A nozzle having an ejection duct structured so as to allow a better distribution of the substances on the inner panes of nasal cavities and similar, such as auricular, vaginal and rectal cavities is described. A conical central portion is mounted in the nozzle outlet portion with its base in the outlet opening providing an annular fluid outlet, the conical central portion is rigidly secured to the inner wall of the outlet portion with baffles. In different embodiments of the invention the outlet portion, the central portion, the baffles and the annular outlet opening vary in shape.