Comparison of Albuterol Sulphate and Base Dry Powder Particulate Deposition Using the Calu-3 Lung Epithelial Model

To effectively predict the fate of formulated inhalation compounds delivered to the lung, a model of the airway epithelium should reflect drug permeability and transport characteristics in vivo. Most cell-based system established for this purpose, study drug transport using wet models and thus do not necessarily represent in vivo conditions. Recently, air-interface models have been established that increase the relevance of in vitro transport studies to the in vivo state (1, 2). The aim of our study was to elucidate the dissolution and diffusion process of deposited dry drug particulates (albuterol) after aerosolization onto the epithelial surface and compare these to conventional in vitro ‘glass’ models. Two forms of albuterol were investigated (albuterol base and albuterol sulphate), to evaluate the effects of lipophilicity and aqueous solubility on the mechanism of transport