Sulfamazone, also known as Sulphenazone, is a long-acting synthetic sulfonamide antibacterial compound with additional antipyretic properties. It is classified under the long-acting sulfonamides, with ATC code J01ED09. The compound has been marketed outside the United States, including under the trade name Marespin in Italy.
Sulfamazone has the molecular formula C₂₃H₂₄N₆O₇S₂, molecular weight 560.60 g/mol, and CAS Number 65761-24-2. PubChem identifies it as a sulfonamide containing pyridazine, pyrazolone, sulfonic acid and aromatic ether structural features.
Sulfamazone belongs to the sulfonamide class of antibacterial compounds. Like other antibacterial sulfonamides, its activity is associated with interference in bacterial folate biosynthesis. Sulfonamides act as structural analogues of 4-aminobenzoic acid (PABA) and competitively inhibit bacterial dihydropteroate synthase, thereby interfering with folate production.
The compound is distinctive from commonly encountered sulfonamides such as sulfamethoxazole and sulfadiazine because of its more complex molecular structure and long-acting pharmacological profile.
Sulfamazone is formally named (1,5-dimethyl-3-oxo-2-phenylpyrazol-4-yl)-[4-[(6-methoxypyridazin-3-yl)sulfamoyl]anilino]methanesulfonic acid. Its structure contains two sulfur atoms, six nitrogen atoms and seven oxygen atoms.
PubChem reports a molecular weight of approximately 560.6 g/mol, while NCATS reports 560.603 g/mol. The substance is racemic and contains one defined stereogenic center in the molecular structure.
Sulfamazone has historically been used as a long-acting sulfonamide antibacterial. NCATS reports that it has been marketed in Italy under the trade name Marespin for certain acute respiratory conditions. It is not approved by the U.S. FDA.
Because regulatory status and approved indications can vary by jurisdiction, pharmaceutical manufacturers should assess the API against the applicable national regulatory framework before use in a finished medicinal product.
Sulfamazone follows the characteristic antibacterial mechanism of sulfonamides. It acts as a structural analogue of PABA and competitively inhibits dihydropteroate synthase (DHPS). This disrupts de novo folate biosynthesis in susceptible microorganisms and inhibits bacterial growth.
Unlike widely monographed APIs such as sulfamethoxazole or sulfadiazine, I could not verify a current USP, BP or Ph. Eur. monograph providing universal numerical release specifications for Sulfamazone.
Therefore, values for assay, related substances, water, residue on ignition, pH and other routine CMS release fields should not be invented. These parameters should be established according to the manufacturer's validated specification, applicable regulatory filing and customer requirements.
Identity can appropriately be established using validated spectroscopic and chromatographic methods, while assay and related substances can be controlled using validated chromatographic procedures.
Sulfamazone is a complex synthetic sulfonamide molecule. Pharmaceutical API manufacturing requires controlled synthesis, purification and isolation followed by validated analytical testing.
Important quality attributes include chemical identity, assay, stereochemical/solid-state characteristics where applicable, related substances, residual solvents and elemental impurities based on the applicable risk assessment.
Sulfamazone has the molecular formula C₂₃H₂₄N₆O₇S₂ and molecular weight 560.6 g/mol. PubChem reports an XLogP3-AA value of approximately 1.6, hydrogen-bond donor count of 3, hydrogen-bond acceptor count of 12, and nine rotatable bonds.
A universally applicable pharmacopoeial numerical solubility specification or melting-point release criterion could not be verified from an authoritative current monograph. Such values should therefore not be presented as official API specifications.
Sulfamazone should be packed in appropriate pharmaceutical-grade containers that protect the API from moisture, contamination and excessive environmental exposure. Storage conditions should follow the validated stability data and applicable product specification.
A pharmaceutical API documentation package may include a Certificate of Analysis (CoA), specification sheet, Safety Data Sheet (SDS), batch analytical records, residual-solvent data, impurity profile and applicable regulatory documentation.
A qualified Sulfamazone API manufacturer should maintain controlled synthetic processes, validated analytical methods and traceable batch documentation. Because no current universal pharmacopoeial release specification could be verified for Sulfamazone, manufacturer-specific quality specifications should be clearly documented and supported by analytical validation and stability data.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |