2000 OPEN FORUM Abstracts
METERED DOSE INHALER (MDI) DRUG DELIVERY WITH THE GENTLE-HALER®
J. L. Rau, Ph.D., RRT, Arzu Ari, M.S., CRT, CPFT, Bethanne Tinkler, M.Ed., RRT, Cardiopulmonary Care Sciences, Georgia State University, Atlanta, GA
Introduction. Previous research has shown that different reservoir devices with integral MDI adaptors do not provide consistent or equivalent emitted doses (ED).1 The Gentle-Haler® is a spacer device accepting the MDI canister of any drug. Purpose. The purpose of this study is to measure total and fine particle fraction (FPF) emitted dose using the Gentle-Haler® with a beta agonist and a corticosteroid. Methods. Three samples of the Gentle-Haler® were tested with three MDI canisters of CFC-formulated albuterol (Ventolin?) and beclomethasone dipropionate (Vanceril?). Emitted doses with the universal spacer device were compared in paired fashion to the dose from the manufacturer's mouthpiece actuator alone. Total dose and FPF were measured using an Andersen 8-stage impactor, with a metal USP throat, operated at 28.3 L/min (±0.5). After discharging 5 actuations to waste with all MDI's tested, 5 actuations were delivered for both drugs at 30 second intervals with impactor sampling, with shaking between actuations. The impactor was allowed to run for an additional 20 seconds after the last puff. Drug collected in the impactor was analyzed using a spectrophotometer at 276 nm and 239 nm for albuterol and beclomethasone respectively. Results. Total and FPF emitted doses are summarized as means (SD).
|Total, ||109.7 (8.8)||56.6 (5.5)||56.5 (2.8)||41.6 (0.19)|
|FPF, ||49.3 (5.4)||47.6 (6.1)||24.9 (3.6)||28.5 (2.4)|
|FPF, %||44.9% (1.4)||83.9% (3.2)||44.0% (5.7)||68.6% (6.1)|
Conclusion. There was no difference in emitted FPF dose for albuterol (p =1.0) or for beclomethasone (p = 0.285) using a Wilcoxon Signed Ranks test.
1. Ahrens R, Lux C, Bahl T, Han T. Choosing the metered-dose inhaler spacer or holding chamber that matches the patient's need: Evidence that the specific drug being delivered is an important consideration. J Allergy Clin Immunol 1995; 96:288-94.