Using Polar Ion-Pairs to Control Drug Delivery to the Airways of the Lungs.

The rapid absorptive clearance of drugs delivered to the airways of the lungs means that many inhaled medicines have a short duration of action. The aim of this study was to investigate whether forming polar ion-pairs can modify drug absorption to slow down clearance from the airways. Salbutamol was used as a model drug and was formulated as ion-pairs in an aqueous solution with three negatively charged hydrophilic counterions: sulfate (molecular weight (MW) 142), gluconate (MW 218), and phytate (MW 736) (association constants of 1.

In vitro investigation on the impact of airway mucus on drug dissolution and absorption at the air-epithelium interface in the lungs.

Although the mucus layer is the first biological barrier encountered by inhaled drugs upon their deposition in the upper airways, its potential impact on drug dissolution and absorption in the lung has hardly been investigated. Bio-relevant in vitro models were therefore used to assess the role of airway mucus in the fate of drug particles at the air-epithelium interface. Salbutamol and indomethacin were used as model Biopharmaceutics Classification System (BCS) class III and class II drugs, respectively.