Sodium hyaluronate, also referred to as hyaluronic acid (HA) or hyaluronan, is a viscoelastic substance that occurs naturally in synovial fluid and is thought to play an important role in lubricating, protecting, and maintaining the health of articular cartilage. Sodium hyaluronate preparations are used as an intraarticular treatment for relief of pain associated with osteoarthritis (OA), with the potential for disease modification through improvement of synovial fluid quality and/or quantity.