Sc. Yu et al., Design and evaluation of an original o/w/o multiple emulsion containing natural cyclodextrins as the emulsifier, STP PHARM S, 9(3), 1999, pp. 273-277
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
.