A system for delivering a medicament to spontaneously breathing patients, comprising: i) a flexible catheter adapted to reach the retro-pharyngeal region of the patient, the catheter including at least a first channel being adapted to convey in the patient&rsquo；s pharyngeal region a flow of liquid medicament and at least a second channel adapted to convey in the patient&rsquo；s pharyngeal region a pressurized flow of gas, ii) first pump means connected to a first end of the at least first channel, adapted to create a pressure which pushes the column of liquid medicament towards the second end of the at least first channel； iii) second pump means connected to a first end of the at least second channel, adapted to create the flow of pressurized gas； so that when the column of liquid medicament and the pressurized gas meet in the pharyngeal cavity, the liquid column is broken into a plurality of particles causing the atomized medicament to be delivered into the patient&rsquo；s lungs； iv) a pressure sensor connected to the at least first channel for measuring a value indicative of the pressure in the patient pharyngeal cavity, such value being use to determine whether the patient is in an inspiration or in an expiration phase and wherein the first pump means are selectively activated only during inspiration phase.
