The Study Of Drug Delivery System Of YuChang Ning

In this paper,the research thinking of TCM drug delivery system was proposed,according to the diversity of effective composition of compound TCM and complexity of pathology and pathogenesis.Through investigating design,preparation and evaluation of YuChang ning,which is the model drug,we not only obtained the capsule releasing in the stomach-colon respectively but also studyed the key problems such as the design thinking, preparing method, evalution technique and so on.In a word,this study made a good example for the research of TCM drug delivery system.With the guidance of corresponding thinking of "prescription-pattern-agent" and theory of modern pharmaceutics, we did systematic research and analysis of modern medical information,which include ulcerative colitis,astragalan,saponin, matrine, as well as oxymatrine.Combining these with pharmacodynamic experiments,we studied out TCM drug delivery system.This system consists of stomach-specific-released unit which was prepared by astragalan and saponin and colon-specific-released unit,which was prepared by matrine and oxymatrine.Screening for preparation method, preparation prescription, coating prescription and coating process, we got the astragalus-micropill and sophora-micropill whose accumulated release rate is 94.7%,96.3% separately in the artificial gastric juice in 20 min.Regarding to colon-specific-released unit, we designed three types of coating-pill that is pH-sensitive monolayer, pH-sensitive double-layer as well as pH-sensitive and enzyme-promoting double controlling type with Eudragit S100,Eudragit E100,Eudragit L100 and chitosan as coating materials.Meanwhile, the relative properties of chitosan applied to administration for the colon-specific was reserached. We also investigated the mixing process of the two units,and the result showed that they could be well-mixed and loaded successfully for once.As can be seen from results of release rate in vitro and in vivo,stomach specific released unit released completely within 30 minutes in gastric juice.It was also indicated that three coating-pills of colon-site-specific posses colon-specific-drug-released characteristics in vitro and in vivo.Beside this,we identified release-mechanism and stability of kinds of coated pellets.Pharmacokinetics results manifested that most drugs in the colon-coated pellets was not absorbed in gastrointestinal tract,but distributed in the colon contents and colon tissue with high-concentration compared with the general solution of oral.Therefore, we reached design objective that the capsule of YuChang delivered to the stomach and colon with two steps.Pharmacodynamic evaluation results showed that the capsule of YuChang ning-delivered-respectively has significant antagonism to the pathological injury of colon tissue induced by trinitrobenzenesulfonic acid in rats.Compared with the same dose of the mixed solution of YuChang ning, the capsule of YuChang ning-delivered-respectively has obvious advantages by inhibiting pro-inflammatory cytokine secretion and inflammatory cell infiltration,as well as regulating free radical systems and immune response.