Patent ID: 9394379
Filing Date: 2016-07-19
CPC Classification: A61K,A61P,C08B,C08J,C08L

Claim Text:
1. A process for preparing hyaluronic acid gel, which comprises steps of: preparing a modified hyaluronic acid by converting a carboxy group contained in the glucuronic acid portion of hyaluronic acid or a salt thereof to a substituted amide group at a modification ratio of 10 mole % to 30 mole % in a solvent consisting of dimethyl sulfoxide, using a condensing agent represented by the following formula (II): wherein each of R wherein the substituted amide group is formed by allowing hyaluronic acid or a salt thereof to react with one or more compounds selected from the following formulas: wherein each of l, and q independently represents an integer selected from 2 to 10; each of t, and y independently represents an integer selected from 1 to 200; each of R wherein the modification ratio is defined as a ratio of total number of substituted amide groups relative to the total number of the carboxy groups originally contained in the hyaluronic acid or the salt thereof; and cross-linking the modified hyaluronic acid to obtain hyaluronic acid gel.