Quinidine Sulfate Extended-Release Tablets
»Quinidine Sulfate Extended-Release Tablets contain amounts of quinidine sulfate and dihydroquinidine sulfate totaling not less than 90.0percent and not more than 110.0percent of the labeled amount of quinidine sulfate,calculated as (C20H24N2O2)2·H2SO4·2H2O.
Packaging and storage— Preserve in well-closed,light-resistant containers.
Labeling— The labeling indicates the Drug Releasetest with which the product complies.
Identification—
A: Shake a quantity of powdered Tablets,equivalent to about 50mg of quinidine sulfate,with 100mLof dilute sulfuric acid (1in 350),and filter:the filtrate so obtained exhibits a vivid blue fluorescence.On the addition of a few drops of hydrochloric acid,the fluorescence disappears.
B: In the test for Chromatographic purity,the RFvalue of the principal spot obtained from the Test preparationcorresponds to that from the Standard preparation.
C: Shake a quantity of the powdered Tablets,equivalent to about 100mg of quinidine sulfate,with 10mLof dilute hydrochloric acid (1in 100),and filter:the filtrate so obtained responds to the tests for Sulfate á191ñ.
Drug release á724ñ—
Test 1— If the product complies with the test,the labeling indicates that the product meets USPDrug Release Test 1.
Medium: 0.1Nhydrochloric acid;900mL.
Apparatus 1: 100rpm.
Times: 1hour;4hours;12hours.
Procedure— Using filtered portions of the solution under test,diluted with 0.1Nhydrochloric acid if necessary,determine the amount of quinidine sulfate dissolved from UVabsorbances at the wavelength of maximum absorbance at about 248nm by comparison with a Standard solution having a known concentration of USP Quinidine Sulfate RSin the same medium.
Tolerances— The percentages of the labeled amount of quinidine sulfate dissolved at the times specified conform to Acceptance Table 1.
Time (hours) Amount dissolved
1 between 20%and 50%
4 between 43%and 73%
12 not less than 70%
Test 2— If the product complies with this test,the labeling indicates that the product meets USPDrug Release Test 2.
Medium: 0.1Nhydrochloric acid;900mL.
Apparatus 1: 100rpm.
Times: 1hour;4hours;12hours.
Procedure— Proceed as directed for Test 1.
Tolerances— The percentages of the labeled amount of (C20H24N2O2)2·H2SO4·2H2Odissolved at the times specified conform to Acceptance Table 1.
Time (hours) Amount dissolved
1 between 10%and 35%
4 between 30%and 55%
12 not less than 75%
Uniformity of dosage units á905ñ: meet the requirements.
Procedure for content uniformity— Proceed as directed for Procedure for content uniformityin the test for Uniformity of dosage unitsunder Quinidine Sulfate Capsules,using 1powdered Tablet instead of the contents of 1Capsule.
Chromatographic purity— Shake a quantity of powdered Tablets,equivalent to about 150mg of quinidine sulfate,with 25mLof diluted alcohol for 10minutes,and filter.Using the filtrate as the test solution,proceed as directed in the test for Chromatographic purityunder Quinidine Sulfate.
Assay— Proceed as directed in the Assayunder Quinidine Sulfate Capsules,using powdered Tablets.
Auxiliary Information— Staff Liaison:Andrzej Wilk,Ph.D.,Senior Scientific Associate
Expert Committee:(PA5)Pharmaceutical Analysis 5
USP28–NF23Page 1696
Phone Number:1-301-816-8305