2.8. Determination of particle droplet size distribution
Droplet size distribution was measured immediately after the
emulsion preparation and after 5, and 30 days of storage using a
Malvern Mastersizer 2000 (Malvern Instruments Ltd, Worcestershire,
UK) laser diffraction particle size analyser using the small
volume sample dispersion unit Hydro 2000SM (Malvern Ltd, UK).
Refractive index of hexadecane and dispersion medium (citric
buffer, 10 mM, pH 3.0) was set to 1.435 and 1.333, respectively.
Consequently, droplet size was described using the surfaceweighted
mean diameter (d32). The measurements were performed
in duplicate in three different emulsion preparations
yielding in total six replicates for each sample.