Packaging and storage—
Preserve in single-dose or in multiple-dose containers, preferably of Type I or Type II glass.
Labeling—
Where necessary, label it to indicate that it is to be diluted before use.
Identification—
The retention time of the major peak in the chromatogram of the
Assay preparation corresponds to that of the
Standard preparation obtained as directed in the
Assay.
pH 
791
:
between 3.0 and 6.5, determined potentiometrically in a solution prepared by adding 5 mL of water and 1 drop of saturated potassium chloride solution to 5 mL of the Injection.
Other requirements—
It meets the requirements under
Injections 1.
Assay—
Assay preparation—
Transfer an accurately measured volume of Injection, equivalent to about 7.5 mg of nitroglycerin, to a 100-mL volumetric flask, dissolve in and dilute with Mobile phase to volume, and mix.
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 C
3H
5N
3O
9 in the portion of Injection taken by the formula:
100C(rU / rS),
in which
C is the concentration, in mg per mL, of nitroglycerin in the
Standard preparation, and
rU and
rS are the peak responses of nitroglycerin obtained from the
Assay preparation and the
Standard preparation, respectively.
