The purpose of this study is to evaluate the extent of moxidectin transfer into the breast milk of lactating women and to provide the initial pharmacokinetic and safety profile of moxidectin in lactating women.

Inclusion criteria:

Healthy lactating women aged 21 to 45 years inclusive at screening. Women should:

• Be at least 12-weeks postpartum after uncomplicated delivery with a full milk supply established.
• Be willing to discontinue breastfeeding permanently and should be in the process of weaning their infant. Care should be taken to ensure that subjects have not discontinued breastfeeding an infant in order to participate in the study.
• Not plan to breastfeed within 9 months of study drug administration.
• Be willing to fully express breast milk from both breasts during the duration of the milk collection portion of the study. Subjects must be able to express milk from each breast at each pumping session using a breast pump.
• Body mass index in the range of 18 to 35 kg/m2.

Exclusion criteria:

• Presence or history of any disorder that may prevent the successful completion of the study.
• Any significant cardiovascular, hepatic, renal, respiratory, gastrointestinal, endocrine, immunologic, dermatologic, hematologic, neurologic, or psychiatric disease.