Convertible plungers, film coated plungers and related syringe assemblies

The plunger assembly of any preceding claim, wherein the plunger is operably connected to the plunger rod by a threaded connection between the plunger and the exterior shaft.

The plunger assembly of any preceding claim, wherein the plunger includes a connector body, the connector body including a threaded surface configured for a threaded engagement with a threaded surface of the exterior shaft.

The plunger assembly of any preceding claim, further including a film coating on at least a portion of the plunger, optionally on a sidewall and a nose cone of the plunger, wherein the film coating has a lubricity that is greater than a lubricity of a material of a sidewall of the plunger, wherein the film coating is optionally an inert fluoropolymer.

The plunger assembly of any preceding claim, wherein the plunger further comprises:

• a sleeve having a first cavity, a second cavity, and at least one rib, the at least one rib being generally aligned with the first cavity, the first cavity being in communication with the second cavity;
• and an insert configured to be displaced from the first cavity to the second cavity, wherein the insert is optionally generally spherical in shape, the insert configured to provide support for the compression of the at least one rib when the insert is positioned in the first cavity.

A dual actuated plunger comprising:

• a sleeve having a first cavity, a second cavity, and at least one rib, the at least one rib being generally aligned with the first cavity, the first cavity being in communication with the second cavity;
• and an insert configured to be displaced from the first cavity to the second cavity, wherein the insert is optionally generally spherical in shape, the insert being configured to provide support for the compression of the at least one rib when the insert is positioned in the first cavity.

A dual actuated plunger comprising:

• an insert, a sleeve, and a connector body, at least a portion of the connector body being positioned within the sleeve between the sleeve and the insert, the connector body being configured to provide support for the compression of the sleeve against an inner surface of a sidewall of a barrel.

A convertible plunger comprising an internal portion and a generally cylindrical exterior surface, wherein at least a portion of the exterior surface is maintained in an initial expanded state by a property of the internal portion, the expanded state being reducible to a constricted state by an operation that is applied to the internal portion of the plunger to alter the property.