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 α,α,α-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.
