US EPA

2577177 

Journal Article 

In vitro performance testing of the novel medspray (R) wet aerosol inhaler based on the principle of Rayleigh break-up 

de Boer, AH; Wissink, J; Hagedoorn, P; Heskamp, I; de Kruijf, W; Buender, R; Zanen, P; Munnik, P; van Rijn, C; Frijlink, HW 

2008 

1 

Pharmaceutical Research
ISSN: 0724-8741
EISSN: 1573-904X 

25 

5 

1186-1192 

English 

18066714 

10.1007/s11095-007-9503-1 

WOS:000254849700020 

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). 

aerodynamic particle sizer; laser diffraction technique; monodisperse aerosol; pulmonary drug delivery; Rayleigh break-up; wet nebulisation