Drug Administration to the Lung

Liquid instillation and nebulised aerosols are the most common methods for pulmonary administration to experimental animals [22, 54, 109, 134], The use of pressurised metered dose inhaler (pMDIs) and dry powder inhaler (DPIs) in preclinical studies is limited by the need for formulation development, which often cannot be performed in early drug discovery due to short supply of test materials. A number of alternative techniques for intra-tracheal administration of coarse sprays and powder formulations have been described [9, 15, 21, 36, 71, 80, 99, 138], 

Breathing pattern Particle properties Dissolution rate 

Blood flow (size, density, shape, charge) Solubility 

Mucociliary clearance Concentration Molecular polar surface area 

Alveolar macrophages Viscosity Hydrogen bonding potential 

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