Raloxifene, as shown in Figure 5.1, is a classic example of a selective estrogen receptor modulator (SERM)^1–7  and a number of studies indicate that the binding affinity of raloxifene is about one third of the binding affinity of estradiol^8,9  to the estrogen receptor. It is an estrogen agonist/antagonist, commonly referred to as a SERM that has benzothiopheneheterocyclic moiety.

It an extensively investigated SERM that partially simulates the effect of estrogens in bone and the cardiovascular system, while functioning as an anti-estrogen in endometrial and breast tissues. It has been approved for the prevention of osteoporosis and reduction...