Prefilled, sterilized syringe with a new and improved plug
AssigneeSchering Corporation
InventorsReiner Kolberg, Ralf-Siegbert Hauck
Life of this patent
Estimating the term…
Abstract
A prefilled medicinal syringe includes a cylinder with a proximal end, a distal end and an outlet. The syringe contains a medicine or a diagnostic agent which is ejected therefrom by a plug. The surfaces of the plug which touch the inside wall of the cylinder are preferably made of polytetrafluoroethylene (TEFLON.RTM.). Preferably the material of which the inside wall of the cylinder is made directly touches the TEFLON.RTM. surfaces of the plug. The plug has at least one sealing lip which forms an acute angle with the axis of the syringe and extends in a direction toward the distal end of the syringe. By so configuring the plug, the prefilled syringe may be autoclaved, stored for an extended time, and still function smoothly without leakage.
Claims23
A prefilled, sterilized, autoclaveable syringe for injecting a fluid medium in the form of a medicine or diagnostic agent wherein the syringe has a selected shelf life, comprising:
- a hollow cylinder of plastic or glass adapted to contain the fluid medium, the cylinder having a smooth cylindrical inner wall surface, a distal end with an outlet and a proximal end for receiving a plunger shaft therethrough;
- a cylindrical plug having a body portion with an axis, the plug being disposed for sliding movement in an axial direction with the hollow cylinder toward the distal end, the plug being adapted to eject the fluid medium from the hollow cylinder by pushing the medium with a distal face of the plug which is adapted to engage the medium;
- the plug having a non-sealing substantially cylindrical portion disposed adjacent to the smooth cylindrical inner wall or surface;
- an annular lip obliquely extending with respect to the axis of the plug in a radial and axial direction from the body portion of the plug, the obliquely extending annular lip having a first surface forming part of the distal face of the plug which is adapted to engage the fluid medium, and a second surface which directly touches the smooth cylindrical inner wall surface of the hollow cylinder, a third surface joining the plug body at a location axially spaced from the first surface, to define a root of the lip where the first and third surfaces join the body of the plug;
- elastic forces in the lip when the plug is at rest within the cylinder having a tension zone in the first surface and a compression zone in another surface;
- and
- at least the annular lip being made of a material selected from the group consisting of polypropylene and polyethylene, wherein the hydrogen atoms of the polypropylene and polyethylene are at least partially replaced by fluorine atoms resulting in polyfluoropropylene and polyfluoroethylene;
- whereby the lip experiences insignificant cold flow during storage so that a selected plug remains sealed during the shelf life of the syringe and the plug does not have excessive frictional drag when used after storage during the shelf life.
A prefilled medical syringe which has been sterilized after prefilling comprising:
- a hollow cylinder of glass or plastic with an inner wall surface, a proximal end and a distal end, the cylinder containing an injectable material in the form of a medicine or injectable material;
- a plug within the hollow cylinder adapted to push the injectable material from the cylinder through the distal end and for sealing the proximal end, the plug being unitary and made of polypropylene or polyethylene material wherein the hydrogen atoms of the polypropylene and polyethylene are at least partially replaced by fluorine atoms resulting in polyfluoropropylene or polyfluoroethylene;
- and
- the plug having a cylindrical portion not in sealing relation with the inside cylindrical wall and an annular lip unitary with the plug and sealingly engaging the plug material with the wall to effect a seal therewith.
Dependencies are inferred from the claim text.