Benzenesulfonamide, 5-[(2,4-diamino-5-pyrimidinyl)oxy]-2-methoxy-4-(1-methylethyl)-, 2-hydroxy-1,2,3-propanetricarboxylate (1:1)

China [CN]

Mechanism of Action and Application Potential

Mechanism of Action: By inhibiting bacterial dihydrofolate synthase, it blocks dihydrofolate synthesis, thereby inhibiting bacterial nucleic acid synthesis and exerting antibacterial effects. It has inhibitory activity against both Gram-positive and Gram-negative bacteria.

Application Potential: It can be used to treat respiratory, urinary tract, and gastrointestinal infections caused by susceptible bacteria. Its citrate salt form is more suitable for development into highly bioavailable oral preparations and can also be administered by injection for rapid peak concentration.

Physicochemical Properties and Quality Control Points

Physicochemical Properties

Appearance: Off-white to light yellow crystalline powder.

Solubility: Easily soluble in water (significantly improved compared to the free base), slightly soluble in ethanol, almost insoluble in diethyl ether.

Stability: Stable under acidic conditions, may undergo hydrolysis under alkaline conditions.  Should be stored in a sealed container in a cool, dry place.

Quality Control Points

Content: Calculated on a dry basis, the free base content should be 98.0%-102.0% of the labeled amount.

Impurities: Single impurity ≤0.5%, total impurities ≤1.0% (mainly controlling intermediates and degradation products from the synthesis process).

Moisture: ≤0.5% (Karl Fischer method).

Heavy Metals: ≤20ppm.