Quinestrol API is a synthetic steroidal estrogen and a 3-cyclopentyl ether derivative of ethinyl estradiol. It is a long-acting estrogenic active pharmaceutical ingredient with a molecular formula of C₂₅H₃₂O₂ and molecular weight of 364.53 g/mol. Quinestrol is identified by CAS 152-43-2 and FDA GSRS UNII JR0N7XD5GZ.
Quinestrol has historically been investigated and used in oral estrogenic pharmaceutical applications. Its prolonged action is associated with its conversion to and storage of active estrogenic metabolites, principally ethinyl estradiol.
Quinestrol is a steroidal estrogen structurally related to ethinyl estradiol. Chemically, it is the 3-cyclopentyl ether of ethinyl estradiol. The compound contains five defined stereocenters and has an exact mass of approximately 364.24023 Da.
Key identity information:
| Parameter | Details |
|---|---|
| Product Name | Quinestrol |
| CAS Number | 152-43-2 |
| Molecular Formula | C₂₅H₃₂O₂ |
| Molecular Weight | 364.53 g/mol |
| FDA UNII | JR0N7XD5GZ |
| PubChem CID | 9046 |
| ChEBI | CHEBI:8716 |
| ChEMBL | CHEMBL1201165 |
| DrugBank | DB04575 |
| Chemical Class | Steroidal estrogen |
| Synonym | Ethinyl estradiol 3-cyclopentyl ether |
| Physical Form | Solid |
FDA GSRS independently confirms the substance name, CAS number, formula and UNII.
Quinestrol is a lipophilic steroidal compound with an estrogenic pharmacological profile. PubChem reports an XlogP of approximately 5.3, hydrogen-bond donor count of 1, hydrogen-bond acceptor count of 2 and topological polar surface area of 29.5 Ų.
The compound is structurally characterized by a steroid nucleus containing a cyclopentyloxy substituent and an ethynyl group. Its molecular structure is stereochemically defined.
Quinestrol is associated with estrogenic pharmaceutical applications. Historical drug references describe its use in estrogen replacement and hormonal therapy, as well as historical applications involving estrogen-responsive conditions.
Potential pharmaceutical-development applications include:
Quinestrol API should be characterized using suitable chromatographic and spectroscopic analytical methods. HPLC, LC-MS, IR and NMR can be used for identity and purity characterization, while appropriate chromatographic methods can be applied for related substances and stereochemical assessment.
Publicly accessible authoritative sources confirm the identity and physical properties of Quinestrol, but I could not verify a current complete USP/IP/BP/Ph. Eur. public numerical API release specification covering assay, individual impurities, total impurities, LOD, residue on ignition and heavy metals.
Therefore, those fields below are deliberately marked N/A rather than fabricated.
Manufacturing Quinestrol API requires controlled steroid chemistry, purification and analytical characterization. Particular attention should be given to chemical identity, chromatographic purity, stereochemical integrity and residual process-related impurities.
A pharmaceutical API quality program should include validated analytical methods, controlled raw materials, batch traceability, appropriate packaging and complete batch documentation.
Quinestrol should be stored in tightly closed, moisture-protective pharmaceutical packaging under controlled temperature and light conditions established through stability studies.
Recommended handling includes:
PubChem describes Quinestrol as a solid and reports an experimentally sourced melting point of 107.5°C.
Quinestrol API documentation can include:
A reliable Quinestrol API manufacturing program should focus on consistent chemical identity, controlled purity, reproducible manufacturing, validated analytical testing and complete documentation. Because a complete current public pharmacopoeial numerical specification could not be verified, the final commercial specification should be established through a validated pharmaceutical quality specification rather than unsupported generic limits.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |