Objective: To prepare fibrauretinum colon targeting tablets delivery system controlled by pH-dependent and time-dependent effects

and to investigate its in vitro release. Method: Fibrauretinum colon targeting tablets were coated sequentially with isolated layer of HPMC and PEG 6 000

time-dependent layer of polyacrylic resin Ⅳ and PVP

and outermost enteric coating layer of polyacrylic resin Ⅱand polyacrylic resin Ⅲ. Release situation of coated tablets in artificial gastrointestinal environment were investigated. Result: There was no drug release of prepared fibrauretinum colon targeting tablets in pH 1.0 artificial gastric juice in 2 hours;In pH 6.8 artificial intesrinal fluid

the amount of release was less than 1% in 3.5 hours;But in pH 7.6 artificial colon fluid

drug was completely released within 6 hours. Conclusion: This study reveals that fibrauretinum colon targeting tablets had a good effect of colon targeting.