Introduction Although 5-fluorouracil is one of the most widely used cytotoxic drugs in the treatment of solid tumors in many organs, it has a severe drawback in its serious side-effects (e.g. gastrointestinal and bone marrow toxicity) and the properties Introduction Although 5-fluorouracil is one of the most widely used cytotoxic drugs in the treatment of solid tumors in many organs, it has a severe drawback in its serious side-effects (e.g. gastrointestinal and bone marrow toxicity) and the properties