U.S. PHARMACOPEIA

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Sulfadiazine Tablets
» Sulfadiazine Tablets contain not less than 95.0 percent and not more than 105.0 percent of the labeled amount of C10H10N4O2S.
Packaging and storage— Preserve in well-closed, light-resistant containers.
Identification— Triturate a quantity of finely powdered Tablets, equivalent to about 500 mg of sulfadiazine, with 5 mL of chloroform, and transfer to a small filter. Wash with another 5-mL portion of chloroform, and discard the filtrate. Triturate the residue with 10 mL of 6 N ammonium hydroxide for 5 minutes, add 10 mL of water, and filter. Warm the filtrate until most of the ammonia is expelled, cool, and add 6 N acetic acid until the reaction is distinctly acid: a precipitate of sulfadiazine is formed. Collect the precipitate on a filter, wash it with cold water, and dry at 105 for 1 hour: the sulfadiazine so obtained melts between 250 and 254, as determined by the method for Class Ia under Melting Range or Temperature 741 and responds to Identification test A under Sulfadiazine.
Dissolution 711
Medium: 0.1 N hydrochloric acid; 900 mL.
Apparatus 2: 75 rpm.
Time: 90 minutes.
Procedure— Determine the amount of C10H10N4O2S dissolved by employing UV absorption at the wavelength of maximum absorbance at about 254 nm on filtered portions of the solution under test, suitably diluted with 0.01 N sodium hydroxide, in comparison with a Standard solution having a known concentration of USP Sulfadiazine RS in the same media.
Tolerances— Not less than 70% (Q) of the labeled amount of C10H10N4O2S is dissolved in 90 minutes.
Uniformity of dosage units 905: meet the requirements.
Residual solvents 467: meet the requirements.
(Official January 1, 2007)
Assay—
Mobile phase and Standard preparation—Prepare as directed in the Assay under Sulfadiazine.
Assay preparation— Weigh and finely powder not less than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 100 mg of sulfadiazine, to a 100-mL volumetric flask, add 75 mL of 0.025 N sodium hydroxide, shake for 30 minutes, dilute with 0.025 N sodium hydroxide to volume, mix, and centrifuge.
Chromatographic system and Procedure—Proceed as directed for Chromatographic system and for Procedure in the Assay under Sulfadiazine. Calculate the quantity, in mg, of C10H10N4O2S in the portion of Tablets taken by the formula:
100C(rU / rS),
in which the terms are as defined therein.
Auxiliary Information— Staff Liaison : Behnam Davani, Ph.D., MBA, Senior Scientist
Expert Committee : (MDAA05) Monograph Development-Antivirals and Antimicrobials
USP29–NF24 Page 2025
Phone Number : 1-301-816-8394