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C11H11N3O2S 249.29

Benzenesulfonamide, 4-amino-N-2-pyridinyl-.
N1-2-Pyridylsulfanilamide [144-83-2].
» Sulfapyridine contains not less than 99.0 percent and not more than 100.5 percent of C11H11N3O2S, calculated on the dried basis.
Packaging and storage— Preserve in well-closed, light-resistant containers.
Clarity and color of solution— A solution of 1.0 g in a mixture of 20 mL of water and 5 mL of 1 N sodium hydroxide is clear and not more deeply colored than pale yellow.
B: Add 5 mL of 3 N hydrochloric acid to about 0.1 g of Sulfapyridine, and boil gently for about 5 minutes. Cool in an ice bath, add 4 mL of sodium nitrite solution (1 in 100), dilute with water to 10 mL, and place the mixture in the ice bath for 10 minutes. To 5 mL of the cooled mixture add a solution of 50 mg of 2-naphthol in 2 mL of sodium hydroxide solution (1 in 10): an orange-red precipitate is formed, and it darkens on standing.
Melting range 741: between 190 and 193.
Acidity— Digest 2.0 g with 100 mL of water at about 70 for 5 minutes, cool at once to about 20, and filter. To 25.0 mL of the filtrate add 2 drops of phenolphthalein TS, and titrate with 0.10 N sodium hydroxide: not more than 0.20 mL is required for neutralization.
Loss on drying 731 Dry it at 105 for 2 hours: it loses not more than 0.5% of its weight.
Residue on ignition 281: not more than 0.1%.
Selenium 291: 0.003%, a 200-mg test specimen being used.
Assay— Proceed with Sulfapyridine as directed under Nitrite Titration 451. Each mL of 0.1 N sodium nitrite is equivalent to 24.93 mg of C11H11N3O2S.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Behnam Davani, Ph.D., M.B.A.
Senior Scientist
(MDAA05) Monograph Development-Antivirals and Antimicrobials
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 3630
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.