Method for producing a vesicle composition
The present invention is a method for producing a vesicle composition having an aqueous phase as a continuous phase, the method including a step of dissolving an oil phase containing component (A) a branched fatty acid having a predetermined structure; component (B) a tertiary amine having a predetermined structure; and component (C) an organic acid having 1 to 10 carbon atoms at a temperature that is equal to or higher than a melting point of the oil phase, and a step of carrying out mixing while adding the aqueous phase to the oil phase which is dissolved.
1. A vesicle composition formed from components (A), (B) and (C) and water and having an aqueous phase as a continuous phase, a vesicle being contained in the vesicle composition at 4 times by volume or more relative to a content of component (A):
(A) a branched fatty acid represented by formula (1)
wherein the formula (1), R 1 represents a methyl group or an ethyl group, and n represents an integer of 5 to 36;
(B) a tertiary amine represented by formula (2)
wherein the formula (2), R 2 represents a straight-chain or branched alkyl or alkenyl group having 6 to 24 carbon atoms, R 3 and R 4 represent identical or different alkyl groups having 1 to 6 carbon atoms or -(AO)mH wherein AO represents an oxyalkylene group having 2 to 4 carbon atoms, m represents an integer of 1 to 6, the m AOs may be identical to or different from each other, and they may be in any sequence;
(C) an organic acid having 1 to 10 carbon atoms;
wherein the vesicle composition is produced by a method comprising a step of a phase inversion emulsification;
an optional component that can be added to the oil phase is not more than 1% of the oil phase;
the vesicle component does not include sterols; and
when the vesicle is spherical shape, an average particle size is 3-20 μm.
2. The vesicle composition according to claim 1 , further comprising (D) a polyhydric alcohol.