Tobramycin Injection »Tobramycin Injection is a sterile solution of Tobramycin Sulfate in Water for Injection,or of Tobramycin in Water for Injection prepared with the aid of Sulfuric Acid.It contains not less than 90.0percent and not more than 120.0percent of the labeled amount of tobramycin (C18H37N5O9). Packaging and storage— Preserve in single-dose or multiple-dose glass or plastic containers.Glass containers are preferably of Type Iglass. USP Reference standards á11ñ USP Endotoxin RS.USP Tobramycin RS. Identification— 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. Bacterial endotoxins á85ñ It contains not more than 2.00USP Endotoxin Units per mg of tobramycin. Sterility á71ñ It meets the requirements when tested as directed for Membrane Filtrationunder Test for Sterility of the Product to be Examined. pHá791ñ: between 3.0and 6.5. Particulate matter á788ñ: meets the requirements for small-volume injections. Other requirements— It meets the requirements under Injections á1ñ. 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: (L/D)(CE/1000)(rU/rS), 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. Auxiliary Information— Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow Expert Committee:(PA7)Pharmaceutical Analysis 7 USP28–NF23Page 1939 Phone Number:1-301-816-8335