[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.

[Opportunities and challenges in development of compound preparations of traditional Chinese medicine: problems and countermeasures in research of ancient classical prescriptions].

As an outstanding representative of traditional Chinese medicine( TCM),ancient classical prescriptions carry the profound accumulation of the splendid civilization of Chinese medicine for thousands of years. It is the best part of the great treasure-house of Chinese medicine after thousands of years' training of TCM theory. It condenses the wisdom of all generations of doctors,and as the summary of clinical experience,it is the most brilliant pearl in the treasure house of TCM. The in-depth research and development of ancient classic prescriptions is a golden key to excavate the treasure house of TCM,which not only conforms to the development trend of TCM industry,but also brings unprecedented opportunities and challenges for the inheritance and innovation of contemporary Chinese herbal compound preparations. However,as a " new member" in the national drug research and development system,classic prescriptions have no specific implementation rules although the guidance is given by macro policies,and there is no successful case of research and development according to the registration requirements. Therefore,unified consensus and standards have not yet been formed for some key issues in the process of the development of the classic prescriptions,and much work is still in the exploration stage,so it is necessary to conduct in-depth research and discussion on these issues. In this paper,the problems in the research process of classical prescriptions were summarized,such as the resources of medicinal materials,the processing of decoction pieces,the prescription dosage,the molding technology and the quality evaluation,and the research strategy was put forward after analysis,hoping to provide a reference for the research and development of classical prescriptions.