Design and evaluation of an original o/w/o multiple emulsion containing natural cyclodextrins as the emulsifier

In this work, the potential of alpha-, beta- and gamma-natural cyclodextrin s as an emulsifier agent was studied in order to prepare stable oil/water/o il multiple emulsions without the addition of surfactants. The stabilizatio n of the multiple emulsions could result from the complexation of natural c yclodextrin with oil components at the oil/water interface. It appeared tha t emulsifier efficiency depended oil rite nature of the cyclodextrin used ( alpha- > beta- > gamma-). In the presence of a hydrophobic model molecule ( benzophenone) in the inner oil phase, only the multiple emulsions prepared with alpha-cyclodextrin were stable. The stability of the emulsions could b e determined by the equilibrium bent een cyclodextrin/soybean oil and cyclo dextrin/benzophenone complexation. The interactions between benzophenone an d cyclodextrin were evaluated by solubility diagrams and circular dichroism .