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 o 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.