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US 5,094,854 AGranted
Liposome composition useful for hypertheria therapy
AssigneeTakeda Chemical Industries, Ltd.
InventorsYasuaki Ogawa, Katsumi Iga, Yasutaka Igari
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Abstract
This invention relates to the liposome compositions which are characterized in that the phase transition temperature of the membrane is in the range of 40.degree. to 45.degree. C. and the osmotic pressure of a drug-containing solution to be entrapped in liposomes is 1.2 to 2.5 times higher than that of body fluid of warm-blooded animals. The compositions are useful for treatment of solid tumors in hyperthermia therapy.
Claims18
A liposome composition for hyperthermia therapy comprising:
- (1) liposomes entrapping a first aqueous solution containing an antitumor agent and an osmotic pressure controlling agent, said liposomes having a membrane which has a main component of phospholipids whose acyl groups are saturated acyl groups, said membrane having a phase-transition temperature of 40.degree.-45.degree. C., and said first aqueous solution having an osmotic pressure of 1.2 to 2.5 times higher than that of body fluid of warm-blooded animals, and
- (2) a second aqueous solution having an osmotic pressure in a ratio of about 0.8 to 1 relative to that of the body fluid of the warm-blooded animals into which said liposomes are dispersed,
- wherein the composition is injectable.
A method for producing a liposome composition for hyperthermia therapy, which comprises the steps of:
- (1) preparing a first aqueous solution containing an antitumor agent and an osmotic pressure controlling agent, said first aqueous solution having an osmotic pressure which is adjusted to 1.2 to 2.5 times higher than that of body fluid of warm-blooded animals,
- (2) mixing said first aqueous solution with a solution which is prepared by dissolving one or more members of phospholipids in an organic solvent to form a W/O emulsion, wherein said phospholipids have acyl groups which are saturated acyl groups and are capable of forming a liposome having a membrane with a phase-transition temperature of 40.degree. to 45.degree. C., and wherein said organic solvent is used in 0.8 to 3 volumes per unit volume of said first aqueous solution,
- (3) evaporating the organic solvent to prepare liposome vesicles entrapping the antitumor agent, wherein said liposome vesicles have a membrane with a phase-transition temperature of 40.degree. to 45.degree. C., and
- (4) dispersing the thus obtained liposomes in a second aqueous solution having an osmotic pressure in a ratio of about 0.8 to 1 relative to that of the body fluid of the warm-blooded animals,
- wherein the composition is injectable...
2 more elements
Dependencies are inferred from the claim text.