This work describes a new dry powder for inhalation containing zanamivir, which is less hygroscopic than Relenza®. The powders were prepared via a spray-drying technique using mannitol as the carrier. A 53 central composite design was used to optimize the formulations. The final optimized powders, characterized with an angle of repose 37.48°, an aerodynamic diameter of 2.346 μm and in vitro deposition of 58.54%, were obtained by using the predicted variable values. Relenza® absorbed a significant amount of water at 66%, 75% and 85% relative humidity (RH; weight changes of approximately 1.38%, 2.18% and 3.72%, respectively).

 

(후략)