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 vaporized. 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 to a patient's 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 and directs the mixed aerosol into the inlet end of the flow passage.