Tobramycin for Injection »Tobramycin for Injection contains an amount of Tobramycin Sulfate equivalent to not less than 90.0percent and not more than 115.0percent of the labeled amount of tobramycin (C18H37N5O9). Packaging and storage— Preserve in Containers for Sterile Solidsas described under Injections á1ñ. USP Reference standards á11ñ USP Endotoxin RS.USP Tobramycin RS. Constituted solution— At the time of use,it meets the requirements for Constituted Solutionsunder Injections á1ñ. Identification— A: It responds to the Identificationtests under Tobramycin. B: It responds to the tests for Sulfate á191ñ. 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,6g being used if it is not packaged for dispensing. pHá791ñ: between 6.0and 8.0,in a solution containing 40mg per mL(or,where packaged for dispensing,in the solution constituted as directed in the labeling). Water,Method Iá921ñ: not more than 2.0%. Particulate matter á788ñ: meets the requirements for small-volume injections. Other requirements— It meets the requirements for Residue on ignitionand Heavy metalsunder Tobramycin.It meets also the requirements for Uniformity of Dosage Units á905ñand Labelingunder 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 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 0.2mg 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 0.2mg of tobramycin (C18H37N5O9)per mL. Procedure— Proceed as directed for Procedurein the Assayunder Tobramycin.Calculate the quantity,in mg,of tobramycin (C18H37N5O9)withdrawn from the container,or in the portion of constituted solution taken by the formula: (L/D)(CE/1000)(rU/rS), in which Lis the labeled quantity,in mg,of tobramycin (C18H37N5O9)in the container,or in the volume of constituted solution taken;Dis the concentration,in mg of tobramycin per mL,of Assay preparation 1or 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. 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