The present subject relates to the solid pharmaceutical dosage form comprising 1-Methylethyl N-[(S)-{[(2R,3R,4R,5R)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-fluoro-3-hydroxy-4-methyltetrahydrofuran-2-yl]methoxy}phenoxyphosphoryl]-l-alaninate known also as sofosbuvir, and a process of preparation of the pharmaceutical dosage form according to the invention.