 4. Subjects who are females of child-bearing potential, defined as being physiologically capable of becoming pregnant, UNLESS using one or more of the following acceptable methods of contraception; established use of oral, injected or implanted hormonal contraception, intrauterine Device IUD or Coil AND barrier Method condom or diaphragm or cervicalvault cap plus spermicidal creamgel. Contraceptive use should continue throughout the study and for 1 month following completion of the study. 