Sodium risedronate

Risedronate sodium was launched as Actonel in the US for treatment of Paget's disease. Risedronic acid is readily obtained by condensation of 2-(3- pyridyl)acetic acid with phosphorous acid in presence of phosphorus oxychloride. Risedronate sodium is an orally active bisphosphonate of third generation, showing more potent bone antiresorptive properties than most of prior bisphosphonates like etidronate which has been used for the same indication since 1978. The biological mechanism by which Risedronate, and generally bisphosphonates, act is not quite clear presently ; recent advances have suggested that aminobisphosphonates interfere with the HMG-CoA pathway and inhibit protein prenylation, causing apoptosis of osteoclasts and macrophages. These apoptotic effects are correlated to the anti-resorptive properties of this class of compounds. In a 2 month clinical trial involving patients with Paget's desease, 30 mg risedronate daily achieved an appreciable reduction of serum alkaline phosphatase levels, an indicator of bone stabilization, in 77% of patients, compared with 11% on etidronate at 400 mg daily for 6 months. Risedronate is also in development for the treatment and prevention of various bone diseases, particularly post-menopausal and corticosteroid-induced osteoporosis.

Fine White to Off-White Crystalline Powder

Risedronic Acid is a pyridinyl biphosphonate bone resorption inhibitor.

Human systemic effects.

Orally active biphosphonate that inhibits farnesyl diphosphate (FPP) synthase. Exhibits antiproliferative and proapoptotic activity in numerous tumor cell lines and inhibits osteoclast-mediated bone reabsorption in vivo .