©上特 “-Bwl 圈上人线 Contents Structure of the respiratory tract Factors governing lung deposition Inhalation Dosage Forms .Physicochemical factors Physiological factors School of Pharmacy Chen Jian ·Metered dose inhalers(MDIs)气雾剂 2012.3 ·Nebulizers喷雾剂 cheniian situ.edu.cn ·Dry powder inhalers(DPIs)粉雾剂 国生一 Structure of the respiratory tract Nasal cavity Pulmonary drug delivery Respiratory diseases Teminal bronchioles Non-respiratory diseases Larynx- Trachea Left bronchus- Diaphragm 国达生 Structure of the respiratory tract Drugs could be absorbed quickly in lung Pulmonary vasculature forms a separate The total surface area of alveoli is 70~100m2 circuit from the systemic circulation: The membrane oflung epithelia is thin The main pulmonary artery starts in the right ventricle (右心室)，then it divides into two branches for the left The surface area of capillary vessel is 90m2 and right lungs.Drugs absorbed into the pulmonary circulation will avoid the first-pass hepatic effect, although they could be metabolized in the respiratory tract. 11 Inhalation Dosage Forms School of Pharmacy Chen Jian 2012.3 chenjian@sjtu.edu.cn Shanghai Jiao Tong University Contents • Structure of the respiratory tract • Factors governing lung deposition • Physicochemical factors • Physiological factors • Metered dose inhalers (MDIs) 气雾剂 • Nebulizers 喷雾剂 • Dry powder inhalers (DPIs) 粉雾剂 Shanghai Jiao Tong University Pulmonary drug delivery • Respiratory diseases • Non-respiratory diseases Structure of the respiratory tract Shanghai Jiao Tong University Drugs could be absorbed quickly in lung • The total surface area of alveoli is 70~100m2 • The membrane of lung epithelia is thin • The surface area of capillary vessel is 90m2 Shanghai Jiao Tong University Structure of the respiratory tract Pulmonary vasculature forms a separate circuit from the systemic circulation: • The main pulmonary artery starts in the right ventricle （右心室）, then it divides into two branches for the left and right lungs. Drugs absorbed into the pulmonary circulation will avoid the first-pass hepatic effect, although they could be metabolized in the respiratory tract