GB2375308A — Inhalers

USPTO Abstract

An inhaler for producing an inhalable aerosol of a powdered medicament includes an aerosolising device in the form of a cylindrical vortex chamber 1. The vortex chamber 1 has a tangential inlet port 3 and an axial exit port 2. The ratio of the diameter of the vortex chamber 1 to the diameter of the exit port 2 is between 4 and 12. The length of the exit port 2 is less than its diameter. The cross-section of the inlet port 3 may be rectangular and is defined at the bottom and at the radially outermost edge by the walls of the vortex chamber 1. The cross-sectional area of the inlet conduit 7, which supplies the medicament in a gas flow to the inlet port 3, decreases in the direction towards the vortex chamber 1 (Fig 4; not shown). The inlet conduit 7 can be curved (Fig 13; not shown). The inhaler is capable of repeatably producing an aerosol of a medicament with a high proportion of particles in the range 1 to 3 microns, while using a relatively small amount of energy.