Objective:To prepare Ginkgo biloba extract stomach floating retention sustained-release tablet

and investigate its in vitro release property. Method: With floating time and floating start time as indexes

single factor test was used to investigate sustained framework material

start floating agent

the amount of HMPC and octadecanol;With composite score of cumulative release rate

floating start time and floating time as index

the amount of HPMC K4M

PVPP

octadecanol and effervescent were selected as factors

orthogonal test was designed to optimize prescription and preparation technology

and in vitro release mechanism of this sustained-release tablet was investigated. Result: Optimum prescription:mass fraction of HPMC K4M

PVPP

G. biloba extract

octadecanol and effervescent were 30%

2%

20%

48%

4%

respectively;with MCC as diluent agent to fill quality.Release dynamical model of G. biloba extract stomach floating retention sustained-release tablet was coincident with Higuchi equation. Conclusion: Prepared sustained-release tablet had good appearance

compressibility and release property

release mechanism of it was dual function of diffusion and dissolution.