THE AER(X)(TM) AEROSOL DELIVERY SYSTEM

Purpose. We describe the AER(X)(TM) aerosol delivery system, a new, bo lus inhalation device that is actuated at preprogrammed values of insp iratory flow rate and inhaled volume. We report on its in vitro charac terization using a particular set of conditions used in pharmacokineti c and scintigraphic studies. Methods. Multiple doses of aerosol were d elivered from single use collapsible plastic containers containing liq uid formulation. The aerosol was generated by forcing the formulation under pressure through an array of 2.5 micron holes. Air was drawn thr ough the device at 70 LPM, and the aerosol was collected onto a filter or Andersen cascade impactor. The emitted dose was quantified from th e filter collection data, and the particle size distribution was obtai ned from the best fit log-normal distribution to the impactor data. Re sults. 57.0 +/- 5.9% of the dose of drug placed as an aqueous solution in the 45 mu L collapsible container was delivered as an aerosol (n = 40). The best fit size distribution had an MMAD = (2.95 +/- 0.06) mu m and a geometric standard deviation sigma(g) = 1.24 +/- 0.01 (n = 6). Conclusions. The AER(X) aerosol delivery system generates a nearly mo nodisperse aerosol with the properties required for efficient and repe atable drug delivery to the lung.