Packaging and storage—
Preserve in tight,light-resistant containers.
Labeling—
Label the container to indicate that the contents are not intended for parenteral use.
Identification—
A:
Dilute a volume of Solution,if necessary,with a 0.8in 1000solution of sodium hydroxide in methanol to obtain a test solution having a concentration of 1mg per mL.The test solution responds to the
Thin-layer Chromatographic Identification Test á201ñ,the Standard solution being prepared at a concentration of 1mg of
USP Diatrizoic Acid RSper mLin a 0.8in 1000solution of sodium hydroxide in methanol,the solvent mixture being a mixture of chloroform,methanol,and ammonium hydroxide (20:10:2),and short-wavelength UVlight being used to locate the spots.
B:
Evaporate a volume of Solution,equivalent to about 500mg of diatrizoate sodium,to dryness,and heat the residue so obtained in a suitable crucible:violet vapors are evolved.
Iodine and iodide—
Using as the
Test preparationa volume of Solution equivalent to 2.0g of diatrizoate sodium and diluting it with water to 24mLin a 50-mLcentrifuge tube provided with a stopper,proceed as directed for
Procedurein the test for
Iodine and iodideunder
Diatrizoate Meglumine.
Assay—
Pipet a volume of Solution,equivalent to about 400mg of diatrizoate sodium,into a 125-mLconical flask.Add 30mLof 1.25Nsodium hydroxide and 500mg of powdered zinc,connect the flask to a reflux condenser,and reflux the mixture for 1hour.Cool the flask to room temperature,rinse the condenser with 20mLof water,disconnect the flask from the condenser,and filter the mixture.Rinse the flask and filter thoroughly,adding the rinsings to the filtrate.Add 5mLof glacial acetic acid and 1mLof tetrabromophenolphthalein ethyl ester TS,and titrate with 0.05Nsilver nitrate VSuntil the yellow precipitate just turns green.Each mLof 0.05Nsilver nitrate is equivalent to 10.60mg of C11H8I3N2NaO4.