Technetium Tc 99m Albumin Colloid Injection »Technetium Tc 99m Albumin Colloid Injection is a sterile,pyrogen-free,aqueous suspension of Albumin Human that has been denatured to produce colloids of controlled particle size and that are labeled with 99mTc.It contains not less than 90.0percent and not more than 110.0percent of the labeled amount of 99mTc as albumin colloid complex,expressed in megabecquerels (millicuries)per mLat the time indicated on the labeling.Other chemical forms of radioactivity do not exceed 10.0percent of the total radioactivity.It may contain suitable reducing agents,buffers,stabilizers,and nonaggregated albumin human.The vials are sealed under a suitable inert atmosphere.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 expressed as total megabecquerels (millicuries)and concentration as megabecquerels (millicuries)per mLat the time of calibration;the expiration date and time and a 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.In addition,the labeling states that it is not to be used if clumping of the albumin is observed,and directs that the container be agitated before the contents are withdrawn into a syringe. 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 7.5and 8.5. Radiochemical purity— A: Unbound pertechnetate—Apply a measured volume of Injection,appropriately diluted,such that it provides a count rate of about 20,000counts per minute,about 10mm from one end of a thin-layer chromatographic strip impregnated with silica gel (see Chromatography á621ñ).Immediately develop the chromatogram over a suitable period by ascending chromatography,using methyl ethyl ketone as the solvent.Allow the chromatogram to dry.Determine the radioactivity distribution of the chromatogram by scanning with a suitable radiation detector.Not more than 10.0%of the total radioactivity is found at the solvent front as unbound pertechnetate. B: Soluble99mTc speciesAcetate buffer— Transfer 20.0mLof 0.2Macetic acid and 30.0mLof 0.2Msodium acetate to a 100-mLvolumetric flask,dilute with water to volume,and mix. Procedure— Transfer 1mLof the Injection containing about 925to 1110MBq (25to 30mCi)to a 12-mLcentrifuge tube,and add 4mLof Acetate buffer.Determine the radioactivity with a suitable counting assembly.Centrifuge at a force of 34,600g (gravity)for 15minutes.Separate the supernatant,and determine its radioactivity.Correct both measurements for decay to the same reference time.Calculate the percentage of soluble 99mTc species taken by the formula: 100(S/I), in which Sis the radioactivity of the supernatant,and Iis the radioactivity of the specimen before centrifuging.Not more than 10.0%of the total radioactivity is found in the supernatant. Particle size distribution— Albumin reagent— Transfer 3.3g of Poloxamer 188,56.6g of dibasic sodium phosphate,and about 800mLof Water for Injection to a 1-liter volumetric flask,and mix.Add 120mLof 25%Albumin Human,dilute with Water for Injection to volume,and mix.The pHof the resulting solution is 8.2±0.7.Store at 2to 8.Just prior to use,transfer 6.2mLof this solution,measured at room temperature,to a 100-mLvolumetric flask.Dilute with Sodium Chloride Injection to volume,and mix. Procedure— Inject 0.5mLof Injection into a 25-mLevacuated or nitrogen-filled vial.Inject 4.5mLof Albumin reagent,and shake.Using a syringe,remove 0.2mLof the resulting mixture,and attach the syringe by means of a locking-type connection to the top of a 25-mm filter housing assembly consisting of a 5.0-µm polycarbonate membrane filter on top followed by a distance of 3cm by a 0.1-µm polycarbonate membrane filter.Pass the mixture through the filters,collecting the filtrate in a suitable container.Wash the filters by passing 12mLof Albumin reagentthrough the filter housing assembly,adding the washing to the first filtrate.Using a suitable ionization chamber,measure the radioactivity in the filtrate and on each filter.Calculate the percentage of radioactivity retained on the 5.0-µm filter taken by the formula: 100F/T, in which Fis the radioactivity on the filter,and Tis the total radioactivity of each filter and filtrate:not more than 7.5%of the total radioactivity is retained on the 5.0-µm filter.Calculate the percentage of radioactivity retained on the 0.1-µm filter by the same