Method for producing liposome

A method for producing liposomes, comprising:

• a step of mixing an oil phase with at least one lipid dissolved in an organic solvent and a water phase and stirring an aqueous solution containing the lipids to thereby prepare an O/W emulsion in which oil phase and water phase are emulsified;
• a step of evaporating the organic solvent from the aqueous solution containing the lipids obtained in the stirring step to form liposomes;
• and
• a step of sterile filtration,
• wherein the organic solvent comprises a mixture of a water-soluble organic solvent and an ester based organic solvent, wherein the water-soluble organic solvent comprises ethanol and wherein the ester-based organic solvent comprises ethyl acetate, and wherein the content of ethyl acetate is 20% to 30% by mass,
• the particle size of the liposomes is 2 to 100 nm,
• sizing processing is not carried out since the liposomes are miniaturized only by stirring step,
• the concentration of the organic solvent contained in the aqueous solution containing the lipids is 15 mass % or less within 30 minutes from after the start of the step of evaporating the organic solvent,
• the step of stirring imparts shearing at a circumferential speed of 20 m/sec or more to the aqueous solution containing lipids, and
• the concentration of the lipid is 40 g/L to 200 g/L in terms of a solution where a mixed solution of a water-soluble organic solvent and an ester-based organic solvent serves as a solvent.