A drug delivery system, which includes an aerosol generator unit, a pumping unit, a flow tube, at least one condensate collector and an aerosol transition adapter. The aerosol generator forms an aerosol from a liquid formulation, which is partially volatilized. The pumping unit supplies the liquid formulation to the aerosol generator unit and a flow tube having an inlet end in fluid communication with an outlet of the aerosol generator unit and an outlet adapted for connection to a patient interface, which supplies ventilation gas to a patients lungs. The system also includes at least one condensate collector adapted to collect condensed liquid or liquid produced by the aerosol generator unit, and a transition adapter arranged to mix aerosol produced by the aerosol generator unit with heated air or ventilation gas and direct the mixed aerosol into the inlet end of the flow passage.