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Ethynodiol Diacetate and Mestranol Tablets
» Ethynodiol Diacetate and Mestranol Tablets contain not less than 90.0 percent and not more than 110.0 percent of the labeled amounts of ethynodiol diacetate (C24H32O4) and mestranol (C21H26O2).
Packaging and storage
Preserve in well-closed containers.
Identification
Place a quantity of finely powdered Tablets, equivalent to about 10 mg of ethynodiol diacetate, in a stoppered, 15-mL centrifuge tube. Add 10 mL of acetonitrile, insert the stopper in the tube, and mix by shaking and inversion for about 2 minutes. Centrifuge at about 1200 rpm for 10 minutes, and decant the supernatant through filter paper into a suitable container. Evaporate a 5-mL aliquot of the filtrate on a steam bath with the aid of a stream of nitrogen, and dissolve the residue in 1 mL of chloroform. Apply 5 µL of the solution under test, 5 µL of a Standard solution of USP Ethynodiol Diacetate RS in chloroform containing 5 mg per mL, and 5 µL of a Standard solution of USP Mestranol RS in chloroform containing 0.5 mg per mL at points about 3 cm from one end of a thin-layer chromatographic plate (see Chromatography
Disintegration
Uniformity of dosage units
Procedure for content uniformity
Proceed as directed in the Assay, except to reduce by half the concentrations in the Standard preparation and the Assay and to inject twice the volume into the chromatograph.
Assay
Mobile phase
Prepare a filtered and degassed mixture of methanol, water, and tetrahydrofuran (63:30:7), making adjustments if necessary (see System Suitability under Chromatography
Standard preparation
Dissolve accurately weighed quantities of USP Ethynodiol Diacetate RS and USP Mestranol RS in a mixture of methanol and water (4:1) to obtain a solution having a known concentration of about 0.2 mg of ethynodiol diacetate per mL and 0.02 mg of mestranol per mL.
Assay preparation
Transfer 10 Tablets to a glass-stoppered flask, and pipet a sufficient volume of a mixture of methanol and water (4:1) into the flask to obtain a solution having final concentration of approximately 0.2 mg of ethynodiol diacetate per mL and 0.02 mg of mestranol per mL. Agitate vigorously until the tablets are completely disintegrated. Shake vigorously by mechanical means for 30 minutes. Allow the solids to settle for 10 minutes, and filter the solution through a 0.5-µm filter.
Chromatographic system
(see Chromatography
Procedure
Separately inject equal volumes (about 25 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of ethynodiol diacetate (C24H32O4) and mestranol (C21H26O2) per Tablet taken by the formula:
0.1CV(rU / rS)
in which C is the concentration, in mg per mL, of the appropriate USP Reference Standard in the Standard preparation, V is the volume, in mL, of the methanol-water solvent added to obtain the Assay preparation, and rU and rS are the peak responses of the corresponding analyte obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information
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USP35NF30 Page 3137
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