Patent US4757128A successfully refreshed from Google Patents.
US4757128A
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High molecular weight polyanhydride and preparation thereof
Assignee: Massachusetts Institute of Technology
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Filing: 1986-08-01
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Granted: 1988-07-12
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Expires: 2006-08-01
Abstract
Abstract High molecular weight polyanhydrides, defined as polyanhydrides having a molecular weight average greater than 20,000 or an intrinsic viscosity of greater than 0.3 dl/g in an organic solvent at room temperature, are formed by melt polycondensation of highly pure isolated prepolymers under optimized reaction conditions, particularly time and temperature with removal of the condensation product. Higher molecular weights are obtained by inclusion of a catalyst with the prepolymers in the melt polymerization. Catalysts used for transterification, ring opening polymerization and related polymerizations may be utilized. The high molecular weight polyanhydrides have improved physico-mechanical properties and are especially well suited for biomedical applications, particularly in controlled release devices for drug delivery.
Inventors
- 👤 Abraham J. Domb
- 👤 Robert S. Langer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:39
CPC Classifications
C; C08; C08G; C08G67/00; C08G67/04
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
156 words
A high molecular weight polyanhydride having a weight average molecular weight of greater than 20,000 and an intrinsic viscosity of greater than 0.3 dl/g in chloroform at 23° C., said polyanhydride produced from at least one dicarboxylic acid selected from the group consisting of: aliphatic dicarboxylic acids having the formula: HOOC--H.sub.2 C--R--CH.sub.2 --COOH; aromatic dicarboxylic acids having the formula: ##STR7## aromatic dicarboxylic acids having the formula: ##STR8## aliphatic-aromatic dicarboxylic acids having the formula: ##STR9## aromatic and aliphatic heterocyclic dicarboxylic acids having the formula: ##STR10## wherein X is selected from the group consisting of oxygen, nitrogen, and sulfur, and n is an integer between 1 and 3; and aromatic and aliphatic heterocyclic dicarboxylic acids of the above formula in combination with at least one dicarboxylic acid selected from the group consisting of aliphatic dicarboxylic acids, aromatic-aliphatic dicarboxylic acids, and aromatic dicarboxylic acids having more than one phenyl group; wherein the R groups are divalent organic radical groups.
Claim 2
Dependent Claim
156 words
A high molecular weight polyanhydride having a weight average molecular weight of greater than 20,000 and an intrinsic viscosity of greater than 0.3 dl/g in chloroform at 23° C., said polyanhydride produced from at least one dicarboxylic acid selected from the group consisting of: aliphatic dicarboxylic acids having the formula: HOOC--H.sub.2 C--R--CH.sub.2 --COOH; aromatic dicarboxylic acids having the formula: ##STR7## aromatic dicarboxylic acids having the formula: ##STR8## aliphatic-aromatic dicarboxylic acids having the formula: ##STR9## aromatic and aliphatic heterocyclic dicarboxylic acids having the formula: ##STR10## wherein X is selected from the group consisting of oxygen, nitrogen, and sulfur, and n is an integer between 1 and 3; and aromatic and aliphatic heterocyclic dicarboxylic acids of the above formula in combination with at least one dicarboxylic acid selected from the group consisting of aliphatic dicarboxylic acids, aromatic-aliphatic dicarboxylic acids, and aromatic dicarboxylic acids having more than one phenyl group; wherein the R groups are divalent organic radical groups.
Claim 3
Dependent Claim
83 words
A high molecular weight polyanhydride synthesized by: polymerizing at least one highly pure prepolymer produced from a mixture of anhydrides prepared from at least one highly pure dicarboxylic acid at a temperature and for a reaction time to form a polyanhydride having a weight average molecular weight in excess of 20,000; removing the polyanhydride condensation product having a weight average molecular weight in excess of 20,000 formed by said polymerization; and stopping said polymerization before said polyanhydride condensation product decreases in molecular weight.
Claim 4
Dependent Claim
83 words
A high molecular weight polyanhydride synthesized by: polymerizing at least one highly pure prepolymer produced from a mixture of anhydrides prepared from at least one highly pure dicarboxylic acid at a temperature and for a reaction time to form a polyanhydride having a weight average molecular weight in excess of 20,000; removing the polyanhydride condensation product having a weight average molecular weight in excess of 20,000 formed by said polymerization; and stopping said polymerization before said polyanhydride condensation product decreases in molecular weight.
Claim 5
Dependent Claim
47 words
The high molecular weight polyanhydride of claim 2 wherein at least one dicarboxylic acid is selected from the group consisting of sebacic acid, 4,4'-[α,w-alkanediylbis(oxy)]bis[benzoic acid], isophthalic acid, dodecanedioic acid, 2,2'-[1,4-phenylenebis(oxy)]bisacetic acid, 1,4-bis(carboxymethyl)benzene, 2,2'-[(1-methylethylidene)bis(4,1-phenyleneoxy)]bisacetic acid, 2,2-bis(4-carboxyphenyl)propane; terephthalic acid; 1,4 phenylene dipropionic acid; 4,4'-(n-alkylidene)bis[benzoic acid]; and cyclohexane dicarboxylic acids.
