Nasal drug delivery to olfactory region based on high-flow auxiliary gas method: A numerical simulation study

In this paper, the high-flow auxiliary gas method (HAGM) was investigated in order to improve the efficiency of drug delivery to the olfactory region. Numerical simulation analysis has been undertaken to evaluate the transport phenomenon of aerosol drugs in the nasal cavity. Meanwhile, the effects of drug particle size, flow rate of auxiliary gas, administration direction, and nozzle insertion depth on delivery efficiency to the olfactory region were studied and discussed. The results show that HAGM can effectively increase the flow rate of airflow in the olfactory region compared with natural breathing. There also exists an optimum value of particle size for the maximum delivery efficiency to the olfactory region, and this optimum value decreases as the flow rate of auxiliary airflow increases. There are significant differences in the effect of auxiliary airflow on delivery to the olfactory area under different particle sizes. The administration direction has a significant impact on delivery to the olfactory region. Entering the olfactory area from the anterior nostril through the gap between the front ends of the middle and inferior turbinate heads and the top of the nasal vestibule may provide an effective route for drug administration to the olfactory region. The combination of small particles and high-flow auxiliary airflow can effectively improve the delivery efficiency to the olfactory region and upper nasal.