INTRODUCTION
Emulsions are unstable colloidal systems that undergo many destabilisation
phenomena (coalescence, flocculation, creaming, etc.) that can be due to various
causes (lack of surfactant to cover the interface, attractive forces, etc.). Therefore, it
is very important for the formulator to know the origins of these processes to be able
to overcome them to get a stable product.
One of the factor responsible for flocculation is the depletion due to the coexistence
of small entities (micelles, microemulsions) and big droplets (emulsion). The latters
undergo an osmotic pressure from the small ones that lead to a compression of the
big drops. This depletion force is attractive and of low energy, hence it is reversible
upon dilution
