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LETROZOLE 112809-51-5

USP 32

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Product Detail

Product Information

Product name	Letrozole
Molecular Formula	C17H11N5
Molecular Weight	285.3
CAS No.	112809-51-5
Quality Standard	USP32, medical grade
Appearance	White powder

COA of Letrozole

Items	Specification
Appearance	White to yellowish, crystalline powder
Identification	A.IR spectrum of sample should be identical to that of Reference Standard;
	The retention time of major peak in the chromatogram of the Assay preparation should correspond to that in the chromatogram of Standard preparation, as obtained in the Assay.
	Showing the white precipitate reaction.
Water	Not more than 0.3%
Residue on Ignition	Not more than 0.1%
Heavy Metals	Not more than 0.001%
Related Compounds	Compound A: Not more than 0.1%
	4,4’,4”-methylidenetrisbenzonitrile: Not more than 0.2%
	Any other impurity: Not more than 0.1%
	All other impurities: Not more than 0.3%
Residual Sovents	Ethanol: Not more than 3000ppm
	Ethyl acetate: Not more than 2000ppm
	DMF: Not more than 880ppm
Microbe Limit	Bacteria: Not more than 200/g
	Mold and yeast: Not more than 50/g
	Escherichia coli: should be absent
Assay(anhydrous)	98.0% to 102.0% of Cl7H11N5 on dried basis
Packaging and Storage	Preserve in tight containers at controlled room temperature.
Conclusion	Conforms to the USP32.

Usage

Function of Letrozole
Letrozole is a new generation of highly selective aromatase inhibitors. It is a synthetic benztriazole derivative. By inhibiting aromatase, estrogen levels are reduced, thereby eliminating the stimulating effect of estrogen on tumor growth. The activity in the body is 150-250 times stronger than that of the first generation aromatase inhibitor amuromet. Because of its high selectivity, it does not affect glucocorticoids, mineralocorticoids, and thyroid function. Large doses have no inhibitory effect on the secretion of adrenal corticosteroids, so it has a high therapeutic index. Various preclinical studies have shown that letrozole has no potential toxicity, mutagenicity and carcinogenic effects on various systems and target organs in the whole body, and has less toxic and side effects, and is well tolerated. Compared with estrogen drugs, the anti-tumor effect is stronger. It is suitable for the treatment of postmenopausal patients with advanced breast cancer who are not responding to anti-estrogen therapy and early treatment of breast cancer.

In December 2005, the British drug and health product regulatory agency approved Letrozole (Fron) produced by Novartis of Switzerland to be used in the treatment of breast cancer patients, allowing it to be used in surgically treated, early menopausal hormone-positive mammary glands Cancer patients. This is the second aromatase inhibitor approved following the approval of AstraZeneca ’s Rainin in June 2005. Both drugs have shown in clinical trials that they can better prevent the risk of breast cancer recurrence compared to current standard tamoxifen treatment.