Research Of Cyclovirobuxine D And Buxine's PK-PD Binding Model

To direct the characteristic of Transdermal Delivery System's delivery and absorption,this paper established PK-PD bingding model by concentration-time-effect three-dimension graphics.On the basis,we approached the feasibility and superiority of CVB-D new dosage form,low dose and keeping effect, instead of original dosage form,and analyzed the correlation between Chinese material medica single composition and utility part.More scientific evidences can provide CVB-D's clinic dosage regimen,and provide clinical application of Chinese Materia Medica Transdermal Delivery,to promote Chinese Materia Medica's development.The paper consists of four parts.1 Research of microdialysis sampling technique's technology and influencing factor1.1 Establishment of Analytical Method for Cyclovirobuxine DThere is no double bond in molecular structure of CVB-D,so it is difficult to determine in ultraviolet extremity.Method of RP-HPLC with precolumn ultraviolet derivatization was applied to detect the content of CVB-D.Chromatogram condition was established as follows:derivatization reagent was phenyl isocyanate,column was BDS-C18,mobile phase methanol:water(85:15),wavelength 240nm,flow rate 1.0ml/min and number of theoretical plates can't be lower than 3000 according to peak area of CVB-D.1.2 Perfusate modifier influencing recoveryCyclovirobuxine D belongs to pregnane derivate,is liposolubility alkaloid.In the normal condition,by microdialysis sampling,CVB-D can not be detected by HPLC.Ringer's solution is aquosity perfusate.Its composition,pH,osmotic pressure,ionic strength and sampling position approach the internal environment,so fit heteropolarity component.CVB-D is alkaloid of easy dissolving organic solvent and slightly soluble aquateic.It has stronger lipophilia,and will easily bind dialysis-membrane by interaction between molecule,so its relate recovery is very low. It is necessary that increase CVB-D solubility in perfusate,and inhibit the binding with dialysis-membrane.We choose some perfusate modifier to increase RR.We investigated perfusate:alcohol,glycerin,DMSO,β-CD.Result indicateds that 4.41mMβ-CD can significantly increase the CVB-D RR.1.3 Flow influencing recoveryRR and flow abide by counter-exponent relation: RR=Ed=1-exp(kA/v)This formula shows RR decrease in exponent form with flow increasing.Flow obviously influence recovery,so it is necessary that investigate flow.We investigate 4,3,2,1,0.5μl/min flow.Result indicateds RR decrease in exponent form with flow increasing,so we choose the best flow on the basis of sampling amount,time and specific request in vivo.1.4 Relationship between RR and RLFor in vivo animal experiment,during the detecting course of dynamic state plasma concentration,plasma concentration can not be detected.In vivo animal's RR can not be detected.Massive research indicated RR and RL is high-consistency.In vivo,RL can substitute RR.The result indicated RR and RL is high-consistency in vitro.1.5 Investigating the recovery's stabilityWe investigating the recovery's stability.Result indicateds RL of in vivo and in vitro,RR of in vivo retain stabilization.2 The feasibility research of microdialysis sampling in pharmacolineticsPart of drug will bind with plasma protein.Its molecular mass will be increasing after binding,and influence the microdialysis sampling efficiency.Usually, microdialysis only detect the liberation drug,so it is necessary that investigate the plasma protein binding efficiency.We investigated the plasma protein binding efficiency of 2.5,5.0,7.5μg/mL.Result indicateds that it retain stabilization.3 Prepare Transdermal DeliveryWe prepared Transdermal Delivery,on the basis of Yu Yang doctor's paper《Preparation and Evaluation of Cyclovirobuxine D Transdermal Delivery System》 4 The research of CVB-D and Buxine's pharmacokinetics and pharmacodynamics4.1 Establishment of myocardial ischemia animal modelNow,myocardial ischemia animal model's establishment include injection of drug(hypophysin,isoprenaline,basergin by intraperitoneal injection,hypo,intravenous injection,coronary artery ligation,electrical stimulating method,et al.We chose injecting ISO,coronary artery ligation preparing model.Effect index is△ST,MDA,LDH,CK.Result indicated three methods can prepare myocardial ischemia animal model,but we chose coronary artery ligation preparing rabbit's model on the basis of PK-PD model.4.2 Establishment of pharmacodynamics of CVB-D and BuxineChoose rabbits,coronary artery ligation preparing myocardial ischemia model, randomly separate into four groups:Buxine patch group,Buxine oral administration, CVB-D patch group,CVB-D oral administration.Record index 0.5,1,2,3,4,6, 8,10,12,16,20h after administration.Result indicated that△ST,MDA,LDH,CK obviously increase after coronary artery ligation.Drug effect achieve peak at 6h. Comparison with patch and oral administration,T_peakis identical.4.3 Establishment of pharmacokinetics of CVB-D and BuxineThe in-vivo pharmacokinetics of CVB-D ethosomes gel patch was studied in rabbit by choosing HPLC as analysis method and CVB-D tablet as reference.The pharmacokinetic parameters were studied by compartment model and statistical moment.Results of absolute fluctuation and relative fluctuation of drug concentration indicated that compared with oral administration,transdermal administration could avoid fluctuation and maintain steady level of blood concentration to some extent. Time of achieve peak of oral administration is more quickly than patch.4.4 Establishment of PK-PD binding model of CVB-D and BuxinePharmacokinetics reflect time-concentration relation of drug in body,explain the body deal with drug.Pharmacodynamics reflect effect-concentration relationship of effect part,explain the drug deal with body.PK-PD describe concentration-effect-time relationship by binding PK and PD.Help understanding the drug changing course in the site of action,by PK-PD binding model.Result indicated time of achieve peak of oral administration is more quickly than patch,exist hysteresis.E～C_p curve showed anticlockwise hysteresis circles.After PK-PD model fit drug effect,E～C_p hysteresis transform E～C_e right-change relationship,time of achieve peak is identical.E～C_e is consistent with Sigmoid- E_maxmodel.Parameter is correlated between CVB-D oral administration and Buxine administration,CVB-D patch and Buxine patch.E_maxof oral administration is higher than patch,and C_maxof oral administration is higher than patch.The plasma concentration of patch is mild.4.5 Research of CVB-D and Buxine pharmacokinetics by microdialysisChoose rabbit,implant probe in ear vein,collect dialysate,analyze by HPLC, rectify real concentration by RR.Result indicated that the concentration by microdialysis is correlated with plasma concentration,manifest the microdialysis sampling technique is feasible in pharmacokinetics.