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Conjugated Estrogens Tablets
» Conjugated Estrogens Tablets contain not less than 73.0 percent and not more than 95.0 percent of the labeled amount of conjugated estrogens as the total of sodium estrone sulfate and sodium equilin sulfate. The ratio of sodium equilin sulfate to sodium estrone sulfate in the Tablets is not less than 0.35 and not more than 0.65.
Packaging and storage— Preserve in well-closed containers.
Labeling— The labeling indicates the Tablet strength and states with which in vitro Drug Release Test the product complies.
Labeling— The labeling indicates the Tablet strength and states with which in vitro Dissolution Test the product complies.
(Official April 1, 2006)
Identification— Tablets respond to the Identification tests under Conjugated Estrogens.
Drug release 724— Proceed as directed for Extended-Release Articles—General Drug Release Standard.
TEST 1 (for products labeled as 0.3-,0.45-, and 0.625-mg tablets)—If the product complies with this test, the labeling indicates that it meets USP Drug Release Test 1.
Medium: water; 900 mL.
Apparatus 2: 50 rpm.
Mobile phase— Prepare a filtered and degassed mixture of 0.025 M monobasic potassium phosphate and acetonitrile (3:1). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard solution— Transfer 10 Tablets to a 1000-mL volumetric flask, dilute with water to volume, and stir vigorously by mechanical means for at least 3 hours. Pipet a filtered 100-mL aliquot of the solution into a 900-mL volumetric flask, and dilute with water to volume.
Test solution— Filter a portion of the solution under test. [NOTE—It is recommended that the filters selected be tested for binding affinity.]
Chromatographic system— The liquid chromatograph is equipped with a 205-nm detector and a 4.6-mm × 3.0-cm column that contains 3-µm packing L1. The flow rate is about 1.5 mL per minute. Chromatograph replicate injections of the Standard solution, and record the responses as directed for Procedure: the relative retention times are about 0.9 for equilin sulfate and 1.0 for estrone sulfate, the estrone sulfate peak being the last major peak in the chromatogram; the resolution, R, between equilin sulfate and estrone sulfate is not less than 1.5; and the relative standard deviation for the estrone sulfate peak is not more than 1.5%. [NOTE—If estrone is present it may be retained on the column for a period longer than 50 minutes and interfere in later chromatographic runs.]
Procedure— Separately inject equal volumes (between 20 and 200 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the responses for the estrone sulfate peaks. Calculate the percentage of estrone sodium sulfate released by the formula:
100(rU / rS),
in which rU and rS are the peak responses obtained from the Test solution and the Standard solution, respectively.
Times and Tolerances— The percentages of estrone sodium sulfate dissolved at the times specified conform to Acceptance Table 1.
Time (hours) Amount dissolved
2 between 19% and 49%
5 between 66% and 96%
8 not less than 80%
TEST 2 (for products labeled as 0.9-mg tablets)—If the product complies with this test, the labeling indicates that it meets USP Drug Release Test 2.
Medium, Apparatus, Mobile phase, Standard solution, Test solution, Chromatographic system, and Procedure— Proceed as directed for Test 1.
Times and Tolerances— The percentages of estrone sodium sulfate dissolved at the times specified conform to Acceptance Table 1.
Time (hours) Amount dissolved
2 between 12% and 37%
5 between 57% and 85%
8 not less than 80%
TEST 3 (for products labeled as 1.25- and 2.50-mg tablets)—If the product complies with this test, the labeling indicates that it meets USP Drug Release Test 3.
Medium, Apparatus, Mobile phase, Standard solution, Test solution, Chromatographic system, and Procedure— Proceed as directed for Test 1.
Times and Tolerances— The percentages of estrone sodium sulfate dissolved at the times specified conform to Acceptance Table 1.
Time (hours) Amount dissolved
2 between 3% and 22%
5 between 37% and 67%
8 between 66% and 96%
12 not less than 80%
Dissolution 711— Proceed as directed for Extended-Release Articles.
TEST 1 (for products labeled as 0.3-, 0.45-, and 0.625-mg tablets)—If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 1.
Medium: water; 900 mL.
Apparatus 2: 50 rpm.
Mobile phase— Prepare a filtered and degassed mixture of 0.025 M monobasic potassium phosphate and acetonitrile (3:1). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard solution— Transfer 10 Tablets to a 1000-mL volumetric flask, dilute with water to volume, and stir vigorously by mechanical means for at least 3 hours. Pipet a filtered 100-mL aliquot of the solution into a 900-mL volumetric flask, and dilute with water to volume.
Test solution— Filter a portion of the solution under test. [NOTE—It is recommended that the filters selected be tested for binding affinity.]
