Determination of the deposited amount of inhalation drugs in realistic human airways by Raman and infrared spectroscopy

Vibrational (Raman and infrared) spectroscopy based methods have been developed to determine the distribution of inhalation drugs (and other aerosols) in human airway replicas. The tested medication was introduced by metered dose inhaler into a realistic human lung tract prepared by 3D printing from computer tomographic data of human respiratory system. The deposited material was collected with silicon substrates attached to the hollow airway's walls in different points. The analysis of the substrates was performed by Raman and infrared spectroscopic mapping of drug's characteristic peak intensities over the surface. The method was verified by comparison with optical microscopic images recorded on the same surface area.