This invention is in the field of chemical restructuring of antimetabolite
agents known to have poor oral bioavailability and to cause tissue
toxicity as a side effect, by producing their orotate derivatives. More
particularly, it concerns orotate derivatives of the methotrexate and
trimetrexate, that are found to improve the oral bioavailability and
clearance compared with their respective forms--methotrexate and
trimetrexate, currently in use. The present invention provides
methotrexate orotate having the formula: ##STR00001##