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. It is marketed under trade names including Urobak and Sinomin, and is most recognized globally as the fixed-dose combination partner with trimethoprim for various medical applications.

SMX is the primary active ingredient in co-trimoxazole formulations, where it is combined with trimethoprim in a 5:1 ratio to produce tablets, suspensions, and injectable preparations. Pharmaceutical manufacturers source SMX as a bulk API for urinary tract infection treatments, which remains one of the highest-volume therapeutic categories globally for chemical suppliers.

Generic drug producers rely on SMX to supply finished-dose forms across regulated and emerging markets. Contract formulators also use SMX in veterinary pharmaceutical preparations for livestock. Demand for sulfonamide-based antibacterials remains substantial in the global market. Sulfamethoxazole is supplied as a white crystalline powder in bulk quantities suited to commercial manufacturing.

It is available to USP, BP, and Ph. Eur. pharmacopoeial specifications, supporting registration requirements across major regulated markets and international territories. Packaging is typically offered in fiber drums or double polyethylene-lined bags. Lot-specific CoA and full regulatory documentation are available upon request for all industrial orders.