A: Dilute the Injection with water to obtain a solution containing 6mg of tobramycin per mL,and proceed as directed for Identificationtest Aunder Tobramycin,beginning with “Apply 3µLof this test solution”.

B: The retention time of the major peak for tobramycin in the chromatogram of the Derivatized assay preparationcorresponds to that in the chromatogram of the Derivatized standard preparation,as obtained in the Assay.

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

Assay preparation— Dilute an accurately measured volume of Injection quantitatively,and stepwise if necessary,with water to obtain a solution containing the equivalent of about 0.2mg of tobramycin per mL.

Procedure— Proceed as directed in the Assayunder Tobramycin.Calculate the quantity,in mg,of tobramycin (C18H37N5O9)in each mLof the Injection taken by the formula: in which Lis the labeled quantity,in mg per mL,of tobramycin (C18H37N5O9)in the Injection;Dis the concentration,in mg per mL,of tobramycin in the Assay preparation,on the basis of the labeled quantity,the volume taken,and the extent of dilution;and the other terms are as defined therein.