Controlled release composite core coated microparticles

• US 4,623,588 A
• Filed: 12/02/1985
• Issued: 11/18/1986
• Est. Priority Date: 02/06/1984
• Status: Expired due to Term

• Current Assignee: BioTex Incorporated
• Original Assignee: BioTex Incorporated
• Inventors: Nuwayser, Elie S., Nucefora, William A.
• Primary Examiner(s): Kittle, John E.
• Assistant Examiner(s): SHAH, MUKUND JETHALAL
• Application Number:
  US06/803,733
• Time in Patent Office: 351 Days
• Field of Search: 424/31, 424/35, 427/3, 427/213, 428/402.24
• US Class Current: 428/402.24
• CPC Class Codes: A61K 9/1647 Polyesters, e.g. poly(lactide-co-glycolide)
• CPC Class Codes: A61K 9/5031 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyethylene glycol, poly(lactide-co-glycolide)
• CPC Class Codes: Y10T 428/2989 Microcapsule with solid core [includes liposome]

Abstract

A process for preparing coated microparticles, which process comprises preparing a solvent solution of an active ingredient to be encapsulated and a film-forming polymer, removing the solvent to provide a dry, composite, uniform admixture of the active ingredient and the polymer material, reducing the composite admixture to a defined smaller particle size distribution, coating the reduced composite core particles in a fluidized bed, with a uniform defined wall thickness of the same or substantially the same film-forming polymer material to provide composite core coated microparticles.

Claims

1. A microparticle suitable for the controlled release of an active ingredient, which microparticle comprises:

(a) a solid composite core material comprising a uniform dispersion of a finely-divided active ingredient and a film-forming polymer, the active ingredient present in an amount of from about 5% to 95% by weight of the core material;

(b) a generally uniform outer wall coating about the composite core material in a wall thickness, to provide for the desired controlled release of the active ingredient, said outer wall coating comprising a film-forming polymer the same or substantially the same as the said film-forming polymer in the core material, to provide for bonding of the wall coating of the film-forming polymer to the core material; and

(c) the microparticle less than about 1000 microns in size.

3. The microparticle of claim 1 which is less than about 200 microns in size.

4. The microparticles of claim 1 wherein the film-forming polymer is selected from the group consisting of a biodegradable polymer, polyvinyl alcohol, and cellulose material.

5. The microparticle of claim 1 wherein the film-forming polymer comprises biodegradable polymer selected from the group consisting of a polylactide, a polyglycolide, or a copolymer of lactide or glycolide.

6. The microparticle of claim 1 wherein the active ingredient is a hydrophobic steroid drug.

7. The microparticle of claim 1 wherein the active ingredient is a drug selected from the group consisting of testosterone, progesterone, nonoxynol-9, povidone iodine, cholesterol, levonorgestrel, tyrosine, norethindrone, lidocaine, etidocaine and bupivcaine.

8. The microparticle of claim 1 wherein the active ingredient comprises from about 20% to 80% by weight of the composite core mateial.

9. The microparticle of claim 1 wherein the outer wall coating thickness is from about 0.1 to 20 microns.

2. A microparticle suitable for the controlled release of an active ingredient, which microparticle comprises:

(a) a solid composite core material comprising a uniform dispersion of a finely-divided active drug ingredient, which drug ingredient comprises a hydrophobic steroid drug, and a film-forming polymer which comprises a biodegradable polymer selected from the group consisting of a polylactide, a polyglycolide, or a copolymer of lactide or glycolide, the active drug ingredient present in an amount of from about 5% to 95% by weight of the core material;

(b) a generally uniform outer wall coating about the composite core material in a wall thickness, to provide for the desired controlled release of the active ingredient, said outer wall coating comprising a film-forming polymer the same or substantially the same as the said film-forming polymer in the core material, to provide for bonding of the wall coating of the film-forming polymer to the core material; and

(c) the microparticle less than about 200 microns in size.