悬浮剂存在的物理不稳定性至少会涉及三个方面 :(1)粒子间因存在相互作用而引起的凝聚和聚集现象 ;(2 )奥氏熟化 (Ostwaldripening) ,即粒子在制剂中出现的晶体长大现象 ;(3)因重力作用导致的分层和粒子沉积现象。前面两种现象只要分散剂和原药选择适当 ,一般可以克服 ,分层及沉积现象在实际工作中则会经常遇到。本文以氰·莠悬浮剂为材料 ,对影响其分层的因素作了探讨 The physical instability of the suspending agent involves at least three aspects: (1) agglomeration and aggregation due to interaction between the particles; (2) Ostwald ripening, ie the appearance of particles in the formulation Growing up; (3) Gradation and particle deposition due to gravity. The first two phenomena as long as the appropriate choice of dispersant and the original drug can generally be overcome, the phenomenon of stratification and deposition in the actual work will often encounter. In this paper, cyanuric sulfate suspending agent as a material, the factors that affect the stratification were discussed