title: Effect of formulation parameters on hydrofluoroalkane-beclomethasone dipropionate drug deposition in humans.
abstract: Chlorofluorocarbon metered dose inhalers (MDIs) and dry powder inhalers currently deliver drug that deposits primarily in the oropharynx and secondarily in the large central airways. Chlorofluorocarbon-beclomethasone dipropionate (CFC-BDP) MDIs deliver more than 90% of the drug in the oropharynx and less than 10% in the lungs. The elimination of chlorofluorocarbons from MDIs provided the opportunity to more optimally target corticosteroids directly to all inflammatory sites. Hydrofluoroalkane-BDP (HFA-BDP) MDIs (QVAR(trade mark)) deliver 50% to 60% of the drug to the lungs with approximately 30% delivered to the mouth. Additionally, the amount of drug delivered to the lungs is distributed throughout the large, intermediate, and small airways. Radiolabeled deposition studies have shown that the HFA-BDP MDI is a "forgiving" aerosol in that even the extreme discoordinated use of the press and breathe MDI still resulted in more than 30% lung deposition. The breath-actuated Autohaler inhaler provided the same lung deposition as an optimally used press and breathe MDI. The dose delivered from either the press and breathe HFA-BDP MDI or the Autohaler was consistent across a wide range of inspiratory flows (eg, flows of 26-137 L/min). Clinical studies have shown that the improvements in lung deposition of HFA-BDP result in equivalent efficacy at approximately one half of the total daily dose compared with current CFC-BDP products.
authors.affiliation: 3M Pharmaceuticals, St. Paul, MN 55144, USA.
authors.forename: C
authors.initials: C
authors.lastname: Leach
mesh_terms: D001507:Beclomethasone / Q000378:metabolism*; D002626:Chemistry, Pharmaceutical; D006801:Humans; D006845:Hydrocarbons, Fluorinated / Q000378:metabolism*; D009330:Nebulizers and Vaporizers / Q000592:standards; D010316:Particle Size; D010353:Patient Education as Topic; D005466:Fluorocarbons
chemical_list: D001507:Beclomethasone; D006845:Hydrocarbons, Fluorinated; C094049:apaflurane; D005466:Fluorocarbons