US Patent 7722891 Multiple emulsions

Storage stable multiple emulsions of a polar phase A1, a nonpolar phase B and a polar phase A2, or of a nonpolar phase B1, a polar phase A and a nonpolar phase B2, employ particulate solids smaller than 1 μm to stabilize the resulting A1/B/A2 or B1/A/B2 multiple emulsions against coalescence, with the proviso that surface-active substances are present only up to a maximum concentration of less than 0.1 times the critical micelle concentration of the surface-active substances in phase A, A1, A2. The multiple emulsions have numerous uses including controlled release of active substances from a dispersed phase.