关键词: 5-氟尿嘧啶；pH依赖-时滞型微丸；结肠定位给药系统

Abstract:

Objective     To evaluate colon-specific release properties of pH-and time-based pellets of 5-fluorouracil(5-FU) in vivo.  Methods    pH-and time-based colon-specific 5-FU pellets were administered to rats by gavage. The rats were sacrificed at different time, and the pellets in different regions of the gastrointestinal tract were collected. Then the morphology of pellets was observed by a scanning electron microscopy, and contents of 5-FU in the pellets and the colonic content were determined by UV and HPLC, respectively. The release characteristics of pellets in different regions of the gastrointestinal tract at different time were evaluated. Results    The content of 5-FU was over 95% in pellets collected in the upper gastrointestinal tract before arriving at the cecum. Content of 5-FU could be detected in the colonic content between 5h and 16h, and was up to 84.26% of the total dosage. Conclusion    Drug concentration of pH- and time-based 5-FU colon-specific pellets is enhanced in the colon, and the colon-specific effect is exerted by oral administration.

Key words: 5-Fluorouracil; pH- and time-based pellets; Colon-specific drug delivery system5