In vitro performance testing of the novel Medspray wet aerosol inhaler based on the principle of Rayleigh break-up

de Boer, A. H., Wissink, J., Hagedoorn, P., Heskamp, I., de Kruijf, W., Bünder, R., Zanen, P., Munnik, P., van Rijn, C. & Frijlink, H. W., 1-May-2008, In : Pharmaceutical Research. 25, 5, p. 1186-1192 7 p.

Research output: Contribution to journalArticleAcademicpeer-review

Purpose: A new inhaler (Medspray(R)) for pulmonary drug delivery based on the principle of Rayleigh break-up has been tested with three different spray nozzles (1.5; 2.0 and 2.5 mu m) using aqueous 0.1% (w/w) salbutamol and 0.9% (w/w) sodium chloride solutions.

Materials and methods: Particle size distributions in the aerosol were measured with the principles of time of flight (APS) and laser diffraction (LDA).

Results: The Medspray(R) inhaler exhibits a highly constant droplet size distribution in the aerosol during dose emission. Droplets on the basis of Rayleigh break-up theory are monodisperse, but due to some coalescence the aerosols from the Medspray(R) inhaler are slightly polydisperse. Mass median aerodynamic diameters at 60 l.min(-1) from APS are 1.42; 1.32 and 1.27 times the theoretical droplet diameters (TD's) and median laser diffraction diameters are 1.29; 1.14 and 1.05 times TD for 1.5; 2.0 and 2.5 mu m nozzles (TD: 2.84; 3.78 and 4.73 mu m respectively).

Conclusions: The narrow particle size distribution in the aerosol from the Medspray(R) is highly reproducible for the range of flow rates from 30 to 60 l.min(-1). The mass median aerodynamic droplet diameter can be well controlled within the size range from 4 to 6 mu m at 60 l.min(-1).

Original languageEnglish
Pages (from-to)1186-1192
Number of pages7
JournalPharmaceutical Research
Issue number5
Publication statusPublished - 1-May-2008


  • Aerosols, Albuterol, Lasers, Microscopy, Electron, Scanning, Nebulizers and Vaporizers, Particle Size, Sodium Chloride, Solutions

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