Study On Preparation Technology And Quality Of Total Saponins Of Dioscorea Zingiberensis

Background and objective:Dioscorea saponins is the major pharmacologically active in the Dioscorea plants, which has a variety of pharmacological effects, such like anti-cancer, hypolipidemic, prevention and treatment of coronary heart disease, hypertension and vascular sclerosis, it also copposites steroid hormone drugs and steroids as an important chemical raw material medicine. Dioscorea (Dioscorea Zingiberensis C.H.Wright) is endemic species in our country, and it has the highest content of dioscin, included in the2010version of "Chinese Pharmacopoeia". The main source of diosgenin is from Dioscorea nowadays. There have been some drugs prepared by the use of diosgenin on the market currently, such as Peltata Guanxinning which use for prevention of coronary heart disease and cardiovascular disease.Diosgenin has clear advantages in many clinical diseases,but there are still some problems in the actual course of study, such as its pharmacological mechanism of action role needed further research to prove; Diosgenin can not intravenous injection directly, because saponin can result in hemolysis; when oral administration directly, the bioavailability of Diosgenin is very low. Thus, Diosgenin needs new formulations of supporting urgently.In the particulate drug delivery systems, use of liposomes increasingly more mature, liposome carriers no matter water-soluble or fat-soluble drug, both has an high encapsulation efficiency, and has a high degree of targeting, can contorl drugs’ release, increasing the stability of drugs to improve their absorption and enhance drug efficacy and so on.This study intends to extract Dioscorea saponin, and prepared into diosgenin liposomes to improve its efficacy, establishing its quality assessment methods. The main contents included as following:Using70%ethanol extraction method, after recovery of ethanol, and then purifict the extract by petroleum ether n-butanol saturated full in water. The content of diosgenin is17.35%after extraction and purification of total saponins in Dioscorea;Prepared diosgenin liposomes by thin film evaporation; through a variety of single factor and response surface optimization curve method to determine the best prescription composition and preparation conditions. The optimal liposome formulations is Methanol:Chloroform=1:2.3, Phospholipid:Cholesterol=4:1, Lipid:Saponin=1:20, the encapsulation efficiency was68.90%; Establishment of diosgenin lipid entrapment efficiency of HPLC methods; Using gel column to separate liposomes with drugs and free drugs; Observing the liposomes witch prepared in the best method, measuring its size, Zeta potential; Investigateing liposomes’ stability and studing it’s in vitro release behavior. Diosgenin saponin liposomes’ average diameter is165.2nm, Zeta potential is-23.2mV, have a good storage stability at-20℃and4℃, and Diosgenin liposomes’ release rate is less than the free drug, it can be proved that diosgenin liposomehas sustained release effect on drug release in vivo.