2010.7.28.Cosmetic Chemistry

WRBCS412A

WRBCS412A Cosmetic Chemistry/Version 1/Feb

2009

Cosmetic:

Substances used to improve or beautify

appearance.

Chemistry

The study of substances – their composition,

properties and interactions with each other.

WRBCS412A Cosmetic Chemistry/Version 1/Feb 2009

The study of the composition, properties and

effects of those substances applied to the

skin, nails and hair for the purpose of

beautifying and improving appearance.


Choose and use products correctly

Discuss the reasons for the choice

Answer product queries from clients

Categorise new products accurately

Read and comprehend literature about new

developments in the industry.



Substance that occupies space which has physical and chemical properties.

Exist in the form of a solid, liquid or gas.

Matter is all around us, even though we can not see air it is still matter. If air were not matter then we would not feel the wind when it blows.

Made up of atoms


Smallest particle of matter

Consist of the nucleus and the orbit

The nucleus contains protons (+) and neutrons (N) while electrons (-) orbit around the nucleus.

Atomic Mass = no. of proton + no. of neutrons

Atomic Number = no. of protons

Number of Electrons = no. of protons



Pure substance that can not be further

decomposed into other element.

E.g. Hydrogen, Oxygen, Carbon.



Pure substance which consists of

chemically combined elements and can be broken down into simpler substances only by chemical means.

E.g. Water = Oxygen (O) + Hydrogen (H) = H2O,

Carbon dioxide = Carbon (C) + Oxygen (O) = CO2

The smallest unit of compound is molecule.


Three types of chemical bonds:

1. Ionic Bonds:

Strongest, when a metal reacts with a non-

metal

Electrons form one atom are donated to the

atom.

2. Covalent Bonds:

When two non-metals react

Electrons are shared between the two atoms

3. Metallic Bonds:

When two metals react.



All matter is composed of atoms, which react to form molecules. Matter that we see, touch, smell and taste everyday is a combination of both atoms and molecules and these combination are classified into two different properties of matter as:

Physical properties of matter

Chemical properties of matter


Physical properties can be seen, felt and

smelt.

Most physical properties of matter can be

easily evaluated without the aid of scientific

instruments.


Physical properties of matter relating to cosmetic products are: Organoleptic Sensory characteristics such as colour and smell

Physical form or state Solid, Liquid and Gas.

Melting point Solid is heated into a liquid. In cosmetic products, a product with a

melting point close to that of the skin’s temperature will spread very easily.

Boiling Point Is the temperature when liquid turn into a gas. E.g. Fragrances are

composed of volatile molecules that evaporated easily.

Conductivity Ability to conduct electricity

Hardness and Softness Refer to the application of products such as lipstick.

Density To measure the weight per unit

Viscosity To describe the thickness of a product


The chemical properties of matter are difficult to examine without carrying out chemical reactions such as:

Elemental composition

pH

Chemical reactivity

Stability

Irritation potential Buffers

Corrosiveness Oxidation Reactions


Buffers

A substance that acts as a store of acid or alkali.

E.g. For an alkali product, an acid would be added and vice versa for an acidic product that an alkali would be added instead.

Oxidation Reactions

When oxygen is combined with the chemical properties.

Reduction

The chemical reaction which accompanies oxidation, but in which a substance loses oxygen. E.g. Fruits


An atom or a molecule that contains an

unpaired electron which can be extremely

reactive.

It is capable of engaging in a chain reactions

which destabilise other molecules and

generated many more free radicals.


The chemistry of materials derived from living things

The chemistry of carbon based chemicals.

Carbon has some unique properties and its ability to bond with other carbon atoms to form long chains.

Carbon containing compounds behave differently to non-carbon or inorganic containing compounds.


There are many types of organic chemicals

which include the following:

Hydrocarbons

Carbohydrates

Alcohols

Carboxylic Acids

Proteins

Lipids


Proteins aid moisturising capability

Proteins are polymers of amino acids.

Amino acids are the building blocks of

protein.

There are around 23 naturally occurring

proteins, 8 are described as “essential”

amino acids which the body cannot produce.

Amino acids are made up of the elements of

Carbon, Hydrogen, Oxygen and Nitrogen.


Proteins are usually subdivided into two major groups:

Soluble Albumins, e.g. Lactalbumin Enzymes, e.g. Lactose dehydrogenase Globins, e.g. Haemoglobin

Insoluble Collagens Elastins Keratins Chitins Wheat proteins


They are characterised by being insoluble in water but soluble if a surfactant such as soaps or detergent which can bind water at one end of the molecule and the lipid at the other. This forms a head and tail structure of hydorphilic and lipophilic ends.

Lipids can be broken into two categories: Nonsaponifiable Saponifiable


Nonsaponifiable Saponifiable

Can not be broken down

by strong alkalis or be

made into soaps.

Nonsaponifiable lipids are

the basis of many body

chemicals such as

cortisone, vitamin D,

testosterone and

progesterone.

Can be made into soaps when attached by strong alkalis such as sodium hydroxide or potassium hydroxide.

They are broken down into two further classes:

1. Simple lipids, comprise of oils, fats and waxes.

2. Complex lipids, such as phospholipids and sphingolipids.


The simplest and most abundant lipids are the triglycerides which consist of a backbone of glycerol (alcohol) with three fatty acids.

Lipids may be of animal origin such as: Lanolin, Emu oil, Fish oil, Beeswax

Plant derived oils of saturated oils: Coconut, cottonseed, cocoa butter

Unsaturated oils (less stable products) include: Sunflower, Safflower, Evening Primrose

Waxes Protective functions as they are waterproofing,

flexible and non reactive. The larger molecules weight waxes such as carnauba

and candela are required in lipsticks to maintain the crayon shape.


There are two major classes of complex

lipids are found in cosmetic products:

Phospholipids

Also known as lecithins and used as

surfactants.

Various phospholipids are used to make

liposomes.


Liposomes are sub-microscopic in size and are very tiny balls of lipids.

The selected lipids are capable of forming bi-layers because they have hydrophilic and hydrophobic ends. The centre of the ball consists of water and water soluble chemicals.

Liposomes are a good delivery vehicle of cosmetic products to the skin. The surfactant bi-layer provides a protective film for both the oil and water soluble ingredients and so stable formulations can be prepared where simple emulsion would be unstable.


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2010.7.28.Cosmetic Chemistry