107868-30-4 Exemestane AKSci H824
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  H824    AKSci Reference Standard
, 98% (HPLC)

CAS Number:107868-30-4
MDL Number:MFCD00866994
Min. Purity Spec:98% (HPLC)
Spectra:HPLC, Polarimetry
Physical Form:White to off-white to light yellow crystalline powder or powder
Melting Point:192-202°C
Optical Rotation:+250° - +300° (c=1, MeOH)
Long-Term Storage:Store long-term at -20°C
Not hazardous material

Solubility:DMSO: >=20mg/mL; H2O: <1mg/mL; EtOH: 15mg/mL
Application(s):Aromatase inhibitor
Form:Free Base


 Exemestane is an irreversible (Type 1), steroidal aromatase inhibitor. Aromatase catalyzes the final and rate-limiting step in the conversion of androgens to estrogens in peripheral tissues. This occurs mainly in adipose tissue, but also in normal and malignant breast tissues, and provides the main source of estrogen in postmenopausal women. The goal of hormone therapy in breast cancer is to deprive tumour cells of estrogens, which are implicated in the development or progression of tumours. Maximal estrogen suppression is produced by a 25 mg dose. It occurs after 2-3 days and returns to baseline in 10-14 days. Exemestane does not have estrogenic activity. Highly selective blockade of aromatase does not interfere with the production of other steroids (eg, adrenal corticosteroids1, aldosterone2, androgens). Evidence suggests that tumour progression is not due to a loss of estrogen suppression but to newly developed tumour resistance, including acquired hypersensitivity of some tumour cells to estrogens. Differences in the mechanism of action may contribute to the apparent lack of cross-resistance between steroidal (eg, exemestane) and nonsteroidal (eg, anastrozole, letrozole) aromatase inhibitors.

[1]Njar VC, Brodie AM. Comprehensive pharmacology and clinical efficacy of aromatase inhibitors. Drugs 1999;58(2):233-55.
[2] Pharmacia & Upjohn Inc. Aromasin product monograph. Mississauga; 10 August 2000.
[3] Kvinnsland S, Anker G, Dirix LY, et al. High activity and tolerability demonstrated for exemestane in postmenopausal women with metastatic breast cancer who had previously failed on tamoxifen treatment. European Journal of Cancer 2000;36(8):976-82.
[4] Pharmacia & Upjohn Inc. New drug submission, part 3 - comprehensive summary. Mississauga: Ontario; 2000.



Signal Word

Hazard Statements
H360; H411

Precautionary Statements
P201; P202; P273; P281; P308+P313; P391; P405; P501

Current as of April 22, 2021

AKSci Reference Standards are high-purity, low-impurity compounds suitable for use as standards.

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 APIs and Bioactives > Aromatose inhibitors