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

USP Reference standards 11— USP Sulfisoxazole Acetyl RS.

Identification— Centrifuge a portion of it, wash the separated solid by centrifugation with several portions of water, and recrystallize from hot alcohol: the crystals so obtained respond to Identification tests A and B under Sulfisoxazole Acetyl.

Uniformity of dosage units 905—

Deliverable volume 698—

pH 791: between 5.0 and 5.5.

Residual solvents 467: meets the requirements.

Assay— Transfer an accurately measured volume of Oral Suspension, previously mixed, equivalent to about 1 g of sulfisoxazole, to a 250-mL beaker. Add 40 mL of hydrochloric acid and 25 mL of glacial acetic acid, and swirl to dissolve. Cautiously add 100 mL of water, and proceed as directed under Nitrite Titration 451, beginning with “Cool to about 15.” Each mL of 0.1 M sodium nitrite is equivalent to 26.73 mg of sulfisoxazole (C11H13N3O3S).

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

USP29–NF24 Page 2044

Phone Number : 1-301-816-8394