Abstract

This study investigated droplet shrinkage and crystallization behaviors of easily crystalline mannitol model material. Different sized droplets were generated from feeds of different solid contents and dried into uniform microparticles via a microfluidic jet spray dryer. The droplet shrinkage behavior was characterized by comparing the size of dried microparticles and initially atomized droplets. Morphology and polymorphs of the microparticles were analyzed via SEM and XRD. Droplet shrinkage and crystallization behaviors were shown to be closing related to size, morphology, and polymorph of the spray dried microparticles. Droplets with small size or low solid content followed perfect shrinkage behavior, while droplets with larger sizes or higher solid contents demonstrated less shrinkage due to the earlier precipitation of a crust. Dense, partially hollow, or hollow spherical particles with different polymorphs (mixture of α- and β-mannitol or fully β-mannitol) were obtained depending on the process parameters, indicating the occurrence of different crystallization behaviors.

摘要

本研究调查了易结晶甘露醇模型材料的液滴收缩和结晶行为。不同尺寸的液滴由不同固体含量的进料产生，并通过微流体喷射喷雾干燥器干燥成均匀的微粒。通过比较干燥的微粒和最初雾化的液滴的尺寸来表征液滴收缩行为。通过SEM和XRD分析微粒的形态和多晶型物。液滴收缩和结晶行为被证明与喷雾干燥微粒的尺寸、形态和多晶型密切相关。小尺寸或低固体含量的液滴遵循完美的收缩行为，而尺寸较大或固体含量较高的液滴由于结壳较早沉淀而表现出较小的收缩。稠密，