HLB Scale (hydrophile-lipophile
balance) and emulsifying Agent:
We discussed about the emulsifying agent(emulsifier).
To select appropriate emulsifying
agent we used the HLB SCALE system.
HLB Scale means
hydrophile-lipophile balance.
HLB system was developed by
William C. Griffin to proper selection of the emulsifying agent.
All emulsifying agents have
lipophilic and hydrophilic part. HLB value of emulsifying agent is based on the
lipophilic and hydrophilic group present into the emulsifying agent.
The HLB value is an indication of
the solubility of the Emulsifying agent.Generally HLB scales apply to the
non-ionic surfactant.
HLB system has an arbitrary scale of
1 - 18.
HLB RANGE
|
USE
|
0-3
|
Anti foaming agent
|
4-6
|
W/O emulsifying agent
|
7-9
|
wetting agent
|
8-18
|
O/W emulsifying agent
|
13-15
|
Detergents
|
10-18
|
stabilizing agent
|
-Higher the HLB value means more
number of hydrophilic groups in the molecule.
Mean more water soluble or
hydrophilic the surfactant is.
-The lower the HLB value the more
lipophilic or oil soluble the surfactant mean more lipid soluble or
lipophilic surfactant is.
-Emulsifying agents exhibiting an
HLB between 3 to 6 are used to produce w/o emulsions.so they are known as w/o
emulsifying agents.
-Example: span 80
-HLB value span 80 of 4.3
-Emulsifying agents that exhibit an
HLB between 6 to 9 form non-stable milky dispersion in water.
-Example: span 40
-HLB Value of span 40 is 6.7
-Emulsifying agents exhibiting an
HLB between 9 to 16 are used to produce o/w emulsions. so they are known
as o/w emulsifying agents. 13–16). Examples include:
-Example: Tween 65
-HLB value of Tween 65 is 10.5
some example:
HLB RANGE
|
USE
|
PEG 400 Monostearate
|
11.6
|
Span 40
|
6.7
|
Span 20
|
8.6
|
Tween 20
|
16.7
|
Tween 40
|
15.6
|
Tween 65
|
10.6
|
Tween 85
|
11.0
|
Sodium oleate
|
18
|
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