Fukumori Y, Ichikawa H, Jono K, Takeuchi Y, Fukuda T
Faculty of Pharmaceutical Sciences, Kobe-Gakuin University, Japan.
Chem Pharm Bull (Tokyo). 1992 Aug;40(8):2159-63. doi: 10.1248/cpb.40.2159.
A simplified model for computer simulation of agglomeration in the Wurster coating process was constructed using droplet size distribution and the relation between the size of agglomerates and the number of primary particles composing them experimentally determined. Computer simulations were applied to the cases where a 2.5% aqueous solution of hydroxypropyl cellulose (containing sodium carboxymethyl cellulose of 10% on a dry basis) was sprayed on four kinds of sharply fractionized lactose powders between 32 and 75 microns. With cores larger than 53 microns, the agitation exerted on particles strongly suppressed the growth of agglomerates, but the fraction of produced agglomerates reached about 50%. The smallest droplet size that was contributable to agglomeration (critical droplet size) was estimated to be 37.1-49.0 microns, increasing with core size, and the weight fraction of droplets larger than this critical size was only 0.5-2.7%, decreasing with increase in core size. The production of even such a minor amount of coarse droplets could be responsible for significant agglomeration.
利用液滴尺寸分布以及通过实验确定的团聚体尺寸与构成它们的初级粒子数量之间的关系，构建了一个用于计算机模拟Wurster包衣过程中团聚现象的简化模型。计算机模拟应用于以下情况：将2.5%的羟丙基纤维素水溶液（含有10%干基的羧甲基纤维素钠）喷洒在四种粒度范围在32至75微米之间的精细分级乳糖粉末上。对于粒径大于53微米的颗粒核，施加在颗粒上的搅拌强烈抑制了团聚体的生长，但产生的团聚体比例达到了约50%。估计对团聚有贡献的最小液滴尺寸（临界液滴尺寸）为37.1 - 49.0微米，随颗粒核尺寸增大而增大，大于此临界尺寸的液滴重量分数仅为0.5 - 2.7%，随颗粒核尺寸增大而减小。即使是如此少量的粗液滴的产生也可能导致显著的团聚。
