Abstract: A plunger rod (104) for use in connection with a syringe barrel (102) is provided. The plunger rod (104) comprises a distal plunger top (105), having a proximal bottom surface (113), and a proximal elongated shaft (106) comprising a proximal end (107a) adapted to receive an applied force along an axis (1000) and a distal end plate (107b) adapted to transmit said applied force along said axis (1000). The plunger rod (104) is adapted to be inserted into the barrel (102) of a syringe (100) extending along the axis (1000). The distal plunger top (105) and the proximal elongated shaft (106) are connected to each other by a releasable connection (115). The releasable connection (115) comprises: distal top rupture means (116) comprising at least one distal top rib (125a) disposed eccentrically from the axis (1000) on the proximal bottom surface (113), and proximal shaft rupture means (117) comprising at least one proximal shaft rib (125b) disposed eccentrically from the axis (1000) on the distal end plate (107b).

Abstract: A syringe (100) comprising a barrel (111) with a lumen is provided. The barrel (111) is adapted to contain a drug, the barrel (111) having a distal end wall portion (198) and a tubular wall (112) extending proximally from said distal end wall portion (198), whereby the barrel (111) extends along an axis (1000). The distal end wall portion (198) has an opening (199) extending into a syringe head (140) adapted to receive a syringe needle, said syringe head (140) having a lumen smaller in transversal cross-section than the barrel lumen; the syringe (100) further comprising: a plunger (196) extending along the axis, said plunger shaft being displaceable along the axis (1000) within said barrel (111).

Abstract: The present invention discloses a plunger rod (104) for use in connection with an injection syringe barrel (102). The plunger rod (104) comprises an elongated rod (114). The elongated rod (114) comprises a proximal end (107) adapted to receive an applied force along an axis (1000). It further comprises a distal end (105) adapted to transmit the applied force along the axis (1000). The plunger rod (104) is adapted to be inserted into a barrel (102) of a syringe (100) extending along the axis (1000). The plunger rod (104) is further adapted to transmit force along the axis (1000) to a plunger stopper (103) disposed within the barrel (102). The plunger rod (104) further comprises a radial spring mechanism (106, 117, 118, 119, 120), adapted to interact with an inner surface of the barrel (102).