FIGURE 3.

Administration technique and deposition pattern. In the figure, the possible variations in the instruction steps prior to, during and after administration of an INC spray are displayed, which affect the deposition pattern of INC particles. The instructions steps include instructions regarding blowing and rinsing the nose prior to administration, instructions regarding the head position, the spray position, the depth of the spray into the nostril, closing the contralateral nostril and the droplet‐size distribution determined by the nasal airflow and the spray velocity during administration and the instruction regarding exhalation after administration. As described in: Section 5.4, from this review, no definitive conclusions regarding which administration technique leads to the desired deposition pattern and highest efficacy can be drawn for all instruction steps. To give insight in how an instruction step can be carried out differently, the figure illustrates the possible variation in these instruction steps. If a variation in the instruction step is possible, two examples of the variation are displayed as illustration a and b. In this figure, no recommendations regarding the correct administration technique according the authors are indicated. For this, we refer to the current standardized Dutch protocol in Table 3.