It is the process of dissolving poorly soluble solute molecules in water in the presence of surfactants. Mc Bain introduced this term in 1937.
The exact mechanism of solubilization is not clear yet. When surfactants with proper HLB values are added to a liquid in very lo v concentrations, the solution behaves as an ideal one.
Surfactant molecules in the solution tend to orient themselves at the liquid-air interface. Addition of surfactant may be continued until all available space is saturated and beyond which the surfactant is forced back into the bulk of the liquid. At still higher concentrations, the surfactant molecules or ions tend to aggregate to form micelles.
Thus micelles are the aggregates of 100 to 150 surfactant molecules. Solubilization concept has been profitably employed in pharmaceutical practice. Water insoluble substances are solubilized using various techniques of solubilization.
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Generally low toxicity soaps are used to provide micelles. Cholesterol can also be solubilized to an appreciable extent by soaps. Proprietary disinfectants such as Lysol, chloroxyxylenol solution and hexachlorophene liquid soaps are formulated on the basis of solubilization phenomenon.
Lyophilic surfactants with HLB values higher than 15 are considered to be the best solubilizing agents.