Ethynodiol Diacetate

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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1 DEFINITION

Ethynodiol Diacetate contains NLT 97.0% and NMT 102.0% of ethynodiol diacetate (C₂₄H₃₂O₄).

2 IDENTIFICATION

Change to read:

A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197K (CN 1-May-2020)

3 ASSAY

Procedure

Mobile phase: Acetonitrile and water (41:59)

Standard stock solution: 2.5 mg/mL of USP Ethynodiol Diacetate RS, prepared as follows. Transfer a suficient amount of USP Ethynodiol Diacetate RS into a suitable volumetric flask and dissolve, by sonication, in a volume of acetonitrile equivalent to 50% of the flask volume.

Dilute with water to volume.

Standard solution: 0.25 mg/mL of USP Ethynodiol Diacetate RS in Mobile phase from Standard stock solution

Sample stock solution: 2.5 mg/mL of Ethynodiol Diacetate, prepared as follows. Transfer a sufficient amount of Ethynodiol Diacetate into a suitable volumetric flask and dissolve, by sonication, in a volume of acetonitrile equivalent to 50% of the flask volume. Dilute with water to volume.

Sample solution: 0.25 mg/mL of Ethynodiol Diacetate in Mobile phase from Sample stock solution

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 200 nm

Column: 4.6-mm × 15-cm; packing L11

Column temperature: 40°

Flow rate: 2 mL/min

Injection volume: 20 μL

System suitability

Sample: Standard solution

[Note—The retention time for ethynodiol diacetate is NLT 18 min.]

Suitability requirements

Tailing factor: 0.75–2.0

Relative standard deviation: NMT 0.7%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of ethynodiol diacetate (C₂₄H₃₂O₄) in the portion of Ethynodiol Diacetate taken:

Result = (r_U/r_S) × (C_S/C_U) × 100

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution

C_S = concentration of USP Ethynodiol Diacetate RS in the Standard solution (mg/mL)

C_U = concentration of Ethynodiol Diacetate in the Sample solution (mg/mL)

Acceptance criteria: 97.0%–102.0%

4 IMPURITIES

Procedure 1

Mobile phase, Sample stock solution, Sample solution, Chromatographic system, and System suitability: Proceed as directed in the Assay.

Analysis

Sample: Sample solution

Calculate the area percentages of the individual impurities in the portion of Ethynodiol Diacetate taken:

Result = (r_U/r_T) × 100

r_U = peak area of each individual peak between the solvent front and the ethynodiol diacetate peak

r_T = sum of the areas of all peaks appearing after the solvent front

Acceptance criteria: See Table 1.

Table 1

Procedure 2: Limit of Conjugated Diene

Sample solution: 0.5 mg/mL in methanol

Blank: Methanol

Instrumental conditions

(See Ultraviolet-Visible Spectroscopy 〈857〉.)

Mode: UV

Analytical wavelength: about 236 nm

Cell: 1 cm

Acceptance criteria: Absorbance is NMT 0.500.

5 SPECIFIC TESTS

Optical Rotation, Specific Rotation〈781S〉

Sample solution: 10 mg/mL in chloroform

Acceptance criteria: −70° to −76°

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in well-closed, light-resistant containers.

USP Reference Standards 〈11〉

USP Ethynodiol Diacetate RS