Abstract
Local therapy has been performed using a nasal spray or nebulizer. However, the drug distribution area in the nasal cavity has been unclear. In this study, a simple method for clarifying the area of drug distribution in the nasal cavity by image analysis was proposed, and the drug distribution areas in a silicon model of the nasal cavity were investigated following distribution of the drug with nasal sprays and an ultrasonic nebulizer. The areas of drug distribution were found to change according to the angle of the nozzle of the spray. When the angle of the spray was inserted to the nostril at the angle of 30 degrees to the horizontal plane, the drug was mainly sprayed around the inferior nasal concha. In contrast, when the angle was more than 45 degrees, the drug was distributed to the middle nasal concha or the upper area of the nasal cavity. In case of the ultrasonic nebulizer, the drug was widely spread in the nasal cavity. The viscosity of the drug had no influence on the drug distribution. There was a tendency for the drug to be distributed to the upper area of the nasal cavity by sniffing, however, the effect changed according to the angle of the nozzle.
