Packaging and storage—
Preserve Injection intended for intravascular injection in single-dose containers, preferably of Type I or Type III glass, protected from light. Injection intended for other than intravascular use may be packaged in 100-mL multiple-dose containers, preferably of Type I or Type III glass, protected from light.
Labeling—
Label containers of Injection intended for intravascular injection to direct the user to discard any unused portion remaining in the container. Label containers of Injection intended for other than intravascular injection to show that the contents are not intended for intravascular injection.
Identification—
A:
Dilute a volume of Injection, if necessary, with a 0.8 in 1000 solution of sodium hydroxide in methanol to obtain a test solution having a concentration of 1 mg per mL. The test solution responds to the
Thin-layer Chromatographic Identification Test 
201
, the Standard solution being prepared at a concentration of 1 mg of
USP Diatrizoic Acid RS per mL in a 0.8 in 1000 solution of sodium hydroxide in methanol, the solvent mixture being a mixture of chloroform, methanol, and ammonium hydroxide (20:10:2), and short-wavelength UV light being used to locate the spots.
B:
Evaporate a volume of Injection, equivalent to about 500 mg of diatrizoate sodium, to dryness, and heat the residue so obtained in a crucible: violet vapors are evolved.
Bacterial endotoxins 85—
It contains not more than 5.6 USP Endotoxin Units per mL for Injections containing 20% of diatrizoate sodium; not more than 1.3 USP Endotoxin Units per mL for Injections containing 25% of diatrizoate sodium; and not more than 5.0 USP Endotoxin Units per mL for Injections containing 50% of diatrizoate sodium.
Iodine and iodide—
Using a volume of Injection equivalent to 2.0 g of diatrizoate sodium, and diluting it with water to 24 mL in a 50-mL centrifuge tube provided with a stopper, proceed as directed for
Procedure in the test for
Iodine and iodide under
Diatrizoate Meglumine.
Heavy metals 231—
In a 50-mL color-comparison tube mix a volume of Injection, equivalent to 1.0 g of diatrizoate sodium, with 5 mL of 1 N sodium hydroxide, dilute with water to 40 mL, and mix. Using this as the
Test preparation, proceed as directed in the test for
Heavy metals under
Diatrizoate Meglumine: the limit is 0.002%.
Free aromatic amine—
Transfer a volume of Injection, equivalent to 1.0 g of diatrizoate sodium, to a 50-mL volumetric flask, dilute with water to 5 mL, and add 10 mL of 0.1 N sodium hydroxide. Proceed as directed in the test for
Free aromatic amine under
Diatrizoate Meglumine, beginning with “To a second 50-mL volumetric flask transfer 4 mL of water.”
Other requirements—
It meets the requirements under
Injections 1.
Assay—
Pipet into a glass-stoppered 125-mL conical flask a volume of Injection, equivalent to about 500 mg of diatrizoate sodium. Add 30 mL of 1.25 N sodium hydroxide and 500 mg of powdered zinc, and reflux the mixture for 1 hour. Cool to room temperature, wash the condenser with 20 mL of water, and filter the mixture. Wash the flask and the filter with small portions of water, adding the washings to the filtrate. Add to the filtrate 5 mL of glacial acetic acid and 1 mL of
tetrabromophenolphthalein ethyl ester TS, and titrate with 0.05 N silver nitrate VS until the color of the yellow precipitate just changes to green. Each mL of 0.05 N silver nitrate is equivalent to 10.60 mg of C
11H
8I
3N
2NaO
4.
