Capecitabine is rapidly absorbed by the intestinal mucosa after oral administration, and then converted into an inactive intermediate 5'-deoxy-5' fluorocytidine in the liver by carboxyl esterase, followed by cytidine removal from liver and tumor tissues. The action of the aminoase is converted to 5'-deoxy-5' fluorouridine and finally catalyzed by thymidine phosphorylase to fluorouracil (5-FU) in tumor tissues.
Clinical studies have shown that the concentration of 5-FU in tumor tissue after oral administration is significantly higher than that of blood and muscle. The efficacy of tumors in a variety of animals was significantly higher than 5-FU. This product has synergistic effects with a variety of anti-tumor drugs.