Technetium Tc 99m Albumin Injection »Technetium Tc 99m Albumin Injection is a sterile,aqueous solution,suitable for intravenous administration,of Albumin Human that is labeled with 99mTc. It contains not less than 90.0percent and not more than 110.0percent of the labeled amount of 99mTc as albumin expressed in megabecquerels (microcuries or millicuries)per mLat the time indicated in the labeling.It may contain antimicrobial agents,buffers,reducing agents,and stabilizers.Other chemical forms of radioactivity do not exceed 10.0percent of the total radioactivity.Its production and distribution are subject to federal regulations (see Biologics á1041ñand Radioactivity á821ñ). Packaging and storage— Preserve in single-dose or in multiple-dose containers,at a temperature between 2and 8. Labeling— Label it to include the following in addition to the information specified for Labelingunder Injections á1ñ:the time and date of calibration;the amount of 99mTc as albumin expressed as total megabecquerels (microcuries or millicuries)and concentration as megabecquerels (microcuries or millicuries)per mLat the time of calibration;the expiration date;and the statement “Caution—Radioactive Material.”The labeling indicates that in making dosage calculations,correction is to be made for radioactive decay,and also indicates that the radioactive half-life of 99mTc is 6.0hours. USP Reference standards á11ñ USP Endotoxin RS. Bacterial endotoxins á85ñ The limit of endotoxin content is not more than 175/VUSP Endotoxin Unit per mLof the Injection,when compared with the USP Endotoxin RS,in which Vis the maximum recommended total dose,in mL,at the expiration date or time. pHá791ñ: between 2.5and 5.0. Radiochemical purity— Not more than 10.0%of unbound Tc 99m (free pertechnetate)and reduced Tc 99m is present,determined as follows. System A— Place a measured volume of Injection,such that it provides a count rate of about 100,000counts per minute,about 3cm from the end of a 2-×17-cm thin-layer chromatographic strip impregnated with silica gel (see Chromatography á621ñ),and allow to dry.Develop the chromatogram over a suitable period (approximately 30minutes)by ascending chromatography,using acetone,and air-dry.Determine the radioactivity distribution by scanning the chromatograph with a suitable collimated radiation detector.Reduced Tc 99m and Tc 99m labeled albumin are located at the origin (RF0to 0.1).Not more than 5.0%of the total radioactivity is found as unbound Tc 99m (free pertechnetate)at the solvent front (RF0.9to 1.0). System B— Prepare a 4-×30-cm strip of chromatographic paper by immersing in 1%human serum albumin for 30minutes and air-drying for 2to 4hours.Place a measured volume of Injection (about 3µL)on the strip,mark the origin,and allow to dry.Develop the chromatogram by descending chromatography (see Chromatography á621ñ),using nitrogen-purged saline TSuntil the solvent front has moved approximately 15cm from the origin,mark the solvent front,and air-dry.Determine the radioactivity distribution by scanning the chromatogram with a suitable collimated radiation detector.Unbound Tc 99m and Tc 99m labeled albumin are at the solvent front (RF0.7to 1.0).Not more than 5.0%of the total radioactivity is found as reduced Tc 99m at the origin (RF0to 0.1). Biological distribution— Inject intravenously between 0.075MBq and 185MBq (2µCi and 5mCi)of the Injection in a volume not exceeding 0.2mLinto the caudal vein of each of two 20-to 25-g mice.Approximately 30minutes after the injection,sacrifice the animals,and drain the blood into a suitable container.Dissect the animals,and place the liver,stomach,and a 1-g specimen of blood,accurately weighed,in separate,suitable counting containers,and discard the tail cut above the injection site.Determine the radioactivity,in counts per minute,in each container with an appropriate detector,using the same counting geometry.Determine the percentage of radioactivity in the liver and stomach taken by the formula: 100(Ai/A), in which Aiis the net radioactivity,in counts per minute,in the organ,and Ais the total radioactivity,in counts per minute,in the liver,stomach,blood,and carcass.Determine the percentage of radioactivity in the blood taken by the formula: [100(B/WS)0.078(WR)]/A, in which Bis the net radioactivity,in counts per minute,in the specimen of blood,WSis the weight,in g,of the blood specimen,WRis the weight,in g,of the mouse,and 0.078is the assumption that the total blood weight of the mouse is 7.8%of the total body weight.Not more than 15.0%of the radioactivity is found in the liver,and not more than 1.0%of the radioactivity is found in the stomach.Not less than 30.0%of the radioactivity is found in the blood. Other requirements— It meets the requirements of the tests for Radionuclide identificationand Radionuclidic purityunder Sodium Pertechnetate Tc 99m Injection.It meets also the requirements under Injections á1ñ,except that it may be distributed or dispensed prior to completion of the test for Sterility,the latter test being started on the day of final manufacture,and except that it is not subject to the recommendation on Volume in Container. Assay for radioactivity á821ñ Using a suitable counting assembly (see Selection of a Counting Assembly),determine the radioactivity,in MBq (µCi)per mL,of Technetium Tc 99m Albumin Injection by use of a calibrated system. Auxiliary Information— Staff Liaison:Andrzej Wilk,Ph.D.,Senior Scientific Associate Expert Committee:(RMI)Radiopharmaceuticals and Medical Imaging Agents USP28–NF23Page 1849 Phone Number:1-301-816-8305