Packaging and storage—
Preserve in well-closed, light-resistant containers.
Labeling—
The labeling indicates the Drug Release test with which the product complies.
Labeling—
The labeling indicates the
Dissolution Test with which the product complies.
(Official April 1, 2006)
Identification—
A:
Shake a quantity of powdered Tablets, equivalent to about 50 mg of quinidine sulfate, with 100 mL of dilute sulfuric acid (1 in 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 RF value of the principal spot obtained from the Test preparation corresponds to that from the Standard preparation.
C:
Shake a quantity of the powdered Tablets, equivalent to about 100 mg of quinidine sulfate, with 10 mL of dilute hydrochloric acid (1 in 100), and filter: the filtrate so obtained responds to the tests for
Sulfate 
191
.
Drug release 724—
TEST 1—
If the product complies with the test, the labeling indicates that it meets USP Drug Release Test 1.
Medium:
0.1 N hydrochloric acid; 900 mL.
Apparatus 1:
100 rpm.
Times:
1, 4, and 12 hours.
Procedure—
Using filtered portions of the solution under test, diluted with 0.1 N hydrochloric acid if necessary, determine the amount of quinidine sulfate dissolved from UV absorbances at the wavelength of maximum absorbance at about 248 nm by comparison with a Standard solution having a known concentration of
USP Quinidine Sulfate RS in 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 it meets USP Drug Release Test 2.
Medium:
0.1 N hydrochloric acid; 900 mL.
Apparatus 1:
100 rpm.
Times:
1, 4, and 12 hours.
Procedure—
Proceed as directed for Test 1.
Tolerances—
The percentages of the labeled amount of (C
20H
24N
2O
2)
2·H
2SO
4·2H
2O dissolved 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% |
Dissolution 711—
Test 1—
If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 1.
Medium:
0.1 N hydrochloric acid; 900 mL.
Apparatus 1:
100 rpm.
Times:
1, 4, and 12 hours.
Procedure—
Using filtered portions of the solution under test, diluted with 0.1 N hydrochloric acid if necessary, determine the amount of (C
20H
24N
2O
2)
2·H
2SO
4·2H
2O dissolved from UV absorbances at the wavelength of maximum absorbance at about 248 nm by comparison with a Standard solution having a known concentration of
USP Quinidine Sulfate RS in the same
Medium.
Tolerances—
The percentages of the labeled amount of (C
20H
24N
2O
2)
2·H
2SO
4·2H
2O dissolved at the times specified conform to
Acceptance Table 2.
| 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 it meets USP Dissolution Test 2.
Medium:
0.1 N hydrochloric acid; 900 mL.
Apparatus 1:
100 rpm.
Times:
1, 4, and 12 hours.
Procedure—
Proceed as directed for Test 1.
Tolerances—
The percentages of the labeled amount of (C
20H
24N
2O
2)
2·H
2SO
4·2H
2O dissolved at the times specified conform to
Acceptance Table 2.
| Time (hours) |
Amount dissolved |
| 1 |
between 10% and 35% |
| 4 |
between 30% and 55% |
| 12 |
not less than 75% |
(Official April 1, 2006)
Chromatographic purity—
Shake a quantity of powdered Tablets, equivalent to about 150 mg of quinidine sulfate, with 25 mL of diluted alcohol for 10 minutes, and filter. Using the filtrate as the test solution, proceed as directed in the test for
Chromatographic purity under
Quinidine Sulfate.
