US 2017/0246394 A1 · PLUNGER WITH REDUCED LEAKAGE DURING STORAGE

Abstract

A plunger seal for a drug delivery device may have a mobile and an enhanced sealing parked state. Optionally, the cartridge is stored with the plunger seal in the parked state. Optionally, drug discharge occurs with the plunger seal in the mobile state. For example in the parked state there may be increased normal force between the plunger seal and an inner wall of the cartridge. Optionally there is limited deformation of the plunger seal between the parked and mobile states. Optionally the plunger seal is biased to the parked state. Optionally, a distal force switches the plunger seal to the mobile state. For example, the plunger seal may have an inner cavity that is expanded radially by core. A biasing element optionally biases the core wedging it proximally to the parked state. A distal force on the core may push it distally to the mobile state.

Claims20

Dependent claims

A method of packaging a drug in a reservoir the reservoir including a cylindrical bore with a proximal opening, said cylindrical bore prefilled in a distal portion thereof with the drug, the method comprising:

providing a plunger seal inserted into said bore in a first state wherein an external surface of said plunger seal includes a sealing region;
moving said plunger seal distally in said bore while the plunger seal is in said first state from outside the bore to a sealing position in the bore between said drug and said proximal opening;
switching said plunger seal to a parked state in said sealing position, said parked state having an increased normal force between said sealing region and an inner surface of said cylindrical bore of said reservoir said increased normal force resulting an increase in friction resistance to longitudinal movement of the plunger seal against the inner wall of the reservoir of at least 30% with respect to said first state and wherein a distortion in the shape of said sealing region between said first state and said parked state is less than 0.2 mm.

Dependencies are inferred from the claim text.

Plunger with reduced leakage during storage

Life of this patent

Plunger with reduced leakage during storage

Life of this patent

Abstract

Claims20