Disclosed are inclusion complexes comprising fulvestrant (7-alpha-[9-(4,4,5,5,5-penta fluoropentylsulphinyl)nonyl]estra-1,3, 5-(10)-triene-3,17-beta-diol) represented by formula (I) and a cyclodextrin and uses of the complexes in the treatment of diseases necessitating antiestrogen therapy or estrogen receptor downregulation such as particular cancers and systemic lupus erythematosus. Also provided are methods of producing the inclusion complexes, methods of treatment using the complexes, formulations comprising the complexes and kits and unit dosages comprising the complexes.
