The Study Of The Effect Of Pharmaceutical Exicipients On Intestinal Absorption Of Alkaloids Of Corydalis Saxicola

Corydalis saxicolae Herba(Yanhuanglian)is the dried herb of Corydalis saxicola Bunting(Papaveraceae),and its alkaloid extract is applied to relieve or cure acute jaundice hepatitis,cirrhosis,hepatic cancer,furuncle and gastroenteritis,etc.Pharmacological studies reveal that the alkaloids of Yanhuanglian,namely dehydrocavidine,palmatine and berberine,show positive anti-HBV activity,as well as liver protective effects.Our prophase research has investigated the physical properties and characteristics of intestinal absorptions of the alkaloids for the sake of a convenient and safe clinical preparation of Yanhuanglian.The result shows that all the above three components possess high hydrophilicity with wide absorption in duodenum,jejunum and ileum.However,what is dissatisfactory is that the apparent permeability coefficients are low.Moreover,the transports are affected by the intestinal transporters.According to the Biopharmaceutics Classification System,dehydrocavidine,palmatine and berberine belong to the Class III(namely with high solubility and low permeability),the oral absorptions of which are susceptible to excipients.As a consequence,excipients are crucial in preparation design.In present study,in vivo and in vitro models with intestinal absorption enhancers were carried out to experiment on the oral absorptions of the three bioactive components,which could provide a scientific basis for preparation research of Yanhuanglian.Main research results are as follows:In Section 1,in vitro single-pass intestinal perfusion technique was established,the concentrations of the components were determined by HPLC,then absorption rate constants and apparent permeability coefficients were calculated,which were latter used to evaluate the promotion effects of different absorption enhancers.The results indicated that both the varieties and concentrations had different’ effects on absorptions.5%PEG200,5%PEG400,0.35%Pluronic 188 and 0.5%COS manifested stronger effects.In Section 2,pharmacokinetic study of dehydrocavidine,palmatine and berberine were investigated using different excipients,i.e.,5%PEG200,5%PEG400,0.35%Pluronic188,0.5%COS,0.35%HP-β-CD and 1%Twain-80,which were all optimized in former study.The plasma concentrations were detected by UPLC-MS/MS,and the pharmcoknetic parameters was calculated by DAS 3.2.2 program.The approach of self-defined weighting coefficient based on the area under the curve from zero to time(AUC0-t)was used to obtain the holistic plasma concentrations of alkaloids in Corydalis saxicola,as well as the integrated Pharmacokinetic model,then the integrated pharmacokinetic parameters were calculated from non-compartmental model analysis.The results showed that 5%PEG200,5%PEG400 and 0.35%Pluronic188 could significantly increase the AUC0-t and Cmax,as well as the decrease of CLz/F,improving the bioavailability after oral administration.0.5%COS could improve the bioavailability of palmatine and berberine;While 0.35%HP-β-CD and 1%Twain-80 could enlarge the AUC0-t of dehydrocavidine and decrease the CLz/F,with unconspicuous effect on berberine.Moreover,0.35%HP-P-CD decreased the bioavailability of palmatine.The result of integrated Pharmacokinetic study showed that AUC0-t of 5%PEG200、5%PEG400、0.35%Pluronic188、0.5%COS、1%Twain-80 increased significantly compared to the control group,as well as the Cmax,with the decrease of CLz/F,which manifested that the bioavailability of these group was improved.Moreover,0.35%Pluronic188、5%PEG200 and 5%PEG400 displayed better effect.In Section 3,Caco-2 cell model was employed to investigated the effects of different excipients on bidirectional transport of dehydrocavidine,which was considered as the major components in Yanhuanglian.The translocation was detected by UPLC-MS/MS,and the apparent permeability coefficients and efflux ratio were computed in order to evaluate the effects of the excipients.The results indicated that 0.35%Pluronic188,5%PEG400,0.5%COS and 5%PEG200 could suppress the activity of efflux transporters apparently,while the effect of 0.35%HP-β-CD was not obvious.In Section 4,the concentration of D-lactate acid in rat plasma and the pathological section of intestinal mucosa were determined and inspected respectively after repeated oral administration of pharmaceutical exicipients,according to which the action of exicipients on morphology and permeability of intestinal mucosa was investigated and evaluated.The result showed that the concentration of D-lactate acid of 5%PEG200 and 5%PEG400 increased significantly compared to the control group.Moreover,in 5%PEG 400 and 0.35%HP-β-CD group,the image definition of intestinal mucosa was lower,with erosion and ulcers.Slight inflammatory cell infiltration and local interstitial edema were observed in other group,however,there were no obvious intestinal erosion and ulcers.