Performance of a Corticosteroid Inhaler with a Spacer Fashioned from a Plastic Cold-Drink Bottle: Effects of Changing Bottle Volume

Abstract

Some clinicians advocate using metered-dose inhaler (MDI) spacers prepared from common household bottles. We evaluated the in vitro aerosol characteristics of fluticasone from the MDI alone and through spacers fashioned from 237-, 500-, 1000-, and 1500-mL polyethylene terephlate plastic cold drink bottles using a cascade impactor. Ten 110-microg actuations of fluticasone were sampled into the impactor during each of five runs with each configuration. The primary outcomes were the respirable dose (i.e., quantity aerosol 1.1-4.7 microm in size) and the quantity trapped in the oropharynx. The mean fluticasone respirable dose from the MDI alone (46.2 microg/actuation) was no different (p > 0.05) compared with the same MDI mated to any of the bottle spacers, regardless of volume. The mean quantity of fluticasone trapped in the oropharynx from the MDI alone (39.2 microg/actuation) was greater (p < 0.001) than the same MDI mated with any bottle spacer (range 1.5-3.5 microg/actuation). These data suggest that any of the bottle spacers tested would be an acceptable method to decrease the quantity of fluticasone that would deposit onto the oropharynx and thereby diminish the risk of topical adverse effects. Among the range of volumes tested, there was no relationship between spacer volume and respirable dose of fluticasone.