INJECTOR WITH REDUCED SHEAR FORCE Russian patent published in 2020 - IPC A61M5/315 

FIELD: medical equipment.

SUBSTANCE: present invention relates to an injector for administering a medicinal preparation, wherein the proposed injector for administering a medicinal composition does not contain a silicone lubricant and has: cylinder extending along longitudinal axis and having inner wall, outer wall and outlet at outlet end opposite to drive end, and a piston unit comprising a compressible section between a drive piston element having a Shore hardness (scale A) in range of 60 to 80, and a passive piston element, having Shore hardness (scale A) in range of 60 to 80. Said piston elements adjoin cylinder inner wall at butt junctions, that provides, therefore, compression of compressible section when piston unit is inserted into cylinder. Compressible section is characterized by volume and has axial length in range from 25 to 90 % of full axial length of piston unit in non-stressed state, wherein compressible section comprises compressible fluid medium and resilient frame connecting driving piston element with passive piston element. Note here that resilient frame is made from elastic polymer and has volume fraction in range of 20 to 40 % of volume of compressible section.

EFFECT: disclosed is an injector with reduced shear force.

12 cl, 3 tbl, 25 dwg