A Study to Evaluate Pharmacokinetics, Pharmacodynamics and Tissue Concentrations of Epelsiban

Inclusion Criteria: For ultrasound training cohort * Female volunteers of childbearing potential; with a negative pregnancy test as determined by human chorionic gonadotropin (hCG) testing at screening and prior to study initiation. * Age between 18 and 35 years old (inclusive). * Body weight \>=50 kilograms (kg) and body mass index (BMI) within the range 18-30 kg/meter (m)\^2 (inclusive). * Normal ovarian and uterine anatomy as assessed by transvaginal ultrasonography. * Capable of giving written informed consent, which includes compliance with the requirements and restrictions listed in the consent form. * Is in good physical and mental health as determined by a responsible and experienced physician, based on a medical evaluation including medical history, and physical examination. For Cohorts 1, 2A, 2B, 2C, 3 * Female volunteers of childbearing potential; with a negative pregnancy test as determined by hCG testing at screening and prior to study initiation. * Agrees to use one of the contraception methods for 2 weeks prior to the start of study to minimize the risk of pregnancy. Female subjects must agree to use contraception until at least 48 hours have passed after the last dose of study drug. OR has only same-sex partners, when this is her preferred and usual lifestyle. Oral contraceptive (OC) pill naive or have discontinued OC at least 2 months prior to study entry. * Age between 18 and 35 years old. * Body weight \>=50 kg and BMI within the range 18-30 kg/m\^2 (in…