Preparation and physicochemical properties of ultra-fine powder of Fritillaria unibracteata / 中草药

ABSTRACT

Objective The morphological and particle size distribution of Fritillaria unibracteata under different preparation conditions and the physicochemical property before and after grinding were studied, which provides the experimental basis for the particle size control and application of ultra-fine powder. Methods The single-factor experiment was carried out. The ultra-fine powder was prepared using ball milling method under different milling time, the weight ratio of ball to material, and rotating speed conditions. The powder morphology was observed by scanning electron microscopy. The particle size and particle size distribution of the powder was determined by laser particle size analyzer. The particle size, particle size distribution, expansion degree, total alkaloid content, and other properties of F. unibracteata powder before and after milling were compared. Results The optimum conditions for powder preparation were as follows: The grinding time was 0.5 h, the weight ratio of ball to material was 12:1, the rotating speed was 250 r/min. The volume average particle size of ultrafine powder was (26.92 ± 0.12) μm, and D90 was (45.15 ± 0.18) μm. After grinding, the particle size decreased, the particle size distribution became narrower, the expansion degree and angle of repose increased, the hygroscopicity of powder did not change significantly, the bulk density decreased, and the alcohol-soluble extract content and total alkaloid content increased greatly. Conclusion Moderate grinding can significantly reduce the size of F. unibracteata powder, improve the particle size distribution, increase the total alkaloid content, and help to improve bioavailability.