2010.7.28.Cosmetic Chemistry

 Cosmetic:

 Substances used to improve or beautify appearance.

 Chemistry

 The study of substances – their composition, properties and interactions with each other.

 The study of the composition, properties and

effects of those substances applied to the skin, nails and hair for the purpose of

 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

 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.



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

 Pure substance that can not be further

decomposed into other element.



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:

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

 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

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

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 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.