| CPC A61K 9/127 (2013.01) [A61K 9/1271 (2013.01); A61K 9/1278 (2013.01); A61K 31/7068 (2013.01)] | 6 Claims | 

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               1. A method of producing a liposome composition, the method comprising the following steps: 
            (a) preparing empty liposomes by an O/W type emulsification of an oil phase, wherein said oil phase comprises hydrogenated soybean phosphatidylcholine, cholesterol, and 1,2-distearoyl-3-phosphatidylethanolamine-polyethlene glycol dissolved in an organic solvent, and an aqueous phase having pH 5-9, and removing the organic solvent after forming the empty liposomes; 
                (b) preparing a drug solution by dissolving gemcitabine or a salt thereof at pH 1-5; 
                (c) mixing the empty liposomes and the drug solution; 
                (d) adjusting pH with a pH adjuster; and 
                (e) heating to 55° C. or higher at pH 5.0 to 13, 
                wherein the liposome composition comprises liposomes which encapsulate gemcitabine or a salt thereof, wherein a lipid forming the liposomes comprises hydrogenated soybean phosphatidylcholine, cholesterol, 1,2-distearoyl-3-phosphatidylethanolamine-polyethlene glycol and a lysophospholipid produced by hydrolysis of hydrogenated soybean phosphatidylcholine, 
                a content ratio of gemcitabine or a salt thereof to the lipid is 2 mass % to 10 mass %, and 
                a content ratio of the lysophospholipid contained in the lipid forming the liposomes with respect to a total amount of hydrogenated soybean phosphatidylcholine contained in the liposomes is 0.01 mol % to 3 mol %. 
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