Objective: To optimize preparation process of Zuojin gastric floating-bioadhesive pellets and investigate its in vitro release characteristics. Method: With release of berberine hydrochloride as indicator to evaluate and optimize formulation.Prescription composition for pellet core of Zuojin gastric floating-bioadhesive pellets was optimized by single factor tests

process parameters of extrusion spheronizatiaon were investigated by orthogonal design while pellets circularity and yield of pill core were used as evaluation index.Pellet core were coated by mixed solution of carbomer and sodium bicarbonate. Result: Optimum preparation process was as follows:extrusion speed of 30 r·min-1

rounding speed of 800 r·min-1

spheronization time of 20 min.All coated pellets which were drifted in 1 min were prepared with HPMC K4M as matrix

MCC PH301 as ball material and disintegrating agent

sodium bicarbonate as drift material.About 80% of pellets were continuous floated within 10 hours

biological adhesion rate was 83.7%-86.8%.Cumulative release rate of berberine hydrochloride in 12 hours was more than 90%. Conclusion: Zuojin gastric floating-bioadhesive pellets has good release properties with uniform appearance

its preparation technology is simple with low production cost.