Fispemifene and its Impurities

Fispemifene belongs to the triphenylethylene group of nonsteroidal SERMs. This places it in the same class as other SERMs like tamoxifen and toremifene. It is a selective estrogen receptor modulator, that was under development for the treatment of male hypogonadism and other male urological conditions. Reference standards of Fispemifene API, and its pharmacopeial, non pharmacopeial impurities, and stable isotopes are listed below.