[Adsorption characteristics of proteins on membrane surface and effect of protein solution environment on permeation behavior of berberine].

In order to explore the adsorption characteristics of proteins on the membrane surface and the effect of protein solution environment on the permeation behavior of berberine, berberine and proteins were used as the research object to prepare simulated solution. Low field NMR, static adsorption experiment and membrane separation experiment were used to study the interaction between the proteins and ceramic membrane or between the proteins and berberine. The static adsorption capacity of proteins, membrane relative flux, rejection rate of proteins, transmittance rate of berberine and the adsorption rate of proteins and berberine were used as the evaluation index. Meanwhile, the membrane resistance distribution, the particle size distribution and the scanning electron microscope (SEM) were determined to investigate the adsorption characteristics of proteins on ceramic membrane and the effect on membrane separation process of berberine. The results showed that the ceramic membrane could adsorb the proteins and the adsorption model was consistent with Langmuir adsorption model. In simulating the membrane separation process, proteins were the main factor to cause membrane fouling. However, when the concentration of proteins was 1 g•L⁻¹, the proteins had no significant effect on membrane separation process of berberine.

[Pharmacokinetics of α-asarone after intranasal and intravenous administration with PLA-α-asarone nanoparticles].

PLA-α-asarone nanoparticles were prepared by using organic solvent evaporation method, and their in vivo distribution and brain targeting after intranasal administration were studied as compared with intravenous administration. The results showed that brain targeting coefficient of PLA-α-asarone nanoparticles after intranasal and intravenous administration was 1.65 and 1.16 respectively. The absolute bioavailability, brain-targeting efficiency and the percentage of nasal-brain delivery of PLA-α-asarone nanoparticles were 74.2%, 142.24 and 29.83%, respectively after intranasal administration. The results of fluorescence labeling showed that the fluorescent intensity of coumarin-6 in the brain tissue was the highest after intranasal administration of PLA-α-asarone fluorescent nanoparticles, achieving the purpose of brain-targeted drug delivery. The fluorescent intensity of coumarin-6 in liver tissue after intravenous administration of PLA-α-asarone nanoparticles was much higher than that after intranasal administration, indicating that intranasal administration of PLA-α-asarone nanoparticles could decrease drug-induced hepatotoxicity. In addition, the fluorescent intensity of coumarin-6 in lung tissue was weaker after intranasal administration, which solved the shortcomings of intranasal administration of α-asarone dry powder prepared by airflow pulverization method. In vivo studies indicated that PLA-α-asarone nanoparticles after intranasal administration had a stronger brain targeting as compared with intravenous administration.

[Studies on preparation by SPG membrane emulsification method and in vitro characterization of tetradrine-tashionone II(A)-PLGA composite microspheres].

Tetradrine-tashionone II(A)-PLGA composite microspheres were prepared by the SPG membrane emulsification method, and the characterization of tetradrine-tashionone II(A) -PLGA composite microspheres were studied in this experiment. The results of IR, DSC and XRD showed that teradrine and tashionone II(A) in composite microspheres were highly dispersed in the PLGA with amorphous form. The results of tetradrine-tashionone II(A) -PLGA composite microspheres in vitro release experiment showed that the cumulative release amounts of tetradrine and tashionone II(A) were 6.44% and 3.60% in 24 h, and the cumulative release amounts of tetradrine and tashionone II(A) were 89.02% and 21.24% in 17 d. The process of drug in vitro release accorded with the model of Riger-Peppas. Tetradrine-tashionone II(A) -PLGA composite microspheres had slow-release effect, and it could significantly reduce the burst release, prolong the therapeutic time, decrease the dosage of drugs and provide a new idea and method to prepare traditional Chinese medicine compound.

[Study of pretreatment on microfiltration of huanglian jiedu decoction with ceramic membranes based on solution environment regulation theory].

To optimize the pretreatment of Huanglian Jiedu decoction before ceramic membranes and verify the effect of different pretreatments in multiple model system existed in Chinese herb aqueous extract. The solution environment of Huanglian Jiedu decoction was adjusted by different pretreatments. The flux of microfiltration, transmittance of the ingredients and removal rate of common polymers were as indicators to study the effect of different solution environment It was found that flocculation had higher stable permeate flux, followed by vacuuming filtration and adjusting pH to 9. The removal rate of common polymers was comparatively high. The removal rate of protein was slightly lower than the simulated solution. The transmittance of index components were higher when adjust pH and flocculation. Membrane blocking resistance was the major factor in membrane fouling. Based on the above indicators, the effect of flocculation was comparatively significant, followed by adjusting pH to 9.

[Studies on baicalin ethylcellulose microspheres for intranasal administration].

In this study, solvent evaporation method was used to preparing baicalin ethylcellulose microspheres for intranasal administration. The prepared microspheres were round with certain rough surface. The average drug loading and entrapment efficiency was (33. 31 ± 0. 045)% , (63. 34 ± 0. 11)% , respectively. As the characteristic crystalline peaks of baicalin were observed in the microspheres sample, the result of X-ray diffractometric analysis indicated that the baicalin was present in crystalline form after its entrapment in ethylcellulose matrix. By investigating the thermogram of microspheres sample, it was found that endothermic peak of baicalin was shifted from 211. 8 °C to 244. 2 °C and associated with the first broad endothermic peak of ethylcellulose. This could confirm that baicalin was loaded into ethylcellulose, nor simply physical mixture. The powder flowability test exhibited that the specific energy of microspheres was 3. 57 mJ . g-1 and the pressure drop was 2. 22 mBar when air kept the speed of 2 mm . s-1 through the powder bed with the force was 15 kPa. The consequence of the baicalin in vitro released from microspheres showed that the pure baicalin sample displayed faster (90%) release than microspheres sample (75%) in 7 h. Fitting model for release curve before 7 h, the results showed that the pure baicalin sample and the microsphere sample accorded with first order model (R2 = 0. 990 4) and Riger-Peppas model(R2 = 0. 961 2), respectively. Ex vivo rabbit nasal mucosa permeability experiment revealed that the value of cumulative release rate per unit area of the microsphere sample was 1. 56 times that of the pure baicalin sample. This provided the foundation for the in vivo pharmacokinetic study.