FEASIBILITY OF DRUG-DELIVERY TO THE RESPIRATORY-TRACT BY A MECHANICALMICRO-SPRAY PUMP

A hand actuated, propellant free spray device is being developed which may be suitable for medical inhalation therapy. The purpose was to ev aluate the feasibility of the mechanical micro spray pump to produce a fine spray whose droplets were suitable for inhalation. The physical and technical requirements have been achieved using an air blast nozzl e which has been improved by changing the geometry and therefore the d ynamic properties within the spray nozzle. The generation of particles above 50 mum in diameter was suppressed and the injection time of the spray increased. Thease features resulted in a finer and more uniform spray. In-vivo experiments were conducted, where 15 mul per stroke of a Tc-99m labeled saline solution was delivered to test persons. The a ctivity was measured by gamma-scintigraphy. It was observed that witho ut and with a spacer, a respective thoracic deposition of 8 %vol and 1 3 %vol was achieved on average.