Estradiol Cypionate

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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Estra-1,3,5(10)-triene-3,17-diol, (17β)-, 17-cyclopentanepropanoate;

Estradiol 17-cyclopentanepropionate CAS RN®: 313-06-4; UNII: 7E1DV054LO.

1 DEFINITION

Estradiol Cypionate contains NLT 97.0% and NMT 103.0% of estradiol cypionate (C₂₆H₃₆O₃), calculated on the dried basis.

2 IDENTIFICATION

Change to read:

A. SPECTROSCOPIC IDENTIFICATION TESTS (197), Infrared Spectroscopy: 197K (CN 1 -May-2020)

B. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

PROCEDURE

Solution A: Acetonitrile

Solution B: Water

Mobile phase: See Table 1

System suitability solution: 1 mg/mL of LISP Estradiol Cypionate System Suitability Mixture RS in acetonitrile

Standard solution: 1 mg/mL of USP Estradiol Cypionate RS in acetonitrile

Sample solution: 1 mg/mL of Estradiol Cypionate in acetonitrile

Chromatographic system

(See Chromatography (621), Systern Suitability)

Mode: LC

Detector: UV 280 nm

Column: 4.6-mm × 25-cm; 5-μm packing L26

Flow rate: 1 mL/min

Injection volume: 25 μL

System suitability

Samples: System suitability solution and Standard solution

NOTE-See Table 2 for the relative retention times.)

Suitability requirements

Resolution: NLT 1.5 between estradiol-9-ene cypionate and estradiol cypionate, System suitability solution

Relative standard deviation: NMT 1.10%, Standard solution

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of estradiol cypionate (C₂₆H₃₆O₃) in the portion of Estradiol Cypionate taken:

Result = (r_U/(r_S) × (C_S /C_U) x 100

r_U = peak response the Sample solution

r_S = peak response from the Standard solution

C_S = concentration of USP Estradiol Cypionate RS in the Standard solution (mg/mL)

C_U = concentration of Estradiol Cypionate in the Sample solution (mg/mL)

Acceptance criteria: 97.0%-103.0% on the dried basis

4 IMPURITIES

RESIDUE ON IGNITION (281): NMT 0.2%

ORSANIC IMPURITIES

Solution A, Solution B, Mobile phase, and Chromatographic system: Proceed as directed in the Assay.

System suitability solution: 1 mg/mL of USP Estradiol Cypionate System Suitability Mixture RS and 2 µg/mL USP Estradiol RS in acetonitrile

Sensitivity solution: 0.5 µg/ml, of USP Estradiol Cypionate RS in acetonitrile

Sample solution: 1 mg/ml, of Estradiol Cypionate in acetonitrile

System suitability

Samples: System suitability solution and Sensitivity solution

Suitability requirements.

[Note-See Table 2 for the relative retention times.]

Resolution: NLT 1.5 between estradiol-9-ene cypionate and estradiol cypionate, System suitability solution

Signal-to-noise ratio: NLT 10, Sensitivity solution

Analysis

Sample: Sample solution

Calculate the percentage of each impurity in the portion of Estradiol Cypionate taken:

Result = (r_u/r_r) x (1/F) x 100

r_U = peak response for each impurity

r_S = sum of the responses of all the peaks

F = relative response factor (see Table 2)

Acceptance criteria: See Table 2. Disregard peaks that are less than 0.05% of the estradiol cypionate peak.

^a 3-Hydroxyestra-1,3,5(10),9(11)-tetraen-17β-yl cyclopentanepropanoate.

^b 3-Hydroxy-4-methylestra-1,3,5(10)-trien-17β-yl cyclopentanepropanoate.

^c Estra-1,3,5(10)-trien-3,17β-diyl di(cyclopentanepropanoate).

5 SPECIFIC TESTS

OPTIGAL RUTATION. Specific Rotation (7815).

Sample solution: 20 mg/mL in dioxane

Acceptance criteria: +39° to +44°

LOSS ON DIRVING (731)

Analysis: Dry at 105° for 4 h.

Acceptance criteria: NMT 1.0%

PACKAGING AND STORAGE: Preserve in tight, light-resistant containers.