manufactured hyaluronic acid products are used in numerous surgical applications including viscoelastic supplementation for the treatment of osteoarthritis , however , traditional sterilization techniques result in the breakdown of such high molecular weight viscoelastic biopolymers and are thus unsuitable . disclosed are processes for obtaining concentrated sterile solutions of high molecular weight biopolymers such as hyaluronic acid . the processes include filter sterilization with a dilute preparation of the biopolymer , and concentration of the dilute filter sterilized biopolymer by ultrafiltration to a desired concentration .