The Fundamental Study On Key Technologies For Domestic Powder Needleless Injection System

Powder Needleless Injection (PNI) is a novel durg delivery technique, by which medicines are transported into intracutaneous, subcutaneous or mucosal tissue through high-speed airflow. Painlessness, safety, convenience and high efficiency are the main advantages of PNI. PNI is suitable for many types of drugs, especially for those which are unstable to acids or enzymes. In the applications, it adapts especially to the patients who are afraid of injector, who need to treat themselves for a long time. It is also applicable for preventing and treating the diseases occuring massively or in field. The research and development of PNI were firstly performed in China in this paper. The main research results are as follows:1. Based on the design principle of the foreign relative products, three type powder-ejectors , type A, B and C, were designed independently and manufactured taking advantage of national aerospace and war industry techniques, especially small arms ballistics, aerodynamics, ergonomics, computer aided design and mechanical design principle. And some patents about PNI were applied. Ejecting test of human skin and gel simulation were made to evaluate the function and specification of PNI. It shows that domestic products prepared by us met the application demands of PNI in dynamics, safety, controllability, comfortableness and compliance.2. Fluoresceinsodium was selected as model drug to evaluate the human skin absorption rate in vitro and bioavailability in vivo of PNI by orthogonal experiments. The results showed that delivery rate of model drug reached 40%, which were 400 times higher than those of the ordinary transdermic preparations and were also higher than those of foreign relative products. The examining process of model drug with HPLC- fluoroscope was established, which is sensitive, fast ,accurate, and could meet the demands of determination both in vivo and in vitro.3. Stimulation test on skin showed that powder-ejectors designed in this paper had no or little hurt on the skin and were almost safe at given conditions.In conclusion, the main technical parameters of PNI system designed by us were equal or/and superior to those of the foreign analogous products. The key technologies of domestic PNI system were solved basically and gap of PNI R&D in this field in China were supplied.