Isosorbide Dinitrate Sublingual Tablets
» Isosorbide Dinitrate Sublingual Tablets contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of C6H8N2O8.
Packaging and storage Preserve in well-closed containers.
USP Reference standards 11
Disintegration 701: 2 minutes, determined as directed for Sublingual Tablets.
Dissolution, Procedure for a Pooled Sample 711
Medium: water; 900 mL.
Apparatus 2: 50 rpm.
Time: 20 minutes.
Mobile phase Prepare a suitable degassed and filtered mixture of pH 3.0, 0.1 M ammonium sulfate and methanol (50:50).
Chromatographic system (see Chromatography 621)The liquid chromatograph is equipped with a 220-nm detector and a 4.6-mm × 5-cm column that contains packing L1. The flow rate is about 1.0 mL per minute. Chromatograph the Standard solution, and record the peak responses as directed under Procedure: the tailing factor is not more than 1.5, and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure Separately inject equal volumes (about 20 µL) of the Standard solution and a filtered aliquot of the solution under test into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the amount of C6H8N2O8 dissolved in comparison with a Standard solution having a known concentration of USP Diluted Isosorbide Dinitrate RS, similarly prepared and chromatographed.
Tolerances Not less than 80% (Q) of the labeled amount of C6H8N2O8 is dissolved in 20 minutes.
Uniformity of dosage units 905: meet the requirements.
Buffer solution, Mobile phase, Internal standard solution, Standard preparation, and Chromatographic system Prepare as directed in the Assay under Diluted Isosorbide Dinitrate.
Assay preparation Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 12.5 mg of isosorbide dinitrate, to a 50-mL volumetric flask, add about 30 mL of Mobile phase, and shake for 30 minutes. Add 8.0 mL of Internal standard solution, cool to room temperature, add 8 mL of a 1 in 10 dilution of Buffer solution in water, dilute with Mobile phase to volume, and mix. Pass a portion through a 0.45-µm filter.
Procedure Proceed as directed for Procedure in the Assay under Diluted Isosorbide Dinitrate. Calculate the quantity, in mg, of C6H8N2O8 in the portion of Tablets taken by the formula:
50C(RU / RS)in which C is the concentration, in mg per mL, of isosorbide dinitrate from the USP Diluted Isosorbide Dinitrate RS taken for the Standard preparation; and RU and RS are the ratios of the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
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USP35NF30 Page 3591Pharmacopeial Forum: Volume No. 31(5) Page 1377