Aerosols and sprays are common dosage forms for the route of administration

The answer to this question would be: inhalation or intranasal

Aerosols and sprays will make a liquid substance spread in the air. This method is used to deliver the drug by inhalation. When the air is inhaled, the drugs will enter the alveolus of the lungs and diffuse into the capillary vessel and then delivered into the body.
Note that this method is different to intranasal. Inhaler used by mouth and the target is lungs. Intranasal is used by the nose and target is the nasal mucosa. Spray mostly used for intranasal since it won't reach long distance as aerosol do.