PT  - JOURNAL ARTICLE
AU  - Leach, CL
AU  - Davidson, PJ
AU  - Boudreau, RJ
TI  - Improved airway targeting with the CFC-free HFA-beclomethasone metered-dose inhaler compared with CFC-beclomethasone
AID  - 10.1183/09031936.98.12061346
DP  - 1998 Dec 01
TA  - European Respiratory Journal
PG  - 1346--1353
VI  - 12
IP  - 6
4099  - http://erj.ersjournals.com/content/12/6/1346.short
4100  - http://erj.ersjournals.com/content/12/6/1346.full
SO  - Eur Respir J1998 Dec 01; 12
AB  - 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.