NEEDLELESS SYRINGE FUNCTIONING WITH A DOUBLE-COMPOSITION PYROTECHNIC CHARGE

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 characterised 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).