Combining a positive expiratory pressure device with a metered-dose inhaler reservoir system using chlorofluorocarbon albuterol and hydrofluoroalkane albuterol : Effect on dose and particle size distributions

BACKGROUND: Combining a positive expiratory pressure (PEP) device with inhalation of albuterol via metered dose inhaler (MDI) may improve drug delivery to the lung, but may also affect dose availability. PURPOSE: Determine the effect of interposing a PEP device on dose availability of albuterol via MDI and reservoir with either a chlorofluorocarbon (CFC) or hydrofluoroalkane (HFA) propellant. METHODS: MDI dose availability of CFC albuterol (Proventil) and HFA albuterol (Proventil HFA) using an Aerosol Cloud Enhancer (ACE) reservoir with and without a PEP device (TheraPEP) attached was determined. Drug availability was assessed using an Andersen 8-stage cascade impactor operated at 28.3 ± 0.5 L/min. The PEP device was inserted between the reverse-firing ACE and the United States Pharmacopeia induction throat. Drug collected on impactor plates was analyzed spectrophotometrically at 276 nm, and the fine particle fraction was determined as the mass of drug 0.05), for either CFC or HFA albuterol. CONCLUSION: Interposing the TheraPEP device at the MIDI-ACE outlet does not change total dose, drug mass < 4.7 μm, or mass median aerodynamic diameter of MDI albuterol, with either CFC or HFA propellants.