Thiotepa for Injection »Thiotepa for Injection is Thiotepa,with or without added substances,that is suitable for parenteral use.It contains not less than 95.0percent and not more than 110.0percent of the labeled amount of thiotepa (C6H12N3PS). Packaging and storage— Preserve in Containers for Sterile Solidsas described under Injections á1ñ,and store in a refrigerator,protected from light. USP Reference standards á11ñ USP Thiotepa RS. Completeness of solution á641ñ The contents of 1container dissolved in Sterile Water for Injection or other diluent as directed in the labeling to obtain a solution containing 3.75mg of thiotepa per mLyields a clear solution. Identification, Infrared Absorption á197SñTest and Standard solutions—Use the Assay solutionand Standard solutionprepared as directed in the Assay. pHá791ñ: between 5.5and 7.5,in a solution,constituted as directed in the labeling,containing 10mg of thiotepa per mL. Bacterial endotoxins á85ñ: not more than 6.25USP Endotoxin Units per mg of thiotepa. Other requirements— It meets the requirements for Sterility Tests á71ñ,Uniformity of Dosage Units á905ñ,and Labelingunder Injections á1ñ. Assay— Remove,as completely as possible,the contents of not less than 20containers of Thiotepa for Injection,weigh,and mix.Transfer an accurately weighed portion of the powder,equivalent to about 75mg of thiotepa,to a suitable container,extract with three 5-mLportions of carbon disulfide,and filter the carbon disulfide extract with the aid of vacuum.Concentrate the combined filtrates under vacuum to approximately 5mL.Transfer the carbon disulfide solution to a 10-mLvolumetric flask with the aid of a few mLof carbon disulfide,and dilute with carbon disulfide to volume (Assay solution).Concomitantly determine the absorbances of this solution and a Standard solution of USP Thiotepa RSin the same medium having a known concentration of about 7.5mg per mL(Standard solution),in 0.1-mm cells,at the wavelength of maximum absorbance at about 10.75µm,with a suitable IRspectrophotometer,using carbon disulfide as the blank.Calculate the quantity,in mg,of thiotepa (C6H12N3PS)in the portion of Thiotepa for Injection taken by the formula: 10C(AU/AS), in which Cis the concentration,in mg per mL,of USP Thiotepa RSin the Standard solution;and AUand ASare the absorbances of the Assay solutionand the Standard solution,respectively. Auxiliary Information— Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist Expert Committee:(PA6)Pharmaceutical Analysis 6 USP28–NF23Page 1919 Pharmacopeial Forum:Volume No.26(6)Page 1574 Phone Number:1-301-816-8389