Back to results
US 5,683,993 AGranted
Compositions and methods for stabilizing polymers
AssigneeCIBA Vision Corporation
InventorFu-Pao Tsao
Life of this patent
Estimating the term…
Abstract
Compositions and methods for reducing the decomposition rate of polymeric bioadhesives and viscosity enhancers, such as poly(acrylic acids). The compositions include at least one strong, stable chelating agent, preferably an organophosphorous compound such as diethylene triamine penta(methylene phosphonic acid). These biocompatible compositions are especially useful in the ophthalmic field.
Claims8
A stabilized aqueous ophthalmic composition, comprising:
- (a) at least one bioadhesive or viscosity enhancing polymer selected from the group consisting of poly(acrylic acids), acrylate copolymers, crosslinked polyacrylic acids and mixtures thereof;
- (b) at least one strong and stable chelating agent having phosphonic acid or phosphonate groups, wherein said chelating agent is capable of complexing with free catalytic metal ions, and wherein said chelating agent has a metal ion complexing strength greater than EDTA and said chelating agent is more stable than EDTA;
- (c) about 0.05 to about 5.0 weight percent of a glucose biopolymer;
- and
- (d) water;
- wherein the composition is ophthalmically compatible.
3 more elements
A composition, comprising:
- (a) about 0.01 to 2.0 weight percent of at least one bioadhesive or viscosity enhancing polymer selected from the group consisting of poly(acrylic acids), acrylate copolymers, crosslinked polyacrylic acids and mixtures thereof;
- (b) about 0.0001 to 0.1 weight percent of at least one strong and stable chelating agent having phosphonic acid or phosphonate groups, wherein said chelating agent is capable of complexing with free catalytic metal ions, and wherein said chelating agent has a metal ion complexing strength greater than EDTA and said chelating agent is more stable than EDTA;
- (c) about 0.1 to 2.0 weight percent poly(alkylene glycol);
- (d) about 0 to 1.2 weight percent of a tonicity enhancer;
- (c) about 0.05 to 5.0 weight percent of a glucose biopolymer;
- (f) about 0.001 to 10 weight percent of a delivery agent;
- and
- (g) water.
5 more elements
A method of stabilizing an aqueous ophthalmic polymer composition, comprising the steps of:
- (a) providing an ophthalmically compatible aqueous composition including a bioadhesive or viscosity enhancing polymer selected from the group consisting poly(acrylic acids), acrylate copolymers, crosslinked polyacrylic acids and mixtures thereof;
- (b) adding at least one strong and stable chelating agent having phosphonic acid or phosphonate groups, wherein said chelating agent is capable of complexing with free metal ions, and wherein said chelating agent has a metal ion complexing strength greater than EDTA and said chelating agent is more stable than EDTA;
- and
- (c) allowing said chelating agent to complex with free catalytic metal ions, thereby producing an ophthalmically compatible composition with metal ion complexes, whereby the polymer in said composition has a decomposition rate which is less than the decomposition rate of the uncomplexed composition;
- wherein said composition includes about 0.05 to about 5.0 weight percent of a glucose biopolymer.
2 more elements
Dependencies are inferred from the claim text.