A: It responds to the Identification tests under Tobramycin.

B: It responds to the tests for Sulfate 191.

Mobile phase, 2,4-Dinitrofluorobenzene reagent, Tris(hydroxymethyl)aminomethane reagent, Standard preparation, Derivatization procedure, Resolution solution, and Chromatographic system— Proceed as directed in the Assay under Tobramycin.

Assay preparation 1 (where it is represented as being in a single-dose container)—Constitute a container of Tobramycin for Injection in a volume of water, accurately measured, corresponding to the volume of diluent 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 containing the equivalent of about 0.2 mg of tobramycin (C18H37N5O9) per mL.

Assay preparation 2 (where the label states the quantity of tobramycin in a given volume of constituted solution)—Constitute a container of Tobramycin for Injection in a volume of water, accurately measured, equivalent to the volume of diluent specified in the labeling. Dilute an accurately measured volume of the constituted solution quantitatively with water to obtain a solution containing about 0.2 mg of tobramycin (C18H37N5O9) per mL.

Procedure— Proceed as directed for Procedure in the Assay under Tobramycin. Calculate the quantity, in mg, of tobramycin (C18H37N5O9) withdrawn from the container, or in the portion of constituted solution taken by the formula: in which L is the labeled quantity, in mg, of tobramycin (C18H37N5O9) in the container, or in the volume of constituted solution taken; D is the concentration, in mg of tobramycin per mL, of Assay preparation 1 or Assay preparation 2, based on 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.