PROBLEM TO BE SOLVED: To provide a method for producing liposomes, by which liposomes including a large number of unilamellar (univesicular) liposomes which have a nano-sized particle diameter, while maintaining a relatively high encapsulation rate can be efficiently obtained and which enables the production of liposomes which include almost no multivesicular liposomes and are particularly suitable for water-soluble drugs.SOLUTION: The method for producing liposomes comprises: a primary emulsification step wherein a W1/O emulsion is prepared a secondary emulsification step wherein a W1/O/W2 emulsion is prepared by emulsifying the W1/O emulsion and an aqueous solvent (W2) using a membrane that has a pore diameter of not less than 0.1 &mum but not more than 5.0 &mum and a step wherein a suspension of liposomes is prepared by removing the organic solvent contained in the W1/O/W2 emulsion. SPG (Shirasu Porous Glass) membrane is preferable as the membrane.COPYRIGHT: (C)2011,JPO&INPIT【課題】ナノサイズの粒径を有し、比較的高い内包率を維持しながら単層(単胞)のものを多く含むリポソームが効率的に得られ、多胞リポソームのほとんど無い、特に水溶性薬剤に適したリポソームの製造方法を提供する。【解決手段】W1/Oエマルションを調製する一次乳化工程;当該W1/Oエマルションと水性溶媒(W2)とを、0.1μm以上5.0μm以下の細孔径を有する膜を用いて乳化し、W1/O/W2エマルションを調製する二次乳化工程;および当該W1/O/W2エマルションに含まれる有機溶媒を除去することによりリポソームの懸濁液を調製する工程;を有することを特徴とするリポソームの製造方法。上記膜としてはSPG膜が好ましい。【選択図】なし
