Rubidium Chloride Rb 82Injection
»Rubidium Chloride Rb 82Injection is a sterile solution,suitable for intravenous administration.It contains not less than 90.0percent and not more than 110.0percent of the labeled amount of 82Rb expressed in megabecquerels (or in millicuries)per mLat the time indicated in the labeling.It is obtained by elution from a strontium 82-rubidium 82generator system.82Rb,with a half-life of 76seconds,is a short-lived positron-emitting radionuclide formed by the radioactive decay of the parent nuclide 82Sr.Strontium Sr 82with a half-life of 25.5days is produced by the proton irradiation of rubidium or spallation of molybdenum.The chemical form of the Injection is 82RbCl.[NOTE—Elute with additive-free Sodium Chloride Injection only.Discard the first 50mLof the eluate each day the generator is eluted.]
Packaging,storage,and labeling— Requirements for packaging,storage,and labeling do not apply;Rubidium Chloride Rb 82Injection is obtained by elution from the generator and is administered by direct infusion.
Bacterial endotoxins á85ñ— It contains 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.
Radionuclide identification (see Radioactivity á821ñ)— [NOTE—Perform this test quickly,because of the rapid decay of the 82Rb.]The gamma-ray spectrum of eluted 82Rb exhibits photopeaks at 511and 777keV.
pHá791ñ: between 4.0and 8.0.
Radionuclidic purity— Using a suitable counting assembly (see Selection of a Counting Assemblyunder Radioactivity á821ñ),determine the radioactivity of each radionuclidic impurity,in kBq per MBq (or µCi per mCi),of Rb 82in the generator eluate by use of a calibrated system as directed under Radioactivity á821ñ.[NOTE—For the following tests,use the generator eluate containing 82Rb that has been allowed to decay for 1hour after the end of elution.]
Sr 82and Rb 83— Obtain a gamma-ray spectrum of the hour-old eluate,and measure the activities of the radionuclidic impurities directly from the spectrum.Sr 82exhibits photopeaks at 511and 777keVand decays with a radioactive half-life of 25.5days.Rb 83exhibits a photopeak at 530keVand decays with a radioactive half-life of 86.2days.The activity levels of Sr 82and Rb 83are not more than 0.02kBq per MBq (0.02µCi per mCi)and not more than 0.05kBq per MBq (0.05µCi per mCi)of Rb 82at the end of elution,respectively.
Sr 85— Obtain a gamma spectrum of the hour-old eluate,and,using the same system and geometry,obtain a gamma spectrum of a pure Rb 82specimen (generator eluate containing 82Rb taken within 10minutes of elution).Sr 85exhibits a major photopeak at 514keVand decays with a radioactive half-life of 64.8days.Sr 85may be determined by subtraction of the 511and 777keVpeaks in the pure Rb 82,from the 511–514keVand 777keVpeaks in the hour-old eluate.The activity level of Sr 85is not more than 0.2kBq per MBq (0.2µCi per mCi)of Rb 82at the end of elution.
Other gamma-ray emitters— The total of other gamma-ray emitting radionuclidic impurities does not exceed 0.005kBq per MBq (0.005µCi per mCi)of Rb 82at the end of elution.
Chemical purity—
Electrolyte solution— Transfer 107g of ammonium chloride,25g of gelatin,and 42mLof hydrochloric acid to a 500-mLvolumetric flask.Add about 450mLof water,and sonicate until a clear solution is obtained.Dilute with water to volume,and mix.
Tin stock standard solution— Dissolve 100mg of metallic tin (Sn),accurately weighed,in 10mLof dilute hydrochloric acid (1in 2),and dilute with water to 100mL.
Tin standard solution A— Transfer 0.5mLof Tin stock standard solutionto a 50-mLvolumetric flask and dilute with 0.1Nhydrochloric acid to volume.
Tin standard solution B— Transfer 1.0mLof Tin standard solution Ato a 50-mLvolumetric flask.Add 10.0mLof 0.9%sodium chloride solution,dilute with Electrolyte solutionto volume,and mix.
Test solution— Obtain a 50-mLeluate from the generator,and allow to stand for at least 1hour to allow for the complete decay of 82Rb.Transfer 10.0mLof the eluate to a 50-mLvolumetric flask,dilute with the Electrolyte solutionto volume,and mix.
Procedure— Transfer a portion of the Test solutionto a polarographic cell,and deaerate by bubbling nitrogen through the solution for 5minutes.Insert the dropping mercury electrode of a suitable polarograph,and obtain the differential pulse polarogram from -0.15to -0.75volts,at a current range of 0.5µA,using a saturated calomel electrode as the reference electrode and a platinum wire as the auxiliary electrode (see Polarography á801ñ).Similarly,transfer a portion of the Tin standard solutionto a polarographic cell and obtain the polarogram.Apeak at -0.52volts indicates the presence of tin.The peak height of the Test solutionis not greater than that of the Tin standard solution (1µg per mL).
Other requirements— It meets the requirements under Injections á1ñ,except that the Injection 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 for Volume in Containerunder Injections á1ñ.
Assay for radioactivity— Using a suitable counting assembly (see Selection of a Counting Assemblyunder Radioactivity á821ñ),determine the radioactivity,in MBq (or in µCi)per mL,of the Injection by use of a calibrated system as directed under Radioactivity á821ñ.
Auxiliary Information— Staff Liaison:Andrzej Wilk,Ph.D.,Senior Scientific Associate
Expert Committee:(RMI)Radiopharmaceuticals and Medical Imaging Agents
USP28–NF23Page 1743
Phone Number:1-301-816-8305