Medium: 0.12Nhydrochloric acid;900mL.

Apparatus 2: 75rpm.

Time: 60minutes.

Procedure— Determine the amount of C16H19N3O4Sdissolved from UVabsorbances at the wavelength of maximum absorbance at about 255nm 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 Cephradine RSin the same medium.

Tolerances— Not less than 85%(Q)of the labeled amount of C16H19N3O4Sis dissolved in 60minutes.

Mobile phase,Standard preparation,Resolution solution,and Chromatographic system— Proceed as directed in the Assayunder Cephradine.

Assay preparation— Place not less than 5Tablets in a high-speed glass blender jar containing an accurately measured volume of water,sufficient to yield a concentration of not less than 5mg of cephradine per mL,and blend for 4±1minutes.Dilute an accurately measured volume of this stock solution quantitatively and stepwise with Mobile phaseto obtain an Assay preparationcontaining about 0.5mg of cephradine per mL.

Procedure— Separately inject equal volumes (about 10µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of cephradine (sum of cephradine and cephalexin)in each Tablet taken by the formula: in which Cis the concentration,in mg per mL,of USP Cephradine RSin the Standard preparation,Pis the designated potency,in µg per mg,of USP Cephradine RS,Lis the labeled quantity,in mg of cephradine,in each Tablet,Dis the concentration,in mg of cephradine per mL,of the Assay preparation,based on the labeled quantity per Tablet,the number of Tablets taken,and the extent of dilution,and rUand rSare the sums of the cephradine and cephalexin peak responses obtained from the Assay preparationand the Standard preparation,respectively.