Chromium Cr 51Edetate Injection

Glycine,N,N¢-1,2-ethanediylbis[N-(carboxymethyl)]-,chromium-51complex.
(Ethylenedinitrilo)tetraacetic acid,chromium-51complex [27849-89-4].
»Chromium Cr 51Edetate Injection is a sterile solution containing radioactive chromium (51Cr)in the form of a complex of chromium (III)with edetic acid,present in excess.It is made isotonic by the addition of Sodium Chloride.It contains not less than 90.0percent and not more than 110.0percent of the labeled amount of 51Cr as edetate complex expressed in megabecquerels (or microcuries or millicuries)per mLat the time indicated in the labeling.Other chemical forms of radioactivity do not exceed 5.0percent of the total radioactivity.It may contain a suitable preservative.It contains not more than 1mg of chromium (Cr)per mL.
Packaging and storage— Preserve in single-dose or 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 51Cr as edetate complex expressed as total MBq (or mCi)and as MBq (or mCi)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 the quantity of chromium,and also indicates that the radioactive half-life of 51Cr is 27.8days.
Radionuclide identification (see Radioactivity á821ñ)— Its gamma-ray spectrum is identical to that of a specimen of 51Cr of known purity that exhibits a photopeak having an energy of 0.320MeV.
Bacterial endotoxins á85ñ: not more than 175/VUSP Endotoxin Unit per mLof the Injection,in which Vis the maximum recommended total dose,in mL,at the expiration date or time.
pHá791ñ: between 3.5and 6.5.
Radiochemical purity—
Electrolyte solution— Dissolve 0.2g of barbital sodium and 10g of sodium nitrate in water to make 1000mL.
Procedure (see Electrophoresis á726ñ)—Soak a 2.5-cm ×17.0-cm ×0.22-mm cellulose strip in 100mLof Electrolyte solutionfor 10to 60minutes.Remove the strip with forceps,and blot to remove excess solution.Attach the strip to the support bridge of an electrophoresis chamber containing Electrolyte solution.Apply to the strip about 10µLof Injection as a 3-mm band at a position 10cm from the cathode.Attach the chamber cover,and perform the electrophoresis at 30Vper cm,using a stabilized current.Remove the strip from the chamber,and blot the ends.Using a suitable scanner and counting assembly,determine the radioactivity distribution:chromium 51Cr edetate moves about 5cm towards the anode;and 51Cr chromic ion moves about 7cm towards the cathode.The radioactivity of the chromium 51Cr edetate band is not less than 95%of the total radioactivity.
Radionuclidic purity— Using a suitable gamma-ray spectrometer (see Selection of a Counting Assemblyin the Assaysection under Radioactivity á821ñ),determine the radioactivity of each radionuclidic impurity observed in the gamma-ray spectrum:not more than 0.1%of any individual impurity is found;and not more than 0.3%of total impurities is found.
Chemical purity— Using a validated limit test and a known analytical technique,demonstrate the absence of any ingredients and reagents employed in the synthetic process.
Limit of free chromium—
Standard solution— Dissolve 0.96g of chromium potassium sulfate dodecahydrate and 2.87g of edetate disodium in 50mLof water,boil for 10minutes,cool,adjust with 0.2Msodium hydroxide to a pHbetween 3.5and 6.5,and dilute with water to 100.0mLto obtain a solution having a known concentration of about 1mg of chromium per mL.
Test solution— Use the Injection.
Procedure— Concomitantly determine the absorbances of the Standard solutionand the Test solutionat the wavelength of maximum absorbance at about 560nm,with a suitable spectrophotometer,using water as the blank:the absorbance of the Test solutionis not more than that of the Standard solution.
Other requirements— It meets the requirements under Injections á1ñ,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 (or µCi)per mL,of 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 467
Phone Number:1-301-816-8305