[Distribution of surface components in spray-dried powder of binary system of berberine hydrochloride and dextran based on hydrodynamic size].

The present study explored the correlation between the hydrodynamic size(i.e., hydrated particle size) and the surface component distribution of spray-dried powder based on the binary system model of berberine hydrochloride and dextran. A variety of mixture solutions containing substances of different proportions were prepared, and the hydrated particle sizes of the solutions were measured by laser light scattering technique. Then the effects of molecular weight and mixing proportion on the particle size were analyzed. After the solutions were spray-dried, the surface components of spray-dried powder were determined by X-ray photoelectron spectroscopy. The changes of hydrated particle size of the two substances in different solutions were measured with the altered solution environments, and the distribution of surface components after spray-drying was observed. The results of particle size measurement showed that different solution environments would change the hydrodynamic size of substances. Specifically, the particle size of berberine hydrochloride increased with the increase in ionic strength and solution pH, while the particle size of dextran decreased with the increase in ionic strength and increased with the increase in solution pH. The results of surface components of the spray-dried powder indicated that berberine hydrochloride was prone to accumulate on the surface of particles during spray-drying because of its large hydrodynamic size. Therefore, hydrodynamic size is considered an important factor affecting the surface component distribution of spray-dried powder. As revealed by scanning electron microscopy of the particle morphology of spray-dried powder, the particles of berberine hydrochloride spray-dried powder were irregularly elliptic, and the particles of dextran and mixture spray-dried powders were irregularly spherical with the shrunken surface. Finally, the FT4 powder rheometer and DVS instrument were used to determine the stability, adhesion, and hygroscopicity of the powder. The results showed that when berberine hydrochloride was enriched on the surface, the adhesion of the mixture increased and the fluidity became worse, but the hygroscopicity was improved to a certain extent. In addition, as found by hygroscopic kinetic curve fitting of spray-dried powder, the hygroscopic behaviors of all spray-dried powder conformed to the double exponential function.

[Effect of N-acetyl-L-cysteine on bioavailability and brain distribution of curcumin by nasal delivery].

Curcumin( Cur) is a natural active substance extracted from the roots or tubers of traditional Chinese medicinal materials. It has anti-inflammatory and anti-tumor activities on brain diseases. Due to the poor stability,low solubility,poor absorption and low bioavailability of curcumin,N-acetyl-L-cysteine( NAC) was used as an absorption enhancer and mixed with curcumin to improve the absorption of curcumin in the body. In this paper,curcumin was smashed by airflow pulverization,and Cur-NAC mixtures were prepared by being grinded with liquid. Then,the raw material and the product were analyzed by differential scanning calorimetry( DSC),X-ray diffraction( XRD) for structural characterization. The dissolution was determined by high performance liquid chromatography( HPLC) analysis. The characteristic peaks of the samples prepared by grinding method were similar to those of the raw materials,while the melting temperature and the accumulated dissolution degree were not significantly changed. The crystal forms of the products were not changed,and no new crystal form was formed after grinding. After the administration of intranasal powder,blood samples were collected from the orbit,while the whole brain tissues were removed from the skull and dissected into 10 anatomical regions. The concentrations of curcumin in these samples were determined by UPLC-MS/MS. The concentrations of curcumin in plasma and brain were compared at different time points. After intranasal administration of two drugs,it was found that the concentration of curcumin after sniffing up the mixtures in plasma was high,and the concentration of the drug in the olfactory bulb,hippocampus,and pons was increased significantly. Within 0. 083-0. 5 h,the olfactory bulb,piriform lobe and hippocampus remained high concentrations,the endodermis,striatum,hypothalamus and midbrain reached high concentrations within 1-3 h; and the cerebellum,pons and brain extension maintained relatively high concentrations within 3-7 h. The experiment showed that nasal administration of Cur-NAC mixtures can significantly improve the bioavailability of curcumin,and lead to significant differences in brain tissue distribution.