PURPOSE: The titled antitumor agent having high effectiveness by oral administrtion, obtained by blending a pyrimidine nucleic acid derivative with a partially novel 1-(2-hydroxyethoxy)methyluracil as an active ingredient.
CONSTITUTION: An antitumor agent containing at least one pyrimidine nucleic acid derivative shown by the formula I (X is F or CF3 ; R is H or OH) and at least one compound shown by the formula II (Y is F, H, Br, I, CH3, etc.). The pyrimidine nuleic acid derivative shown by the formula I has improved antitumor activity in vitro, but it has reduced antitumor activity, in vivo, espe cially by oral administration, by its decomposition with pyrimidine nucleoside phosphporylaser in the intestine. The compound shown by the formula II inhibits strongly the decomposition enzyme activity in the intestine, so antitumor activity in the intesteine is maintained. 1mol compound shown by the formula I is prefer ably blended with 0.1W10mol compound shown by the formula II.
HANASHIMA NOBUAKI
SUZUKI YOSHIKI
