Assessment of Nasal Spray Deposition Pattern in a Silicone Human Nose Model Using a Color-Based Method

Purpose To develop a simple and inexpensive method to visualize and quantify droplet deposition patterns. Methods Deposition pattern was determined by uniformly coating the nose model with Sar-Gel® (a paste that changes from white to purple on contact with water) and subsequently discharging sprays into the nose model. The color change was captured using a digital camera and analyzed using Adobe® Photoshop. Several tests were conducted to validate the method. Deposition patterns of different nasal sprays (Ayr, Afrin, and Zicam) and different nasal drug delivery devices (Afrin nasal spray and PARI Sinustar nasal nebulizer) were compared. We also used the method to evaluate the effect of inhaled flow rate on nasal spray deposition. Results There was a significant difference in the deposition area for Ayr, Afrin, and Zicam. The deposition areas of Afrin nasal spray and PARI Sinustar nasal nebulizer (2 min and 5 min) were significantly different. Inhaled flow rate did not have a significant effect on the deposition pattern. Conclusions Lower viscosity formulations (Ayr, Afrin) provided greater coverage than the higher viscosity formulation (Zicam). The nebulizer covered a greater surface area than the spray pump we evaluated. Aerosol deposition in the nose model was not affected by air flow conditions.