Abstract: Oral administration may lead to drugs inactivate since gastric fluid digestion,hence it is valuable to study gastrointestinal stability of oral-administrated drugs.Artificial gastrointestinal fluid model is widely used in this study in vitro with the advantages of easy operation and repeatability.This paper summarized the different experimental designs of the model,its application in drug discovery and the problems.At last,a developed method considering time,pH value,enzyme concentration and the speed of stirring was proposed in order to provide a reference for using the artificial gastrointestinal fluid models in future.

Key words: artificial gastrointestinal fluid model, drug stability, factorial design