Pressurised metered dose inhalers (pMDIs) provide essential therapy fo
r a large proportion of the 70 million people in the world affected by
asthma. However, current pMDIs contain chlorofluorocarbons (CFCs) and
will have to be phased out. Several classes of propellants have been
considered as alternatives to CFCs and the pharmaceutical industry has
taken forward two hydrofluoroalkanes (HFA) - HFA-134a and HFA-227 - f
or development in non-CFC pMDIs. The development of non-CFC pMDIs to d
ate has resulted in the worldwide introduction of a salbutamol pMDI (w
ith a HFA-134a propellant) which is identical both in vitro and in viv
o to CFC pMDIs. The beclomethasone pMDI under development has superior
lung deposition and much reduced oropharyngeal deposition compared wi
th the CFC pMDI, with the potential for significant benefits for patie
nts.