§
Luxuse
Patent Intelligence
Sign In
← Back to Patent Explorer
US4916204A Expired / Lapsed US ⏱️ 0.0 years remaining

Pure polyanhydride from dicarboxylic acid and coupling agent

Assignee: Massachusetts Institute of Technology
•
Filing: 1987-07-31
•
Granted: 1990-04-10
•
Expires: 2007-07-31
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A method for synthesizing polyanhydrides in solution using coupling agents and a removable acid acceptor to effect a one-step polymerization of dicarboxylic acids. As used in the method, these coupling agents include phosgene, diphosgene, and acid chlorides. Insoluble acid acceptors include insoluble polyamines and crosslinked polyamines such as polyethyleneimine and polyvinylpyridine and inorganic bases such as K 2 CO 3 , Na 2 CO 3 , NaHCO 3 , and CaCO 3 . The only byproduct formed is a removable hydrochloric acid-acid acceptor. Examples are provided of the polymerization of highly pure polyanhydrides using phosgene, diphosgene or an acid chloride as the coupling agent, in combination with either an insoluble acid acceptor or a soluble acid acceptor in a solvent wherein the polymerization byproduct or polymer is insoluble. A particularly important application of these polyanhydrides is in the formation of drug delivery devices containing bioactive compounds. The method is also useful in the polymerization of dicarboxylic acids including heat liable dipeptides of glutamic or aspartic acid.

Inventors

  • 👤 Abraham J. Domb
  • 👤 Robert S. Langer
  • 👤 Eyal Ron
  • 👤 Steven Giannos
  • 👤 Rohit Kothari
  • 👤 Edith Mathiowitz

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 09:37
CPC Classifications
A; A61; A61K; A61K31/00; A61K31/33; A61K31/335; A61K31/365; A61K31/38; A61K31/39; C; C08; C08G; C08G67/00; C08G67/04; C08G69/00; C08G69/02; C08G69/08; C08G69/10

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 59 words
A highly pure polyanhydride produced by reacting a dicarboxylic acid with phosgene or diphosgene in the presence of an acid acceptor and in a solvent to produce a polyanhydride soluble in said solvent and byproduct acid acceptor insoluble in said solvent, and removing insoluble byproduct acid acceptor and any unreacted phosgene or diphosgene, said polyanhydride consisting essentially of polyanhydride.
Claim 2
Dependent Claim 59 words
A highly pure polyanhydride produced by reacting a dicarboxylic acid with phosgene or diphosgene in the presence of an acid acceptor and in a solvent to produce a polyanhydride soluble in said solvent and byproduct acid acceptor insoluble in said solvent, and removing insoluble byproduct acid acceptor and any unreacted phosgene or diphosgene, said polyanhydride consisting essentially of polyanhydride.
Claim 3
Dependent Claim 26 words
The highly pure polyanhydride of claim 1 wherein the insoluble acid acceptor is selected from the group consisting of insoluble polyamines, crosslinked polyamines, and inorganic bases.
Claim 4
Dependent Claim 37 words
The highly pure polyanhydride of claim 2 wherein the acid acceptor is selected from the group consisting of K 2 CO 3 , Na 2 CO 3 , NAHCO 3 , CaCO 3 , poly(4-vinylpyridine) and polyethyleneimine.
Claim 5
Independent Claim 54 words
A method for preparing highly pure polyanhydride comprising reacting a dicarboxylic acid with phosgene or diphosgene in the presence of an acid acceptor and in a solvent to produce a polyanhydride and byproduct acid acceptor insoluble in said solvent, and removing insoluble byproduct acid acceptor and any unreacted phosgene or diphosgene from said polyanhydride.
Claim 6
Independent Claim 54 words
A method for preparing highly pure polyanhydride comprising reacting a dicarboxylic acid with phosgene or diphosgene in the presence of an acid acceptor and in a solvent to produce a polyanhydride and byproduct acid acceptor insoluble in said solvent, and removing insoluble byproduct acid acceptor and any unreacted phosgene or diphosgene from said polyanhydride.
Claim 7
Dependent Claim 24 words
The method of claim 4 wherein the insoluble acid acceptor is selected from the group consisting of insoluble polyamines, crosslinked polyamines, and inorganic bases.
Claim 8
Dependent Claim 36 words
The method of claim 5 wherein the insoluble acid acceptor is selected from the group consisting of polyethyleneimine, poly(4-vinylpyridine), K 2 CO 3 , Na 2 CO 3 , NaHCO 3 , and CaCO 3 .

References Cited (Backward Citations)

US4789724A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-04-09 1993-10-09 1994-04-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-04-09 1997-10-09 1998-04-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-04-09 2001-10-09 2002-04-10 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag