In Vitro and In Vivo Testing of Medspray Inhaler Technolog

Jeroen Wissink

Medspray B.V.
Hogekamp - SP 18, Veldmaat 10, 7522 NM Enschede, The Netherlands              
Tel +31 53 489 4372  Email: wissink@medspray.nl

Biography

Mats Persson, Managing Director for SHL Medical Jeroen M. Wissink (born 26 November 1971 in Denekamp, The Netherlands) is managing director and co-founder of Medspray in the Netherlands. He has a technical background and developed micromachined fluidic devices for Life Sciences at former microtechnology group at 3T BV and the MESA+ Research Institute at the University of Twente, and specialized in aerosol drug delivery devices. He is a member of the MAD (‘Dutch Medical Aerosol Thinktank).

Company Profile

Medspray develops, produces and supplies spray nozzles using micro & nano technology. Medspray creates small nozzle holes (1 to 4 µm) in a silicon base plate. Pressing a fluid through these plain orifice nozzles results in the Rayleigh break-up of jets, resulting in very uniform droplets. The droplets are basically twice the size of the orifices. The nozzle surface is so thin that viscous energy losses are minimized. This leads to a low operating pressure.

Medspray’s nozzle technology enables the creation of disposable inhaler devices, producing well defined drug droplets. Targeting the medication to a specific zone in the lungs is possible due to the mono-dispersity, the narrow size distribution, of the droplets. Medspray develops, produces and supplies the spray nozzles. Our partners develop the dosing system and the plastic devices.

Abstract

Medspray® inhalers for pulmonary drug delivery based on the principle of Rayleigh break-up have been tested in vitro and in vivo with three different spray nozzles (1.5; 2.0 and 2.5 μm) using aqueous 0.1% (w/w) salbutamol and 0.9% (w/w) sodium chloride solutions.

In the past Particle size distributions in the aerosol were measured with the principles of time of flight (APS) and laser diffraction (LDA), giving a detailed insight in droplet coalescence behaviour of the used mouthpiece/nozzle systems. Now these measurements have been complemented with NGI measurements operated at humidities higher than 90%, the procedure will be reported.

The inhalers exhibit 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® 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 μm nozzles (TD: 2.84; 3.78 and 4.73 μm respectively).

The narrow particle size distribution in the aerosol from the Medspray® 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 μm at 60 l.min−1. An overview of devices in development programs will demonstrate the potential and the limitations.