Emulsifier or emulsifying agent and emulsion

Emulsifier or emulsifying agents are the substance which used to increase the stability of emulsion.

  

It is also known as the emulgent. Emulgent (Emulsifying agent) is also known as the surfactants.

  

These agents have both a hydrophilic and a lipophilic part in their chemical structure.HLB scale is used to decide the which emulsifying agents shall be used 

Emulsifying agent works by following way:

1) Formation of a protective barrier

2)Reduction of interfacial tension

3) Decreasing the potential for coalescence by forming an electrical double layer.

some commonly used emulsifying agents include tragacanth, sodium lauryl sulfate, sodium dioctyl  sulfosuccinate, Spans, Tweens, CMC, poly sorbate 

Emulsifying agents can be classified according to Chemical structure

• Natural emulsifying agent
• Semi synthetic emulsifying agent
• Synthetic emulsifying agent

• Natural emulsifying agent:

The emulsifying agent which derived from natural origin is known as the natural emulsifying agent.

They are may b from plant origin or animal origin.

The plant origin emulsifying agent is carbohydrates and include gums and mucilaginous substances. They are variable in chemical composition and their emulsifying property.

Agar, tragacanth, alginates, gum, pectins,acacia, starch are the example of natural plant origin emulsifying agents.

The animal origin emulsifying agent :

Gelatin, albumin, Lecithin, cholesterol

• Semi synthetic emulsifying agent:

Semi synthetic emulsifying agent is the emulsifying agent which are mainly from cellulose derivatives.

methylcellulose, carboxymethylcellulose are example of semi synthetic emulsifying agents

• Synthetics emulsifying agent:

The agent which synthetically derived.

They are categorized as 

Cationic:

Cationic emulsifying agents are the emulsifying agent in which hydrophilic side content positive charged ion.

Example: benzalkonium chloride, benzethonium chloride

Anionic:

anionic emulsifying agents are the emulsifying agent in which hydrophilic side content negative charged ion.

Example: sodium oleate potassium oleate, triethanolamine stearate, detergents (sodium lauryl sulfate, sodium dioctyl sulfosuccinate, sodium docusate).

 Nonionic:

Nonionic emulsifying agents are the emulsifying agents in which hydrophilic both positive and negative charges.

 Example:

sorbitan esters, Spans, polyoxyethylene derivatives of sorbitan esters (Tweens), glyceryl esters 

Difference between Emulsion and Suspension 
Definition of Emulsion, Types of Emulsion  
Application of Emulsion 
Pharmaceutical industry and Emulsion 
HLB Scale and Emulsifying Agent  
What is Mayonnaise Emulsion