A 3D Model of the Human Lung Airway for Evaluating Permeability of Inhaled Drugs.

Current in vitro cell-based methods, relying on single cell types, have structural and functional limitations in determining lung drug permeability, which is a contributing factor affecting both local and systemic drug levels. To address this issue, we investigated a 3D human lung airway model generated using a cell culture insert, wherein primary human lung epithelial and endothelial cells were cocultured at an air-liquid interface (ALI). To ensure that the cell culture mimics the physiological and functional characteristics of airway tissue, the model was characterized by evaluating several parameters such as cellular confluency, ciliation, tight junctions, mucus-layer formation, transepithelial electrical resistance, and barrier function through assaying fluorescein isothiocyanate-dextran permeability.

Determination of five positive control drugs in hERG external solution (buffer) by LC-MS/MS to support in vitro hERG assay as recommended by ICH S7B.

ICH S7B recommends screening for hERG channel block using patch clamp recordings to assess a drug's proarrhythmic risk. Block of the hERG channel has been associated with clinical QT prolongation as well as the rare, but potentially fatal ventricular tachyarrhythmia Torsade de Pointes (TdP). During recording, drug concentrations perfused to the cells can deviate from nominal concentrations due to molecule-specific properties (such as non-specific binding), thereby introducing error when assessing drug potency.