Liposphere delivery systems for local anesthetics
First Claim
Patent Images
1. A liposphere comprising:
- a core formed of a hydrophobic material existing as a solid at a temperature of 30°
C. having anesthetic activity as a result of an anesthetic compound, anda phospholipid coating surrounding the core, wherein the hydrophobic ends of the phospholipid are embedded in the solid core and the hydrophilic ends of the phospholipid are exposed on the surface of the liposphere,the combination forming a spherical structure having an average particle diameter between 0.35 and 250 microns,wherein the core may contain a vehicle for the anesthetic compound, and the anesthetic compound, vehicle, and phospholipid coating are in a ratio of anesthetic compound to vehicle to phospholipid between 1;
0;
0.01 and 1;
100;
100.
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Abstract
A local anesthetic microsuspension system is disclosed that includes lipospheres, that are solid, water-insoluble microparticles that have a layer of a phospholipid embedded on their surface. The core of the liposphere is a solid anesthetic such as lidocaine or marcaine, or an anesthetic dispersed in an inert solid vehicle, such as a wax. Anesthetic lipospheres provide a controlled delivery of local anesthetics to achieve extended, effective relief from pain by slowly releasing the anesthetic from the solid hydrophobic core. This is highly preferred over the situation in which an aqueous solution of local anesthetic must be frequently administered because it is quickly systemically absorbed.
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Citations
29 Claims
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1. A liposphere comprising:
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a core formed of a hydrophobic material existing as a solid at a temperature of 30°
C. having anesthetic activity as a result of an anesthetic compound, anda phospholipid coating surrounding the core, wherein the hydrophobic ends of the phospholipid are embedded in the solid core and the hydrophilic ends of the phospholipid are exposed on the surface of the liposphere, the combination forming a spherical structure having an average particle diameter between 0.35 and 250 microns, wherein the core may contain a vehicle for the anesthetic compound, and the anesthetic compound, vehicle, and phospholipid coating are in a ratio of anesthetic compound to vehicle to phospholipid between 1;
0;
0.01 and 1;
100;
100. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of inducing local anesthesia comprising administering to a patient lipospheres comprising:
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a core formed of a hydrophobic material existing as a solid at 30°
C. having anesthetic activity as a result of an anesthetic compound, anda phospholipid coating surrounding the core, wherein the hydrophobic ends of the phospholipid are embedded in the solid core and the hydrophilic ends of the phospholipid are exposed on the surface of the liposphere, the combination forming a spherical structure having an average particle diameter between 0.35 and 250 microns, wherein the core may contain a vehicle for the anesthetic compound, and the anesthetic compound, vehicle, and phospholipid coating are in a ratio of anesthetic compound to vehicle to phospholipid between 1;
0;
0.01 and 1;
100;
100in a pharmaceutically acceptable carrier. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A method of making lipospheres formed of a core that is a hydrophobic material existing as a solid at a temperature of 30°
- C. and a phospholipid coating surrounding the core, wherein the hydrophobic ends of the phospholipid are embedded in the solid core and the hydrophilic ends of the phospholipid are exposed on the surface of the resulting spherical liposphere structure having an average particle diameter between 0.35 and 250 microns, comprising
forming a liquid of the hydrophobic core material, adding phospholipid to the core material, adding an aqueous solution to the liquid core material and phospholipid mixture, and mixing the liquid core material and phospholipid until a suspension of lipospheres is formed. - View Dependent Claims (26, 27, 28, 29)
- C. and a phospholipid coating surrounding the core, wherein the hydrophobic ends of the phospholipid are embedded in the solid core and the hydrophilic ends of the phospholipid are exposed on the surface of the resulting spherical liposphere structure having an average particle diameter between 0.35 and 250 microns, comprising
Specification