Sustained release material and method of manufacturing the same

• US 5,156,623 A
• Filed: 04/05/1991
• Issued: 10/20/1992
• Est. Priority Date: 04/16/1990
• Status: Expired due to Term

• Current Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Original Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Inventors: Hakamatsuka, Yasuharu, Irie, Hiroyuki
• Primary Examiner(s): Isabella, David J.
• Assistant Examiner(s): BRITTINGHAM, DEBRA
• Application Number:
  US07/681,084
• Time in Patent Office: 564 Days
• Field of Search: 604/890.1, 604/891.1, 623/11
• US Class Current: 604/890.1
• CPC Class Codes: A61K 9/0024 Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue compositions for intravenous administration, normal injectable solutions or dispersions for, e.g. subcutaneous administration A61K9/0019; brain implants A61K9/0085; (coated) prostheses, catheters or stents A61L
• CPC Class Codes: A61K 9/1611 Inorganic compounds
• CPC Class Codes: A61K 9/501 Inorganic compounds
• CPC Class Codes: A61M 31/002 Devices for releasing a drug at a continuous and controlled rate for a prolonged period of time artificial gland structures or devices A61F2/022; intra-uterine contraceptive devices A61F6/14; tampons for introducing into the vagina A61F13/20, A61L15/00; suppositories or bougies for intra-vaginal or intra-uterine application A61K9/02; physical forms of medicinal preparations for sustained or differential drug release A61K9/20, A61K9/50

Abstract

A sustained release material to be buried at a position close to a diseased part in a living body to slowly release an impregnated liquid drug includes a core mainly consisting of a ceramic material and having a plurality of pores formed at a predetermined porosity, and a surface layer mainly consisting of a ceramic material, formed around the outer surface of the core, and having a plurality of pores having a pore size or porosity smaller than that of the pores formed in the core.

Claims

1. A sustained release material to be buried at a position close to a diseased part in a living body to slowly release an impregnated liquid drug, comprising:

a porous core into which said liquid drug is impregnated;

a dense first interlayer formed around said core;

a porous portion formed around said first interlayer;

a dense surface layer formed to cover said first interlayer and said porous portion;

a first communication path for allowing sad porous core to communicate with said porous portion; and

a second communication path for allowing said porous portion to communicate with the exterior.

2. A sustained release material according to claim 1, wherein said porous portion comprises a second interlayer formed around said first interlayer.

3. A sustained release material according to claim 2, wherein said second communication path further allows said first interlayer to communicate with the exterior.

4. A sustained release material according to claim 2, wherein each of said core, said first and second interlayers, and said surface layer consists of a material selected from the group consisting of β

-tricalcium phosphate, apatite hydroxide, a composite body of β

-tricalcium phosphate and apatite hydroxide, calcium phosphate, alumina, and zirconia.

5. A sustained release material according to claim 1, wherein said porous portion comprises a plurality of porous projections formed around said first interlayer.