An efficient method to determine the Hydrophile-Lipophile Balance of surfactants using the phase inversion temperature deviation of C E /n-octane/water emulsions.

Objective: The aim of this study was to develop a fast and an efficient method to determine the Hydrophile-Lipophile Balance (HLB) number of cosmetic and pharmaceutics surfactants.

Methods: This method is based on the deviation of the phase inversion temperature induced by the addition of the test compound, with respect to the phase inversion temperature of a reference system, which includes an ethoxylated surfactant. This method is called PIT-deviation.

Results: Three calibration curves are set up with three reference ethoxylated surfactants. These calibration curves make it possible to evaluate the interfacial behaviour of certain chemicals. More particularly, these curves make it possible to easily determine the surfactant HLB.

Conclusion: In this study, a fast and accurate method has been developed to determine the hydrophilic-lipophilic balance (HLB) number of amphiphilic chemicals. This new method can be applied to establish an HLB number of all commercial amphiphilic ingredients. Compounds which have a PIT-deviation close to zero are also discussed.