Effect of physical properties of carrier particles on drug emission from a dry powder inhaler device

In the present study, we investigated the effects of the physical properties of carrier lactose particles on drug emission from a novel dry powder inhaler device, Jethaler. Fine sodium salicylate (SS) particles used as the model drug particles for inhalation were prepared by a jet mill and these were mixed with carrier lactoses having different particle sizes. In vitro SS emission properties from the Jethaler were evaluated by a cascade impactor. The SS emission from the Jethaler increased when the lactoses had lower amounts of fine lactose particles. This emission was influenced by SS remaining in the capsule rather than adhering to the inside wall in the Jethaler. In the capsule, the air stream did not smoothly disintegrate mixtures that contained larger amounts of fine lactose particles after inhalation. These findings suggested that the SS emission from the Jethaler were greatly improved using the carrier lactose having lower amounts of fine particles, because this lactose caused loose agglomerative properties that resulted in almost complete emptying of the mixture remaining in the capsule.