Schroeter Jeffry D, Kimbell Julia S, Asgharian Bahman
CIIT Centers for Health Research, Research Triangle Park, North Carolina, 27709-2137, USA.
J Aerosol Med. 2006 Fall;19(3):301-13. doi: 10.1089/jam.2006.19.301.
The human nasal passages effectively filter particles from inhaled air. This prevents harmful pollutants from reaching susceptible pulmonary airways, but may leave the nasal mucosa vulnerable to potentially injurious effects from inhaled toxicants. This filtering property may also be strategically used for aerosolized nasal drug delivery. The nasal route has recently been considered as a means of delivering systemically acting drugs due to the large absorptive surface area available in close proximity to the nostrils. In this study, a computational fluid dynamics (CFD) model of nasal airflow was used with a particle transport and deposition code to predict localized deposition of inhaled particles in human nasal passages. The model geometry was formed from MRI scan tracings of the nasal passages of a healthy adult male. Spherical particles ranging in size from 5 to 50 microm were released from the nostrils. Particle trajectories and deposition sites were calculated in the presence of steady-state inspiratory airflow at volumetric flow rates of 7.5, 15, and 30 L/min. The nasal valve, turbinates, and olfactory region were defined in the CFD model so that particles depositing in these regions could be identified and correlated with their release positions on the nostril surfaces. When plotted against impaction parameter, deposition efficiencies in these regions exhibited maximum values of 53%, 20%, and 3%, respectively. Analysis of preferential deposition patterns and nostril release positions under natural breathing scenarios can be used to determine optimal particle size and flow rate combinations to selectively target drug particles to specific regions of the nose.
人类鼻腔通道能有效过滤吸入空气中的颗粒。这可防止有害污染物到达易受影响的肺部气道，但可能使鼻黏膜易受吸入毒物潜在的伤害作用。这种过滤特性也可被策略性地用于雾化鼻内给药。由于鼻孔附近有较大的吸收表面积，鼻内给药途径最近被视为一种全身作用药物的给药方式。在本研究中，使用了一个鼻腔气流的计算流体动力学（CFD）模型，并结合颗粒传输和沉积代码来预测吸入颗粒在人类鼻腔通道中的局部沉积情况。模型几何形状由一名健康成年男性鼻腔通道的MRI扫描图像形成。从鼻孔释放出大小在5至50微米范围内的球形颗粒。在7.5、15和30升/分钟的体积流速下，在稳态吸气气流存在的情况下计算颗粒轨迹和沉积位置。在CFD模型中定义了鼻瓣、鼻甲和嗅觉区域，以便能够识别沉积在这些区域的颗粒，并将其与它们在鼻孔表面的释放位置相关联。当与撞击参数作图时，这些区域的沉积效率分别显示出最大值53%、20%和3%。在自然呼吸情况下对优先沉积模式和鼻孔释放位置的分析可用于确定最佳的颗粒大小和流速组合，以将药物颗粒选择性地靶向到鼻子的特定区域。
