Sodium iodide (Na131I).
Sodium iodide (Na131I) [7790-26-3].

Packaging and storage— Preserve in single-dose or in multiple-dose containers that previously have been treated to prevent adsorption.

Labeling— Label it to include the following:the time and date of calibration;the amount of 131Ias iodide expressed as total megabecquerels (microcuries or millicuries)and as megabecquerels (microcuries or millicuries)per mLat the time of calibration;the name and quantity of any added preservative or stabilizer;a statement of the intended use,whether oral or intravenous;a statement of whether the contents are intended for diagnostic or therapeutic use;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 131Iis 8.08days.

USP Reference standards á11ñ— USP Endotoxin RS.

Radionuclide identification (see Radioactivity á821ñ)— Its gamma-ray spectrum is identical to that of a specimen of iodine 131of known purity that exhibits a major photopeak having an energy of 0.364MeV.

Bacterial endotoxins á85ñ— Solution intended for intravenous use meets the requirements of the Bacterial Endotoxins Test á85ñ,the limit of endotoxin content being not more than 175/VUSP Endotoxin Unit per mLof the Solution,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 9.0.

Radiochemical purity— Place a measured volume of a solution containing 100mg of potassium iodide,200mg of potassium iodate,and 1g of sodium bicarbonate in each 100mL,25mm from one end of a 25-×300-mm strip of chromatographic paper (see Chromatography á621ñ),and allow to dry.To the same area add a similar volume of appropriately diluted Solution such that it provides a count rate of about 20,000counts per minute,and allow to dry.Develop the chromatogram over a period of about 4hours by ascending chromatography,using dilute methanol (7.0in 10).Dry the chromatogram in air,and determine the radioactivity distribution by scanning with a suitable collimated radiation detector:the radioactivity of the iodide 131Iband is not less than 95%of the total radioactivity,and its RFvalue falls within ±5%of the value found for sodium iodide when determined under parallel conditions.Confirmation of the identity of the iodide band is made by the addition to the suspected iodide band of 6drops of acidified hydrogen peroxide solution (prepared by adding 6drops of 1Nhydrochloric acid to 10mLof hydrogen peroxide solution)followed by the dropwise addition of starch TS;the development of a blue color indicates presence of iodide.

Other requirements— Solution intended for intravenous use meets the requirements under Injections á1ñ,except that the Solution 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— Using a suitable counting assembly (see Selection of a Counting Assemblyunder Radioactivity á821ñ),determine the radioactivity,in MBq (µCi)per mL,of Solution by use of a calibrated system as directed under Radioactivity á821ñ.

Expert Committee:(RMI)Radiopharmaceuticals and Medical Imaging Agents

USP28–NF23Page 1037

Phone Number:1-301-816-8305