PRODUCTION OF A COMPOSITION CONTAINING A COMPLEX BETWEEN A MEMBRANE COMPOSED OF A LIPID MONOLAYER AND A NUCLEIC ACID, AND, A LIPID MEMBRANE FOR ENCAPSULATING THE COMPLEX THEREIN
The present invention relates to a method for producing a composition containing a complex between a membrane composed of a lipid monolayer (reversed micelle) and a nucleic acid, and a lipid membrane for encapsulating the complex therein, comprising the following steps A to D:Step A: preparing a complex between the nucleic acid and a liposome comprising a cationic lipid represented by the formula (I) and/or a cationic lipid other than cationic lipid represented by the formula (I)Step B: preparing a dispersion liquid by dispersing the complex in water or ethanol aqueous solutionStep C: preparing a solution by dissolving the formula (I) and/or the cationic lipid other than cationic lipid represented by the formula (I) in ethanol or an ethanol aqueous solution andStep D: mixing the dispersion liquid and the solution, and optionally adding waterwherein the formula (I) is(wherein:R1 and R2 are, the same or different, each linear or branched alkyl, alkenyl or alkynyl having 12 to 24 carbon atoms,X1 and X2 are hydrogen atoms, or are combined together to form a single bond or alkylene,X3 is absent or is alkyl having 1 to 6 carbon atoms, or alkenyl having 3 to 6 carbon atoms,when X3 is absent,Y is absent, a and b are 0, L3 is a single bond, R3 is alkyl having 1 to 6 carbon atoms, alkenyl having 3 to 6 carbon atoms, or alkyl having 1 to 6 carbon atoms or alkenyl having 3 to 6 carbon atoms substituted with 1 to 3 substituent(s), which is(are), the same or different, amino, monoalkylamino, dialkylamino, trialkylammonio, hydroxy, alkoxy, carbamoyl, monoalkylcarbamoyl, or dialkylcarbamoyl, and L1 and L2 are -O-,Y is absent, a and b are, the same or different, 0 to 3, and are not 0 at the same time, L3 is a single bond, R3 is alkyl having 1 to 6 carbon atoms, alkenyl having 3 to 6 carbon atoms, or alkyl having 1 to 6 carbon atoms or alkenyl having 3 to 6 carbon atoms substituted with 1 to 3 substituent(s), which is(are), the same or different, amino, monoalkylamino, dialkylamino,
