Study on colon-specific pectin/ethylcellulose film-coated 5-fluorouracil pellets in rats

The purpose of the present study is to assess the biodistribution and pharmacokinetics of pectin/ethylcellulose film-coated and uncoated pellets containing 5-fluorouracil (5-FU) in rats. Both coated and uncoated pellets were orally administered to the rats at a dosage equivalent to 15 mg/kg. 5-FU concentrations in different parts of the gastrointestinal (GI) tract and plasma were quantitatively analyzed using a high-performance liquid chromatography (HPLC) assay. 5-FU released from uncoated pellets mainly distributes in the upper GI tract, however, 5-FU released from coated pellets mainly distributes in the cecum and colon. In plasma, the observed mean Cmax from the coated pellets group (3.65 ± 2.3 μg/mL) was lower than that of the uncoated pellets group (23.54 ± 2.9 μg/mL). The AUC values obtained from the uncoated pellets and the coated pellets were 49.08 ± 3.1 and 9.06 ± 1.2 μg h/mL, respectively. The relatively high local drug concentration with prolonged exposure time provides a potential to enhance anti-tumor efficacy with low systemic toxicity for the treatment of colon cancer.