Professor Mark Banaszak Holl of The University of Alabama at Birmingham

"Materials for Inhaled Aerosol Treatment of Disease: Optical Photothermal Infrared Microscopy (O-PTIR) as an Advanced Characterization Method for Assessing the Emitted Dose of Complex Dry Powder Inhaler Formulations"

Dry Powder Inhalers (DPIs) are used every day by millions of people to treat symptoms of asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), and other lung diseases. The aerosols emitted by the DPIs into the patient’s lungs are highly engineered nano- to microparticles containing a mixture of excipient(s) and drug(s). Improved characterization of these materials offers an opportunity to better understand current formulations and the factors contributing to aerosolization performance.
Optical photothermal infrared spectroscopy (O-PTIR) offers rapid IR, Raman, and fluorescence imaging capability with a resolution of ~300-500 nm. This allows assessment of relative ratios of drug/drug/excipient at the particle level and, thus an understanding of the distributions of particle composition as a function of particle aerodynamic characteristics within the ~ 1-5 micron size range of interest for delivery to the lung. We will present data illustrating how particle composition can vary with as function of formulation, inhaler actuation conditions, and aerodynamic particle size distribution (APSD).
O-PTIR is a powerful tool for characterization of dry powder inhalers and offers substantial promise for name brand/generic comparisons and optimization of formulations during product development.

1 Department of Mechanical and Materials Engineering, University of Alabama at Birmingham
2 School of Pharmacy, University of Sydney
3 Division of Therapeutic Performance I, Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration
4 Complex Drug Analysis Branch 2, Division of Complex Drug Analysis, Office of Testing and Research, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, US Food and Drug Administration

Mark M. Banaszak Holl,1 Dipesh Khanal,2 Sheikh Tanzina Haque,1 Blessy Joseph,1 Elizabeth Bielski,3 Bryan Newman,3 Huzeyfe Yilmaz,4 Snober Ahmed,4 Hak-Kim Chan2