EP0330180A1
Expired / Lapsed
EP
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Polylactic acid type microspheres containing physiologically active substance and process for preparing the same
Assignee: Biomaterials Universe Inc
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Filing: 1989-02-22
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Granted: —
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Expires: 2009-02-22
Abstract
Abstract Microspheres comprising polylactic acid and a water soluble physiologically active substance and having a mean particle size of from about 0.01 µm to 300 µm, which show not more than 30 % of an eluted amount of said physiologically active substance based on the content of said physiologically active substance in the polylactic acid type microspheres after 24 hours in in vitro elution test in phosphate buffer of pH 7.4 at 37°C, and a process for preparing the same. The polylactic acid type microspheres of this invention is advantageous in that the active substance can be uniformly incorporated into the microspheres without loss of the activity, can gradually release the active substance for a long time of period of more than one week.
Inventors
- 👤 Suong-Hyu Hyon
- 👤 Yoshito Ikada
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 02:57
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/51; A61K9/5107; A61K9/513; A61K9/5146; A61K9/5153; A61K9/14; A61K9/16; A61K9/1605; A61K9/1629; A61K9/1641; A61K9/1647; Y; Y10; Y10S; Y10S977/00; Y10S977/70; Y10S977/773; Y10S977/902; Y10S977/904; Y10S977/915; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2989
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
27 words
A microsphere which comprises polylactic acid and a water soluble physiologically active substance and has a mean particle size of from about 0.01 µm to 300 µm.
Claim 2
Dependent Claim
27 words
A microsphere which comprises polylactic acid and a water soluble physiologically active substance and has a mean particle size of from about 0.01 µm to 300 µm.
Claim 3
Dependent Claim
94 words
The microsphere of claim 1, wherein said water soluble physiologically active substance is a member selected from the group consisting of a polypeptide type or proteinaceous substance, an antimicrobial agent, an antitumor agent, an antipyretic, an antiinflammatory agent, an analgesic, an antitussive, an expectorant, an antidepressant, a muscle relaxant, an antiulcer agent, an antiallergic agent, a hypotensive, a diuretic, an antidiabetic, a cardiotonic, a vasodilating agent, an antiarrhythmic agent, an anticoagulating agent, a hemostatic agent, a narcotic antagonist, an antitubercular agent, a hormone, an immunoactivator, an antiepleptic agent, an antihistaminic and an agricultural agent.
Claim 4
Dependent Claim
43 words
The microsphere of claim 1, wherein said polylactic acid is a member selected from the group consisting of a L-lactic acid polymer, a D,L-lactic acid polymer, a copolymer of L-lactic acid and glycolic acid and a copolymer of D,L-lactic acid and glycolic acid.
Claim 5
Dependent Claim
49 words
The microsphere of claim 1, which has not more than 30 % of an eluted amount of said physiologically active substance based on the content of said physiologically active substance in the microsphere after 24 hours in in vitro elution test in phosphate buffer of pH 7.4 at 37°C.
Claim 6
Dependent Claim
81 words
A process for preparing microsphere comprising polylactic acid and a water soluble physiologically active substance, which comprises preparing a solution of the water soluble physiologically active substance and the polylactic acid uniformly dissolved in a mixed solvent comprising a hydrophilic organinc solvent and water or in an organic acid, mixing the solution with a poor solvent immiscible with said mixed solvent or organic acid to give an O/O type or W/O type emulsion, and subjecting the emulsion to solvent evaporation drying.
Claim 7
Dependent Claim
81 words
A process for preparing microsphere comprising polylactic acid and a water soluble physiologically active substance, which comprises preparing a solution of the water soluble physiologically active substance and the polylactic acid uniformly dissolved in a mixed solvent comprising a hydrophilic organinc solvent and water or in an organic acid, mixing the solution with a poor solvent immiscible with said mixed solvent or organic acid to give an O/O type or W/O type emulsion, and subjecting the emulsion to solvent evaporation drying.
Claim 8
Dependent Claim
43 words
The process of claim 5 wherein said polylactic acid is a member selected from the group consisting of a L-lactic acid polymer, a D,L-lactic acid polymer, a copolymer of L-lactic acid and glycolic acid and a copolymer of D,L-lactic acid and glycolic acid.
Claim 9
Dependent Claim
45 words
The process of claim 5 wherein said hydrophilic organic solvent for the solvent of the polylactic acid is a member selected from the group consisting of acetonitrile, dioxane, acetone, ethyl alcohol, methyl alcohol, tetrahydrofuran, dimethylformamide, dimethylacetoamide, phenol, dimethyl sulfoxide, propyl alcohol, glycerol and ethylene glycol.
Claim 10
Dependent Claim
30 words
The process of claim 5 wherein said organic acid for the solvent of the polylactic acid is a member selected from the group consisting of acetic acid and formic acid.
Claim 11
Dependent Claim
45 words
The process of claim 5 wherein said poor solvent immiscible with the mixed solvent or the organic acid is a member selected from the group consisting of silicone oil, liquid paraffin, cotton oil, sesame oil, castor oil, cone oil, whale oil, toluene, xylene and hexane.
References Cited (Backward Citations)
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