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US 5,188,837 AGranted
Lipsopheres for controlled delivery of substances
AssigneeNova Pharmaceutical Corporation
InventorAbraham J. Domb
Life of this patent
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Abstract
A microsuspension system and method for its preparation is disclosed. The microsuspension contain lipospheres, which are solid, water-insoluble microparticles that have a layer of a phospholipid embedded on their surface. The core of the liposphere is a solid substance to be delivered, or a substance to be delivered that is dispersed in an inert solid vehicle, such as a wax.
Claims21
A liposphere comprising
- a core formed of a hydrophobic material existing as a solid at a temperature of at least 30.degree. 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 liposphere,
- the combination forming a spherical structure having an average particle diameter of between 0.3 and 250 microns.
A method of preparation of a liposphere comprising:
- (a) providing a hydrophobic liquid which forms a solid at a temperature of at least 30.degree. C.;
- (b) adding to the liquid hydrophobic material a phospholipid followed by an aqueous solution at a temperature higher than the melting temperature of the hydrophobic material to form a dispersion;
- (c) mixing the dispersion at a temperature above the melting temperature of the hydrophobic material until a homogeneous fine preparation is obtained;
- and
- (d) rapidly cooling the preparation to a temperature at which the hydrophobic material solidifies,
- to form a liposphere comprising
- a core formed of a hydrophobic material existing as a solid at a temperature of 30.degree. 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 liposphere,
- the combination forming a spherical structure having an average particle diameter of between 0.3 and 250 microns.
6 more elements
Dependencies are inferred from the claim text.