[Properties of small nebulizers and their suitability for aerosol therapy]

The current methods of measurement for particle size spectra do not seem to be applicable for small Hand-Held Nebulizers without impairing the relations of the amounts of fine and coarse particles. Therefore a simple method was developed that before-hand allowed a rough determination of these amounts. Measurements on four Hand-Held Nebulizers, three of them of the rubber ball nozzle-type and one ultrasonic, revealed that 90-95% of the medicament was unable to pass a 15 cm long rippled aerosol hose of 25 mm diameter. Therefore most of the drug is transformed into coarse particles and the application of Hand-Held Nebulizers is justified only for the therapy of the upper airways and for diseases where a resorption of the medicament in the main bronchi will suffice.