Encapsulation of lipophilic fragrance by polymerization of the intermediate aqueous phase of an oil-in-water-in-oil (O/W/O) double emulsion

Abstract

This paper deals with the encapsulation of lipophilic compounds in an oil-in-water-in-oil (O/W/O) double emulsion. Such encapsulation is of special interest in cosmetics where fragrance is generally a mixture of various lipophilic reactive species. One of the most important challenges in encapsulation is to prevent the immediate leakage of the encapsulated species. In this context, our strategy was to develop capsules by separating the compartments containing the compounds to encapsulate and the locus of polymerization. This is achieved by polymerizing the water phase of an O/W/O double emulsion. In the first part, the formulation and the free radical polymerization of reverse (W/O) simple emulsions with various hydrophilic monomers were studied. Two monomers were selected: methacrylamide (MAM) and oligoethyleneglycolmethacrylate (OEGMA). In the second part, O/W/O double emulsions were formulated and several compositions for which only multiple droplets have been observed were identified. Then, the aqueous phase was polymerized. Conversion of monomers was not complete, although the polymerizations occurred without coagulum.