A: Ultraviolet Absorption á197Uñ—

Solution: 20µg per mL.

Medium: 0.1Msodium bicarbonate.

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

C: It meets the requirements of the tests for Sodium á191ñ.

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

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

pH3.6buffer,pH7.0buffer,Mobile phase,Internal standard solution,Standard preparation,and Chromatographic system— Prepare as directed in the Assayunder 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 pH7.0bufferto obtain a stock solution containing about 1mg of cefazolin per mL.Transfer 5.0mLof this solution to a 100-mLvolumetric flask,add 5.0mLof Internal standard solution,dilute with pH7.0bufferto 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 pH7.0bufferto obtain a stock solution containing about 1mg of cefazolin per mL.Transfer 5.0mLof this solution to a 100-mLvolumetric flask,add 5.0mLof Internal standard solution,dilute with pH7.0bufferto volume,and mix.

Procedure— Proceed as directed in the Assayunder 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 Lis the labeled quantity,in mg,of cefazolin in the container,or in the volume of constituted solution taken;Dis the concentration,in mg per mL,of cefazolin in the stock solution used in preparing Assay preparation 1or 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 unitshas been performed using the Procedure for content uniformity,use the average of these determinations as the Assayvalue.