A: The retention time of the major peak for l-lysine in the chromatogram of the Test preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the test for Content of L-lysine.

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

Mobile phase— Mix 62 volumes of methanol and 38 volumes of water, and adjust with glacial acetic acid to a pH of 3.0, making adjustments if necessary (see System Suitability under Chromatography 621).

Stock standard solution— Transfer about 36 mg of l-lysine, accurately weighed, to a 100-mL volumetric flask, dilute with water to volume, and mix.

Standard preparation— Transfer 2.0 mL of Stock standard solution to a glass-stoppered, 10-mL volumetric flask, add 2.0 mL of a 1.4% solution of tris(hydroxymethyl)aminomethane and 3.0 mL of a 1.5% solution of 1-fluoro-2,4-dinitrobenzene in dehydrated alcohol, insert the stopper tightly, and mix. Heat at 50 in a water bath for 30 minutes. Remove the flask from the water bath, allow to cool, dilute with methanol to volume, and mix.

Test preparation— Transfer about 150 mg of Ceforanide for Injection, accurately weighed, to a 100-mL volumetric flask, add water to volume, and mix. Transfer 2.0 mL of the resulting solution to a glass-stoppered, 10-mL volumetric flask, and proceed as directed under Standard preparation, beginning with “add 2.0 mL of a 1.4% solution of tris(hydroxymethyl)aminomethane.”

Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 254-nm detector and a 4.6-mm × 25-cm column that contains 5- to 10-µm packing L1. The flow rate is about 1.5 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed under Procedure: the column efficiency determined from the derivatized l-lysine peak is not less than 1500 theoretical plates; the tailing factor for the same peak is not more than 1.3, the resolution; R, between the derivatized l-lysine peak and the 1-fluoro-2,4-dinitrobenzene peak is not less than 4.5; the capacity factor, k¢, is not less than 4 and not more than 6; and the relative standard deviation for replicate injections is not more than 1.5%.

Procedure— Separately inject equal volumes (about 20 µL) of the Standard preparation and the Test preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the percentage of l-lysine in the Ceforanide for Injection taken by the formula: in which C is the concentration, in µg per mL, of l-lysine in the Stock standard solution; M is the quantity, in mg, of Ceforanide for Injection taken; and rU and rS are the peak responses obtained from the Test preparation and the Standard preparation, respectively. Use this percentage to calculate, on an l-lysine-free basis, the result from Assay preparation 1 obtained as directed in the Assay.

Mobile phase , Standard preparation, and Chromatographic system—Prepare as directed in the Assay under Ceforanide.

Assay preparation 1— Dissolve a suitable quantity of Ceforanide for Injection, accurately weighed, in Mobile phase, and dilute quantitatively and stepwise with Mobile phase to obtain a solution having a concentration of about 1 mg of ceforanide per mL. Use this solution within 5 minutes.

Assay preparation 2 (where it is represented as being in a single-dose container)—Constitute Ceforanide 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 and stepwise with Mobile phase to obtain a solution containing about 1 mg of ceforanide per mL. Use this solution within 5 minutes.

Assay preparation 3 (where the label states the quantity of ceforanide in a given volume of constituted solution)—Constitute Ceforanide 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 and stepwise with Mobile phase to obtain a solution containing about 1 mg of ceforanide per mL. Use this solution within 5 minutes.

Procedure— Proceed as directed for Procedure in the Assay under Ceforanide. Calculate the quantity, in µg, of ceforanide (C20H21N7O6S2) in each mg of the Ceforanide for Injection taken by the formula: in which M is the concentration, in mg per mL, of Assay preparation 1 based on the weight of Ceforanide for Injection taken and the extent of dilution, and the other terms are as defined therein. Calculate the quantity, in mg, of C20H21N7O6S2 withdrawn from the container, or in the portion of constituted solution taken by the formula: in which L is the labeled quantity, in mg, of ceforanide in the container, or in the volume of constituted solution taken; D is the concentration, in mg of ceforanide per mL, of Assay preparation 2 or Assay preparation 3, 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 defined therein.