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US5318779A
Expired / Lapsed
US
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Drug-impregnated ceramic
Assignee: Olympus Corp
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Filing: 1990-03-15
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Granted: 1994-06-07
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Expires: 2010-03-15
Abstract
Abstract A drug-impregnated ceramic to be embedded in a living body is disclosed, and includes a porous ceramic having pores with a pore size of 10 to 300 mu m, a drug impregnating the porous ceramic via the pores, and a surface layer for controlling the release of the drug. The surface layer is formed to cover at least a portion of the outer surface of the porous ceramic and has a porosity lower than that of the porous ceramic.
Inventors
- 👤 Yasuharu Hakamatsuka
- 👤 Hiroyuki Irie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:24
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/0012; A61K9/0019; A61K9/0024; A61K9/20; A61K9/2004; A61K9/2009; A61K9/28; A61K9/2806; A61K9/2813
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
111 words
In a drug-impregnated ceramic which is to be embedded in a living body for release of the drug impregnated therein, into the body, the improvement wherein said drug-impregnated ceramic comprises: a porous ceramic having pores with a pore size of 10 to 300 μm, said drug being impregnated into said pores; and a means to control the release of sad drug from the pores of said porous ceramic comprising a surface layer covering at least a portion of the outer surface layer of said porous ceramic and having a pore size smaller than that of said porous ceramic to control release of the drug from the pores of the porous ceramic.
Claim 2
Dependent Claim
111 words
In a drug-impregnated ceramic which is to be embedded in a living body for release of the drug impregnated therein, into the body, the improvement wherein said drug-impregnated ceramic comprises: a porous ceramic having pores with a pore size of 10 to 300 μm, said drug being impregnated into said pores; and a means to control the release of sad drug from the pores of said porous ceramic comprising a surface layer covering at least a portion of the outer surface layer of said porous ceramic and having a pore size smaller than that of said porous ceramic to control release of the drug from the pores of the porous ceramic.
Claim 3
Dependent Claim
31 words
The ceramic according to claim 1, wherein said surface layer has pores with a pore size of less than 10 μm and a film thickness of not more than 300 μm.
Claim 4
Dependent Claim
20 words
The ceramic according to claim 1, wherein said porous ceramic and said surface layer can decompose within a living body.
Claim 5
Dependent Claim
21 words
The ceramic according to claim 3, wherein said porous ceramic comprises a calcium phosphate compound having a Ca/P ratio of 1.45-1.55.
Claim 6
Dependent Claim
14 words
The ceramic according to claim 3, wherein said porous ceramic consists of tricalcium phosphate.
Claim 7
Dependent Claim
35 words
The ceramic according to claim 3, wherein said surface layer consists of tricalcium phosphate having pores with a pore size of less than 10 μm and a film thickness of not more than 300 μm.
Claim 8
Dependent Claim
35 words
The ceramic according to claim 3, wherein said surface layer consists of collagen having pores with a pore size of not more than 10 μm and a film thickness of not more than 300 μm.
Claim 9
Dependent Claim
23 words
The ceramic according to claim 1, wherein said surface layer is formed of porous ceramic material which can decompose within a living body.
Claim 10
Dependent Claim
23 words
The ceramic according to claim 8, wherein the porous ceramic material of the surface layer has the same composition as the porous ceramic.
Claim 11
Dependent Claim
23 words
The ceramic according to claim 3, wherein said surface layer is formed of porous ceramic material which can decompose within a living body.
Claim 12
Dependent Claim
23 words
The ceramic according to claim 10, wherein the porous ceramic material of the surface layer has the same composition as the porous ceramic.
Claim 13
Dependent Claim
27 words
The ceramic according to claim 11, wherein said porous ceramic layer and said porous ceramic material comprise a calcium phosphate compound having a Ca/P ratio of 1.45-1.55.
Claim 14
Dependent Claim
20 words
The ceramic according to claim 11, wherein said porous ceramic layer and said porous ceramic material consists of tricalcium phosphate.
Claim 15
Dependent Claim
35 words
The ceramic according to claim 11, wherein said surface layer consists of tricalcium phosphate having pores with a pore size of less than 10 μm and a film thickness of not more than 300 μm.
Claim 16
Dependent Claim
38 words
The ceramic according to claim 11, wherein the surface layer is in contact with only the outer surface of said porous ceramic and covers the entire outer surface of said porous ceramic except for a drug injection port.
Claim 17
Dependent Claim
29 words
The drug-impregnated ceramic of claim 1 wherein the porosity of the porous ceramic is 30 to 70% and the pore size is equal to or greater than 150 μm.
Claim 18
Dependent Claim
27 words
The drug-impregnated ceramic of claim 16 wherein the surface layer is 4 to 300 μm thick and has a pore size of the up to 10 μm.
Claim 19
Dependent Claim
12 words
The drug-impregnated ceramic of claim 1 wherein the drug is an antibiotic.
Claim 20
Dependent Claim
12 words
The drug-impregnated ceramic of claim 12 wherein the drug is an antibiotic.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-06-06 | 1997-12-06 | 1998-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-06 | 2001-12-06 | 2002-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-06 | 2005-12-06 | 2006-06-07 | $7700.00 | Window Closed / Lapsed |