Biovisc orho 75 mg contains 75 mg per 3 ml of hyaluronic acid in buffered phosphate saline solution as active ingredient . hyaluronic acid is similar to a natural accruing substance in joints and works as lubricant and shock absorber. hyaluronic acid lubricates the joint causing pain relief . it is used for treating patients with knee pain caused by osteoarthritis (joint inflammation) who have not responded positively to pain relievers, exercise, or physical therapy. This medication is taken by injection into the effected joint and usually takes few days to work and will last for few months .