The present invention provides compositions containing endoxifen, formulations and liposomes of endoxifen, methods of preparation of such agents and formulations, and use of such agents and formulations for the treatment of breast cancer and other breast diseases and diseases susceptible to endoxifen. In particular, the compositions of the present invention include liposomes, complexes, vesicles, emulsions, micelles and mixed micelles of endoxifen in which the compositions further contain any of a variety of neutral or charged lipids and desirably, cholesterol and cholesterol derivatives, sterols, Z- and E-guggulsterones, phospholipids, fatty acids, vitamin D, and vitamin E. The present invention also provides methods of preparing endoxifen. The present invention provides methods for treating and preventing breast cancer and other breast related diseases by administrating novel formulations or compositions comprising a therapeutically effective amount of endoxifen.
