2003 Volume 63 Issue 4 Pages 228-237
Novel 4-fluid nozzle spray driers have a unique nozzle which has two liquid passages and two gas passages. We spotlighted a novel atomizing principle of the 4-fluid nozzle spray drier and attempted to prepare particles for dry powder inhalation (DPI) using Sodium Salicylate (SS) as a model drug. The effect of operating condition for spraying, such as inlet temperature, drug concentration of spray solution and feed rate on the powder properties of SS particles, was studied. An vitro pulmonary inhalation study of SS particles was performed with a cascade impactor. More than 90% of the SS particles were within the diameter range of 0.5-7.0 μm, which is called the respirable fraction (RF). It was feasible to control the diameter of the SS particles within the RF range by varying the drug concentration of the spray solution. Spray-dried SS particles showed a high capsule-emitted percent and high drug delivery percent for RF as compared to jet-milled SS particles. Furthermore, smaller spray-dried SS particles showed a higher drug delivery point for RF.
