Hydrophilic–lipophilic balance (HLB) is the balance of the size and strength of the hydrophilic and lipophilic moieties of a surfactant molecule. The HLB scale ranges from 0 to 20. In the range of 3.5 to 6.0, surfactants are more suitable for use in W/O emulsions.
What do you mean by HLB system?
Hydrophilic Lipophilic Balance The HLB system, which stands for “Hydrophilic Lipophilic Balance”, indicates how the proportion of those groups will affect surfactant behavior in emulsions. HLB numbers correspond to the degree of water or oil solubility of a particular surfactant. Lower HLB numbers indicate better oil (non-polar) solubility.
What is HLB system and its method for estimation?
In the HLB System, each emulsifier is assigned a numerical value which we call its HLB. … An emulsifier that is lipophilic in character is assigned a low HLB number (below 9.0), and one that is hydrophilic is assigned a high HLB number (above 11.0). Those in the range of 9-11 are intermediate.
What is HLB in physical pharmacy?
HLB is an acronym for hydrophilic-lipophilic balance. It is based on the idea that some molecules of surfactants may have hydrophilic groups.
Who proposed HLB system?
William C. Griffin Created by William C. Griffin in the late 1940s, the HLB System is one of the most successful strategies for developing stable emulsions.
Why is HLB calculated?
HLB is an index of the solubilizing properties of emulsifiers and indicates the type of emulsion (o/w or w/o) that the emulsifier is best suited for (Table 2). HLB values can be calculated based on the molecular structure of the emulsifier or determined empirically.
Is zwitterionic a surfactant?
Zwitterionic or amphoteric surfactants are surfactants that carry both a positive and a negative charge. As stated, these charges can either be permanent or dependent on the pH value.
How is HLB value calculated?
HLB= E / 5 can be calculated with this equation. E: Percentage by weight of ethyleneoxide • HLB value of fatty acid esters of polyhydric alcohols such as glyceryl monostearate, HLB= 20 [1-(S / A)] is calculated with that equation. The HLB values of some of the most frequently used surfactants are shown in Table 11.1.