The effect of delay, multiple actuations and spacer static charge on the in vitro delivery of budesonide from the Nebuhaler.

A multistage liquid impinger was used to determine the amount of budesonide available from the Nebuhaler spacer device following alteration of spacer static charge, delay in sampling from the spacer, and multiple actuations of the metered dose inhaler into the spacer prior to sampling. The mean amount of budesonide (s.d.) recovered per 200 micrograms actuation in particles smaller than 5 microns increased from 30.5 micrograms (8.8) to 69.3 micrograms (17.9) with a low static spacer. A 20 s delay between actuation and inhalation reduced the amount recovered to 10.9 micrograms (3.2), but no reduction was seen when using a low static spacer after the same delay. Multiple actuations into the spacer before sampling also reduced the recovery to 24.8 micrograms (3.4) after two actuations, and 13.5 micrograms (7.6) after five actuations. When using a Nebuhaler with budesonide metered dose inhalers, more respirable drug will be obtained if the aerosol is inhaled immediately after actuation, and multiple actuations into the spacer device are avoided. Low static spacers may also improve drug delivery. Attention to the details of spacer use may reduce the incidence of therapeutic failure and the cost of inhaled medications.