Sulfisoxazole Tablets
» Sulfisoxazole Tablets contain not less than 95.0 percent and not more than 105.0 percent of the labeled amount of C11H13N3O3S.
Packaging and storage— Preserve in well-closed, light-resistant containers.
Identification— Extract a quantity of powdered Tablets, equivalent to about 1 g of sulfisoxazole, with 50 mL of alcohol by boiling on a steam bath for 3 minutes, then immediately filter into a beaker. Allow to stand until a quantity of fine, needle-like crystals form. Cool, filter off the crystals, recrystallize from a small volume of alcohol, and dry at 105: the crystals respond to Identification test A under Sulfisoxazole.
Dissolution 711—
Medium: dilute hydrochloric acid (1 in 12.5); 900 mL.
Apparatus 1: 100 rpm.
Time: 30 minutes.
Procedure— [note—Because of the pH-dependent nature of the UV absorption spectrum, prepare the standard and specimen solutions in the same strength of acid at approximately equal concentrations.] Determine the amount of C11H13N3O3S dissolved from UV absorbances at the wavelength of maximum absorbance at about 267 nm of filtered portions of the solution under test, suitably diluted with water, if necessary, in comparison with a Standard solution having a known concentration of USP Sulfisoxazole RS in the same medium.
Tolerances— Not less than 70% (Q) of the labeled amount of C11H13N3O3S is dissolved in 30 minutes.
Uniformity of dosage units 905: meet the requirements.
Assay— Weigh and finely powder not less than 20 Tablets. Weigh accurately a portion of the powder, equivalent to about 800 mg of sulfisoxazole, transfer to a 250-mL conical flask, and proceed as directed in the Assay under Sulfisoxazole, beginning with “add 50 mL of dimethylformamide.”
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
1-301-816-8394		 (MDAA05) Monograph Development-Antivirals and Antimicrobials
Reference Standards Lili Wang, Technical Services Scientist
1-301-816-8129
RSTech@usp.org
711 Margareth R.C. Marques, Ph.D.
Senior Scientist
1-301-816-8106		 (BPC05) Biopharmaceutics05
USP32–NF27 Page 3636