Chemistry Reference
In-Depth Information
Figure 5.7
75). The top insert repre-
sents an FFT of a particle revealing its internal nanostructure. [Reproduced from
Yaghmur et al. (2005) .]
Cryo-TEM observation of EME droplets (
α
=
5.4 STABILITY OF THE INTERNALLY OIL-LOADED
NANOSTRUCTURES
In order to prove that the composition of the oil-loaded internal nanostruc-
tures did not change with time, the dispersions' stability against ageing was
studied. Two examples of hexosomes and EMEs are presented in Figure 5.8.
Intriguingly, there was no change in the internal nanostructures of these dis-
persions after 4 months of storage at room temperature. The presented data
show that the oil molecules were maintained in the internal nanostructure of
the particles. There was no experimental evidence found for a leakage with
time, that is, the solubilized oil did not move from the internal nanostructures
to the continuous aqueous phase. In other words, there was no indication of a
formation of TC-rich normal O/W emulsion droplets in addition to the MLO-
rich nanostructured dispersion.
These fi ndings support our hypothesis that the internal structure of the
dispersed particles was formed only through self-assembly principles. On this
basis, there was no evidence of a reorganization of the lipid (and lipid-oil)
molecules during the preparation of the dispersions. Thus, these constituents
behaved as pseudocomponents at all investigated temperatures: The solubi-
lized oil (and water) was maintained in the MLO nanostructure during the
dispersing procedure. In other words, our results showed no indication of any
signifi cant change in the composition at the interfacial fi lm when a high-energy
input was applied in the presence of the polymeric stabilizer F127. It should
be pointed out that the reorganization of the lipid (and oil) molecules could
be induced by replacing the primary surfactant MLO by any surfactant that
would not remain bound with oil and water during the dispersing procedure.
Search WWH ::
Custom Search