The study involves healthy adult volunteers who do not have any known medical condition. Participants will receive a single dose of the experimental drug aticaprant in two forms: a standard oral tablet taken by mouth and a very small amount given by an intravenous infusion. The oral tablet contains 10 mg of the medication, while the infusion provides a microdose of 100 µg of a radiolabeled version of the same drug.

The purpose of the study is to determine the drug’s bioavailability, meaning how much of the medication reaches the bloodstream when taken as a pill compared with the tiny IV dose. By comparing the two administrations, researchers can learn how the body absorbs and processes the medication.

Volunteers will first swallow the tablet, then, after a short waiting period, receive the IV microdose. Blood samples will be collected at several time points over the next few hours to measure the amount of drug in the blood. The entire procedure is completed within a single visit, and no additional treatments are given.