{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,26]],"date-time":"2026-10-26T20:09:26Z","timestamp":1793045366661,"version":"4.5.0"},"reference-count":0,"publisher":"European Respiratory Society (ERS)","issue":"6","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Eur Respir J"],"published-print":{"date-parts":[[1998,12,1]]},"abstract":"<jats:p>Hydrofluoroalkane-134a (HFA) beclomethasone dipropionate (BDP) was formulated in a metered-dose inhaler (MDI) to deliver a particle size of 1.1 microm compared with 35 microns for currently marketed chlorofluorocarbon (CFC)-BDP products. Two phase I single-dose human deposition studies were conducted using technetium 99m-radiolabelled BDP in a press-and-breathe actuator without an add-on spacer. A healthy volunteer study (n=6) showed that 55-60% of the HFA-BDP ex-actuator dose was deposited in the lungs, with 29-30% deposited in the oropharynx. CFC-BDP deposition was 4-7% in the lungs and 90-94% in the oropharynx. The pattern of deposition within the lung showed that HFA-BDP was spread diffusely throughout the lung airways, whereas CFC-BDP was confined to the central airways with little, if any, peripheral airway deposition. A second study with asthmatics (n=16) confirmed that 56% of the HFA-BDP dose was deposited in the airways, with 33% in the oropharynx. In conclusion, hydrofluoroalkane-134a-beclomethasone dipropionate deposition was much greater in the airways than chlorofluorocarbon-beclomethasone dipropionate, with a concomitant reduction in oropharyngeal deposition. The increased lung deposition efficiency of the hydrofluoroalkane propellant has led to a reduction in the amount of beclomethasone dipropionate needed to achieve a similar efficacy. The penetration of the hydrofluoroalkane to the small airways may provide asthma treatment not afforded by conventional chlorofluorocarbons.<\/jats:p>","DOI":"10.1183\/09031936.98.12061346","type":"journal-article","created":{"date-parts":[[2002,11,1]],"date-time":"2002-11-01T23:29:18Z","timestamp":1036193358000},"page":"1346-1353","source":"Crossref","is-referenced-by-count":349,"title":["Improved airway targeting with the CFC-free HFA-beclomethasone metered-dose inhaler compared with CFC-beclomethasone"],"prefix":"10.1183","volume":"12","author":[{"given":"CL","family":"Leach","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"PJ","family":"Davidson","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"RJ","family":"Boudreau","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"81","published-online":{"date-parts":[[1998,12,1]]},"container-title":["European Respiratory Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1183\/09031936.98.12061346","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,2,24]],"date-time":"2025-02-24T07:12:12Z","timestamp":1740381132000},"score":1,"resource":{"primary":{"URL":"https:\/\/publications.ersnet.org\/lookup\/doi\/10.1183\/09031936.98.12061346"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1998,12,1]]},"references-count":0,"journal-issue":{"issue":"6","published-online":{"date-parts":[[1998,12,1]]},"published-print":{"date-parts":[[1998,12,1]]}},"alternative-id":["10.1183\/09031936.98.12061346"],"URL":"https:\/\/doi.org\/10.1183\/09031936.98.12061346","relation":{},"ISSN":["0903-1936","1399-3003"],"issn-type":[{"value":"0903-1936","type":"print"},{"value":"1399-3003","type":"electronic"}],"subject":[],"published":{"date-parts":[[1998,12,1]]}}}