LUNG DEPOSITION OF FENOTEROL AND FLUNISOLIDE DELIVERED USING A NOVEL DEVICE FOR INHALED MEDICINES - COMPARISON OF RESPIMAT WITH CONVENTIONAL METERED-DOSE INHALERS WITH AND WITHOUT SPACER DEVICES

Study objectives: To compare lung deposition of fenoterol or flunisoli de administered from a novel, multidose inhalation device delivering l iquid droplets (RESPIMAT; Boehringer Ingelheim Ltd; Bracknell, UK) or from conventional metered-dose inhalers (MDIs) with and without spacer s. Design: Two randomized, three-way crossover studies. Setting: Clini cal research laboratory. Participants: Healthy, nonsmoking volunteers. Interventions: Ln one study, radiolabeled aerosols of fenoterol from the RESPIMAT device and from a conventional MDI with or without an Aer ochamber spacer (Trudell Medical; London, Ontario Canada). In the seco nd study, radiolabeled aerosols of flunisolide from a RESPIMAT device, from a RESPIMAT device modified by inclusion of a baffle/impactor in the mouthpiece, and from a conventional MDI with an Inhacort spacer (B oehringer Ingelheim; Ingelheim, Germany). Measurements and results: As sessment of the deposition of fenoterol or flunisolide in the lung and oropharynx using gamma scintigraphy. Safety was assessed based on rep orted adverse effects and spirometry (FEV1, FVC, and peak expiratory n ow rate) to detect any paradoxical bronchoconstriction. The RESPIMAT d evice delivered significantly more fenoterol to the lungs than either an MDI alone or an MDI with Aerochamber (39.2% vs 11.0% and 9.9% of me tered dose, respectively; p<0.01). Oropharyngeal deposition of fenoter ol from the new device was lower than that from the MDI (37.1% vs 71.7 %, respectively; p<0.01). The RESPIMAT device deposited significantly more flunisolide in the lungs compared with MDI plus spacer (44.6% vs 26.4%, respectively; p<0.01), while resulting in similar oropharyngeal deposition (26.2% vs 31.2%, respectively). Introduction of a baffle i nto the RESPIMAT system reduced lung deposition of flunisolide to 29.5 %, and oropharyngeal deposition to 7.8% (p<0.01). Conclusion: The RESP IMAT device may prove to be an effective alternative to MDIs for the a dministration of inhaled bronchodilators and corticosteroids. The high lung deposition and low oropharyngeal deposition may lead to improved efficacy and tolerability of inhaled medications, especially corticos teroids.