A study conducted in healthy adults to investigate if a new macitentan tablet leads to the same fate of macitentan in the body (time of onset, time of presence, amount in the blood) as the marketed macitentan tablet.

The purpose of this study is to establish biocomparison of 2 types of tablets containing macitentan: a pediatric dispersible tablet and the adult film-coated tablet. A single oral dose of each tablet will be given to healthy subjects on 2 different periods separated by a washout phase of 10 to 14 days.

Biocomparison will be based on the comparison of the pharmacokinetic parameters of macitentan with the two types of tablets using specific statistical methods. The pharmacokinetic parameters will be considered equivalent if specific criteria defined in the study protocol are met.

Inclusion Criteria:

• Signed informed consent
• Healthy on the basis of the physical examination, vital signs (systolic and diastolic blood pressure, heart rate), 12-lead ECG, and laboratory tests performed at screening

Exclusion Criteria:

• History or clinical evidence of any disease and/or condition, which might interfere with the absorption, distribution, metabolism or excretion of the study drug
• Previous history of fainting, collapse, syncope, orthostatic hypotension, or vasovagal reactions
• History or clinical evidence of alcoholism or drug abuse within the 3 -year period prior to screening
• Excessive caffeine consumption
• Smoking within 3 months prior to screening and inability to refrain from smoking during the course of the study
• Previous treatment with any prescribed medications (including vaccines) or over-the counter medications within 2 weeks prior to first study drug administration
• Loss of 250 mL or more of blood within 3 months prior to screening
• Any circumstances or conditions, which, in the opinion of the investigator, may affect full participation in the study or compliance with the protocol