Magnetically-localizable, biodegradable lipid microspheres

• US 4,331,654 A
• Filed: 06/13/1980
• Issued: 05/25/1982
• Est. Priority Date: 06/13/1980
• Status: Expired due to Term

• Current Assignee: Eli Lilly and Company
• Original Assignee: Eli Lilly and Company
• Inventors: Morris, Robert M.
• Primary Examiner(s): Schwartz, Richard A.
• Application Number:
  US06/159,321
• Time in Patent Office: 711 Days
• Field of Search: 424/14, 424/199, 424/38, 128/1.3, 252/62.53
• US Class Current: 424/450
• CPC Class Codes: A61K 9/5094 Microcapsules containing magnetic carrier material, e.g. ferrite for drug targeting
• CPC Class Codes: G01N 2446/20 the magnetic material being present in the particle core
• CPC Class Codes: G01N 2446/80 characterised by the agent used to coat the magnetic particles, e.g. lipids

Abstract

Drug carrier formulation consisting of magnetically-localizable, biodegradable lipid microspheres.

Claims

1. A magnetically-localizable, biodegradable, substantially water-free drug carrier formulation consisting essentially of lipid microspheres containing a magnetically-responsive substance, one or more biodegradable lipids and one or more non-toxic surfactants.

2. Microspheres according to claim 1 in which the magnetically-responsive substance is finely divided magnetite.

3. Microspheres according to claim 2 in which the magnetite particles have an average size less than 1000 A.

4. Microspheres according to claim 1 in which one of the lipids is a fatty acid having an even number of carbon atoms.

5. Microspheres according to claim 1 melting in the range 30°

-100°

C.

6. Microspheres according to claim 1 in which one or more non-ionic surfactants is employed.

7. Microspheres according to claim 1 in which the average particle size is less than 4μ

.

8. Microspheres according to claim 1 of less than 5μ

in diameter.

9. Microspheres according to claim 1 comprising palmitic acid, magnetite particles of average size less than 1000 A, lecithin and polyoxy ethylene sorbitan mono-oleate having an average size of less than about 4μ

.

10. A magnetically-localizable, biodegradable drug carrier formulation consisting of a lipid soluble drug dispersed in lipid microspheres, substantially free of water, said lipid microspheres being composed of one or more biodegradable lipids, a magnetically responsive substance and one or more non-toxic surfactants.

11. A drug carrier formulation according to claim 10 in which the drug is an oncolytic agent.