Sulfisoxazole is a short-acting sulfonamide antibacterial active pharmaceutical ingredient (API). It belongs to the sulfonamide class of antimicrobial compounds and contains an isoxazole ring substituted with a sulfonamide group.
Sulfisoxazole has CAS Number 127-69-5, molecular formula C₁₁H₁₃N₃O₃S and molecular weight 267.31 g/mol. It is also known by names including Sulfafurazole and Sulphafurazole.
Sulfisoxazole is chemically identified as 4-amino-N-(3,4-dimethyl-5-isoxazolyl)benzenesulfonamide. It is generally characterized as a white to yellowish crystalline powder.
The API contains a sulfanilamide structure linked to a dimethyl-substituted isoxazole ring. Its identity and purity can be evaluated through spectroscopic, chromatographic and pharmacopoeial analytical procedures.
Sulfisoxazole has a molecular weight of 267.31 g/mol and is slightly soluble in water, while showing greater solubility in alcohol and alkaline media.
Sulfisoxazole is associated with antibacterial pharmaceutical applications as a sulfonamide antimicrobial.
Its antibacterial action is based on interference with bacterial folate biosynthesis. Sulfonamides act as structural analogues of para-aminobenzoic acid (PABA) and competitively inhibit dihydropteroate synthase, reducing the formation of folate intermediates required for bacterial growth.
Sulfisoxazole has historically been used against susceptible Gram-positive and Gram-negative bacterial organisms.
Sulfisoxazole API can be evaluated using pharmacopoeial identity, assay, moisture, inorganic-residue and impurity testing.
The USP monograph specifies Sulfisoxazole at 99.0–101.0% calculated on the dried basis. It also specifies a melting range of 194–199°C, loss on drying of not more than 0.5%, and residue on ignition of not more than 0.1%.
Typical analytical controls may include:
Swapnroop Drugs and Pharmaceuticals provides pharmaceutical API manufacturing capabilities for Sulfisoxazole with quality-focused analytical controls and documentation.
Sulfisoxazole API can be handled according to applicable pharmacopoeial requirements and agreed customer specifications. Quality evaluation can address identity, assay, moisture, inorganic residue, impurities and physical characteristics.
For pharmaceutical companies requiring Sulfisoxazole API from an India-based manufacturer, specification alignment, analytical testing, batch consistency and appropriate documentation are important considerations.
Sulfisoxazole API should be stored in suitable, tightly closed pharmaceutical packaging that protects the material from contamination, moisture and excessive environmental exposure.
The USP monograph specifies preservation in tight, light-resistant containers.
Recommended handling includes:
Depending on customer and regulatory requirements, documentation may include:
Swapnroop Drugs and Pharmaceuticals focuses on pharmaceutical API manufacturing with quality systems, analytical evaluation and documentation intended to support pharmaceutical applications.
Sulfisoxazole API is handled according to defined quality requirements with attention to identity, assay, impurities, physical characteristics and batch-to-batch consistency.
Customers can discuss Sulfisoxazole API requirements, applicable specifications, packaging and documentation with Swapnroop Drugs and Pharmaceuticals.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 99.0–101.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |
| Heavy Metals | NMT 30 ppm |
| Melting Point | 194–199°C |