US4917893A
Expired / Lapsed
US
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Prolonged release microcapsules
Assignee: Takeda Pharmaceutical Co Ltd
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Filing: 1987-09-30
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Granted: 1990-04-17
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Expires: 2007-09-30
Abstract
Abstract A microcapsule produced by preparing a water-in-oil emulsion comprising an inner aqueous layer containing said water-soluble drug and a drug retaining substance therefor and an oil layer containing a polymer substance, then thickening or solidifying said inner aqueous layer to a viscosity of not lower than about 5000 centiposes and finally subjecting the resulting emulsion to in water drying gives prolonged release of water-soluble drug.
Inventors
- 👤 Hiroaki Okada
- 👤 Yasuaki Ogawa
- 👤 Takatsuka Yashiki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:08
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/5005; A61K9/5021; A61K9/5031; A61K38/00; A61K38/04; A61K38/05; A61K38/08; A61K38/09; A61K38/16; A61K38/17; A61K38/33; A61K38/36; A61K38/37; A61K9/14; A61K9/16; A61K9/1605; A61K9/1629; A61K9/1641; A61K9/1647; A61K9/1682; A61K9/1694; A61K9/5089; B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/12; B01J13/125; Y; Y10; Y10S; Y10S424/00; Y10S424/15; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985; Y10T428/2989
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
103 words
A spherical microcapsule for an injectable preparation, having an average diameter of 2-200 μm, the spherical microcapsule comprising particles of a mixture of a biologically active polypeptide and a drug-retaining substance selected from the group consisting of gelatin, albumin, pectin and agar, the weight ratio of the drug-retaining substance to the biologically active polypeptide being in the range of about 2.5/1 through about 1/1, the particles being dispersed in a spherical microcapsule matrix composed of a lactic acid-glycolic acid polymer having a monomer ratio within the range of about 78/22 to 50/50 and an average molecular weight within the range of about 5,000-100,000.
Claim 2
Dependent Claim
103 words
A spherical microcapsule for an injectable preparation, having an average diameter of 2-200 μm, the spherical microcapsule comprising particles of a mixture of a biologically active polypeptide and a drug-retaining substance selected from the group consisting of gelatin, albumin, pectin and agar, the weight ratio of the drug-retaining substance to the biologically active polypeptide being in the range of about 2.5/1 through about 1/1, the particles being dispersed in a spherical microcapsule matrix composed of a lactic acid-glycolic acid polymer having a monomer ratio within the range of about 78/22 to 50/50 and an average molecular weight within the range of about 5,000-100,000.
Claim 3
Dependent Claim
19 words
The microcapsule according to claim 1, wherein the biologically active polypetide is luteninizing hormone releasing hormone or its derivative.
Claim 4
Dependent Claim
88 words
The microcapsule according to claim 2, wherein the luteinizing hormone releasing hormone or its derivative is a polypeptide of the formula: (Pyr)Glu-R.sub.1 -Trp-Ser-R.sub.2 -R.sub.3 -R.sub.4 -Arg-Pro-R.sub.5 wherein R 1 is His, Tyr, Trp or p-NH 2 -Phe; R 2 is Tyr or Phe; R 3 is Gly or D-amino acid residue which may have a protective group; R 4 is Leu, Ile or Nle and R 5 is Gly-NH-R 6 or NHR 6 , wherein R 6 is hydrogen or lower alkyl which may be substituted by hydroxyl.
Claim 5
Dependent Claim
31 words
The microcapsule according to claim 3, wherein R 1 is His, R 2 Tyr, R 3 is D-Leu, R 4 is Leu and R 5 is NHCH 2 CH 3 .
Claim 6
Dependent Claim
33 words
The microcapsule according to claim 3, wherein R 1 is His, R 2 is Tyr, R 3 is D-Ala protected with naphthyl, R 4 is Leu and R 5 is Gly-NH 2 .
Claim 7
Dependent Claim
13 words
The microcapsule according to claim 1, wherein the drug retaining substance is gelatin.
Claim 8
Dependent Claim
22 words
The microcapsule according to claim 1, wherein the lactic acid-glycolic acid polymer is a copolymer having a monomer molar ratio of 78/22.
Claim 9
Dependent Claim
40 words
An injectable preparation comprising a therapeutically effective amount of spherical microcapsules according to claim 1 and a pharmaceutically acceptable vehicle, the preparation providing release of the polypeptide to a patient over a period of at least two weeks after administration.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-16 | 1993-10-16 | 1994-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-16 | 1997-10-16 | 1998-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-16 | 2001-10-16 | 2002-04-17 | $7700.00 | Window Closed / Lapsed |