EP0350246A2
Expired / Lapsed
EP
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Sustained release microcapsule for water soluble drug
Assignee: Takeda Pharmaceutical Co Ltd
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Filing: 1989-07-03
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Granted: —
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Expires: 2009-07-03
Abstract
Abstract Sustained release microcapsules including a water soluble drug and an organic basic substance as a drug retaining substance of this invention not only have a high rate of incorporation (trapping rate), but also show little initial release so that they can be administered safely and bring about persistent, stable sustained release.
Inventors
- 👤 Toshio Yoshioka
- 👤 Hiroaki Okada
- 👤 Yasuaki Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 13:16
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/5005; A61K9/5021; A61K9/5031; A61K9/14; A61K9/16; A61K9/1605; A61K9/1617; A61K9/1629; A61K9/1641; A61K9/1647
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
33 words
A sustained release microcapsule of a water soluble drug which contains a water soluble drug and an organic basic substance as a drug retaining substance and of which wall is made of polymer.
Claim 2
Dependent Claim
33 words
A sustained release microcapsule of a water soluble drug which contains a water soluble drug and an organic basic substance as a drug retaining substance and of which wall is made of polymer.
Claim 3
Dependent Claim
18 words
The microcapsule according to Claim 1, wherein pKa of the organic basic substance is not more than 8.0.
Claim 4
Dependent Claim
33 words
The microcapsule according to Claim 1, wherein the organic basic substance is organic base, basic amino acid, polypeptide containing basic amino acid, basic derivative of saccharide, natural basic macromolecule or synthetic basic macromolecule.
Claim 5
Dependent Claim
14 words
The microcapsule according to Claim 3, wherein the organic base is N-methylglucamine or diethanolamine.
Claim 6
Dependent Claim
16 words
The microcapsule according to Claim 3, wherein the basic amino acid is arginine, lysin or histidine.
Claim 7
Dependent Claim
16 words
The microcapsule according to Claim 3, wherein the natural basic macromolecule is chitosan, poly-L-lysine, and protamine.
Claim 8
Dependent Claim
19 words
The microcapsule according to Claim 1, wherein the water soluble drug is physiologically active polypeptide, antibiotic or antitumor agent.
Claim 9
Dependent Claim
25 words
The microcapsule according to Claim 7, wherein the physiologically active polypeptide is luteinizing hormone-releasing hormone, luteinizing hormone-releasing hormone derivative, thyrotropin-releasing hormone or thyrotropin-releasing hormone derivative.
Claim 10
Dependent Claim
14 words
The microcapsule according to Claim 7, wherein the antitumor agent is bleomycin or methotrexate.
Claim 11
Dependent Claim
12 words
The microcapsule according to Claim 1, wherein the polymer is biocompatible polymer.
Claim 12
Dependent Claim
36 words
The microcapsule according to Claim 10, wherein the biocompatible polymer is a polymer having acidic residues and is a member selected from the group consisting of poly-fatty acid ester, poly-α-cyanoacrylic ester, poly-β-hydroxybutyric ester and polyamino acid.
Claim 13
Dependent Claim
25 words
The microcapsule according to Claim 10, wherein the biocompatible polymer is a homopolymer of lactic acid or a copolymer of lactic acid and glycolic acid.
Claim 14
Dependent Claim
23 words
The microcapsule according to Claim 1, the concetration of the organic basic substance is from 0.1% to 90(w/w) in a internal water phase.
Claim 15
Dependent Claim
101 words
A method of producing the microcapsule according to Claim 1, which comprises dissolving a water soluble drug in water, disolving or susponding an organic basic substance thereto to make an internal water phase, adding the phase to an oil phase containing the polymer and emulsifying to make w/o emulsion, and then i) adding the w/o emulsion to a third water phase to make w/o/w three phased emulsion, and then drying the w/o/w emulsion, or ii) adding a coaservating agent to the w/o emulsion under stirring to deposit and solidify the w/o emulsion, filtrating and washing the resulting microcapsules and then drying.
References Cited (Backward Citations)
No citation records indexed.
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