The radially innermost end of the particle inlet passage 10 opens into the particle entrainment chamber 8 and the radially outer end of the passage 10 is arranged to communicate with a particle source 11 containing a payload of particles. When the cassette is engaged in a recess provided in the exterior side wall of the main body 1, for example to form an interference fit therewith, a hole in the cassette provided at the base of the reservoir 12 lines up in communication with the particle inlet passage 10.

A safety test by Kelly and colleagues (2008) [6] found a PCNFI device failed to prevent contamination. the second convergence or constriction 43 is provided by the upstream end of the upstream parallel-sided section 32 of the bore of the nozzle 31 .the middle image shows the distribution of particles across a diametral slice of the target and the left hand image shows an enlarged view of particle penetration at the center of the slice, from which a maximum penetration of 250 ⁇ m can be measured. Original Assignee Powder Pharmaceuticals Inc Priority date (The priority date is an assumption and is not a legal conclusion. By avoiding the formation of a substantial concentration of the particles within the core of the target area with no or few particles around the boundary of the target area, increased payloads of particles may be delivered without the central core of the target area becoming overloaded with particles. Such filters have an upper limit to gas velocity through the filter so as to ensure that they operate to the specification. suitable surfactants include, for example, Tergitol® and Triton® surfactants (Union Carbide Chemicals and Plastics, Danbury, Conn.

shows one possible way of sealing a metered quantity of powder in a sealed container until it is ready for use. the silencer consists of a first passage 80 which the gas upon which rebounding from the target plane passes along. the above embodiments all utilize a first convergence 5 , 5 ′ to create a reduced pressure region which can be used to draw the particles into the gas flow path. particles can be delivered at a large range of velocities with potentially non-uniform spatial distribution across the target surface. The instrument was completely successful in providing anesthesia in thirty-six of the forty-five procedures.

is a top plan view of the target area of the gel target, a side cross-sectional view through the gel target and a graph showing the penetration depth variation with position after the firing at the gel target of particles from the needleless syringe shown in FIG. the chamber of increased cross-section is thought to provide a discontinuity to the gas flow which leads to the creation within the chamber of a transsonic jet, which jet passes through the chamber and attaches to the walls of the nozzle bore 3 in the region of the second convergence 9 . Preventing contamination between injections with multi-use nozzle needle-free injectors: a safety trial".