Abstract: The invention provides liposomes characterized in that the lipid membrane thereof contains a glycolipid resulting from O-glycoside or S-glycoside bonding of a lipid and at least one carbohydrate selected from the group consisting of uronic acids, uronosyl-oligosaccharides, oligosaccharides composed of glucosamine and glucuronic acid, oligosaccharides composed of galactosamine and glucuronic acid, oligosaccharides composed of glucuronic acid and xylose, oligosaccharides composed of glucuronic acid and glucose, oligosaccharides composed of glucuronic acid and galactose, oligosaccharides composed of glucuronic acid and mannose, oligosaccharides composed of galacturonic acid and rhamnose, ketoaldonic acids, 2-acetamido-2-deoxyuronic acids, 2-acetamido-2-deoxyuronic acid-containing oligosaccharides, 6-O-carboxyethyl-.beta.-D-glucose, 6-O-carboxymethyl-.beta.-D-glucose, 6'-O-carboxymethyl-.beta.-D-maltose and 6'-O-carboxyethyl-.beta.-D-maltose.

Abstract: The present invention provides(1) a method for preparing lipid powder for use in the preparing liposome, which comprises supplying at a constant speed an organic solvent solution of lipids having liposome membrane forming ability to a tubular heater heated externally, evaporating the organic solvent in the heater to prepare a mixture substantially of solids and organic solvent vapor and introducing this mixture at a high speed into a vacuum chamber of not more than 300 mm Hg, to volatilize the organic solvent instantaneously and dry the solids, and(2) a method for preparing liposomes comprising dispersing the lipid powder obtained by the above method (1) into an aqueous solvent.

Abstract: This invention provides a process for preparing a phosphatidylcholine derivative represented by the formula ##STR1## wherein R represents straight- or branched-chain andsaturated or unsaturated hydrocarbon group, the process comprising the steps of(i) providing a suspension or solution of glycerophosphatidylcholine and a carrier in a solvent and removing the solvent from the suspension or solution by distillation to obtain a powder, and(ii) reacting the glycerophosphatidylcholine present in the powder with an acid anhydride or acid halide in a solvent and in the presence of a basic catalyst to acylate the glycerophosphatidylcholine.