A dry powder inhalation system suitable for transpulmonary administration.
The dry powder inhalation system is characterized by using a combination
of: (1) a vessel housing a freeze-dried composition prepared by
freeze-drying a composition liquid containing ingredients in a
non-dissolved form, and has: (i) a non-powder cake-like form, (ii) a
disintegration index of 0.05 or more, and (iii) a property of becoming
fine particles having a mean particle diameter (mass median aerodynamic
diameter) of 10 microns or less or a fine particle fraction of 10% or
more upon receipt of an air impact having an air speed of at least 1
m/sec and an air flow rate of at least 17 ml/sec; and (2) a device
comprising a member capable of applying the air impact to the
freeze-dried composition in said vessel, and a member for discharging the
powder-form freeze-dried composition that has been made into fine
particles.