15. Non-pregnant, non-lactating females must meet one of the following criteria: no reproductive potential because of menopause (one year without menses) or because of a hysterectomy, bilateral oophorectomy, or tubal ligation; or subject agrees to be heterosexually inactive at least 21 days prior to enrollment and throughout the duration of the study; or agrees to consistently practice contraception at least 21 days prior to enrollment and throughout the duration of the study by one of the following methods: abstinence, condoms (male or female with or without a spermicide), diaphragm or cervical cap with spermicide, intrauterine device, contraceptive pills or patch, Norplant, Depo-Provera or other FDA approved contraceptive method, or male partner has previously undergone a vasectomy as declared in medical history.