Am. J. Respir. Crit. Care Med.,
Volume 157, Number 2, February 1998, 518-521
Automatic Actuation of a Dry Powder Inhaler into a
Nonelectrostatic Spacer
HANS
BISGAARD
Pulmonary Service, Department of Pediatrics, Rigshospitalet, National University Hospital, Copenhagen, Denmark
This article describes a new "automatic spacer" device, which has been developed to improve the delivery of inhaled medication to young children. In the device, a dry powder inhaler (DPI) is mechanically
actuated into a nonelectrostatic spacer, producing an aerosol cloud of fine drug particles (aerodynamic diameter, < 4.7 µm) with a long half-life. The new device combines the principal advantages
of the conventional spacer and the DPI. It has the potential to provide a high ratio between lung
dose and pharyngeal dose, without need for coordination or forced inhalation, and it avoids exposure of the patient to the additives and propellants used in pressurized metered dose inhalers. Studies with the protototype device show a high yield of fine drug particles in the aerosol (mass median
aerodynamic diameter, 2.8 µm), a high repeatability of drug delivery owing to the mechanical nature
of the actuation (relative standard deviation, 12%), and a prolonged residence time of the fine particle
aerosol (half-life of the fallout of the fine particles, 82 s). These features should prove advantageous in the treatment of young children with inhaled medication.
