Three-position plungers, film coated plungers and related syringe assemblies
A three-position plunger is provided including a sleeve having an opening at a distal end, a pre-load cavity proximal to and in communication with the opening, a first cavity proximal to and in communication with the pre-load cavity, a second cavity proximal to and in communication with the pre-load cavity, and at least one rib. The rib(s) is generally aligned with the first cavity. The plunger further includes an insert configured to be displaced from the pre-load cavity to the first cavity and from the first cavity to the second cavity. The insert is configured to provide support for the compression of the rib(s) when the insert is positioned in the first cavity.
1. A prefilled syringe comprising a barrel having an inner wall and a drug product contained within a product containing area, the prefilled syringe further comprising: a three-position plunger disposed in its entirety within the barrel, the three-position plunger having a generally cylindrical exterior surface, the three-position plunger comprising: a sleeve having an opening at a distal end thereof, a nose cone and a sidewall including a storage sealing section that comprises at least one rib and a liquid sealing section disposed between the nose cone and the storage sealing section, the sleeve further comprising a pre-load cavity proximal to and in communication with the opening, a first cavity proximal to and in communication with the pre-load cavity, and a second cavity proximal to and in communication with the first cavity, the at least one rib being generally aligned with the first cavity the three-position plunger further comprising an insert that is pre-inserted into the pre-load cavity in a pre-load mode in which compressive force or radial pressure that the three-position plunger exerts against the inner wall is unaffected by disposal of the insert in the pre-load cavity, the insert being configured to be displaced from the pre-load cavity to the first cavity and from the first cavity to the second cavity, the insert being configured to compress the at least one rib outwardly when the insert is positioned in the first cavity, the storage sealing section being generally aligned with the first cavity and maintaining an expanded state by the insert being disposed within the first cavity, the insert applying outward radial pressure against an interior surface of the three-position plunger at a location radially inward of the storage sealing section, the expanded state providing a compressive force of the storage sealing section against the inner wall, the three-position plunger being reducible to a constricted state, wherein the compressive force against the inner wall is reduced or removed entirely by effectuating axial displacement of the insert from the first cavity to the second cavity upon application of force onto the three-position plunger in a direction toward the drug product, wherein the three-position plunger in the constricted state provides less compressive force against the sidewall than when in the expanded state, such that force needed to axially displace the three-position plunger in the constricted state is less than would be required to axially displace the three-position plunger in the expanded state, and wherein the liquid sealing section provides a liquid tight seal against the inner wall both when the three-position plunger is in the expanded state and when the three-position plunger is in the constricted state.
2. The prefilled syringe of claim 1 , wherein the three-position plunger further includes a connector body operably connected to the sleeve, wherein a portion of the connector body is positioned within the sleeve and is configured to provide support for compression of the sleeve against an inner surface of the inner wall of the barrel.
3. The prefilled syringe of claim 2 , wherein the three-position plunger further includes a plunger rod having a shaft configured to displace the insert from the first cavity to the second cavity when the shaft is displaced from a first position to a second position, wherein the plunger rod is operably connected to the connector body.
4. The prefilled syringe of claim 1 , wherein the three-position plunger further includes a film coating or molded cap on at least a portion of the sleeve, wherein the film coating or molded cap has a lubricity that is greater than a lubricity of a material of a sidewall of the plunger.
5. The prefilled syringe of claim 1 , wherein the syringe is made from an injection moldable thermoplastic material and comprises an organo-siloxane coating or layer, as a plunger-contacting surface, substantially without presence of a flowable lubricant.
6. The prefilled syringe of claim 5 , wherein the organo-siloxane coating or layer is a pH protective coating, as a top layer of a trilayer coating set.
7. The prefilled syringe of claim 1 , the sleeve having an external profile that is unaffected by disposal of the insert in the pre-load cavity.
8. The prefilled syringe of claim 1 , wherein a narrowing transition region separates each cavity from an adjacent cavity so as to make each cavity a physically distinct compartment.
9. The prefilled syringe of claim 8 , the sleeve having an external profile that is unaffected by disposal of the insert in the pre-load cavity.