| 摘要 |
The technical field of the invention is that of pre-filled and disposable needleless syringes, used for intradermal, subcutaneous and intramuscular injections of liquid active principle for therapeutic use in human and veterinary medicine. The inventive syringes ( 1 ) are mainly characterized in that they function with a pyrotechnic charge ( 6 ) consisting of a mixture of powder with high burning rate and a powder with low burning rate. Indeed, the combustion of the powder with a high burning rate enables to communicate instantly, through a piston ( 3 ), a very high speed to the active principle ( 4 ), whereas the combustion of the powder with a low burning rate enables to maintain a threshold pressure level to proceed with the injection, so as to ensure that the active principle ( 4 ) penetrates through the skin. Thus, the injection is properly and homogeneously without any loss of active liquid ( 4 ). |
