Chlorofluorocarbon-free inhalation devices in asthma: are there clinical implications?
Alternative non-chlorofluorocarbon (CFC) propellants have been developed and have been shown to be safe alternatives to CFC propellants. Salbutamol (albuterol) and beclomethasone dipropionate (BDP) in metered dose inhalers (MDIs) have been most studied. Salbutamol sulfate non-CFC MDIs have remained as a suspension formulation, and there is good evidence that salbutamol sulfate non-CFC MDIs are equivalent to salbutamol sulfate CFC MDIs. BDP non-CFC MDIs have a new formulation which is a solution and has a significantly smaller particle size than BDP delivered from CFC MDIs. This has resulted in more of the metered dose from the non-CFC MDI reaching the lower respiratory tract, with a consequent reduction of the dose deposited in the throat. This change allows a smaller dose of the non-CFC BDP to be equivalent to the CFC formulation. However, efficacy studies will be needed with other medications that are delivered in non-CFC MDIs because this finding with BDP relates to the solution formulation and particle size. The non-CFC propellant hydrofluoroalkane (HFA)-134a functions better at a lower temperature than its CFC comparator.
Ruffin
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Respiratory Medicine Unit, The Queen Elizabeth Hospital Campus, Woodville, South Australia, Australia.
Southcott
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