Tolazamide Tablets »Tolazamide Tablets contain not less than 95.0percent and not more than 105.0percent of the labeled amount of C14H21N3O3S. Packaging and storage— Preserve in tight containers. USP Reference standards á11ñ USP Tolazamide RS. Identification— Triturate a quantity of Tablets,equivalent to about 250mg of tolazamide,with 50mLof chloroform,and filter.Evaporate the filtrate to dryness,and dry in vacuum at 60for 3hours:the residue so obtained responds to Identificationtest Aunder Tolazamide. Dissolution á711ñ Medium: 0.05MTris(hydroxymethyl)aminomethane,pH7.6,adjusted,if necessary,with hydrochloric acid to a pHof 7.6;900mL. Apparatus 2: 75rpm. Time: 30minutes. Procedure— Determine the amount of C14H21N3O3Sdissolved from UVabsorbances at the wavelength of maximum absorbance at about 224nm of filtered portions of the solution under test,suitably diluted with Dissolution Medium,in comparison with a Standard solution having a known concentration of USP Tolazamide RSin the same medium.[NOTE—Sonicate the Standard solution until the Reference Standard is dissolved.] Tolerances— Not less than 70%(Q)of the labeled amount of C14H21N3O3Sis dissolved in 30minutes. Uniformity of dosage units á905ñ: meet the requirements. Assay— Internal standard preparation ,Mobile phase,and Standard preparation—Prepare as directed in the Assayunder Tolazamide. Assay preparation— Weigh and finely powder not less than 10Tablets.Weigh accurately a portion of the powder,equivalent to about 300mg of tolazamide,and transfer to a suitable container.Add 100.0mLof Internal standard solutionand about 20glass beads.Securely close the container,and shake vigorously for approximately 30minutes.Centrifuge,and use the clear liquid as the Assay preparation. Procedure— Proceed as directed for Procedurein the Assayunder Tolazamide.Calculate the quantity,in mg,of C14H21N3O3Sin the portion of Tablets taken by the formula: 100C(RU/RS), in which the terms are as defined therein. Auxiliary Information— Staff Liaison:Elena Gonikberg,Ph.D.,Scientist Expert Committee:(PA4)Pharmaceutical Analysis 4 USP28–NF23Page 1946 Phone Number:1-301-816-8251