TABLE 1

Critical drug attributes: inhaled drugs for treatment of respiratory diseases

AttributeFunctionTypical MechanismsReferences
Retention in lungProvide a reasonable dosing regimen Limit peak systemic exposureSlow dissolution, typically neutral lipophilic compoundsHochhaus et al., 1995; Hochhaus et al., 1997; B├Ąckman and Olsson, 2020
Low permeability, typically antibacterials or antifungals acting on microorganisms in Epithelial Lining Fluid (ELF)Biller, 2015
Tissue interaction, typically bases; lysosomal trapping, typically dibasesNaline et al., 2018; Mindell, 2012; Cooper et al., 2008
High PotencyLimit therapeutic doseTarget-dependent
Low oral bioavailabilityLimit systemic exposureMetabolic liability, low permeabilityProcopiou et al., 2010; Biggadike et al.. 2008