Ethinyl Estradiol is a synthetic estrogen and an active pharmaceutical ingredient (API) widely used in hormonal pharmaceutical formulations. It is a potent estrogenic compound with improved oral activity compared with naturally occurring estradiol.
Ethinyl Estradiol is commonly used in combination with progestins in combined oral contraceptive formulations and is also used in selected hormone-related pharmaceutical preparations.
Ethinyl Estradiol is a synthetic derivative of estradiol containing an ethynyl group at the 17α-position. This structural modification contributes to its high oral estrogenic activity.
CAS Number: 57-63-6
Molecular Formula: C₂₀H₂₄O₂
Molecular Weight: 296.41 g/mol
Ethinyl Estradiol acts primarily through estrogen receptors (ERα and ERβ). After binding to estrogen receptors, it influences estrogen-responsive gene transcription and produces estrogenic effects.
In combined hormonal contraceptives, its estrogenic activity contributes to suppression of the hypothalamic-pituitary-ovarian axis, helping inhibit ovulation.
Its pharmacological effects include:
Ethinyl Estradiol is used in pharmaceutical formulations for:
The exact indication depends on the final pharmaceutical formulation and applicable regulatory labeling.
Ethinyl Estradiol is a steroidal estrogen API with defined chemical and stereochemical characteristics. Pharmaceutical-grade material requires appropriate control of identity, assay, related substances and other quality attributes.
Typical quality evaluation may include:
Pharmaceutical-grade Ethinyl Estradiol should comply with the applicable pharmacopoeial monograph, approved specification and regulatory requirements.
A qualified supplier should provide Certificate of Analysis (CoA), specification sheet, SDS/MSDS, batch traceability and applicable regulatory documentation.
Store Ethinyl Estradiol in a tightly closed container, protected from excessive moisture, heat and direct light, according to the manufacturer's approved storage and stability requirements.
| Parameter | Specification |
|---|---|
| Appearance | White to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 1.0% |
| Residue on Ignition | NMT 0.5% |
| Heavy Metals | NMT 20 ppm |
| pH (1% Solution) | 2.0 – 4.0 |
| Individual Impurity | NMT 0.5% |
| Total Impurities | NMT 1.0% |