I. Basic Information

• Product Name: 7-[9-(4,4,5,5,5-Pentafluoropentylsulfinyl)nonyl]estra-1,3,5(10)-triene-3,17β-diol

• CAS Number: 129453-61-8

• Molecular Formula: C32H47F5O3S

• Molecular Weight: 606.77

• Appearance and Physical State: White powder

II. Physical Properties

• Density: 1.201 g/cm³

• Melting Point: 104~106°C

• Boiling Point: 674.8°C at 760 mmHg

• Flash Point: 361.9°C

• Refractive Index: 1.521

• Vapor Pressure: 3.95E-19 mmHg at 25°C

• Solubility: >5 mg/mL in dimethyl sulfoxide (DMSO)

III. Pharmacological Action

• Drug Type: Antineoplastic agent

• Mechanism of Action: Fulvestrant is a competitive estrogen receptor (ER) antagonist with an affinity for ER that is close to that of estrogen and 100 times that of tamoxifen. By competitively binding to ER, it blocks and downregulates ER, thereby inhibiting the estrogen signaling pathway and affecting estrogen-related processes necessary for cell cycling.

• Indications: It is used for the treatment of locally advanced or metastatic breast cancer that is estrogen receptor-positive and has recurred after or during anti-estrogen adjuvant therapy, or has progressed during anti-estrogen therapy, in postmenopausal women (including naturally menopausal and surgically menopausal women).