EP0299730A2
Expired / Lapsed
EP
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Process of preparing dl-lactic acid-glycolic acid-copolymer
Assignee: Mitsui Chemicals Inc
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Filing: 1988-07-13
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Granted: —
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Expires: 2008-07-13
Abstract
Abstract A process for copolymerizing lactide and glycolide uses a specific amount of stannous octoate as a catalyst in the presence of a polymerization regulator at temperature of 200-230°C to prepare dl-lactic acid-glycolic acid-copolymers which contain 50-60 mol % of a dl-lactic acid unit and 40-50 mol % of a glycolic acid unit and having inherent viscosity of 0.4-0.6 in chloroform. The catalyst is used in an amount of 0.005-0.015 % by weight based on the aggregate amount of lactide and glycolide.
Inventors
- 👤 Hiroshi Takayanagi
- 👤 Tadashi Kobayashi
- 👤 Takayoshi Masuda
- 👤 Hosei 45 Azanishiakatsuchi Shinoda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 23:26
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/20; A61K9/2004; A61K9/2022; A61K9/2031; A61K9/204; C; C08; C08G; C08G63/00; C08G63/02; C08G63/06; C08G63/08; C08G63/78; C08G63/82; C08G63/823
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
84 words
A process for the copolymerization of a lactide and a glycolide to prepare a dl-lactic acid-glycolic acid-copolymer containing 50-60 mol % of a lactic acid unit and 40-50 mol % of a glycolic acid unit and having an inherent viscosity of 0.4-0.6 in chloroform, wherein the copolymerization is conducted in the presence of a polymerization regulator at a temperature of 200-230°C by using stannous octoate as a catalyst in an amount of 0.005-0.015 wt.% based on the sum of the lactide and the glycolide.
Claim 2
Dependent Claim
84 words
A process for the copolymerization of a lactide and a glycolide to prepare a dl-lactic acid-glycolic acid-copolymer containing 50-60 mol % of a lactic acid unit and 40-50 mol % of a glycolic acid unit and having an inherent viscosity of 0.4-0.6 in chloroform, wherein the copolymerization is conducted in the presence of a polymerization regulator at a temperature of 200-230°C by using stannous octoate as a catalyst in an amount of 0.005-0.015 wt.% based on the sum of the lactide and the glycolide.
Claim 3
Dependent Claim
16 words
A process according to claim 1, wherein the polymerization regulator is an α-hydroxy lower fatty acid.
Claim 4
Dependent Claim
34 words
A process according to claim 2, wherein the α-hydroxy lower fatty acid is dl-lactic acid containing water and the amount thereof is 0.25-0.50 wt.% based on the sum of the lactide and the glycolide.
Claim 5
Dependent Claim
24 words
A process according to claim 1, 2 or 3, wherein the catalyst is used in an amount of 0.008-0.012 wt.% on the aforesaid basis.
Claim 6
Dependent Claim
23 words
A process according to any of claims 1 to 4, wherein the polymerization is conducted at a temperature in the range of 215-225°C.
Claim 7
Dependent Claim
30 words
A process according to claim 1, wherein the polymerization regulator is selected from alcohols such as lauryl alcohol and α-hydroxy lower fatty acids such as dl-lactic acid and glycolic acid.
Claim 8
Dependent Claim
27 words
dl-lactic acid-glycolic acid-copolymers made by the process according to any of claims 1 to 6 and having the properties recited in Table 2, Examples 1 to 6.
Claim 9
Dependent Claim
14 words
A drug delivery system having, as its matrix, a copolymer according to claim 7.
References Cited (Backward Citations)
No citation records indexed.
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