Effect of formulation parameters on hydrofluoroalkane-beclomethasone dipropionate drug deposition in humans

• Published in: Journal of allergy and clinical immunology 1999-12, Vol.104 (6), p.s250-s252
• Main Author: Leach, Chet
• Format: Article
• Language: English
• Subjects: Beclomethasone; Beclomethasone - metabolism; Chemistry, Pharmaceutical; Humans; Hydrocarbons, Fluorinated - metabolism; lung deposition; Nebulizers and Vaporizers - standards; Particle Size; Patient Education as Topic
• ISSN: 0091-6749; 1097-6825
• DOI: 10.1016/S0091-6749(99)70041-2

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 ™) 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. (J Allergy Clin Immunol 1999;104:S250-2.)