Selective delivery of 5-fluorouracil (5-FU) to i.p. tissues using 5-FU microspheres in rats.

A new formulation has been developed for the delivery of 5-fluorouracil (5-FU) in treating peritoneal carcinomatosis. The new formulation (5-FU-MS) involves the incorporation of 5-FU into microspheres composed of a poly(glycolide-co-lactide) matrix. The incorporated 5-FU is released slowly over a 3 week period. We investigated the drug distribution and pharmacokinetics of 5-FU in rats receiving an i.p. injection of 5-FU-MS or aqueous 5-FU solution. The concentration of 5-FU was higher in the i.p. tissues (omentum and mesentery) and lower in the extraperitoneal tissues (blood plasma, lung and heart) in rats given 5-FU-MS than in rats given the aqueous 5-FU solution. Pharmacokinetic analysis showed that the area under the curve (AUC) was significantly greater in the omentum and the mesentery than in other tissues of rats given 5-FU-MS. There was no significant difference in the AUC in the tissues of rats given the aqueous 5-FU solution.