Fig. 4.

PBPK model for inhaled drugs (PulmoSim™). Subscripts: l lung, g gut, s solution, t tissue, v vasculature; parameters: k _diss dissolution rate constant, k _mu mucociliary rate constant, k _gut elimination rate constant from the gut, k _el elimination rate constant from the central compartment, FU fraction unbound, CL _ab absorptive clearance across tissue, V physiological distribution volumes, Q _G flow rate to the gut vasculature, Q _L flow rate to the pulmonary vasculature, Q _P intercompartmental clearance; light green boxes, pulmonary compartments; dark green boxes, gut compartments; red boxes, vasculature compartments in the specific organs; blue boxes, systemic disposition compartments