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 2.3 Buffer and Standard preparation— Prepare as directed in the Assay under Cefamandole Nafate.

Assay preparation 1 (where the article is represented as being in a single-dose container)—Constitute Cefamandole Nafate 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 water to obtain a solution having a concentration of about 2 mg of cefamandole per mL. Transfer 5.0 mL of this solution to a 50-mL volumetric flask, add 30.0 mL of pH 2.3 Buffer, dilute with water to volume, and mix.

Assay preparation 2 (where the label states the quantity of cefamandole in a given volume of constituted solution)—Constitute Cefamandole Nafate for Injection in a volume of water, accurately measured, corresponding to the volume of solvent specified in the labeling. Quantitatively dilute an accurately measured volume of the constituted solution with water to obtain a solution containing about 2 mg of cefamandole per mL. Transfer 5.0 mL of this solution to a 50-mL volumetric flask, add 30.0 mL of pH 2.3 Buffer, dilute with water to volume, and mix.

Assay preparation 3— Using an accurately weighed quantity of Cefamandole Nafate for Injection, prepare as directed for Standard preparation under Cefamandole Nafate. Determine the sodium carbonate content of a separate, accurately weighed, 1-g portion of Cefamandole Nafate for Injection dissolved in 100 mL of water. Add methyl orange TS, and titrate with 0.2 N sulfuric acid VS. Each mL of 0.2 N sulfuric acid is equivalent to 10.60 mg of Na2CO3.

Procedure— Proceed as directed for Procedure in the Assay under Cefamandole Nafate. Calculate the quantity, in mg, of cefamandole (C18H18N6O5S2) in the portion of constituted solution taken by the formula: in which C is the concentration, in mg per mL, of USP Cefamandole Nafate RS in the Standard preparation; L is the labeled quantity, in mg, in the portion of constituted solution taken; D is the concentration, in mg per mL, of cefamandole in Assay preparation 1 or in Assay preparation 2, based on the volume of constituted solution taken and the extent of dilution; and the other terms are as defined therein. Calculate the potency, in µg of cefamandole (C18H18N6O5S2) per mg, of the Cefamandole Nafate for Injection taken by the formula: in which W is the weight, in mg, of the Cefamandole Nafate for Injection taken in each mL of Assay preparation 3, 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.