Claim 6
Dependent Claim
20 words
The high molecular weight polyanhydride of claim 2 synthesized by polymerizing at least one highly pure prepolymer with a catalyst.
Claim 7
Dependent Claim
25 words
The high molecular weight polyanhydride of claim 4 wherein said catalyst is selected from the group of catalysts consisting of acid, base and coordination catalysts.
Claim 8
Dependent Claim
36 words
The high molecular weight polyanhydride of claim 5 wherein the catalyst is selected from the group consisting of (CH 3 COO) 2 Cd, alkaline earth metal oxides, calcium carbonate and complexes of diethylzinc and hydroxylated compounds.
Claim 9
Dependent Claim
86 words
A composition comprising a high molecular weight polyanhydride synthesized by: polymerizing at least one highly pure prepolymer produced from a mixture of anhydrides prepared from at least one highly pure dicarboxylic acid at a temperature and for a reaction time to form a polymer having a weight average molecular weight in excess of 20,000; removing the polyanhydride condensation product having a weight average molecular weight in excess of 20,000 formed by said polymerization; and stopping said polymerization before said polyanhydride condensation product decreases in molecular weight.
Claim 10
Dependent Claim
86 words
A composition comprising a high molecular weight polyanhydride synthesized by: polymerizing at least one highly pure prepolymer produced from a mixture of anhydrides prepared from at least one highly pure dicarboxylic acid at a temperature and for a reaction time to form a polymer having a weight average molecular weight in excess of 20,000; removing the polyanhydride condensation product having a weight average molecular weight in excess of 20,000 formed by said polymerization; and stopping said polymerization before said polyanhydride condensation product decreases in molecular weight.
Claim 11
Dependent Claim
159 words
A composition comprising a high molecular weight polyanhydride having a weight average molecular weight of greater than 20,000 and an intrinsic viscosity of greater than 0.3 dl/g in chloroform at 23° C., said polyanhydride produced from at least one dicarboxylic acid selected from the group consisting of: aliphatic dicarboxylic acids having the formula: HOOC--H.sub.2 C--R--CH.sub.2 --COOH; aromatic dicarboxylic acids having the formula: ##STR11## aromatic dicarboxylic acids having the formula: ##STR12## aliphatic aromatic dicarboxylic acids having the formula: ##STR13## aromatic and aliphatic heterocyclic dicarboxylic acids having the formula: ##STR14## wherein X is selected from the group consisting of oxygen, nitrogen, and sulfur, and n is an integer between 1 and 3; and aromatic and aliphatic heterocyclic dicarboxylic acids of the above formula in combination with at least one dicarboxylic acid selected from the group consisting of aliphatic dicarboxylic acids, aromatic-aliphatic dicarboxylic acids, and aromatic dicarboxylic acids having more than one phenyl group, wherein R groups are divalent organic radical groups.
Claim 12
Dependent Claim
159 words
A composition comprising a high molecular weight polyanhydride having a weight average molecular weight of greater than 20,000 and an intrinsic viscosity of greater than 0.3 dl/g in chloroform at 23° C., said polyanhydride produced from at least one dicarboxylic acid selected from the group consisting of: aliphatic dicarboxylic acids having the formula: HOOC--H.sub.2 C--R--CH.sub.2 --COOH; aromatic dicarboxylic acids having the formula: ##STR11## aromatic dicarboxylic acids having the formula: ##STR12## aliphatic aromatic dicarboxylic acids having the formula: ##STR13## aromatic and aliphatic heterocyclic dicarboxylic acids having the formula: ##STR14## wherein X is selected from the group consisting of oxygen, nitrogen, and sulfur, and n is an integer between 1 and 3; and aromatic and aliphatic heterocyclic dicarboxylic acids of the above formula in combination with at least one dicarboxylic acid selected from the group consisting of aliphatic dicarboxylic acids, aromatic-aliphatic dicarboxylic acids, and aromatic dicarboxylic acids having more than one phenyl group, wherein R groups are divalent organic radical groups.
Claim 13
Dependent Claim
72 words
A high molecular weight polyanhydride having a weight average molecular weight of greater than 20,000 and an intrinsic viscosity of greater than 0.3 dl/g in chloroform at 23° C., wherein said polyanhydride is produced from at least one dicarboxylic acid selected from the group consisting of sebacic acid, 4,4'-[α,w-alkanediylbis(oxy)]bis[benzoic acid], isophthalic acid, dodecanedioic acid, 2,2'-[1,4-phenylenebis(oxy)]bisacetic acid, 1,4-bis(carboxymethyl)benzene, 2,2'-[(1-methylethylidene)bis(4,1-phenyleneoxy)]bisacetic acid, 2,2-bis(4-carboxyphenyl)propane; terephthalic acid; 1,4 phenylene dipropionic acid; 4,4'-(n-alkylidene)bis[benzoic acid]; and cyclohexane dicarboxylic acids.
