GlaxoSmithKline (GlaxoSmithKline) is one of the world's largest pharmaceutical companies, formed by the merger of GlaxoWellcome and SmithKline in 2000 and headquartered in London, England. GlaxoSmithKline mainly produces pharmaceuticals, vaccines and health products, and its famous products include Ventia, Lamotrigine, Cardifenacin, Heptin, Fenbendazole, Neocontrol, Bactrim, and Comfort. In the 2013 World Top 500 ranking, GlaxoSmithKline was ranked 253rd.