US5643607A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Prolonged release microcapsules
Assignee: Takeda Pharmaceutical Co Ltd
•
Filing: 1995-06-02
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Granted: 1997-07-01
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Expires: 2015-06-02
Abstract
Abstract This invention provides a microcapsule designed for zero order release of a physiologically active polypeptide over a period of at least two months, which is produced by preparing a water-in-oil emulsion comprising an inner aqueous layer containing about 20 to 70% (w/w) of said polypeptide and an oil layer containing a copolymer or homopolymer having a weight-average molecular weight of 7,000 to 30,000, wherein the composition ratio of lactic acid/glycolic acid in the copolymer or homopolymer is 80/10 to 100/0, and then subjecting said water-in oil emulsion to microencapsulation.
Inventors
- 👤 Hiroaki Okada
- 👤 Yayoi Inoue
- 👤 Yasuaki Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:13
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/14; A61K9/16; A61K9/1605; A61K9/1629; A61K9/1641; A61K9/1647; A61K38/00; A61K38/04; A61K38/06; A61K38/066; A61K38/08; A61K38/09; A61K9/5005; A61K9/5021; A61K9/5031
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
105 words
A microcapsule exhibiting zero order release of luteinizing hormone-releasing hormone (LH-RH) analog for a period of at least two months upon administration, which is produced by preparing a water-in-oil emulsion comprising an inner aqueous phase free from a drug retaining substance containing 35 to 60% (W/W) of the LH-RH analog, and an oil phase containing a homopolymer of lactic acid having a weight-average molecular weight of 14,100 to 18,200 and a dispersion degree (ratio of weight-average molecular weight to number-average molecular weight) of 1.5 to 2.5, as the material for forming an outer wall of the microcapsule and then subjecting said water-in-oil emulsion to microencapsulation.
Claim 2
Dependent Claim
105 words
A microcapsule exhibiting zero order release of luteinizing hormone-releasing hormone (LH-RH) analog for a period of at least two months upon administration, which is produced by preparing a water-in-oil emulsion comprising an inner aqueous phase free from a drug retaining substance containing 35 to 60% (W/W) of the LH-RH analog, and an oil phase containing a homopolymer of lactic acid having a weight-average molecular weight of 14,100 to 18,200 and a dispersion degree (ratio of weight-average molecular weight to number-average molecular weight) of 1.5 to 2.5, as the material for forming an outer wall of the microcapsule and then subjecting said water-in-oil emulsion to microencapsulation.
Claim 3
Dependent Claim
21 words
A microcapsule according to claim 1, which exhibits zero order release for a period of at least three months upon administration.
Claim 4
Dependent Claim
22 words
A microcapsule according to claim 1, wherein the concentration of homopolymer in the oil phase is from 2 to 60% by weight.
Claim 5
Dependent Claim
21 words
A microcapsule according to claim 1, wherein the LH-RH analog is water-soluble and has a molecular weight of 1,000 or more.
Claim 6
Dependent Claim
110 words
A process for preparing a microcapsule exhibiting zero order release of luteinizing hormone-releasing hormone (LH-RH) analog for a period of at least two months upon administration, which comprises preparing a water-in-oil emulsion comprising an inner aqueous phase free from a drug retaining substance containing 35 to 60% (W/W) of the LH-RH analog, and an oil phase containing a homopolymer of lactic acid having a weight-average molecular weight of 14,100 to 18,200 and a dispersion degree (ratio of weight-average molecular weight to number-average molecular weight) of 1.5 to 2.5, as the material for forming an outer wall of the microcapsule, and then subjecting said water-in-oil emulsion to in-water drying or phase-separation.
Claim 7
Dependent Claim
110 words
A process for preparing a microcapsule exhibiting zero order release of luteinizing hormone-releasing hormone (LH-RH) analog for a period of at least two months upon administration, which comprises preparing a water-in-oil emulsion comprising an inner aqueous phase free from a drug retaining substance containing 35 to 60% (W/W) of the LH-RH analog, and an oil phase containing a homopolymer of lactic acid having a weight-average molecular weight of 14,100 to 18,200 and a dispersion degree (ratio of weight-average molecular weight to number-average molecular weight) of 1.5 to 2.5, as the material for forming an outer wall of the microcapsule, and then subjecting said water-in-oil emulsion to in-water drying or phase-separation.
Claim 8
Dependent Claim
27 words
A process according to claim 5, wherein the water-in-oil emulsion is dispersed in an aqueous phase and the resulting water/oil/water ternary emulsion is subjected to in-water drying.
Claim 9
Dependent Claim
23 words
A process according to claim 5, wherein the water-in-oil emulsion is dispersed in an aqueous phase containing polyvinyl alcohol as an emulsifying agent.
Claim 10
Dependent Claim
21 words
A process according to claim 5, wherein the LH-RH analog is water-soluble and has a molecular weight of 1,000 or more.
Claim 11
Dependent Claim
16 words
A process according to claim 5, wherein the LH-RH analog is (pyr)Glu-His-Trp-Ser-Tyr-D-Leu-Leu-Arg-ProNHC 2 H 5 .
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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) | 2000-06-30 | 2000-12-30 | 2001-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-06-30 | 2004-12-30 | 2005-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-06-30 | 2008-12-30 | 2009-07-01 | $7700.00 | Window Closed / Lapsed |