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)

Mobile phase, Diluent, Standard preparation, Resolution solution, and Chromatographic system— Prepare as directed in the Assay under Ampicillin.

Assay preparation 1 (where it is represented as being in a single-dose container)—Constitute Ampicillin for Injection in an accurately measured volume of Diluent, corresponding to the volume of solvent specified in the labeling. Withdraw all of the withdrawable contents, using a suitable hypodermic needle and syringe, and quantitatively dilute with Diluent to obtain a solution containing about 1 mg of ampicillin per mL. Use this solution promptly after preparation.

Assay preparation 2 (where the label states the quantity of ampicillin in a given volume of constituted solution)—Constitute 1 container of Ampicillin for Injection in a volume of Diluent, accurately measured, corresponding to the volume of solvent specified in the labeling. Quantitatively dilute an accurately measured portion of the constituted solution with Diluent to obtain a solution having a concentration of about 1 mg of ampicillin per mL. Use this solution promptly after preparation.

Procedure— Proceed as directed for Procedure in the Assay under Ampicillin. Calculate the quantity, in mg, of ampicillin (C16H19N3O4S) in the container and in the volume of constituted solution taken by the formula: in which L is the labeled quantity, in mg, of ampicillin (C16H19 N3O4S) in the container, or in the volume of constituted solution taken; D is the concentration, in mg of ampicillin (C16H19N3O4S) per mL, of Assay preparation 1 or Assay preparation 2, based on the labeled quantity in the container or in the portion of constituted solution taken, respectively, and the extent of dilution; and the other terms are as previously defined. 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.