Sodium iodide (Na123I).
Sodium iodide (Na123I) [41927-88-2].

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

Labeling— Label it to include the following: the time and date of calibration; the amount of 123I as iodide expressed as total megabecquerels (microcuries or millicuries) per mL at the time of calibration; the name and quantity of any added preservative or stabilizer; a statement to indicate whether the contents are intended for oral or for intravenous use; the expiration date and time; 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 123I is 13.2 hours.

USP Reference standards 11— USP Endotoxin RS.

Radionuclide identification (see Radioactivity 821)— Its gamma-ray spectrum is identical to that of a specimen of 123I of known purity that exhibits a major photoelectric peak having an energy of 0.159 MeV.

Radionuclidic purity— Using a suitable counting assembly (see Selection of a Counting Assembly under Radioactivity 821), determine the radionuclidic purity of the Solution: not less than 85.0% of the total radioactivity is present as I 123.

Bacterial endotoxins 85— The limit of endotoxin content is not more than 175/V USP Endotoxin Unit per mL of the Injection, when compared with the USP Endotoxin RS, in which V is the maximum recommended total dose, in mL, at the expiration date or time.

pH 791: between 7.5 and 9.0.

Radiochemical purity— Place a measured volume of a solution, containing 100 mg of potassium iodide, 200 mg of potassium iodate, and 1 g of sodium bicarbonate in each 100 mL, 25 mm from one end of a 25- × 300-mm strip of chromatographic paper (see Chromatography 621), 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 20,000 counts per minute, and allow to dry. Develop the chromatogram over a period of about 4 hours by ascending chromatography, using dilute methanol (7 in 10). Dry the chromatogram in air, and determine the radioactivity distribution by scanning with a suitable collimated radiation detector: the radioactivity of the iodide 123I band is not less than 95.0% of the total radioactivity, and its RF value falls within ±5.0% of the value found for sodium iodide when determined under similar conditions. Confirmation of the identity of the iodide band is made by the addition to the suspected iodide band of 6 drops of acidified hydrogen peroxide solution (prepared by adding 6 drops of 1 N hydrochloric acid to 10 mL of hydrogen peroxide solution) followed by the dropwise addition of starch TS: the development of a blue color indicates the presence of iodide.

Other requirements— Solution intended for intravenous use meets the requirements under Injections 1, except that it 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 Assembly under Radioactivity 821), determine the radioactivity, in MBq (µCi) per mL, of Solution by use of a calibrated system as directed under Radioactivity 821.

Expert Committee : (RMI05) Radiopharmaceuticals and Medical Imaging Agents 05

USP29–NF24 Page 1147

Phone Number : 1-301-816-8305