EP1190705A1 — Method of regulating leakage of drug encapsulated in liposomes

USPTO Abstract

The present invention provides a method of inhibiting the leakage of a drug encapsulated in liposomes, which comprises satisfying at least two requirements selected from the group consisting of the following three requirements: using at least two lipid bilayers of the liposomes, controlling the average particle size of the liposomes to 120 nm or more, and using lipid having a phase transition temperature higher than in vivo temperature as lipid constituting the liposomes. Also, the present invention provides a liposome preparation which is stable in vivo and satisfies at least two requirements selected from the group consisting of the following three requirements: the number of lipid bilayers of the liposomes is at least two, the liposomes have an average particle size of 120 nm or more, and lipid constituting the liposomes has a phase transition temperature higher than in vivo temperature.