2. Females must be non-pregnant, non- lactating and either be of non-childbearing potential (i.e. sterilized via hysterectomy or bilateral tubal ligation or at least 1 year post-menopausal) or of child bearing potential, but practicing a medically acceptable method of birth control. Examples of medically acceptable methods for this protocol include barrier (diaphragm or condom) with spermicide, an intrauterine device (IUD), oral contraceptives, a levonorgestrel implant, intrauterine progesterone contraceptive system, medroxyprogesterone acetate contraceptive injection, and abstinence.