Pharmaceutical composition of small-sized liposomes and method of preparation

• US 20060078605A1
• Filed: 08/28/2003
• Published: 04/13/2006
• Est. Priority Date: 08/29/2002
• Status: Abandoned Application

• Current Assignee: Carlos Alberto Genaro Mammarella
• Original Assignee: Carlos Alberto Genaro Mammarella
• Inventors: Mammarella, Carlos Alberto Genaro
• Application Number:
  US10/526,180
• Publication Number:
  US 20060078605A1
• Time in Patent Office: Days
• US Class Current: 424/450
• CPC Class Codes: A61K 9/127 Liposomes
• CPC Class Codes: A61K 9/1271 Non-conventional liposomes, e.g. PEGylated liposomes, liposomes coated with polymers liposome as conjugate A61K47/6911

Abstract

A pharmaceutical composition of small sized unilamellar liposomes for the supply active principles by injection, with an improved permanency in the blood flow, where the unilamellar membrane contains a mixture of saturated lipids encompassing at least one lysophospholipid in a quantity from about 0.5 mol % to about 6.0 mol % with reference total lipids and the production method. Additionally, liposomes of high encapsulation efficiency of an active principle like doxorubicine are prepared through the adding of a solution of calcium ions.

Claims

1. A pharmaceutical composition of small-sized, unilamellar liposomes, for parenteral administration of an active compound, comprising:

liposomes with an average diameter from about 75 nm to about 300 nm, wherein the unilamellar membrane contains a mixture of saturated lipids, said unilamellar membrane containing at least one lysophospholipid in an amount of about 0.5 mol % to 6.0 mol % regarding the total lipid content, and a therapeutic compound being encapsulated inside said liposomes.

2. A composition according to claim 1, wherein the lysophospholipid is selected from lysophosphatidylcholine, lysophosphatidylinositol, lysophosphatidylserine and lysophosphatidic acid or combinations thereof.

3. A composition according to claim 1, wherein the saturated lipids are selected from phosphatidylcholine, cholesterol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylglycerol, natural phosphatidylcholine (soy and/or egg), distearoyl phosphatidylethanolamine derivatized with O-methylated polyethyleneglycol 750-5000, dipalmitoyl phosphatidylethanolamine derivatized with O-methylated polyethyleneglycol 750-5000 or combinations thereof.

4. A composition according to claim 3, wherein distearoyl phosphatidylethanolamine is derivatized with O-Methyl-polyethylene-glycol 2000.

5. A composition according to claim 3, wherein dipalmitoyl phosphatidyl ethanolamine is derivatized with O-methyl-polyethylene-glycol

6. A composition according to claim 1, wherein the active principle is a cytotoxic agent.

7. A composition according to claim 6, wherein the cytotoxic agent is selected from anthracyclinic antibiotics, taxanes and platinum salts.

8. A composition according to claim 7, wherein the anthracyclinic antibiotic is selected from the group consisting in doxorubicin, epirubicin and daunorubicin and pharmaceutically acceptable salts thereof.

9. A pharmaceutical composition of unilamellar, small sized liposomes for parenteral administration of an active compound, according to claim 1, comprising:

liposomes with an average diameter from about 75 nm to about 300 nm, wherein said unilamellar membrane contains a mixture of saturated lipids, comprising at least one lysophospholipid in an amount of about 0.5 mol % to about 6.0 mol % related to the total lipid content, and encapsulated doxorubicin inside said liposomes in a ratio of about 8.5% by weight to about 11.5% by weight related to the total weight of lipids in the liposomes.

10. A method of preparing a composition according to claim 1, comprising the steps of:

forming liposomes from a solution containing saturated lipids and at least a lysophospholipid in an amount of about 0.5 mol % and 6.0 mol % regarding the total lipid content, and evaporation to dryness;

taking the film up in aqueous solution;

submitting the foregoing solution to freezing and thawing cycles extruding through membranes of decreasing pore up to a membrane of 50 nm pore, obtaining liposomes with an average diameter of about 75 nm to about 300 nm, dialyzing the liposome suspension, and mixing the dialyzed liposome suspension with a solution of the active compound.

11. A method according to claim 10, wherein the lysophospholipid is selected among lysophosphatidylcholine, lysophosphatidylinositol, lysophosphatidylserine and lysophosphatidic acid.

12. A method of preparing a composition of claim 9, comprising the steps of:

forming liposomes from a solution containing saturated lipids and at least a lysophospholipid in an amount of about 0.5 mol % to 6.0 mol % regarding the total lipid content, and evaporating to dryness;

taking the film up in a solution of an ammonium salt;

submitting the foregoing solution to freezing and thawing cycles extruding through membranes of decreasing pore up to a membrane of 50 nm pore, obtaining liposomes with an average diameter of about 75 nm to about 300 nm;

dialyzing the liposome suspension against an aqueous solution without ammonium ions;

mixing the dialyzed liposome suspension with a solution of about 50 mM to about 200 mM of a soluble calcium salt and a solution of doxorubicin at a concentration of about 2 to about 30 mg/ml, obtaining a percentage of more than 80% of encapsulation of doxorubicin.

13. A method according to claim 12, wherein the calcium salt is calcium chloride.

14. A method according to claim 12, wherein the volume ratio of calcium chloride solution to doxorubicin solution is of 1:

10 (v;

v).

15. A method according to claim 12, wherein the percentage of encapsulated doxorubicin increases between 20 to 70% in the presence of calcium chloride, compared to a method which does not use calcium chloride.

16. A method according to claim 13, wherein the volume ratio of calcium chloride solution to doxorubicin solution is of 1:

10 (v;

v).