FIELD: medical equipment.
SUBSTANCE: invention relates to medical equipment, namely to injectors for the injection of a pharmaceutical composition. The injector comprises cylinder (22) having inner wall (23), piston rod (10), and plug (1) having case (2), which has working surface (3) opposite to outlet surface (4), an axial length between working surface (3) and outlet surface (4), and a transverse diameter. Moreover, in the axial location from working surface (3), specified plug (1) contains deformable sealing element (5) made of thermoplastic elastomer (TPE), wherein deformable sealing element (5) surrounds case (2) of the plug and has an outer diameter exceeding the specified transverse diameter, while the axial extent of deformable sealing element (5) is from 5% to 95% of the axial length of case (2) of the plug, while deformable sealing element (5) provides sealing of an annular gap between case (2) of the plug and inner wall (23) of cylinder (22). Moreover, in the specified axial location of deformable sealing element (5), plug (1) has cavity (6), where an axial length of cavity (6) is from 5% to 50% of the axial length of case (2) of the plug. Moreover, case (2) of the plug has a tubular part for accommodation of piston rod (10) in an access diameter, and cavity (6) is formed at an interface between case (2) of the plug and piston rod (10) and/or at an interface between deformable sealing element (5) and piston rod (10), and a transverse length of specified cavity (6) is at least 50% of an outer diameter of deformable sealing element (5) and greater than the specified access diameter. Alternatively, in the specified axial location of deformable sealing element (5), plug (1) has cavity (6), where the axial length of cavity (6) is from 5% to 50% of the axial length of case (2) of the plug. Moreover, cavity (6) is a partial cavity, the transverse length of which is at least 50% of the outer diameter of deformable sealing element (5), and which has a hole facing working surface (3) of plug (1), or a hole facing outlet surface (4) of plug (1).
EFFECT: obtainment of an injector.
17 cl, 17 dwg, 6 tbl
