Sulfamethoxazole

Sulfamethoxazole (CAS 723-46-6), commonly abbreviated as SMX, is a sulfonamide antibacterial active pharmaceutical ingredient used in the manufacture of finished antimicrobial drug products. Also marketed as Urobak and Sinomin.

Where is Sulfamethoxazole used?

• Co-trimoxazole formulations: combined with trimethoprim in a 5:1 ratio for tablets, suspensions, and injectable preparations
• Urinary tract infection treatments: bulk API for pharmaceutical manufacturers
• Generic drug producers: finished-dose forms across regulated and emerging markets
• Veterinary pharmaceutical preparations for livestock: used by contract formulators
• SMX is the primary active ingredient in co-trimoxazole formulations.

Good to know: Most recognized globally as the fixed-dose combination partner with trimethoprim. It is available to USP, BP, and Ph. Eur. pharmacopoeial specifications.

Commercial specifications

• Packaging: fiber drums or double polyethylene-lined bags
• Lot-specific CoA and full regulatory documentation available upon request