©上特 “-B✉ 国上人生 L Contents Structure of the respiratory tract Inhalation Dosage Forms Factors governing lung deposition School of Pharmacy Metered dose inhalers(MDIs) Chen Jian Dry powder inhalers(DPIs) 2013.5 cheniian @situ.edu.cn ·Nebulizers 国生一 圈上生 Structure of the respiratory tract Inhalation Dosage Forms .The lung is a series of bifurcating tubes Respiratory diseases .Trachea ·Asthma ·Bronchi Chronic obstructive pulmonary diseases ·Bronchiole (COPDs) .Alveolus Non-respiratory diseases Surface area of the airways increases with each generation 国坠生 Structure of the respiratory tract Drugs could be absorbed quickly in lung Pulmonary vasculature forms a separate circuit from the systemic circulation: The total surface area very big The main pulmonary artery starts in the right The membrane of lung epithelia is thin ventricle,then it divides into two branches for the The blood supply is abundant 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. 11 Inhalation Dosage Forms School of Pharmacy Chen Jian 2013.5 chenjian@sjtu.edu.cn Shanghai Jiao Tong University Contents • Structure of the respiratory tract • Factors governing lung deposition • Metered dose inhalers (MDIs) • Dry powder inhalers (DPIs) • Nebulizers Shanghai Jiao Tong University Inhalation Dosage Forms • Respiratory diseases • Asthma • Chronic obstructive pulmonary diseases (COPDs) • Non-respiratory diseases Shanghai Jiao Tong University Structure of the respiratory tract • The lung is a series of bifurcating tubes • Trachea • Bronchi • Bronchiole • Alveolus • Surface area of the airways increases with each generation Shanghai Jiao Tong University Drugs could be absorbed quickly in lung • The total surface area very big • The membrane of lung epithelia is thin • The blood supply is abundant 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, 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