Cascade Impactor Performance of Commercial pMDI Formulations Using Modified Induction Ports

Area of Science:

• Pharmaceutical Sciences
• Inhalation Technology
• Aerosol Science

Background:

• The standard induction port (IP) in the Next Generation Pharmaceutical Impactor (USPIP) lacks physiological relevance, limiting the predictability of in vitro aerosol data for in vivo lung deposition.
• This limitation is critical for accurate drug delivery assessments.

Purpose of the Study:

• To evaluate the impact of replacing the USPIP with two modified induction ports (mIP and mIPext) designed using human tracheal geometry.
• To assess the improved predictability of in vitro aerosol deposition data for in vivo lung deposition.

Main Methods:

• Developed modified induction ports (mIP, mIPext) based on CT scans of a human trachea.
• Tested selected formulations with available in vivo lung deposition data.
• Compared in vitro deposition results with in vivo observations using both modified and standard IPs.

Main Results:

• All tested formulations showed increased deposition in the modified induction ports.
• Modified induction ports (mIP, mIPext) demonstrated superior in vitro-in vivo correlation compared to the USPIP.
• The mIP provided the most accurate correlation, with average deviations of 5 ± 4% (3 μm FPF cutoff).

Conclusions:

• Modified induction ports significantly enhance the predictability of in vitro aerosol deposition for in vivo lung deposition.
• The mIP design offers a more physiologically relevant and accurate tool for aerosol analysis in pharmaceutical development.
• Improved in vitro-in vivo correlation facilitates better drug product design and regulatory assessment.