Chromium Cr 51 Edetate Injection

Glycine, N,N¢-1,2-ethanediylbis[N-(carboxymethyl)]-, chromium-51 complex.
(Ethylenedinitrilo)tetraacetic acid, chromium-51 complex [27849-89-4].
» Chromium Cr 51 Edetate 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 90.0 percent and not more than 110.0 percent of the labeled amount of 51Cr as edetate complex expressed in megabecquerels (or microcuries or millicuries) per mL at the time indicated in the labeling. Other chemical forms of radioactivity do not exceed 5.0 percent of the total radioactivity. It may contain a suitable preservative. It contains not more than 1 mg of chromium (Cr) per mL.
Packaging and storage— Preserve in single-dose or multiple-dose containers, at a temperature between 2 and 8.
Labeling— Label it to include the following, in addition to the information specified for Labeling under Injections 1: 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 mL at 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 27.8 days.
Radionuclide identification (see Radioactivity 821) Its gamma-ray spectrum is identical to that of a specimen of 51Cr of known purity that exhibits a photopeak having an energy of 0.320 MeV.
Bacterial endotoxins 85: not more than 175/V USP Endotoxin Unit per mL of the Injection, in which V is the maximum recommended total dose, in mL, at the expiration date or time.
pH 791: between 3.5 and 6.5.
Radiochemical purity—
Electrolyte solution— Dissolve 0.2 g of barbital sodium and 10 g of sodium nitrate in water to make 1000 mL.
Procedure (see Electrophoresis 726)—Soak a 2.5-cm × 17.0-cm × 0.22-mm cellulose strip in 100 mL of Electrolyte solution for 10 to 60 minutes. 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 10 µL of Injection as a 3-mm band at a position 10 cm from the cathode. Attach the chamber cover, and perform the electrophoresis at 30 V per 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 5 cm towards the anode; and 51Cr chromic ion moves about 7 cm 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 Assembly in the Assay section under Radioactivity 821), 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 0.96 g of chromium potassium sulfate dodecahydrate and 2.87 g of edetate disodium in 50 mL of water, boil for 10 minutes, cool, adjust with 0.2 M sodium hydroxide to a pH between 3.5 and 6.5, and dilute with water to 100.0 mL to obtain a solution having a known concentration of about 1 mg of chromium per mL.
Test solution— Use the Injection.
Procedure— Concomitantly determine the absorbances of the Standard solution and the Test solution at the wavelength of maximum absorbance at about 560 nm, with a suitable spectrophotometer, using water as the blank: the absorbance of the Test solution is not more than that of the Standard solution.
Other requirements— It meets the requirements under Injections 1, except that it is not subject to the recommendation on Volume in Container.
Assay for radioactivity 821 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— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Ian DeVeau, Ph.D.
Director, Veterinary Drugs and Radiopharmaceuticals
(RMI05) Radiopharmaceuticals and Medical Imaging Agents 05
Reference Standards Lili Wang, Technical Services Scientist
85 Radhakrishna S Tirumalai, Ph.D.
Senior Scientist
(MSA05) Microbiology and Sterility Assurance
USP32–NF27 Page 1927