid soaps
R-COO – M+
R-OSO3 – M+
R-SO3 – M+
2. Surfactant having anionic groups
connected through ester links
GROUPS GENERAL FORMULA
Monoglyceride sulphates R-COO-CH2
Polyethylene glycol esters
3. Surfactant having anionic groups
12 connected through ether links
GROUP GENERAL FORMULA
Alkyl ether sulphates
R(O-CH2-CH2)n OSO3 M+
Phenol ether sulphates R-C6H4-(O-CH2-CH2)n
4. Surfactant having anionic groups
connected through amide links
GROUPS GENERAL FORMULA
R-CO-N-CH2-COO- M+ CH3
Those surfactants in which surface-active ion is
positively charged in solutions , are cationic
These can be further divided into two different
Where R=hydrophobic chain or an aromatic
X= suitable anion
A. Nitrogenous surfactants
These surfactants can be grouped on the
basis of a placement of cationic
B. Non-nitrogenous surfactants
A. Nitrogenous surfactants
1.Quaternary ammonium salts in which
nitrogen is directly attached to the
15 2. Surfactants in which cationic group
separated from the hydrophobic part:-
3. Surfactants in which cationic group
located in a heterocyclic ring:-
4. Dicationic surfactants:-
B. Non-Nitrogenous surfactants :-
In non-ionic surfactants hydrophilic part of
the molecule is made up of multiple
uncharged polar groups.
For example , hydroxyl groups or ether
linkages in ethylene oxide chains.
Surfactants can be further sub-classified on
their chemical nature.
In general formula R= hydrophobic chain
n= whole number
4. Ampholytic surfactants
The characteristics of ampholytic surfactants
in that they are able to form a surface-
active ion with both positive and negative
Those surface active agents are sub-
classified on their chemical nature.
Groups of compound and general formulae
In general formulae, R= carbon chain of 12-
I. Alkylamino acids
II. Acylamino acids
Surfactants play an important role as
cleaning, wetting, dispersing,emulsifying,foaming
and anti-foaming agents in many practical
applications and products, including:
In Formulation of Shampoo
Shampoo is a hair care product used for
the removal of oils, dirt, skin particles,
dandruff, environmental pollutants and
other contaminant particles that gradually
build up in hair. The goal is to remove the
unwanted build-up without stripping out so
much as to make hair unmanageable.
Shampoo, when lathered with water, is a
surfactant, which, while cleaning the hair
and scalp, can remove the natural oils
(sebum) which lubricate the hair shaft.
Emollient, any substance that softens the
skin by slowing evaporation of water.
The basic building blocks of most emollients
are long chain hydrocarbons, often
combined with alcohols and acids in the
form of esters.
When selecting emollients for a
formulation, the stability in terms of
hydrolysis and oxidation must be
28 Emollients are available as ,
lotions – good for hairy or damaged areas of skin (such
as weeping eczema) as they are thin and spread easily,
but they’re not very moisturizing
sprays – good for hard-to-reach areas and for sore or
infected skin that shouldn’t be touched; quickly
creams – good for daytime use as they’re not very
greasy and are absorbed quickly
ointments – good for very dry, thickened skin and for
night-time use as they are greasy, thick and very
moisturizing; they’re usually free of preservatives so are
suitable for sensitive skin, but they shouldn’t be used on
bath oils and shower products
The emollients comprise a long list of
material which may be classified in following
1. Hydrocarbon oils and wax :- Mineral oils
2. Silicone oils :- Dimethyl polysiloxanes
Methyl phenyl polysiloxanes
3. Triglyceride esters :- Vegetable fats and oils
Animal fats and oils
4. Acetoglyceride esters :- Acetylated
5. Ethoxylated glycerides :- Ethoxylated glyceryl
6. Alkyl esters :- Methyl , isopropyl and butyl
esters of fatty acids ; lauryl lactate , myristyl
lactate ,cetyl lactate
7. Alkenyl esters :- Oleyl myristate
8. Fatty acids :- Lanolin acids
Lauric , myristic , isostearic , oleic acids
9. Fatty alcohol :- Lauryl , myristyl , oleyl , steryl and
10. Fatty alcohol ethers :- Ethoxylated lauryl , cetyl ,
stearyl ,isostearyl , oleyl , cholesterol and lanolin
11. Ether-esters :- Fatty acid esters of ethoxylated fatty
12. Lanolin and Derivatives :- Lanolin , Lanolin oil ,
Lanolin wax , Lanolin alcohols , Lanolin fatty acids
13. Polyhydric alcohols (polyols) and polyether
derivatives :- Propylene glycol (2000 ,4000),
polyoxypropylene glycols etc.
14. Polyhydric alcohol (polyol) esters :- polyethylene
glycol (200-6000) mono- and di-fatty acid esters , 1,3-
butylene glycol monostearate etc
15. Wax esters :- Lanolin , beeswax , spermaceti ,
16. Beeswax derivatives :- Polyoxyethylene sorbitol
beeswax. These are reaction products of beeswax
with ethoxylated sorbitol of varying ethylene oxide
content , forming a mixture of ether-esters.
