Engineered aerosol medicine and drug delivery methods for optimal respiratory therapy.

The human lung is an effective route for noninvasive drug delivery because it provides a large surface area for rapid absorption, a minimal physical barrier, an absence of extreme pH and metabolism, no first-pass liver, a rich blood supply, and poor bioavailability of oral drugs. The physical and electrical properties of active pharmaceutical ingredient and excipient interactively influence 5 electromechanical deposition mechanisms of respiratory medicinal aerosols while flowing through the airways, including nose, mouth, pharynx, trachea, bronchi, bronchioles, and alveoli. The therapeutic particles from a specific device during the inhalation process come out as an aerosolized form. The dispersion of these pharmaceutical powders is often difficult because the fine powders are cohesive as a result of the strong interparticle adhesion forces: van der Waals, capillary, and electrostatic attractions. Typically, cohesive forces are proportional to the diameter d of the particles, whereas the detachment forces for resuspending the particles forming aerosol are proportional to d when aerodynamic shear force is used for the dispersion. Thus, the