Formulation of shear rate sensitive multiple emulsions.

This work mainly concentrates on the formulation of W/O/W multiple emulsions capable of breaking and releasing their inner aqueous phase under shear rates compatible with agroalimentary, pharmaceutical and cosmetic applications. Three kinds of multiple emulsions were studied: one with a high concentration of primary emulsion, not viscosified in the external aqueous phase; multiple emulsions gelified with a synthetic polymer (Carbopol 974P((R))); and other multiple emulsions thickened with chemically modified cellulose (hydroxypropylcellulose). The results of this study show the influence of the composition of the external aqueous phase of the emulsions on their fragmentation and release as a function of the shear rate. Despite these differences of behavior with respect to the shear rate, each emulsion fits to Taylor's theoretical framework, indicating that the bursting mechanisms of the globules under shear are the same whatever the composition of the multiple emulsions.