Packaging and storage—
Preserve Injection intended for intravascular or intrathecal use in single-dose containers, preferably of Type I glass, and protected from light.
Labeling—
Label containers of Injection to direct the user to discard any unused portion remaining in the container and to check for the presence of particulate matter before using. Label it also to state its routes of administration.
Identification—
A:
Evaporate a volume of Injection, equivalent to about 500 mg of iopamidol, to dryness, and heat the residue so obtained in a suitable crucible: violet vapors are evolved.
B:
It responds to the
Thin-Layer Chromatographic Identification Test 
201
, the test solution and the Standard solution being prepared at a concentration of 0.5 mg per mL in a mixture of methanol and water (9:1), the solvent mixture being chloroform, methanol, ammonium hydroxide, and water (60:30:9:1), and short-wavelength UV light being used to locate the spots.
Particulate matter 788—
The Injection labeled for intrathecal use meets the requirements for small-volume injections.
Free aromatic amine—
Transfer an accurately measured volume of Injection, equivalent to about 500 mg of iopamidol, to a 25-mL volumetric flask, dilute with water to 20 mL, and mix. To a second 25-mL volumetric flask transfer 16 mL of water and 4.0 mL of Standard solution prepared by dissolving a suitable quantity of
USP Iopamidol Related Compound A RS in water and diluting with water to obtain a solution having a concentration of 62.5 µg per mL. Proceed as directed in the test for
Free aromatic amine under
Iopamidol, beginning with “to the third 25-mL volumetric flask add 20 mL of water.” The absorbance of the solution from the iopamidol is not greater than that of the Standard solution (0.05%).
Free iodine—
Transfer a volume of Injection, equivalent to 2.0 g of iopamidol, to a glass-stoppered test tube. Add 2 mL of 2 N sulfuric acid and 1.0 mL of toluene, shake, and allow the layers to separate: the toluene layer shows no red color.
Limit of free iodide—
Transfer 10.0 mL of Injection to a beaker, add 40 mL of water, and mix. Proceed as directed in the
Limit of free iodide test under
Iopamidol beginning with “add 2.0 mL of 0.001 M potassium iodide.” Not more than 3.1 mL of 0.001 N silver nitrate is required (0.04 mg of iodide per mL).
Other requirements—
It meets the requirements under
Injections 1.
Assay—
Solution A, Solution B, Mobile phase, System suitability solution, and Chromatographic system—
Proceed as directed in the test for
Related compounds under
Iopamidol.
Standard preparation—
Dissolve about 20 mg of
USP Iopamidol RS, accurately weighed, in about 10 mL of water, and dilute quantitatively and stepwise with water to obtain a solution having a known concentration of about 80 µg of
USP Iopamidol RS per mL.
Assay preparation—
Dilute an accurately measured volume of Injection, equivalent to about 1000 mg of iopamidol, quantitatively and stepwise with water to obtain a solution having a concentration of about 80 µg of iopamidol per mL.
Procedure—
Separately inject equal volumes (about 20 µL) of the
Standard preparation and the
Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of iopamidol (C
17H
22I
3N
3O
8) in the portion of Injection taken by the formula:
12.5C(rU / rS),
in which
C is the concentration, in µg per mL, of
USP Iopamidol RS in the
Standard preparation; and
rU and
rS are the peak responses obtained from the
Assay preparation and the
Standard preparation, respectively.
