A: The chromatogram of the Assay preparation obtained as directed in the Assay exhibits a major peak for cefuroxime, the retention time of which corresponds to that exhibited in the chromatogram of the Standard preparation obtained as directed in the Assay.

B: It responds to the tests for Sodium 191.

pH 3.4 acetate buffer— Transfer 50 mL of 0.1 M sodium acetate to a 1000-mL volumetric flask, dilute with 0.1 N acetic acid to volume, and mix.

Mobile phase— Prepare a suitable mixture of pH 3.4 acetate buffer and acetonitrile (about 10:1). Filter through a membrane filter (1 µm or finer porosity), and degas.

Internal standard solution— Prepare a solution of orcinol in water containing 1.5 mg per mL.

Standard preparation— Dissolve a suitable quantity of USP Cefuroxime Sodium RS, accurately weighed, in water to obtain a solution having a known concentration of about 1 mg of cefuroxime (C16H16N4O8S) per mL. Immediately transfer 5.0 mL of the resulting solution to a 100-mL volumetric flask, add 20.0 mL of Internal standard solution, dilute with water to volume, and mix. This Standard preparation contains about 0.05 mg of cefuroxime per mL.

Assay preparation— Using a suitable quantity of Cefuroxime Sodium, accurately weighed, proceed as directed in the first sentence under Standard preparation. Immediately transfer 5.0 mL of the resulting solution to a 100-mL volumetric flask, add 20.0 mL of Internal standard solution, dilute with water to volume, and mix.

Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 254-nm detector and a 4.6-mm × 15-cm column that contains 5-µm packing L15. The flow rate is about 2 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed under Procedure: the column efficiency determined from the analyte peak is not less than 1300 theoretical plates; the tailing factor for the analyte peak is not more than 2.0; the resolution, R, between the analyte and internal standard peaks is not less than 3.5; and the relative standard deviation for replicate injections is not more than 2.0%.

Procedure— Separately inject equal volumes (about 10 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. The relative retention times are about 0.5 for cefuroxime and 1.0 for orcinol. Calculate the quantity, in µg, of cefuroxime per mg of the Cefuroxime Sodium taken by the formula: in which C is the concentration, in mg of cefuroxime (C16H16N4O8S) per mL, in the Standard preparation; M is the concentration, in mg per mL, in the Assay preparation based on the weight of Cefuroxime Sodium taken and the extent of dilution; and RU and RS are the peak response ratios of the cefuroxime peak to the internal standard peak obtained from the Assay preparation and the Standard preparation, respectively.