Sildenafil citrate (Steroids) CAS: 171599-83-0 Assay: 99% min. USP32 Packing: 1kg/foil bag, 5kg/drum. Delivery: Express courier. MF: C28H38N6O11S MW: 666.7 Character: White Solid. mp 187-189°C Usage: An orally active selective type 5 cGMP phosphodiesterase inhibitor. pharmaceutical material Biological Activity: Orally active, potent inhibitor of phosphodiesterase 5 (PDE5) (IC 50 = 4 nM). Enhances nitric oxide-dependent relaxation of human corpus cavernosum in vitro . Mobile Phone No.:+86-18872220718 TEL:+86-27-50756029 FAX:+86-27-88048077 E-mail:judy26@ycphar.com Skype ID:live:judy10010