KINETICS OF SWELLING-BREAKDOWN OF A W O/W MULTIPLE EMULSION - POSSIBLE MECHANISMS FOR THE LIPOPHILIC SURFACTANT EFFECT/

The properties and behavior of a W/O/W multiple emulsion formulation w ere analyzed during a swelling-breakdown process. Various experimental analyses, such as granulometry, rheology and conductimetry were perfo rmed, as well as a micropipette aspiration method. The predominant rol e of the lipophilic surfactant during the swelling phase was confirmed . Two different mechanisms can be proposed, Both imply the migration o f the lipophilic surfactant from one interface to another and probably take place successively. The lipophilic surfactant could diffuse from the first to the second interface, thus rigidifying the membrane, or from the oily phase to the first interface, resulting in delayed coale scence of the aqueous droplets during swelling, (C) 1998 Elsevier Scie nce B.V.