Construction And Evaluation Of Albumin Nanoparticles Loaded With Douglas Fir Phospholipid Complex

Objective:Taxifolin（TAX）has strong antioxidant activity,but its poor water solubility and poor permeability restrict the drug release and transmembrane process,which hinders drug absorption and efficacy.Based on this study,a novel drug delivery system of phospholipid-complexed albumin nanoparticles was constructed to enhance the affinity between drug and cell membrane by phospholipid complex and improve the drug absorption through membrane;albumin nanoparticles stabilized the form of phospholipid-complexed formulation and made the formulation nanosized to enhance the drug solubility.In this way,the aim of improving the water solubility,lipid solubility and in vivo absorption of TAX was achieved.Methods:In vitro analysis of TAX was established by high performance liquid chromatography（HPLC）;Taxifolin phospholipid complex（TAX-PC）was prepared by solvent volatilization method,and the prescription process was optimized by single-factor investigation combined with response surface;solubility and oil-water partition coefficient were determined to verify the physicochemical properties of TAX-PC;The formation mechanism of TAX-PC was investigated by Fourier infrared spectroscopy（FT-IR）,differential scanning calorimetry（DSC）and X-ray diffraction（XRD）;The Nab ^TMtechnology was used to prepare Douglas-fir phospholipid complex albumin nanoparticles（TAX-PC/BSA NPs）,and the preparation process was optimized by combining the one-way investigation method and Box-Behnken design（BBD）;the TAX-PC/BSA NPs were characterized by transmission electron microscopy（TEM）,particle size,DSC,FT-IR and XRD,and to verify the improvement of drug water and lipid solubility;The in vitro antioxidant activity of the formulation was investigated by DPPH radical scavenging,ABTS radical scavenging and Fe³⁺total reducing power assay;the in vitro digestive release was simulated to explore the release pattern of the formulation in human digestive environment;the intestinal absorption of TAX,TAX-PC and TAX-PC/BSA NPs was investigated by in vivo unidirectional intestinal perfusion method to lay the foundation for the study of oral formulation of TAX.Results:TAX-PC significantly improved the lipid and water solubility of the drug（oil-water partition coefficient log P=1.41>1;2.18 times higher solubility compared with TAX）;DSC,FT-IR,XRD characterization presumed that the formation mechanism of TAX-PC mainly relied on hydrogen bonding;TAX-PC was further loaded into TAX-PC/BSA NPs and optimized to obtain the best prescription and process:drug/BSA ratio 1:9.39,oil-water ratio 1:11.51,sonication time 7.76 min,the encapsulation rate（EE%）,drug loading（DL%）and leakage rate（LR%）could reach（86.14±0.38）%,（7.27±0.03）%and（0.87±0.04）%.Physicochemically,the solubility of TAX-PC/BSA NPs increased 38.48times compared to TAX,and the drug solubility was significantly enhanced.TEM observed that TAX-PC/BSA NPs were sphere-like with the mean particle size,polydispersity coefficient（PDI）and zeta potential of（184.9±0.98）nm,0.275±0.01 and（-36.6±0.53）m V,respectively.The formation of TAX-PC/BSA NPs was further verified by DSC,FT-IR and XRD;the DPPH,ABTS radical scavenging and total Fe³⁺reducing power of TAX-PC/BSA NPs were significantly higher than that of TAX（p<0.05）,and the antioxidant activity was significantly increased;In vitro simulated digestion results showed that the cumulative release rates of TAX,TAX-PC,and TAX-PC/BSA NPs were（48.26±0.71）%,（71.86±1.83）%,and（82.73±0.62）%,respectively.TAX-PC/BSA NPs reduced drug absorption in the stomach and enhanced drug release in the intestine to some extent.The results of in vivo unidirectional intestinal perfusion showed that TAX-PC and TAX-PC/BSA NPs were absorbed in all intestinal segments of duodenum,jejunum,ileum and colon,among which the improved absorption was more obvious in the jejunum and ileum,and the upper part of small intestine was presumed to be the best absorption site for TAX-PC/BSA NPs.The absorption status of TAX-PC/BSA NPs was also significantly enhanced compared to TAX-PC with significant difference（p<0.05 or p<0.01）,which was suitable for drug absorption.Conclusion:The binary drug delivery system of phospholipid complex albumin nanoparticles constructed in this study effectively improved the lipid solubility and solubility of the drug,enhanced the in vitro antioxidant activity and in vivo intestinal absorption of the drug,and provided a new option for TAX drug administration.