A: Ultraviolet Absorption 197U—

Solution: 20 µg per mL.

Medium: 0.1 M sodium bicarbonate.

B: The retention time of the major peak for cefazolin in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.

C: It meets the requirements of the tests for Sodium 191.

Test solution: 55 mg per mL, in 0.1 M sodium bicarbonate.

Procedure for content uniformity— Perform the Assay on individual containers using Assay preparation 1 or Assay preparation 2, or both, as appropriate.

(Official January 1, 2007)

pH 3.6 Buffer, pH 7.0 Buffer, Mobile phase, Internal standard solution, Standard preparation, and Chromatographic system— Prepare as directed in the Assay under Cefazolin.

Assay preparation 1 (where it is packaged for dispensing and is represented as being in a single-dose container)—Constitute Cefazolin for Injection in a volume of water, accurately measured, corresponding to the volume of solvent specified in the labeling. Withdraw all of the withdrawable contents, using a suitable hypodermic needle and syringe, and dilute quantitatively with pH 7.0 buffer to obtain a stock solution containing about 1 mg of cefazolin per mL. Transfer 5.0 mL of this solution to a 100-mL volumetric flask, add 5.0 mL of Internal standard solution, dilute with pH 7.0 buffer to volume, and mix.

Assay preparation 2 (where the label states the quantity of cefazolin in a given volume of constituted solution)—Constitute Cefazolin for Injection in a volume of water, accurately measured, corresponding to the volume of solvent specified in the labeling. Dilute an accurately measured volume of the constituted solution quantitatively with pH 7.0 buffer to obtain a stock solution containing about 1 mg of cefazolin per mL. Transfer 5.0 mL of this solution to a 100-mL volumetric flask, add 5.0 mL of Internal standard solution, dilute with pH 7.0 buffer to volume, and mix.

Procedure— Proceed as directed in the Assay under Cefazolin. Calculate the quantity, in mg, of cefazolin (C14H14N8O4S3) in the container, and in the volume of constituted solution taken by the formula: in which L is the labeled quantity, in mg, of cefazolin in the container, or in the volume of constituted solution taken; D is the concentration, in mg per mL, of cefazolin in the stock solution used in preparing Assay preparation 1 or Assay preparation 2, on the basis of the labeled quantity in the container, or in the volume of constituted solution taken, respectively, and the extent of dilution; and the other terms are as defined therein. Where the test for Uniformity of dosage units has been performed using the Procedure for content uniformity, use the average of these determinations as the Assay value.