Apparatus and method for measuring regional distribution of therapeutic aerosols and comparing delivery systems

Abstract An apparatus has been designed to estimate the respiratory tract distribution of therapeutic aerosols. It consists of an accurate life size model of the human oral passage extending from lips to mid-trachea, a Y branch for flow adjustment and a cascade impactor. Aerosol delivery devices are positioned to introduce the generated aerosol into the oral entrance, simulating their in vivo delivery. The aerosol which penetrates the oral airway model cast passes to the cascade impactor for aerodynamic size classification to estimate regional delivery to the bronchial and pulmonary zones. The apparatus has been tested using a metered dose inhaler (MDI) at a range of inspiratory flow rates.