Insoluble breviscapin was chosen as the model drug.Bi-layer osmotic pump technology and gel matrix technology were used to prepare the breviscapin sustained and controlled release preparations.Dissimilarity factors（f1） and similarity factors（f2） were applied as similar judgment index to compare the effects of in vitro conditions on the release behavior of different types of breviscapin sustained and controlled release preparations.The tolerance of in vitro release conditions of bi-layer osmotic pump technology and gel matrix technology were studied.The results showed that in vitro release conditions have a greater impact on the gel matrix sustained release formulations,while have almost no effects on the osmotic pump controlled release formulations.Therefore,osmotic pump controlled release technology is less affected by the drug release environment.And it has a very good application prospect.
