图生 国上认连 Advantages of inhalation dosage forms for systemic diseases Advantages of inhalation dosage forms for .A noninvasive'needle-free'delivery system; pulmonary diseases Suitable for a wide range of substances from small High concentrations directly to the disease site; molecules to very large proteins, Minimizes risk of systemic side-effects Enormous absorptive surface area and a highly permeable Rapid clinical response; membrane in the alveolar region; Bypass the barriers to therapeutic efficacy; The slow clearance in the lung results in prolonged Achieve a similar or superior therapeutic effect at a residency in the lung. fraction of the systemic dose .A low enzymatic environment that is devoid of hepatic first-pass metabolism; 国生一 圈上生 Particles transit through the airway of the lung Physicochemical factors governing lung deposition according to three mechanisms Aerodynamic diameter Inertial impaction ·Size Sedimentation ·Morphology ·Diffusion ·Density ·lygroscopicity ·Particle velocity 国垫生 国活生 Physiological factors governing lung Factors affecting absorption deposition Factors affecting deposition Inhaled volume ·Drug properties ·Flow rate ·Molecular weight ·Breath holding Kow 22 Shanghai Jiao Tong University Advantages of inhalation dosage forms for pulmonary diseases • High concentrations directly to the disease site; • Minimizes risk of systemic side-effects • Rapid clinical response; • Bypass the barriers to therapeutic efficacy; • Achieve a similar or superior therapeutic effect at a fraction of the systemic dose. Shanghai Jiao Tong University Advantages of inhalation dosage forms for systemic diseases • A noninvasive ‘needle-free’ delivery system; • Suitable for a wide range of substances from small molecules to very large proteins; • Enormous absorptive surface area and a highly permeable membrane in the alveolar region; • The slow clearance in the lung results in prolonged residency in the lung; • A low enzymatic environment that is devoid of hepatic first-pass metabolism; 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 diameter • Size • Morphology • Density • Hygroscopicity • Particle velocity Shanghai Jiao Tong University Physiological factors governing lung deposition • Inhaled volume • Flow rate • Breath holding Shanghai Jiao Tong University Factors affecting absorption • Factors affecting deposition • Drug properties • Molecular weight • KO/W