Packaging and storage
Preserve in tight, light-resistant containers.
Identification
B:
Ultraviolet Absorption 197U
Solution:
10 µg per mL.
Medium:
alcohol.
Absorptivities at 290 nm, calculated on the dried basis, do not differ by more than 3.0%.
Ordinary impurities 466
Test solution:
methanol.
Standard solution:
methanol.
Eluant:
a mixture of toluene and acetone (1:1).
Visualization:
1.
Organic volatile impurities, Method IV 467:
meets the requirements.
Other requirements
It meets the requirements for Residue on ignition, Selenium, and Heavy metals under Sulfisoxazole.
Assay
Transfer about 1 g of Sulfisoxazole Acetyl, accurately weighed, to a 250-mL beaker. Add 15 mL of glacial acetic acid, swirl to dissolve, then add 25 mL of hydrochloric acid and 80 mL of water. Proceed as directed under
Nitrite Titration 451, beginning with Cool to about 15
. Each mL of 0.1
M sodium nitrite is equivalent to 30.94 mg of C
13H
15N
3O
4S.