“…Although most studies have used empirical or simplified analytical models to predict lung deposition for lung PBPK modeling of pharmaceutical drugs, two have used CFD . A CFD model using a Lagrangian particle‐tracking method was used to predict emitted dose, MMAD, and FPF of four amiloride hydrochloride (HCi) formulations from an Aerosolizer device, where predicted values showed reasonable agreement with impactor‐based emitted dose data, although MMAD values were underpredicted . These predicted values were used as inputs for a Gastroplus PCAT model of nebulized amiloride HCl, where the predictions agreed reasonably well with available PK data in terms of C max and time to maximum plasma concentration, as illustrated in Figure , especially for the case in which the absorption rate constant in the pulmonary region was reduced by 50% .…”