| Studies have shown that the mechanism by which surface-active dosage excipients promote drug absorption may affect intestinal wall permeability,including membrane transporter function,in addition to increasing the solubility of active ingredients.Based on the multi-target Caco-2 cell lipid raft chromatography constructed by our research group in the early stage,emodin,an insoluble active monomer of traditional Chinese medicine,was used as the model drug to investigate the chromatographic behavior of Caco-2 cell lipid raft for solubilized excipients.The solubilization characteristics and mechanism of the selected excipients(sodium cholic acid and glycyrrhizic acid)with retained activity on the lipid raft chromatography of Caco-2 cells were studied,and the dissolution changes of the combined decoction components of glycyrrhizin-rhubarb were investigated.At the same time,emodin micelles with glycyrrhizic acid as the carrier were constructed.Caco-2 cell lipid raft chromatography and Caco-2 cell model were used to investigate the absorption and transport of emodin in monomer,micellar,single decoction of rhubarb and combined decoction of rhubarb-licorice.Chapter Ⅰ ReviewThis chapter summarizes the solubilization methods of poorly soluble drugs in order to provide a reference for the solubilization of poorly soluble drugs in lipid raft chromatography.And,it summarizes the research progress of the effect of licorice on the "harmonization of various drugs",with a view to the solubilization behavior of glycyrrhizic acid.Introduce the construction and evaluation of the Caco-2 cell model.Finally,the effect of solubilizing excipients on the activity of P-glycoprotein is introduced,with a view to provide reference and thinking for the study of solubilization and absorption behavior of refractory active ingredients of traditional Chinese medicine.Chapter Ⅱ Chromatographic behavior of solubilized excipients based on Caco-2 cell lipid raft chromatographyThe total protein content of the extracted Caco-2 cell lipid raft was adjusted to construct the Caco-2 cell lipid raft chromatography.The chromatographic behavior of the solution-enhancing excipients was investigated online,and the influence of the selected excipients on its adsorption was further investigated with emodin as the model drug.Compared with the blank silica gel column,the retention time of sodium cholate on the Caco-2 lipid raft column is 7 min～12.5 min,and the retention time of glycyrrhizic acid on the Caco-2 lipid raft column is 110min～230min.Sodium cholate and glycyrrhizic acid are obviously retained on the lipid raft chromatography,which may have an adsorption effect with the lipid raft target.Taking emodin as the model drug,the adsorption behavior of emodin after solubilization with sodium cholate and the total protein content of the extracted Caco-2 cell lipid raft was adjusted to construct the Caco-2 cell lipid raft chromatography.The chromatographic behavior of the solution-enhancing excipients was investigated online,and the influence of the selected excipients on its adsorption was further investigated with emodin as the model drug.Compared with the blank silica gel column,the retention time of sodium cholate on the Caco-2 lipid raft column is 7 min～12.5 min,and the retention time of glycyrrhizic acid on the Caco-2 lipid raft column is 110min～230min.Sodium cholate and glycyrrhizic acid are obviously retained on the lipid raft chromatography,which may have an adsorption effect with the lipid raft target.Taking emodin as the model drug,the adsorption behavior of emodin after solubilization with sodium cholate and glycyrrhizic acid was investi glycyrrhizic acidted.The detection signal of emodin was enhanced,and the solubilization was indeed realized.The retention time on the Caco-2 lipid raft was 5-20 min and 30-200 min,respectively,which was significantly different from that on the blank column.It was speculated that emodin acted on the target of the lipid raft of Caco-2 cells after solubilization.was investited.The detection signal of emodin was enhanced,and the solubilization was indeed realized.The retention time on the Caco-2 lipid raft was 5-20 min and 30-200 min,respectively,which was significantly different from that on the blank column.It was speculated that emodin acted on the target of the lipid raft of Caco-2 cells after solubilization.Chapter Ⅲ Study on solubilization of emodin by sodium cholate and glycyrrhizic acidThe physical properties of the selected solubilization excipients(sodium cholate,glycyrrhizic acid)were investigated,including the equilibrium solubility of emodin in their media and the oil-water distribution coefficient,and the solubilization curve of emodin was drawn.Balanced solubility studies have proved that emodin is almost insoluble in water and easily soluble in alkaline