Patent ID: 7456275

Claim:
A hyaluronic acid modification product, in which hyaluronic acid and/or a pharmaceutically acceptable salt thereof is covalently bound to a block polymer, selected from polyethylene oxide-polypropylene oxide-polyethylene oxide block polymer, polypropylene oxide-polyethylene oxide-polypropylene oxide block polymer, polyethylene oxide-polylactic acid/polyglycolic acid copolymer-polyethylene oxide block polymer, polylactic acid/polyglycolic acid copolymer-polyethylene oxide-polylactic acid/polyglycolic acid copolymer block polymer, polyethylene oxide-polylactic acid-polyethylene oxide block polymer and polylactic acid-polyethylene oxide-polylactic acid block polymer wherein the phase transition temperature of said hyaluronic acid modification product in physiological saline and/or phosphate physiological saline is in the range from 20° C. to 35° C. when the concentration of said hyaluronic acid modification product is 10% w/v or less, wherein the most part of said block polymer is bound to said hyaluronic acid and/or a pharmaceutically acceptable salt thereof at one of the two ends of said block polymer.