Polymer solution for visco-supplementation

A method for producing a sterile aqueous polymer solution, comprising mixing the following ingredients:

• a) at least one hyaluronic acid or hyaluronic acid derivative having a molar mass Mn ranging from 20,000 to 3,000,000 Dalton;
• b) one water-soluble alkali salt or alkaline earth salt of polystyrene sulfonic acid;
• c) water;
• and
• d) at least 0.5 wt. % ß-propiolactone;
• wherein a) and b) are in a mass ratio of a):b) of 1:1 to 1:0.001;
• to form a polymer solution suitable for visco-supplementation;
• and
• storing the polymer solution thus prepared for at least 24 hours at 4-40° C.

A polymer solution comprising:

• a) at least one hyaluronic acid or hyaluronic acid derivative having a molar mass Mn ranging from 500,000 to 3,000,000 Dalton;
• b) at least one water-soluble alkali salt or alkaline earth salt of polystyrene sulfonic acid;
• and
• c) water;
• wherein the polymer solution comprises a) and b) in a mass ratio of a):b) of 1:1 to 1:0.001;
• and
• wherein the polymer solution is suitable for visco-supplementation.