Virchow Laboratories Limited Virchow Laboratories Limited is the largest producer of Sulfamethoxazole in the world with an output of 4,800 MT per annum. The Virchow plant is located in a spread of 20 acres in Hyderabad, India. Virchow produces all the critical high purity raw materials and intermediates such as Sodium Methoxide, Isoxamine and N-Acetyl Sulfanilyl Chloride in-house in production facilities dedicated to the production of Sulfamethoxazole. Virchow has perfectly implemented current Good Manufacturing Practices (cGMPs) in its system and its production facilities have been audited and approved by Therapeutic Goods Administration, Australia and the US Food and Drug Administration. Virchow has been audited by, and is the preferred supplier of Sulfamethoxazole to Glaxo Smithkline, Hoffmann La Roche, Merck Generics, Shionogi & Co. and various generic manufacturers worldwide.