Method for releasing an active principle contained a multiple emulsion
First Claim
1. A process for releasing an active principle comprising a multiple emulsion wherein the multiple emulsion comprises a water-in-oil-in water emulsion comprising an inverse emulsion Ei with an aqueous phase A1, in dispersion in the form of droplets of direct emulsion Ed, in a continuous aqueous phase A2, wherein the emulsion Ed is stabilized by a surfactant having an HLB of greater than 14 present in its continuous phase;
- the emulsion Ei is stabilized by a surfactant having an HLB of less than 7 present in its continuous phase; and
the amount of the surfactant present in the aqueous phase A2 of the emulsion Ed is adjusted to an amount greater than the critical concentration threshold of this surfactant, for converting said multiple emulsion into a direct-emulsion, with a concentration threshold being between 7 and 20 CMC (Critical Micelle Concentration) for a surfactant having an HLB of the order of 40 and greater than 100 CMC for a surfactant having an HLB between 14 and 20 CMC;
wherein the active principle is in solution in the aqueous phase A1 and said active principle is released into the aqueous phase A2 by adjusting the concentration of the surfactant present in said aqueous phase A2 with the release time being shorter at concentrations equal to or greater than this surfactant'"'"'s critical concentration threshold.
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Abstract
A method for the controlled release of an active principle contained in a multiple water-in-oil-in-water emulsion characterized in that the multiple emulsion comprises an invert emulsion Ei with an aqueous phase A1 containing at least a hydrophilic active principle. The emulsion Ei is dispersed in the form of direct emulsion droplets Ed, in a continuous aqueous phase A2, with the two emulsions Ed and Ei stabilized by at least a surfactant, present in their respective continuous phases. The multiple emulsion is brought in the presence of an effective amount of an agent for transforming it into a direct emulsion and induce the release of the active principle, contained in the aqueous phase A1 of emulsion Ei, in the aqueous phase A2.
78 Citations
9 Claims
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1. A process for releasing an active principle comprising a multiple emulsion wherein the multiple emulsion comprises a water-in-oil-in water emulsion comprising an inverse emulsion Ei with an aqueous phase A1, in dispersion in the form of droplets of direct emulsion Ed, in a continuous aqueous phase A2, wherein the emulsion Ed is stabilized by a surfactant having an HLB of greater than 14 present in its continuous phase;
- the emulsion Ei is stabilized by a surfactant having an HLB of less than 7 present in its continuous phase; and
the amount of the surfactant present in the aqueous phase A2 of the emulsion Ed is adjusted to an amount greater than the critical concentration threshold of this surfactant, for converting said multiple emulsion into a direct-emulsion, with a concentration threshold being between 7 and 20 CMC (Critical Micelle Concentration) for a surfactant having an HLB of the order of 40 and greater than 100 CMC for a surfactant having an HLB between 14 and 20 CMC;
wherein the active principle is in solution in the aqueous phase A1 and said active principle is released into the aqueous phase A2 by adjusting the concentration of the surfactant present in said aqueous phase A2 with the release time being shorter at concentrations equal to or greater than this surfactant'"'"'s critical concentration threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- the emulsion Ei is stabilized by a surfactant having an HLB of less than 7 present in its continuous phase; and
Specification