- An unwillingness of female subject of child bearing potential to use adequate contraception, as defined in the study restriction section. If necessary, women of non-child bearing potential (i.e. post-menopausal or surgically sterile e.g. tubal ligation or hysterectomy or bilateral oophorectomy) will be confirmed. Postmenopausal status will be confirmed by serum follicle stimulating hormone (FSH) and oestradiol concentrations at screening. Surgical sterility will be defined as females who have had a documented hysterectomy, tubal ligation or bilateral oophorectomy.