17. Vegetable waxes :- Carnubba , candelilla
18. Phospholipids :- Lecithin and derivatives
19. Sterols :- Cholesterol , Cholesterol fatty acid esters.
20. Amides :- Fatty acid amides , ethoxylated fatty
acid amides , solid fatty acid alkanolamides.
This medication is used as a moisturizer to treat or
prevent dry, rough, scaly, itchy skin and
minor skin irritations (e.g., diaper rash, skin burns
from radiation therapy).
Emollients are substances that soften and
moisturize the skin and decrease itching and
flaking. Some products (e.g., zinc oxide, white
petrolatum) are used mostly to protect the skin
against irritation (e.g., from wetness).
Dry skin is caused by a loss of water in the upper
layer of the skin. Emollients/moisturizers work by
forming an oily layer on the top of the skin that
traps water in the skin.
Petrolatum, lanolin, mineral
oil and dimethicone are common emollients.
Humectants, including glycerin, lecithin, and
propylene glycol, draw water into the outer layer
of skin. Many products also have ingredients that
soften the horny substance (keratin) that holds the
top layer of skin cells together (e.g., urea, alpha
hydroxy acids such as lactic/citric/glycolic acid,
This helps the dead skin cells fall off, helps the skin
keep in more water, and leaves the skin feeling
smoother and softer.
Rheology is the science of flow. Every time
a lotion is poured, a cream squeezed from
a tube or a lipstick applied, rheology is
involved. Even when products are at rest, it
plays an important part in controlling
stability and suspension.
Viscosity can be temperature dependent.
Correct choice of rheological additive
allows you to create the ideal flow
39 NO CLASS EXAMPLES
1 Natural gums Gum karaya
2 Cellulose derivatives Hydroxyethyl cellulose
3 Electrolytes Ammonium chloride
4 Carboxyvinyl polymers Polymer of acrylic acid cross-
linked with poly functional
agent (Carbopol 934)
5 Others Ethoxylated fatty acid-
Antimicrobial agents used as
Preservatives are used to prevent spoilage of cosmetic
41 There are two main reason for spoilage of cosmetics ;
Oxidation of oils and fats
Water promotes the growth of micro-organisms , therefore all
cosmetic preparations containing water as one of the
ingredients are susceptible to microbial growth.
Examples of preservatived used in cosmetics :-
Alcohols (Benzoic acid , sorbic acid , salicylic acid
, vanillic acid)
Organic acids (Ethyl alcohol , chlorobutanol)
Aldehydes (Formaldehyde , cinnamic aldehyde )
Phenolic compounds ( Cresol , phenol , Bis-
Mercury compounds ( Thiomersol , Nitromersol)
Ideal properties of
It should be compatible with the formulation.
It should be soluble to such an extent that effective
concentration is achieved.
It should remain stable to provide sustained anti-
It should be colorless and odorless.
It should be non-toxic.
It should be non-irritant or non-allergic in
USE OF PRESERVATIVES
the use of preservatives is essential in most products to prevent
product damage caused by microorganisms and to protect
the product from inadvertent contamination by the consumer
An ingredient that protects the product from the growth of
microorganisms is called an antimicrobial. A preservative may
also be added to a product to protect it against damage and
degradation caused by exposure to oxygen, and in this
instance, these ingredients are also called antioxidants.
Without preservatives, cosmetic products, just like food, can
become contaminated, leading to product spoilage and
possibly irritation or infections. Microbial contamination of
products, especially those used around the eyes and on the
skin, can cause significant problems. Preservatives help prevent
Factors affecting antimicrobial
1. Dissociation & pH :-
3. Interference by Ingredients of cosmetics:-
Soaps and anionic surfactants in lower concentration
promote growth of Gram-negative bacteria.
Hydrophilic polymers like PEG, gum tragacanth, methyl
cellulose, CMC and PVP have only marginal effect in
reducing efficency of majority of anti-microbials.
Addition of certain materials to the aqeuous phase of
emulsions help in minimizing adverse effect of non-ionic
surfactants on preservatives.
Susceptibility of organism:-
Different antimicrobial agents have different
activity against microbes.
For example, HYDROXY BENZOATE are active
against moulds, fungi and yeast but less active
CHLOROBUTANOL has antibacterial and anti-fungal
PHENYL MERCURIC NITRATE is active against
bacteria , fungi, moulds and yeasts
Influence of solid particles :-
A number of cosmetic preparations contain
insoluble solid particles.
Salient of these are kaolin, chalk, zinc oxide, talc
Preservatives can be absorbed on the surface of
The extent of adsorption will depend on the nature
of solid particles and the pH of the preparation.
Preservatives can also interact with plastics.
PHENOLIC and QUATERNARY AMMONIUM
COMPOUNDS have been reported to react with