The present invention relates to a process for the preparation of a liquisolid powder, wherein the process comprises the steps of providing a solution comprising 2-{4-[N-(5,6-diphenylpyrazin-2-yl)-N-(isopropylamino]butoxy}-N-(methanesulfonyl)acetamide (selexipag) and a solvent, wherein said solvent is a non-volatile solvent, a mixture of non-volatile solvents, or a mixture of non-volatile and volatile solvents, to form a solution comprising selexipag and mixing the solution thus obtained with a solid porous carrier, thereby obtaining a liquisolid powder.The present invention further refers to a process for the preparation of a solid final dosage form, comprising the additional step of formulating the liquisolid powder in a final dosage form.The present invention also relates to a liquisolid powder comprising selexipag, a final dosage form comprising the liquisolid powder, and the use thereof in a method of prevention or treatment of pulmonal arterial hypertension.
