Potentiation of the antitumor effect of 5-fluoro-2'-deoxyuridine esters in combination with acyclothymidine esters on L1210 in mice via oral administration

Article abstract of DOI:10.1002/jps.2600771108

Fifteen pyrimidine-related compounds were evaluated for their ability to inhibit enzymatic degradation of 5-fluoro-2'-deoxyuridine (FUdR). Acyclothymidine [5-methyl-1-(2'-hydroxyethoxymethyl)uracil] showed the highest inhibitory effect on the phosphorolytic degradation of FUdR in various tissue homogenates derived from mouse, rat, and beagle organs. Both the drug (FUdR) and the inhibitor (acyclothymidine) were esterified with appropriate aliphatic acids in order to synchronize their behavior after simultaneous oral administration. The antitumor activity of orally administered FUdR esters was potentiated by the simultaneous oral administration of the acyclothymidine esters, but not by acyclothymidine.