Chromatographic system— The liquid chromatograph is equipped with a 205-nm detector and a 4.6-mm × 3.0-cm column that contains 3-µm packing L1. The flow rate is about 1.5 mL per minute. Chromatograph replicate injections of the Standard solution, and record the responses as directed for Procedure: the relative retention times are about 0.9 for equilin sulfate and 1.0 for estrone sulfate, the estrone sulfate peak being the last major peak in the chromatogram; the resolution, R, between equilin sulfate and estrone sulfate is not less than 1.5; and the relative standard deviation for the estrone sulfate peak is not more than 1.5%. [NOTE—If estrone is present it may be retained on the column for a period longer than 50 minutes and interfere in later chromatographic runs.]
Procedure— Separately inject equal volumes (between 20 and 200 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the responses for the estrone sulfate peaks. Calculate the percentage of estrone sodium sulfate released by the formula:
100(rU / rS),
in which rU and rS are the peak responses obtained from the Test solution and the Standard solution, respectively.
Times and Tolerances— The percentages of estrone sodium sulfate dissolved at the times specified conform to Acceptance Table 2.
Time (hours) Amount dissolved
2 between 19% and 49%
5 between 66% and 96%
8 not less than 80%
TEST 2 (for products labeled as 0.9-mg tablets)—If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 2.
Medium, Apparatus, Mobile phase, Standard solution, Test solution, Chromatographic system, and Procedure— Proceed as directed for Test 1.
Times and Tolerances— The percentages of estrone sodium sulfate dissolved at the times specified conform to Acceptance Table 2.
Time (hours) Amount dissolved
2 between 12% and 37%
5 between 57% and 85%
8 not less than 80%
TEST 3 (for products labeled as 1.25- and 2.50-mg tablets)—If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 3.
Medium, Apparatus, Mobile phase, Standard solution, Test solution, Chromatographic system, and Procedure— Proceed as directed for Test 1.
Times and Tolerances— The percentages of estrone sodium sulfate dissolved at the times specified conform to Acceptance Table 2.
Time (hours) Amount dissolved
2 between 3% and 22%
5 between 37% and 67%
8 between 66% and 96%
12 not less than 80%
(Official April 1, 2006)
Uniformity of dosage units— Assay 10 individual Tablets as directed in the Assay, and calculate the average content of conjugated estrogens, as the average of the total contents of sodium estrone sulfate and sodium equilin sulfate, in the 10 Tablets. The requirements are met if the content of each of the Tablets is not less than 85.0% and not more than 115.0% of the average content of conjugated estrogens. If the content of not more than 2 Tablets falls outside the range of 85.0% to 115.0% of the average content but not outside the range of 75.0% to 125.0%, assay an additional 20 Tablets. The requirements are met if the content of not more than 2 of the 30 Tablets falls outside the limits of 85.0% and 115.0% of that average, and no unit is outside the range of 75.0% to 125.0% of the average content.
Residual solvents 467: meet the requirements.
(Official January 1, 2007)
Assay—
Internal standard solution, Stock solution, pH 5.2 Acetate buffer, System suitability solution, Standard preparation, and Chromatographic system— Proceed as directed in the Assay under Conjugated Estrogens.
Assay preparation— If the Tablets are sugar-coated, carefully remove the color and sugar coatings with water, leaving the shellac coating intact, and dry under nitrogen. Weigh and finely powder not fewer than 20 of the Tablets. Transfer an accurately weighed quantity of the powder, equivalent to about 2 mg of total conjugated estrogens, to a 50-mL centrifuge tube fitted with a polytef-lined screw-cap and containing 15 mL of pH 5.2 Acetate buffer and 1 g of barium chloride. Proceed as directed in the Assay preparation under Conjugated Estrogens, beginning with “Cap the tube tightly.”
Procedure— Separately inject equal volumes (about 1 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Separately calculate the quantities, in mg, of sodium estrone sulfate and sodium equilin sulfate in the portion of Tablets taken by the formula:
0.005(1.381CS)(RU / RS),
in which 1.381 is the factor converting free estrogen to the conjugate sodium salt; CS is the concentration, in µg per mL, of USP Estrone RS or USP Equilin RS in the Stock solution; and RU and RS are the ratios of the peak response of the appropriate analyte to that of the internal standard obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information— Staff Liaison : Daniel K. Bempong, Ph.D., Scientist
Expert Committee : (MDPS05) Monograph Development-Pulmonary and Steroids
USP29–NF24 Page 851
Pharmacopeial Forum : Volume No. 31(1) Page 155
Phone Number : 1-301-816-8143