The technical transition to CFC-free inhalers.

Pressurised metered dose inhalers (pMDIs) provide essential therapy for 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--for development in non-CFC pMDIs. The development of non-CFC pMDIs to date has resulted in the worldwide introduction of a salbutamol pMDI (with a HFA-134a propellant) which is identical both in vitro and in vivo to CFC pMDIs. The beclomethasone pMDI under development has superior lung deposition and much reduced oropharyngeal deposition compared with the CFC pMDI, with the potential for significant benefits for patients.