国必生 国上认生 Particles transit through the airway of the lung Physicochemical factors governing lung deposition according to three mechanisms Aerodynamic properties Inertial impaction ·Size .Sedimentation ·Morphology ·Diffusion ·Density ·Hygroscopicity Moving speed of particles 国生一 国生 Physiological factors governing lung deposition Factors affecting absorption Inhaled volume Factors affecting lung deposition ·Flow rate ·Drug properties ·Breath holding ·Molecular weight ·Konw 国坠生 Definition and Classification Metered dose inhalers Pharmaceutical aerosol ·Aerosol .It may be defined as an aerosol product .Propellant-driven metered dose inhaler containing therapeutically active ingredients Pressurized metered dose inhaler dissolved,suspended,or emulsified in a propellant or a mixture of solvent and propellant ·Pressurized aerosol and intended for inhale or topical administration or administration into body cavities. 22 Shanghai Jiao Tong University Particles transit through the airway of the lung according to three mechanisms • Inertial impaction • Sedimentation • Diffusion Shanghai Jiao Tong University Physicochemical factors governing lung deposition • Aerodynamic properties • Size • Morphology • Density • Hygroscopicity • Moving speed of particles Shanghai Jiao Tong University Physiological factors governing lung deposition • Inhaled volume • Flow rate • Breath holding Shanghai Jiao Tong University Factors affecting absorption • Factors affecting lung deposition • Drug properties • Molecular weight • KO/W Shanghai Jiao Tong University Metered dose inhalers • Aerosol • Propellant-driven metered dose inhaler • Pressurized metered dose inhaler • Pressurized aerosol Shanghai Jiao Tong University Definition and Classification Pharmaceutical aerosol • It may be defined as an aerosol product containing therapeutically active ingredients dissolved, suspended, or emulsified in a propellant or a mixture of solvent and propellant and intended for inhale or topical administration or administration into body cavities