environments;both sodium cholate and glycyrrhizin can increase the solubility of emodin,and the solubilization effect of glycyrrhizic acid is better than that of sodium cholate at a concentration of 0.05%;The oil-water partition coefficient of emodin logP=1.58.Due to the introduction of solubilizer,the logP value of emodin has been reduced.It is proved that both 0.05%sodium cholate and 0.05%glycyrrhizic acid can improve the hydrophilicity of emodin,and glycyrrhizic acid solubilization is better.The results show that solubilization ability of glycyrrhizic acid to emodin was similar to that of sodium cholate.Therefore,glycyrrhizic acid was selected for subsequent experiments based on the physical solubilization performance and compatibility feasibility of traditional Chinese medicine.Chapter Ⅳ Study on the surface activity of glycyrrhizic acidThe solubilization mechanism of glycyrrhizin was further studied.The critical micelle concentrations of glycyrrhizin monomer(99%glycyrrhizic acid)and glycyrrhizin mixture(75%glycyrrhizic acid)were determined by fluorescence spectrophotometry and surface tension method,respectively.The critical micelle concentration of 99%glycyrrhizic acid solution is about 0.1mg·mL-1,and the critical micelle concentration of 75%glycyrrhizic acid solution is about 0.07 mg·mL-1.The CMC of 75%glycyrrhizic acid solution was significantly lower than that of 99%glycyrrhizic acid solution,and 75%glycyrrhizic acid was more likely to form micelles.Chapter Ⅴ Construction and optimization of the determination method of free anthraquinone in rhubarb and licoriceThe liquid phase method was established and the methodology was investigated to determine the content of free anthraquinone in rhubarb,and to investiglycyrrhizic acidte the influence of different crude drug ratio and crude drug form on the dissolution amount of free anthraquinone in rhubarb.The results of the liquid phase methodological investiglycyrrhizic acidtions all met the relevant indicators.The constructed HPLC method is suitable for the free anthraquinone content in the rhubarb-glycerin pair.According to the experimental results,the total free anthraquinone content in the rhubarb-co-decoction is significantly higher than that in the rhubarb single decoction,indicating that the addition of licorice increases the total free anthraquinone in the rhubarb,and the dissolution of five free anthraquinones in rhubarb-licorice 4:4 compatibility is higher.In addition,the dissolution of free anthraquinones from rhubarb after crushed crude drug was significantly increased,indicating that the form of crude drug has a greater impact on the dissolution of active ingredients.The amount of five free anthraquinones was higher when the mixture of rhubarb-liquorice powder was 4:4.Chapter Ⅵ The construction and evaluation of emodin micelle with glycyrrhizic acid as carrierThe emodin-glycyrrhizic acid micelles were prepared by thin film dispersion method.Morphological characterization and particle size evaluation were carried out.Choose emodin/glycyrrhizic acid(m/m,1/2)as the optimal formulation to prepare emodin micelles,the particle size of the prepared micelles was(168.64±5.69)nm,and the polydispersion(PDI)was 0.17±0.01,Zeta potential was-(35.33±0.94)mV,the encapsulation efficiency was about 23.68%,and the drug loading was about 9.92%;Transmission electron microscopy showed that the micelles formed by emodinglycyrrhizic acid were nearly round nano-scale particles.The prepared nanoscale micelles had a negative charge on the surface,good particle size uniformity and high physical stability.Chapter Ⅶ Study on absorption effect of rhubarb and licorice based on Caco-2 cell modelThe adsorption properties of rhubarb extract and drug-carrying micelles on Caco2 cell lipid raft chromatography were investigated.Caco-2 cell model was established to evaluate the absorption of emodin.Rhubarb extract and drug-carrying micelle were significantly retained on the Caco-2 cell lipid raft chromatography,suggesting that the active ingredients in rhubarb were specifically adsorbed to the target on the Caco-2 cell lipid raft.The emodin of the four systems was mainly transported passively in Caco-2 cell model.The difference of the apparent permeability coefficient indicated that the emodin was the most easily absorbed in the single decoction of rhubarb,the permeability coefficient was greater than 10-5,and the absorption of emodin monomer,emodin micellae and rhubarb codecoction was moderate.The ratio of emodin in micelle and co-decoction increased,which indicated that glycyrrhizic acid in licorice had solubilization effect and promoted drug effusion in absorption,thus inhibiting drug absorption.This may be one of the mechanisms to explain the contradictory phenomenon of liquorice increasing and dissolving toxin. |
PDF Full Text Request