This document discusses humectants and surfactants used in cosmetics. It defines surfactants as substances that lower surface tension and classify them as anionic, cationic, non-ionic and zwitterionic. Anionic surfactants are commonly used in foaming products like shampoos due to their high foaming, cleansing and washing abilities. Humectants are substances that increase skin moisture by retarding its loss. Common humectants used in cosmetics include propylene glycol, hexylene glycol and glycerin. They are included in products like lotions, creams and lip treatments to hydrate skin.

1. An Assignment on
What is Humectant &
Surfactant.Types of
Humectant and Surfactant
used in cosmetics.
University of Science and Technology Chittagong
(USTC)
Submitted by
Md. Irfan Uddin
Roll:-1083
Reg:-1086
Course Name:-Cosmetology
Course code:-PHR-407
Submitted to
Mrs. Jaushan Ara
Lecturer,
Department of Pharmacy,
University of Science and
Technology Chittagong (USTC)
Department of Pharmacy

2. Surfactants are termed as surface-active agents also wetting agents , emulsifying agents or
suspending agents depending on its properties and use.
Surface-active agents are substances which, at low concentrations, adsorb onto the surfaces
or interfaces of a system and alter the surface or interfacial free energy and the surface or
interfacial tension.
Surfactants are monomers , it has a characteristic structure possessing both hydrophobic
groups / non-polar regions (their "tails") usually contain a C 12— C 1 8 hydrocarbon chain
and hydrophilic groups / Polar Regions(their "heads
Therefore, they are soluble in both organic solvents and water, so they called amphiphilic.
Fig:-Surfactant Molecule
Surfactants

3. Surfactants can work in three different ways:
Roll-up, Emulsification and Solubilization.
(a) Roll-up mechanism: The surfactant lowers the oil/solution and fabric/solution
interfacial tensions and in this way lifts the stain of the fabric.
(b) Emulsification: The surfactant lowers the Oil solution interfacial tension and makes
easy emulsification Of the Oil.
(c) Solubilization: Through interaction with the micelles Of a surfactant in a solvent
(water), a substance spontaneously dissolves to form a stable and clear solution.
Mechanism of action of surfactants

4. Surfactant can be classified based on charge groups present in their head. A nonionic
surfactant do not have any charge groups over its head. The head of an ionic surfactant
carries a net charge. If the charge is negative, the surfactant is more specifically called
anionic and if the charge is positive, it is called cationic.
If a surfactant contains a head with two oppositely charged groups, it is termed zwitterion.
1. Anionic surfactants
2. Cationic surfactants
3. Non-ionic surfactants
4. Zwitterionic/ amphoteric surfactants
Anionic surfactants
are considered to be the go to surfactant for many formulations. This group of surfactants
is also the most commonly used among foaming product productions,like shampoos or
body washes.
The reasoning for this is because the anionic surfactant's primary functions are creating
high foam, high cleansing, and high washing capabilities in a finished product
Cationic surfactants
These surfactants are best used in recipes where foaming is not necessarily mandatory such
as hair conditioners.
Classification of surfactants

5. Hydrating substance are used in cosmetics products to retard moist increase the moisture
content in skin that is in contact with the products.
 Target area in the body for treatment with humectants are dry skin.
 Hydration plays an important role in maintaining the metabolism, enzyme activity
mechanical properties, appearance, and finally barrier function of skin.
Examples of some humectants include: Propylene glycol,hexylene glycol and
butylene glycol, Glyceryl triacetate .
• Cosmetic products, including shampoo, conditioner, frizz serum, lotions, creams,
lip treatments, cleansers, after-sun lotion, and some soaps or body lotions
Humectants

6. Fig:-Moisturizing Cream Fig:-Moisturizing Lotion
Reference:-
 Martin M. Reiger "Harry's Cosmeticology" Chemical Publishing Co,Eight Edition,
Volume I of 2, Page no. 261—271.
 Andre O. Barel, Marc Pay e, Howaerd I. Maibach "Handbook of Cosmetic Science and
Technology" CRC Press, Fourth Edition, Page no. 93—100.