- Healthy male or female 18 to 55 years of age. Women had to be postmenopausal (more than 12 months since last period); surgically sterile (hysterectomy or tubal ligation or bilateral oophorectomy at least 6 months prior to enrollment); using an intrauterine device; a non-hormonal double barrier contraceptive method (i.e., diaphragm or spermicide plus male condom) for the duration of the trial and with a negative pregnancy test at screening and upon each check-in to the study facility,