| abstract |
The invention concerns a method for preparing a multiple emulsion comprising an invert emulsion consisting of an internal aqueous phase dispersed in an internal organic phase, dispersed in an external aqueous phase: the internal aqueous phase comprising optionally at least a hydrophilic active substance; the internal organic phase comprising optionally at least a hydrophobic active substance; the invert emulsion comprising at least an internal surfactant and/or at least an internal amphiphilic polymer; the external aqueous phase comprising optionally at least a hydrophilic active substance and at least an external surfactant and/or an external amphiphilic polymer. The inventive method is characterized in that it comprises the following steps: a) preparing the invert emulsion; b) preparing the external aqueous phase; c) introducing the external aqueous phase in the invert emulsion, without stirring; d) stirring the whole emulsion; e) optionally diluting the resulting concentrated multiple emulsion, by adding while stirring, a diluting aqueous phase comprising at least an external surfactant and/or at least an external amphiphilic polymer so as to obtain a diluted multiple emulsion. |