Droplet size and zeta potential are critical indicators of emulsion stability

Emulsions are two phase dispersion of liquids that are normally not miscible. The most common examples are oil in water and water in oil emulsions. The Emulsion - Particle Sizing Systemsparticle size and zeta potential of the emulsion droplets are important physical characteristics that influence emulsion stability. The droplet size can be measured on either the Nicomp DLS system or the AccuSizer SPOS system. The Nicomp can also measure the zeta potential during the formulation in order to optimize the surface chemistry to optimize dispersion stability.

AccuSizer for measuring emulsions

Specific applications where the AccuSizer is extensively used to measure emulsions droplet size includes lipid injectable emulsions (total parenteral nutrition, or TPN) following the USP <729> Method II testing procedure and soft drink flavor emulsions.

The Nicomp is often used for USP <729> Method I testing and microemulsions.


Read the sections below for additional information on these applications.

Soft Drink Emulsions

Flavoring emulsions used in the production of bottled soft drinks must consist of droplets of uniform size that are small enough to prevent agglomeration or Ostwald ripening, both of which can result in the “breaking” of the emulsion and formation of a cosmetically undesirable “neck ring” inside the bottle. Since the process leading up to the neck ring is gradual, it can be detected in it’s early stages.