Patent ID: 9579341
Date: 2017-02-28
CPC Classifications: A61K,C07C,C08B

Claim:
1. A method for preparing a preserved hyaluronic acid composition, the method consisting essentially of: dissolving a cationic preservative which is poly[oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylenedichloride] in a first quantity of a solvent; dissolving a quantity of hyaluronic acid (HA) or physiologically-acceptable salt thereof in a second quantity of the solvent wherein the ratio of the first quantity of solvent to the second quantity of solvent is between 1.8:1 and 2.2:1; and adding the dissolved HA or physiologically-acceptable salt thereof to the dissolved cationic preservative, wherein precipitation of the cationic preservative and the HA or physiologically-acceptable salt thereof is substantially prevented by preparing separate HA or physiologically-acceptable salt thereof and separate cationic preservative solutions which are then combined.