Sulfametrole is a synthetic sulfonamide antibacterial active pharmaceutical ingredient. It is also known as Sulfametrol and Sulfametrolum. The compound has CAS No. 32909-92-5, molecular formula C₉H₁₀N₄O₃S₂, and molecular weight 286.32 g/mol. PubChem and the Merck Index identify Sulfametrole as a sulfonamide antibiotic.
Sulfametrole is chemically classified as a substituted aniline, aromatic ether, thiadiazole and sulfonamide. Its IUPAC name is 4-amino-N-(4-methoxy-1,2,5-thiadiazol-3-yl)benzene-1-sulfonamide.
Sulfametrole belongs to the sulfonamide class of antibacterial compounds. It has historically been used both alone and, importantly, in combination with trimethoprim. Clinical literature has evaluated trimethoprim/sulfametrole combinations for bacterial infections, including intravenous and oral administration.
The API is registered internationally under the INN Sulfametrole, and the FDA GSRS-linked substance record assigns it UNII F5AK41IPQG.
Sulfametrole contains a 4-amino-benzenesulfonamide moiety linked to a 4-methoxy-1,2,5-thiadiazole ring. Its molecular formula is C₉H₁₀N₄O₃S₂ and its molecular weight is 286.32 g/mol. The compound has the InChIKey IZOYMGQQVNAMHS-UHFFFAOYSA-N.
Sulfametrole should be distinguished from Sulfametrole Sodium, which is a separate salt form. FDA/NCATS substance records list Sulfametrole Sodium separately from the parent Sulfametrole substance.
Sulfametrole has been used as an antibacterial sulfonamide and has particular historical relevance in combination therapy with trimethoprim. EMA documentation specifically recognizes medicinal products containing sulfametrole/trimethoprim.
Clinical literature has investigated trimethoprim/sulfametrole for difficult-to-treat bacterial infections and compared the combination with trimethoprim/sulfamethoxazole.
As a sulfonamide antibacterial, Sulfametrole acts as an analogue of para-aminobenzoic acid (PABA) and interferes with bacterial folate biosynthesis. Sulfonamides inhibit dihydropteroate synthase, reducing the formation of folate intermediates required for bacterial nucleotide synthesis.
When combined with trimethoprim, inhibition occurs at sequential stages of bacterial folate metabolism, providing a pharmacological rationale for the combination.
Quality control for Sulfametrole API should include identity, assay, related substances, residual solvents, water/moisture, elemental impurities and other applicable quality attributes.
Importantly, I could not verify a current USP, BP or Ph. Eur. monograph providing universal numerical API release limits for Sulfametrole. Therefore, numerical values for assay, individual impurities, total impurities, water, pH or residue on ignition should not be invented.
A manufacturer-specific specification should instead be supported by validated analytical methods, stability data and applicable regulatory requirements.
Sulfametrole API manufacturing involves controlled chemical synthesis, purification, crystallization and drying. Process controls should address starting materials, reaction conditions, process-related impurities and residual solvents.
Final quality testing should confirm identity and purity while ensuring that impurities and other critical quality attributes remain within the approved product specification.
Sulfametrole is represented by the molecular formula C₉H₁₀N₄O₃S₂ and molecular weight 286.32 g/mol. PubChem identifies it as a sulfonamide antibiotic and provides the molecular structure and chemical identifiers.
Because I could not verify a current pharmacopoeial monograph with universal physical-property release criteria, melting point and numerical solubility values should not be presented as official API specifications without a validated source.
Sulfametrole should be stored in suitable pharmaceutical-grade, well-closed packaging that protects the API from moisture, contamination and environmental exposure. Final storage conditions should follow the manufacturer's validated stability data and approved specification.
Typical API documentation may include a Certificate of Analysis (CoA), specification sheet, Safety Data Sheet (SDS), batch analytical records, impurity profile, residual-solvent data and applicable regulatory documentation.
A qualified Sulfametrole API manufacturer should maintain controlled manufacturing processes, validated analytical methods and complete batch traceability. Consistent control of identity, assay, related substances and stability-related attributes is essential for pharmaceutical-grade Sulfametrole.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |