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US 6,486,213 B1Granted
Block and graft copolymers and methods relating thereto
AssigneeUniversity of Washington
InventorsGuohua Chen, Allan S. Hoffman
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AssigneeUniversity of Washington
InventorsGuohua Chen, Allan S. Hoffman
Estimating the term…
There is disclosed block and graft copolymers, and hydrogels thereof, which, in one embodiment, contain both a temperature-sensitive polymer component and a pH-sensitive polymer component, and the use of such copolymers for topical drug delivery to a treatment area. The block and graft copolymers may be physically mixed with one or more drugs (or with other polymers) to form a copolymer-drug mixture. These mixtures may be applied as solid particles suspended in a pharmaceutically acceptable carrier, or as a liquid which gels upon contact with the treatment area. Upon contact with the treatment area, the pH-sensitive polymer component hydrates and swells, thereby causing release of the drug from the mixture. In addition, such hydration and swelling causes the pH-sensitive polymer component to adhere to the tissue of the treatment area, thus prolonging contact time. The temperature-sensitive polymer component resists hydration and swelling of the mixture, thereby imparting a sustained and controlled release of the drug to the treatment area. In another embodiment of this invention, block and graft copolymers, and hydrogels thereof, are disclosed having broad industrial applicability.
A graft copolymer comprising a backbone pH-sensitive polymer component with a pendant temperature-sensitive polymer component grafted thereto, wherein the graft copolymer has a critical temperature ranging from 20° C. to 40° C. measured at a pH between 6.0 to 8.0, wherein the temperature sensitive polymer component is a block copolymer, and wherein the pH-sensitive polymer component comprises a carboxylic acid-containing polymer.
A graft copolymer comprising a backbone pH-sensitive polymer component with a pendant temperature-sensitive polymer component grafted thereto, wherein the graft copolymer has a critical temperature ranging from 20° C. to 40° C. measured at a pH between 6.0 to 8.0, wherein the temperature sensitive polymer component is a random or block copolymer, the pH-sensitive polymer component comprises a carboxylic acid-containing polymer, and at least one of the pH-sensitive or temperature-sensitive polymer components is lightly cross-linked with crosslinker molecules.
A graft copolymer comprising a backbone temperature-sensitive polymer component with a pendant pH-sensitive polymer component grafted thereto wherein the graft copolymer has a critical temperature ranging from 20° C. to 40° C. measured at a pH between 6.0 to 8.0, wherein the temperature sensitive polymer component is a block copolymer, and wherein the pH-sensitive polymer component comprises a carboxylic acid-containing polymer.
A graft copolymer comprising a backbone temperature-sensitive polymer component with a pendant pH-sensitive polymer component grafted thereto, wherein the graft copolymer has a critical temperature ranging from 20° C. to 40° C. measured at a pH between 6.0 to 8.0, wherein the temperature sensitive polymer component is a random or block copolymer, the pH-sensitive polymer component comprises a carboxylic acid-containing polymer, and at least one of the pH-sensitive or temperature-sensitive polymer components is lightly cross-linked and the graft copolymer is a hydrogel.
Dependencies are inferred from the claim text.