1. A medical injection device comprising a container body (1) and a stopper (2) inserted slidably into the container body (1) for discharging a fluid (3) through an opening in said container body (1), wherein: at least the distal part (20) of the restrictor (2) in contact with the fluid (3) is made of a thermoplastic polyolefin, the limiter (2) further comprises at least one o-ring (4, 4 ′) held in at least one circumferential groove (210, 210 ′), and the decree Noe medical injection device is characterized in that: - said at least one sealing ring (4, 4 ') is made of butyl rubber type； and - a cross section of said at least one circumferential groove (210, 210 ′) of the stopper (2) is configured to compress said at least one o-ring (4) in the axial direction and in the radial direction when the at least one the o-ring (4) is engaged in the circumferential groove (210) between the stopper (2) and the inner wall (10) of the container body (1). 2. A device according to claim 1, characterized in that the axial compression of said at least one o-ring (4, 4 ′) is at least 14.4%, and the radial compression is at least 20% .3. A device according to claim 1 or 2, characterized in that the diameter (⌀) of said at least one o-ring (4) at rest is greater than the width (w) of said corresponding at least one circumferential groove (210) .4. A device according to claim 1 or 2, characterized in that the material of said at least one o-ring (4) is bromobutyl. The device according to claim 1 or 2, characterized in1. Медицинское инъекционное устройство, содержащее корпус (1) контейнера и ограничитель (2), вставленный с возможностью скольжения в корпус (1) контейнера для выпуска текучей среды (3) через отверстие в указанном корпусе (1) контейнера, при этом:- по меньшей мере дистальная часть (20) ограничителя (2), находящаяся в контакте с текучей средой (3), выполнена из термопластичного полиолефина,- ограничитель (2) дополнительно содержит по меньшей мере одно уплотнительное кольцо (
