Characteristics of propellant evaporation and drug deposition for pressurized metered dose inhaler substituting hfa-134A

摘要

In the issue of the transfer to CFC-free pMDIs, effectiveness of the inhaler has been investigated conventionally from the fact not only the characteristics of pharmaceutical properties but the physical parameters of aerosol dynamics, such as evaporation rate of propellant and Stokes number of drug particles.~1 In this report, the inhalation conditions are discussed with the experimental data of these physical parameters obtained by a phase doppler method, in which both the particle diameter and the droplet velocity are simultaneously measured at the outlet of inhaler.