The Comparison between Pilot-Grade Spray Dryer and Laboratory-Grade Spray Dryer: Structure, Powder Properties and Application for Direct Compaction.

This study investigates the improvements in direct compaction powder properties achieved through particle design using laboratory and pilot-scale spray dryers. Hydroxypropyl methylcellulose and polyvinylpyrrolidone were used as modifying agent, which have low hygroscopicity and surface tension, good flowability, and excellent compactibility. Ammonium bicarbonate and sodium bicarbonate were used as pore-forming agents, and the composite particles were prepared using laboratory and pilot-scale spray dryers. The results showed that the structure of the composite particles and porous particles can effectively improve the flowability, tabletability, and disintegration behaviour; the composite particles prepared by laboratory-scale spray drying have better tabletability; the composite particles prepared by spray drying at pilot-scale had better flowability. In summary, there are significant differences in the properties of products prepared by different scales of spray drying. It will be beneficial to choose the appropriate equipment and the appropriate experimental design. Consequently, this study may contribute to the development of natural plant tablets.