C12H14N4O4S 310.33

Benzenesulfonamide, 4-amino-N-(5,6-dimethoxy-4-pyrimidinyl)-.
N1-(5,6-Dimethoxy-4-pyrimidinyl)sulfanilamide [2447-57-6].

Packaging and storage— Preserve in well-closed, light-resistant containers.

USP Reference standards 11— USP Sulfadoxine RS.

Identification—

Melting range 741: between 197 and 200.

Loss on drying 731— Dry it at 105 for 4 hours: it loses not more than 0.5% of its weight.

Residue on ignition 281: not more than 0.1%.

Heavy metals, Method II 231: 0.002%.

Chromatographic purity— Prepare a solution in a mixture of alcohol and ammonium hydroxide (9:1) having a concentration of about 20 mg per mL. Prepare a Standard solution of USP Sulfadoxine RS having a concentration of about 0.10 mg per mL in a mixture of alcohol and ammonium hydroxide (9:1). Separately apply 10 µL each of the test solution and the Standard solution to a suitable chromatographic plate (see Chromatography 621) coated with a 0.25-mm layer of chromatographic silica gel. Develop the chromatogram in a solvent system consisting of a mixture of chloroform, methanol, and dimethylformamide (20:2:1) until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the chamber, and air-dry. Spray the dried plate with a 1 in 10 solution of sulfuric acid in alcohol, and expose to nitrous fumes generated by adding 7 M sulfuric acid dropwise to a solution containing 10% sodium nitrite and 3% potassium iodide. Dry the plate in a current of warm air for 15 minutes, and spray with a 1 in 200 solution of N-(1-naphthyl)ethylenediamine dihydrochloride in alcohol. No spot in the test solution, other than the principal spot, is greater in size and intensity than the spot obtained from the Standard solution.

Residual solvents 467: meets the requirements.

Assay— Proceed with Sulfadoxine as directed under Nitrite Titration 451. Each mL of 0.1 M sodium nitrite is equivalent to 31.03 mg of C12H14N4O4S.

Expert Committee : (MDAA05) Monograph Development-Antivirals and Antimicrobials

USP29–NF24 Page 2030

Phone Number : 1-301-816-8394