Complete abstinence from intercourse from 2 weeks prior to administration of the investigational product. Throughout the study, and for a time interval (5 days) after completion or premature discontinuation from the study. History of bilateral tubal ligation Sterilization of male partner; or, Implants of levonorgestrel; or, Injectable progestogen, or, Oral contraceptive (combination therapy with ethinyl estradiol plus a progestin) with a placebo week every 1-3 months; or, Any intrauterine device (IUD) with published data showing that the highest expected failure rate is less than 1% per year (not all IUD's meet this criterion) in use at least 30 days prior to study drug administration; or, Spermicide plus a mechanical barrier (e.g., spermicide plus a male condom or a female diaphragm); or, Any other barrier methods (only is used in combination with any of the above acceptable methods) in use at least 14 days prior to study drug administration; or, Any other methods with published data showing that the highest expected failure rate for that method is less than 1% per year.