Valve stopper for a medical injection device and medical injection device for injecting at least one composition
The invention relates to a valve stopper configured to be positioned inside a barrel of an injection device for injecting a composition through a distal, including: a membrane having a proximal and distal face, the membrane being configured to separate a, distal chamber of the barrel from a proximal chamber; a lateral wall extending from the membrane to define a distal cavity, the lateral wall having a circumferential sealing surface configured to sealingly engage the inner surface of the barrel; where the proximal face presents a concave shape and the membrane includes a notch extending through the membrane between the proximal and distal face, being configured to selectively create a fluid path through the membrane from the proximal face to the distal face depending on the pressure exerted by a composition onto the proximal face of the membrane for transferring fluid only from the second chamber to the first.
1 . A valve stopper configured to be positioned inside a barrel of an injection device for injecting at least one composition through a distal end of the barrel, the valve stopper comprising:
a membrane comprising a proximal face having a concave shape and a distal face, the membrane being configured to separate a first, distal chamber of the barrel from a second, proximal chamber of the barrel, wherein the membrane is a monolithic membrane,
a lateral wall extending distally, or both distally and proximally, from the membrane defining at least a distal cavity, the lateral wall comprising a circumferential sealing surface configured to sealingly engage an inner surface of the barrel,
wherein the membrane comprises a notch extending through at least a part of a thickness of the membrane between the proximal face and the distal face, the notch being configured to transition between a closed position and an open position defining a fluid path through the membrane from the proximal face to the distal face depending on a pressure exerted by a composition onto the proximal face of the membrane, the notch maintained in the open position depending on the pressure exerted, the lateral wall extending further distally than the distal face in the closed position and the open position, and
wherein the membrane permits transfer of fluid only from the second proximal chamber to the first distal chamber through the cavity.
2 . The valve stopper of claim 1 , wherein the lateral wall comprises an inner recess configured to induce collapsing of the valve stopper under a mechanical pressure exerted in a distal direction.
3 . The valve stopper of claim 2 , wherein the inner recess is an annular groove extending in the lateral wall of a circumference of the valve stopper.
4 . The valve stopper of claim 1 , wherein the sealing surface comprises three ribs, including a middle rib and two lateral ribs, and the membrane is aligned with the middle rib.
5 . The valve stopper of claim 1 , wherein the notch extends through a part of the membrane from the distal face of the membrane.
6 . The valve stopper of claim 1 , wherein the notch is a split that extends through the membrane between the proximal face and the distal face said split forming a valve configured to open or close the cavity depending on the pressure exerted by the composition onto the proximal face of the membrane.
7 . The valve stopper of claim 1 , wherein the notch is in the form of a line, passing through a center of the proximal face of the membrane.
8 . The valve stopper of claim 7 , wherein the notch further comprises two segments, each segment extending on both sides of an end of the line.
9 . The valve stopper of claim 1 , wherein the distal face of the membrane has a planar or convex shape, a curvature of the distal face extending away from the proximal face.
10 . The valve stopper of claim 1 , wherein the notch has a length that is superior to a quarter of the diameter of the cavity and inferior to the diameter of said cavity.
11 . A valve stopper configured to be positioned inside a barrel of an injection device for injecting at least one composition through a distal end of the barrel, the valve stopper comprising:
a membrane comprising a proximal face having a concave shape and a distal face, the membrane being configured to separate a first, distal chamber of the barrel from a second, proximal chamber of the barrel,
a lateral wall extending distally, or both distally and proximally, from the membrane defining at least a distal cavity, the lateral wall comprising a circumferential sealing surface configured to sealingly engage an inner surface of the barrel,
wherein the membrane comprises a notch extending through at least a part of a thickness of the membrane between the proximal face and the distal face, the notch being configured to transition between a closed position and an open position defining a fluid path through the membrane from the proximal face to the distal face depending on a pressure exerted by a composition onto the proximal face of the membrane, the notch maintained in the open position depending on the pressure exerted, wherein the notch extends only in a part of the thickness of the membrane, thereby delimiting a tear part in the thickness of the membrane that is not traversed by the notch, said tear part being configured to tear along the notch under a determined pressure exerted by the composition to create the fluid path, the lateral wall extending further distally than the distal face in the closed position and the open position, and
wherein the membrane permits transfer of fluid only from the second proximal chamber to the first distal chamber through the cavity.
12 . The valve stopper of claim 11 , wherein the tear part of the membrane forms a valve configured to open or close the cavity depending on the pressure exerted by the composition onto the proximal face of the membrane.
13 . The valve stopper of claim 11 , wherein the depth of the notch is at least 0.1 mm.
14 . The valve stopper of claim 11 , wherein the notch has an oblong shape, or is in the form of a cross comprising two segments that intersect at a center of the cross.
15 . A medical injection device for injecting at least one composition, comprising:
a barrel extending from a proximal end to a distal end,
a plunger stopper adapted to be translationally movable inside the barrel,
the valve stopper, of claim 1 , arranged between the distal end of the barrel and the plunger stopper, adapted to be transitionally movable inside the barrel, wherein the lateral wall of the valve stopper sealingly engages the inner surface of the barrel.
16 . The medical injection device of claim 15 , said medical injection device being adapted to sequentially inject two compositions, wherein the valve stopper separates two chambers of the barrel including a first chamber between the valve stopper and the distal end of the barrel containing a first composition, and a second chamber between the valve stopper and the plunger stopper containing a second composition.
17 . The medical injection device of claim 15 , wherein the valve stopper has the successive following positions:
a rest position, wherein the fluid path is closed,
a sealing position, wherein the valve stopper is more distal than in the rest position, wherein the fluid path is closed, the proximal face of the membrane being subjected to a pressure that is inferior to a valve opening force of the notch,
an injection position, wherein the valve stopper abuts the distal end of the barrel, the fluid path being opened due to a pressure exerted on the proximal face of the membrane that is superior to the valve opening force of the notch.
18 . The medical injection device of claim 17 , wherein the valve stopper further has a collapsed position wherein the plunger stopper abuts the valve stopper and said valve stopper is collapsed.
19 . The medical injection device of claim 15 , being a syringe.
20 . The medical injection device of claim 15 , wherein the proximal face of the membrane has a radius of curvature which is from 1.2 to 2.3 times greater than an inner diameter of the barrel.