EP0452111A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Biodegradable high-molecular polymers, production and use thereof
Assignee: Takeda Pharmaceutical Co Ltd
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Filing: 1991-04-10
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Granted: —
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Expires: 2011-04-10
Abstract
Abstract The invention provides a method of purifying biodegradable aliphatic polyesters which comprises dissolving, in a readily water-soluble organic solvent, a biodegradable aliphatic polyester which contains low-molecular substances and adding water to the resulting solution to thereby remove said low-molecular substances, biodegradable aliphatic polyesters obtained by said method and containing low-molecular substances with a molecular weight of 1,000 or less in an amount of not higher than 3%, and drug-containing compositions which comprise any of said biodegradable polyesters.
Inventors
- 👤 Minoru Yamada
- 👤 Toshiro Heya
- 👤 Yasuaki Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 19:13
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/5005; A61K9/5021; A61K9/5031; A61K9/14; A61K9/16; A61K9/1605; A61K9/1629; A61K9/1641; A61K9/1647; C; C08; C08G; C08G63/00; C08G63/88; C08G63/90
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
42 words
A method of purifying biodegradable aliphatic polyesters which comprises dissolving, in a readily water-soluble organic solvent, a biodegradable aliphatic polyester which contains low-molecular substances and adding water to the resulting solution to thereby precipitate high-molecular substances and to remove said low-molecular substances.
Claim 2
Dependent Claim
27 words
The method according to claim 1, wherein the readily water-soluble organic solvent is a member selected from the group consisting of acetone, tetrahydrofuran, dioxane, dimethylformamide and dimethylsulfoxide.
Claim 3
Dependent Claim
14 words
The method according to claim 2, wherein the readily water-soluble organic solvent is acetone.
Claim 4
Dependent Claim
31 words
The method according to claim 1, wherein water is used in an amount of 50 to 150 parts by volume per 100 parts by volume of the readily water-soluble organic solvent.
Claim 5
Dependent Claim
33 words
A biodegradable high-molecular aliphatic polyester containing low-molecular substances with a molecular weight of 1,000 or less in an amount of not higher than 3% by weight obtained by the method of claim 1.
Claim 6
Dependent Claim
29 words
The biodegradable high-molecular aliphatic polyester according to claim 5, wherein the biodegradable high-molecular aliphatic polyester is a polymer having a weight average molecular weight of about 3,000 to 50,000.
Claim 7
Dependent Claim
38 words
The biodegradable high-molecular aliphatic polyester according to claim 5, wherein the biodegradable high-molecular aliphatic polyester is a polymer of about 50 to 100 mole percent of lactic acid and about 50 to 0 mole percent of glycolic acid.
Claim 8
Dependent Claim
38 words
The biodegradable high-molecular aliphatic polyester according to claim 5, wherein the biodegradable high-molecular aliphatic polyester is a polymer of about 25 to 100 mole percent of hydroxybutyric acid and about 75 to 0 mole percent of glycolic acid.
Claim 9
Dependent Claim
25 words
A microcapsule for injectable sustained release which contains an effective amount of a water-soluble drug and the biodegrable high-molecular weight aliphatic polyester of claim 5.
Claim 10
Dependent Claim
14 words
The microcapsule according to claim 9, wherein the water-soluble drug is a water-soluble polypeptide.
Claim 11
Dependent Claim
80 words
A method for producing a microcapsule for injectable sustained release which contains an effective amount of ingredient and the biodegradable high-molecular aliphatic polyester of claim 5, which comprises preparing a w/o emulsion with a solution containing the ingredient serving as an inner water phase and a solution containing the biodegradable high-molecular aliphatic polyester serving as an oil phase, dispersing said emulsion in a water phase to give a (w/o)/w ternary phase emulsion, and then evaporating the solvent in oil phase.
References Cited (Backward Citations)
No citation records indexed.
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