[Experimental study on injection completion rate and performance for needle-free insulin injection]

Abstract

As a relatively novel technique for drug delivery, the needle-free injection technique is characterized by transporting the drug liquid to the designated subcutaneous position through a high-speed micro-jet. Although this technique has been applied in many fields, the research on its drug dispersion mechanism and injection performance is insufficient. The presented study aims to identify critical parameters during the injection process and describe their influence on the injection effect. The injection completion rate and performance of a needle-free injector under various operating conditions were compared based on mouse experiments. The results show that the nozzle diameter imposes a more significant influence on jet characteristics than other injection parameters. Moreover, the injection completion rate increases with the nozzle diameter. The nozzle diameters of 0.14 mm and 0.25 mm correspond to injection completion rates of 89.7% and 95.8%, respectively. Furthermore, by analyzing the rate of blood glucose change in the tested mice, it is found that insulin administration through the needle-free injection can achieve a drug effect duration longer than 120 min, which is better than that obtained using conventional needle-syringe technique. In summary, the obtained conclusions can provide an important reference for the optimal design and extending application of the air-powered needle-free injector.

Keywords: Injection completion rate; Insulin; Mouse; Needle-free injector; Skin mound.

图 1

Schematic view of experimental equipment for jet pressure measurement 射流压力采集实验装置示意图

图 2

Time-dependent stagnation pressure of jet at different injection parameters 不同注射参数对应的射流滞止压力随时间的变化

图 3

Actual injection volume of the needle-free injector at D = 0.25 mm，P = 0.55 MPa D = 0.25 mm，P = 0.55 MPa工况下无针注射器的实际注射量

图 4

Injection completion rate obtained from mouse experiments 通过小鼠实验获得的注射完成率

图 5

Injection area and skin mound 注射区域与皮丘形状

图 6

Injection result under different views 不同视角下的注射结果图

图 7

Effect of nozzle diameter on characteristic dimensions of mouse skin mound 喷嘴直径对小鼠皮丘特征尺寸的影响

图 8

Variations of mouse blood glucose parameters with injection duration 小鼠血糖参数随注射时间的变化