A Review on Different Analytical Methods: Letrozole

Abstract

Letrozole is a third-generation aromatase inhibitor used for hormonal-sensitive breast cancer in postmenopausal women. Several analytical methods were developed to analyze Letrozole. The present review clearly covers all the analytical techniques used for the analysis of Letrozole available till date, which helps the researchers in developing new methods for estimation of Letrozole by considering the pros and cons of the previously developed methods. Figure 1: Structure of Letrozole. Letrozole (Figure 1) is chemically known as 4-[(4-cyanophenyl)-(1, 2, 4-triazol-1-yl) methyl] benzonitrile, with molecular formula C 17 H 11 N 5 and is freely soluble in dichloromethane; slightly soluble in ethanol; practically insoluble in water. It is a third-generation aromatase inhibitor used for hormonal-sensitive breast cancer in postmenopausal women. A very low daily dose of Letrozole is sufficient for unveiling antitumor activity and it is highly potent and selective and well tolerated [1]. Aromatase inhibitors can be classified based on their chemical structure as steroidal (type I inhibitors) and nonsteroidal (type II inhibitors), where anastrozole and Letrozole are nonsteroidal inhibitors and exemestane is a steroidal inhibitor [2]. Catalysis of enzyme aromatase was the final step in biosynthesis of estrogen so this step can be inhibited for inhibition of estrogen production [3].