Packaging and storage—
Preserve in tight containers, preferably of glass, and store at controlled room temperature. Each container holds not more than 100 Sublingual Tablets.
Labeling—
The labeling indicates that the Sublingual Tablets are for sublingual use, and the label directs that the Sublingual Tablets be dispensed in the original, unopened container, labeled with the following statement directed to the patient. “Warning: To prevent loss of potency, keep these tablets in the original container or in a supplemental nitroglycerin container specifically labeled as being suitable for Nitroglycerin Sublingual Tablets. Close tightly immediately after each use.”
Identification—
A:
Thin-Layer Chromatographic Identification Test 
201
—
Test solution—
Transfer an amount of finely powdered Sublingual Tablets, equivalent to about 1 mg of nitroglycerin, to a glass-stoppered vessel, add 1 mL of acetone, shake by mechanical means for 30 minutes, and filter.
Standard solution:
1 mg per mL, in acetone.
Developing solvent system:
a mixture of toluene, ethyl acetate, and glacial acetic acid (16:4:1).
Procedure—
Proceed as directed in the chapter. Spray with a solution of diphenylamine in methanol (1 in 100), and irradiate the plate with short- and long-wavelength UV light for about 10 minutes.
B:
The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.
Uniformity of dosage units 905:
meet the requirements.
PROCEDURE FOR CONTENT UNIFORMITY—
Mobile phase, Standard preparation, and Chromatographic system—
Proceed as directed in the
Assay under
Diluted Nitroglycerin.
Test preparation—
Transfer 1 Sublingual Tablet to a suitable container, and dissolve in and dilute with Mobile phase to obtain a solution containing about 0.075 mg of nitroglycerin per mL.
Procedure—
Separately inject equal volumes (about 20 µL) of the
Standard preparation and the
Test preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of nitroglycerin (C
3H
5N
3O
9) in the portion of Sublingual Tablets taken by the formula:
VC(rU / rS),
in which
V is the volume, in mL, of
Mobile phase used to prepare the
Test preparation; C is the concentration, in mg per mL, of
USP Diluted Nitroglycerin RS in the
Standard preparation; and
rU and
rS are the peak responses for nitroglycerin obtained from the
Test preparation and the
Standard preparation, respectively. The content of each of the 10 Sublingual Tablets is within the range of 75.0% and 135.0% of the labeled claim. If the content of not more than 1 Sublingual Tablet is outside the range of 75.0% and 135.0% and if the content of none of the Sublingual Tablets is outside the range of 60.0% and 150.0%, test 20 additional units. The requirements are met if the content of each of the additional 20 units falls within the range of 75.0% and 135.0% of the labeled claim.
Assay—
Mobile phase, Standard preparation, and Chromatographic system—
Prepare as directed in the
Assay under
Diluted Nitroglycerin.
Assay preparation—
Dissolve not fewer than 20 Sublingual Tablets in Mobile phase, and dilute quantitatively, and stepwise if necessary, with Mobile phase to obtain a solution containing about 0.075 mg per mL of nitroglycerin.
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 nitroglycerin (C
3H
5N
3O
9) per Sublingual Tablet taken by the formula:
100 / (TDC)(rU / rS),
in which
T is the number of Sublingual Tablets taken;
D is the dilution factor of the
Assay preparation; C is the concentration, in mg per mL, of
USP Diluted Nitroglycerin RS in the
Standard preparation; and
rU and
rS are the peak responses for nitroglycerin obtained from the
Assay preparation and the
Standard preparation, respectively.
(Official October 1, 2006)