Claim 14
Dependent Claim
72 words
A high molecular weight polyanhydride having a weight average molecular weight of greater than 20,000 and an intrinsic viscosity of greater than 0.3 dl/g in chloroform at 23° C., wherein said polyanhydride is produced from at least one dicarboxylic acid selected from the group consisting of sebacic acid, 4,4'-[α,w-alkanediylbis(oxy)]bis[benzoic acid], isophthalic acid, dodecanedioic acid, 2,2'-[1,4-phenylenebis(oxy)]bisacetic acid, 1,4-bis(carboxymethyl)benzene, 2,2'-[(1-methylethylidene)bis(4,1-phenyleneoxy)]bisacetic acid, 2,2-bis(4-carboxyphenyl)propane; terephthalic acid; 1,4 phenylene dipropionic acid; 4,4'-(n-alkylidene)bis[benzoic acid]; and cyclohexane dicarboxylic acids.
Claim 15
Independent Claim
80 words
A method for synthesizing a high molecular weight polyanhydride comprising: polymerizing at least one highly pure prepolymer prepared from at least one highly pure dicarboxylic acid at a temperature and for a reaction time to form a polyanhydride having a weight average molecular weight in excess of 20,000; removing the polyanhydride condensation product having a weight average molecular weight in excess of 20,000 formed by said polymerization; and stopping said polymerization before said polyanhydride condensation product decreases in molecular weight.
Claim 16
Independent Claim
80 words
A method for synthesizing a high molecular weight polyanhydride comprising: polymerizing at least one highly pure prepolymer prepared from at least one highly pure dicarboxylic acid at a temperature and for a reaction time to form a polyanhydride having a weight average molecular weight in excess of 20,000; removing the polyanhydride condensation product having a weight average molecular weight in excess of 20,000 formed by said polymerization; and stopping said polymerization before said polyanhydride condensation product decreases in molecular weight.
Claim 17
Dependent Claim
16 words
The method of claim 10 wherein the polymer is polymerized in the presence of a catalyst.
Claim 18
Dependent Claim
20 words
The method of claim 11 wherein the catalyst is selected from the group consisting of acid, base, and coordination catalysts.
Claim 19
Dependent Claim
33 words
The method of claim 12 wherein said catalyst is selected from the group consisting of (CH 3 COO) 2 Cd, alkaline earth metal oxides, calcium carbonate, and complexes of diethylzinc and hydroxylated compounds.
Claim 20
Dependent Claim
29 words
The method of claim 10 further comprising forming at least one prepolymer from at least one highly pure dicarboxylic acid by refluxing said dicarboxylic acid in an aliphatic anhydride.
Claim 21
Dependent Claim
37 words
The method of claim 10 further comprising forming at least one prepolymer from at least one highly pure dicarboxylic acid by reacting said dicarboxylic acid with an aliphatic acid chloride in the presence of an organic base.
Claim 22
Dependent Claim
26 words
The method of claim 10 wherein said temperature is between 140° C. and 250° C. and said reaction time is between 10 minutes and 300 minutes.
Claim 23
Dependent Claim
17 words
The method of claim 10 wherein said polymerization is stopped before said polyanhydride forms an insoluble gel.
Claim 24
Dependent Claim
20 words
The method of claim 10 wherein said temperature is approximately 180° C. and said reaction time is approximately 90 minutes.
Claim 25
Dependent Claim
130 words
The method of claim 10 further comprising selecting at least one dicarboxylic acid from the group consisting of: aliphatic dicarboxylic acids having the formula: HOOC--H.sub.2 C--R--CH.sub.2 --COOH; aromatic dicarboxylic acids having the formula: ##STR15## aromatic dicarboxylic acids having the formula: ##STR16## aliphatic-aromatic dicarboxylic acids having the formula: ##STR17## aromatic and aliphatic heterocyclic dicarboxylic acids having the formula: ##STR18## wherein X is selected from the group consisting of oxygen, nitrogen, and sulfur, and n is an integer between 1 and 3; and aromatic and aliphatic heterocyclic dicarboxylic acids of the above formula in combination with at least one dicarboxylic acid selected from the group consisting of aliphatic dicarboxylic acids, aromatic-aliphatic dicarboxylic acids, and aromatic dicarboxylic acids having more than one phenyl group, wherein the R groups are divalent organic radical groups.
Claim 26
Dependent Claim
44 words
The method of claim 19 wherein at least one dicarboxylic acid is selected from the group consisting of: sebacic acid, 4,4'-[α,w-alkanediylbis(oxy)]bis[benzoic acid], isophthalic acid, dodecanedioic acid, 2,2'-[1,4-phenylenebis(oxy)]bisacetic acid, 1,4-bis(carboxymethyl)benzene, 2,2'-[(1-methylethylidene)bis(4,1-phenyleneoxy)]bisacetic acid, 2,2-bis(4-carboxyphenyl)propane; terephthalic acid; 1,4 phenylene dipropionic acid; 4,4'-(n-alkylidene)bis[benzoic acid]; and cyclohexane dicarboxylic acids.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1991-07-12 | 1992-01-11 | 1992-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-12 | 1996-01-11 | 1996-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-12 | 2000-01-11 | 2000-07-12 | $7700.00 | Window Closed / Lapsed |