Labeling—
Label the Tablets to state both the content of oxtriphylline and the content of anhydrous theophylline. The labeling indicates the
Dissolution Test with which the product complies.
(Official April 1, 2006)
Identification—
A:
The retention time exhibited by theophylline in the chromatogram of the
Assay preparation corresponds to that of theophylline in the chromatogram of the
Standard preparation, as obtained in the
Assay.
B:
Transfer a quantity of finely ground Tablets, equivalent to about 100 mg of oxtriphylline, to a suitable test tube, and proceed as directed in
Identification test
B under
Oxtriphylline Delayed-Release Tablets, beginning with “add 10 mL of methanol.”
Drug release 
724
—
Test 1
(for products labeled as 400-mg tablets)—If the product complies with this test, the labeling indicates that it meets USP Drug Release Test 1. Proceed as directed for Method B under Delayed-Release Articles—General Drug Release Standard, except to use Acceptance Table 1 under Extended-Release Articles—General Drug Release Standard.
pH 7.5 Buffer—
Transfer 27.22 g of monobasic potassium phosphate to a 4-L volumetric flask, add 1 L of water and 816 mL of 0.2 N sodium hydroxide, and dilute with water to about 3800 mL. Adjust with 0.2 N sodium hydroxide or phosphoric acid to a pH of 7.5, and dilute with water to volume.
Medium:
0.1 N hydrochloric acid for the first hour, then pH 7.5 Buffer; 900 mL.
Apparatus 2:
50 rpm.
Procedure—
Determine the amount of C
12H
21N
5O
3 dissolved from UV absorbances at the wavelength of maximum absorbance at about 248 nm on filtered portions of the solution under test, diluted with
Medium if necessary, in comparison with a Standard solution having a known concentration of
USP Oxtriphylline RS in the same
Medium.
Times and Tolerances—
| Time (hours) |
 Amount dissolved |
| 1 |
between 5% and 30% |
| 3 |
between 50% and 70% |
| 5 |
between 65% and 85% |
| 7 |
not less than 75% |
Test 2
(for products labeled as 600-mg tablets)—If the product complies with this test, the labeling indicates that it meets USP
Drug Release Test 1. Proceed as directed for
Method B under
Delayed-Release Articles—
General Drug Release Standard, except to use
Acceptance Table 1 under
Extended-Release Articles—
General Drug Release Standard.
pH 7.5 Buffer
, Medium, Apparatus, and Procedure—Proceed as directed for Test 1.
Times and Tolerances—
| Time (hours) |
Amount dissolved |
| 1 |
between 15% and 40% |
| 3 |
between 50% and 70% |
| 7 |
not less than 75% |
Dissolution 711—
Test 1
(for products labeled as 400-mg tablets)—If the product complies with this test, the labeling indicates that it meets USP
Dissolution Test 1. Proceed as directed for
Method B under
Apparatus 1 and Apparatus 2, Delayed-Release Dosage Forms, except to use
Acceptance Table 2.
pH 7.5 Buffer—
Transfer 27.22 g of monobasic potassium phosphate to a 4-L volumetric flask, add 1 L of water and 816 mL of 0.2 N sodium hydroxide, and dilute with water to about 3800 mL. Adjust with 0.2 N sodium hydroxide or phosphoric acid to a pH of 7.5, and dilute with water to volume.
Medium:
0.1 N hydrochloric acid for the first hour, then pH 7.5 Buffer; 900 mL.
Apparatus 2:
50 rpm.
Procedure—
Determine the amount of C
12H
21N
5O
3 dissolved from UV absorbances at the wavelength of maximum absorbance at about 248 nm on filtered portions of the solution under test, diluted with
Medium if necessary, in comparison with a Standard solution having a known concentration of
USP Oxtriphylline RS in the same
Medium.
Times and Tolerances—
| Time (hours) |
Amount dissolved |
| 1 |
between 5% and 30% |
| 3 |
between 50% and 70% |
| 5 |
between 65% and 85% |
| 7 |
not less than 75% |
Test 2
(for products labeled as 600-mg tablets)—If the product complies with this test, the labeling indicates that it meets USP
Dissolution Test 2. Proceed as directed for
Method B under
Apparatus 1 and Apparatus 2, Delayed-Release Dosage Forms, except to use
Acceptance Table 2.
pH 7.5 Buffer, Apparatus, Medium, and Procedure—
Proceed as directed for Test 1.
Times and Tolerances—
| Time (hours) |
Amount dissolved |
| 1 |
between 15% and 40% |
| 3 |
between 50% and 70% |
| 7 |
not less than 75% |
(Official April 1, 2006)
