The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 26, 2002
Filed:
Jun. 07, 1995
Guohua Chen, Seattle, WA (US);
Allan S. Hoffman, Seattle, WA (US);
University of Washington, Seattle, WA (US);
Abstract
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.