formula:not less than 82.5%of the total radioactivity is retained,and not more than 10.0%of the total radioactivity passes through the 0.1-µm membrane. Biological distribution— Inject intravenously between 55.5and 111MBq (1.5and 3.0mCi)of Injection,in a volume of 0.1mL,into the caudal vein of each of three 20-g to 40-g mice.Fifteen minutes after injection,sacrifice the animals,and remove the tails,and discard.Carefully remove the liver and lungs of each.Place each organ and the remaining carcass in separate,suitable counting containers,and determine the radioactivity,in MBq (mCi),in each container in a calibrated ionization chamber,using the same counting geometry.Determine the percentage of radioactivity in the liver and the lungs taken by the formula: 100(A/B), in which Ais the radioactivity,in MBq (mCi),in the organ,and Bis the total radioactivity,in MBq (mCi),in the lungs,liver,and carcass.Not less than 80%of the radioactivity is found in the liver and not more than 5%of the radioactivity is found in the lungs,in not less than two of the three mice. Albumin content— Each container,prior to constitution with Sodium Pertechnetate Tc 99m Injection,contains not less than 0.8mg and not more than 1.2mg of aggregated (insoluble)albumin and not less than 8mg and not more than 12mg of nonaggregated (soluble)albumin. Procedure— Acetate buffer— Transfer 20.0mLof 0.2Macetic acid and 30.0mLof 0.2Msodium acetate to a 100-mLvolumetric flask,dilute with water to volume,and mix.Adjust by the addition,if necessary,of 0.2Macetic acid or 0.2Msodium acetate to a pHof 4.9±0.1. Basic acetate buffer— Transfer 50mLof 1Nsodium hydroxide to a 500-mLvolumetric flask.Dilute with Acetate bufferto volume,and mix. Standard preparation— Using a “To contain”pipet,transfer 2.0mLof 7Percent Bovine Serum Albumin Certified Standard (see under Reagentsin the section Reagents,Indicators,and Solutions),to a 250-mLvolumetric flask.Rinse the pipet with Basic acetate buffercollecting the rinse in the volumetric flask.Dilute with Basic acetate bufferto volume,and mix. Standard solutions— Into 5separate graduated test tubes pipet 1,2,3,4,and 5mLof the Standard preparation.Dilute the first four with Basic acetate bufferto a final volume of 5.0mL.Pipet 5mLof Biuret Reagent TSinto each tube,and mix.Incubate each at 37±1for 30minutes.Allow to cool to room temperature.Determine the absorbances of the solutions in 1-cm cells at the wavelength of maximum absorbance at about 555nm using a mixture of Basic acetate bufferand Biuret Reagent TS(1:1)as the blank.Plot the concentration,in mg per mL,versus the absorbance of each Standard solutionand draw the best straight line through the points to obtain the standard curve. Test preparation— Constitute the contents of each of 2containers with 2.0mLof Acetate bufferand allow to stand for 30minutes.Transfer the contents of both containers to a centrifuge tube rinsing the containers with four 1-mLportions of Acetate buffer.Collect all the washings in the same centrifuge tube.Centrifuge the tube for 15minutes at 4at a force of 86,400g (gravity).Quantitatively transfer the supernatant to a 50-mLvolumetric flask.Add 5.0mLof 1Nsodium hydroxide,dilute with Acetate bufferto volume,and mix.Pipet 5mLof this solution into a test tube to obtain the Soluble albumin test solution.Dissolve the residue from the centrifugation in 5.0mLof Basic acetate bufferto obtain the Insoluble albumin test solution.Treat each solution in the same manner as described under Standard solutions,beginning with “Pipet 5mLof Biuret Reagent TS”and determine the absorbance of each solution as directed for Standard solutions.From the observed absorbance of each Test preparation,determine the concentration of total albumin from the standard curve.Multiply the concentration obtained for the Soluble albumin test solutionby 25to obtain the mg of soluble albumin per container.Multiply the concentration obtained for the Insoluble albumin test solutionby 2.5to obtain the mg of insoluble albumin per container. 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 date of 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 (mCi)per mL,of Technetium Tc 99m Albumin Colloid by the 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 1851 Phone Number:1-301-816-8305