THE PRESENT INVENTION PROVIDES AN FTD AND TPI-CONTAINING ORALLY ADMINISTRABLE PHARMACEUTICAL COMPOSITION WHICH CAN BE ORALLY ADMINISTERED AND IS STABLE EVEN UNDER HIGH-HUMIDITY CONDITIONS. AN ORALLY ADMINISTRABLE PHARMACEUTICAL COMPOSITION WHICH COMPRISES a, a, a-TRIFLUOROTHYMIDINE AND 5-CHLORO-6-(2-IMINOPYRROLIDINE-1-YL)METHYL-2, 4 (1H, 3H) -PYRIMIDINE DIONE HYDROCHLORIDE AS ACTIVE INGREDIENTS AND ADDITIVES HAVING A CRITICAL RELATIVE HUMIDITY OF 85% OR MORE AT 25°C AS AN EXCIPIENT.