The universality of low-energy nano-emulsification

Extensive studies have been done on nano-emulsions and emulsification methods to provide nanometric-scaled templates for the formulation of nanoparticles. The so-called "low-energy" methods are of particular interest as they prevent the potential degradation of fragile encapsulated molecules. This work deals with new concepts in nano-emulsification using low-energy methods. Three-model ternary systems, water/nonionic surfactant/oil, were studied and compared. Nano-emulsions were generated using both spontaneous emulsification and the PIT method, so as to study the links between these two nano-emulsification methods. The influence of the composition and formulation variables on the nano-emulsion properties and emulsification procedures were thus investigated. This study pioneers the concept of the universality of low-energy nano-emulsification, proving that all these low-energy methods (i.e. spontaneous emulsification and the phase inversion temperature (PIT) method) are governed by a single unique mechanism. It thus provides a better understanding of low-energy nano-emulsification processes and notably the PIT method, useful in the fields of nanoparticle and nano-pharmaceutic formulations. These results are fundamental in establishing experimental procedures for the incorporation of drugs in nano-emulsions. (C) 2009 Elsevier B.V. All rights reserved.