Patent Description:
Medicament delivery devices which are capable of delivering medicaments from a medicament cartridge are well known. Typically, a user must provide energy to drive a medicament through a needle. In case of a manually operable device, this is done by a stopper that has to be continuously pressed during the injection. The stopper is usually made from a soft material, e. natural rubber or synthetic rubber. However, the soft material of the stopper may cause dose accuracy problems, respectively when delivering high concentrated medicaments, such as insulin with a concentration of more than <NUM> insulin units/ml. Injection forces may be too high for the user, in particular if the patient is elderly or has dexterity problems. In this case, the user might deliver an underdose or an overdose resulting in health risks, e. Hypoglycemia.

<CIT> describes a piston stopper for an injection device, wherein the piston stopper includes a stopper body manufactured from an inflexible material and a stopper body holder detachably connected to it. A membrane body is placed like a cap onto the stopper body, wherein the membrane is formed from an elastic material.

Furthermore, <CIT>, <CIT>, <CIT> and <CIT> describe piston stoppers for injection devices.

Moreover, <CIT> describes a composite hypodermic syringe piston comprising a rigid inner sheath part and a resilient elastic outer sheath part. The parts are chemically fused in a modular mold. <CIT> describes a syringe comprising a stopper with a rigid plunger rod tip and an elastomeric plunger ring. <CIT> describes an injection device comprising a plunger having a recess with a ramp surface that urges a gripper element, wherein the gripper element may be an 'O' ring.

Furthermore, <CIT>, <CIT> and <CIT> describe piston stoppers for injection devices.

Thus, there remains a need for an improved medicament delivery device.

It is an object of the present invention to provide an improved medicament delivery device.

The object is achieved by a medicament delivery device according to claim <NUM>.

Exemplary embodiments of the invention are given in the dependent claims.

According to the invention, a medicament delivery device comprises a medicament cartridge adapted to contain a medicament and a stopper slidably arranged within the cartridge. According to the invention, the stopper comprises a rigid body that is enclosed partially by a soft sealing component.

The rigid body reduces the elasticity of the stopper compared to a soft stopper and thus allows reduced injection forces required to drive the medicament from the cartridge through a needle and a better dose accuracy as well as a shorter injection times compared to the state of the art. This is particularly useful if a high concentrated medicament, such as insulin with a concentration of more than <NUM> insulin units, has to be delivered in small dose volume increments.

In an exemplary embodiment, the rigid body of the stopper is made from a hard plastic material such as polypropylene (e.g., Borealis Bormed™ BE860MO, Borealis Bormed™ BH348MO, Borealis Bormed™ DM55pharm, Borealis Bormed™ HD810MO, Borealis Bormed™ HD850MO, Borealis Bormed™ HF840MO, Borealis Bormed™ HF855MO, Borealis Bormed™ RB801CF, Borealis Bormed™ RD804CF, Borealis Bormed™ RD808CF, Borealis Bormed™ RE806CF, Borealis Bormed™ RF825MO, Borealis Bormed™ RF830MO, Borealis Bormed™ RG835MO, Borealis Bormed™ SC820CF, Borealis Bormed™ TD109CF), polyethylene (e.g., high-density polyethylene (HDPE), such as e.g. PE GF <NUM>), polyoxymethylene, polyamide or cyclo olefin copolymer (e.g. Zeon Chemical's Zeonex™).

Furthermore, a diameter of the rigid body is smaller than an inner diameter of the cartridge. Thus, the rigid body alone cannot seal against an inner wall of the cartridge. This allows the arrangement of the soft sealing component.

According to the invention, the soft sealing component comprises two sealing portions, each forming a ring around the circumference of the rigid body, wherein the sealing portions are spaced from each other in the direction of a longitudinal axis of the cartridge. The sealing portions enable a local elasticity of the stopper just for a required sliding movement of the stopper within the cartridge. The ring-shaped arrangement of the sealing portions compared to a full soft cover of the rigid body maintains the advantage of low injection force, because there is a reduced contact area between the stopper and a cartridge inner wall compared to a stopper that is made completely by a soft rubber material. This requires less injection forces, so that the injection process is user-friendly in particular if the patient is elderly.

In an exemplary embodiment, the soft sealing component comprises two sealing portions, each forming a ring around the circumference of the rigid body, wherein the sealing portions are spaced from each other in the direction of a longitudinal axis of the cartridge and the surface where the soft sealing component is contacting the rigid material in a groove which has a slope versus the longitudinal axis. Said groove having said slope ensures freedom to move for the soft sealing component and optimum positioning and constant friction force.

In an exemplary embodiment, the soft sealing component is made from or comprises a resilient material such as natural rubber or synthetic rubber. Some examples are punched o-rings from bromobutyl compound or injection moulded o-rings made of thermoplastic styrene block copolymers.

In a further exemplary embodiment, the cartridge is made from or comprises glass.

In an exemplary embodiment, an inner wall of the medicament cartridge is coated with a sliding layer enabling an easy sliding of the stopper within the cartridge.

In an exemplary embodiment, the sliding layer comprises silicon oil.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the invention, are given by way of illustration only, since various changes and modifications of the invention will become apparent to those skilled in the art from this detailed description.

The present invention will become more fully understood from the detailed description given herein below and the accompanying drawing that is given by way of illustration only, and thus, is not limitative of the present invention, and wherein:.

<FIG> is a schematic longitudinal section of an exemplary embodiment of a medicament delivery device <NUM> with a longitudinal axis A extending from a proximal direction P to a distal direction D. The shown medicament delivery device <NUM> may be designed as an injection pen device.

In an exemplary embodiment, the medicament delivery device <NUM> comprises a case <NUM> that is adapted to receive a pre-filled medicament cartridge <NUM>.

The case <NUM> extends from a proximal end <NUM> to a distal end <NUM> and is of a substantially cylindrical shape. In an exemplary embodiment, the case <NUM> comprises a dose window <NUM> presenting a set dose of a medicament M, i. high concentrated insulin, contained in the medicament cartridge <NUM>. In an exemplary embodiment, the dose is settable by operating a dial knob <NUM>. The dial knob <NUM> is coupled to the case <NUM> on its proximal end <NUM>. The dial knob <NUM> is rotatable around the longitudinal axis A with respect to the case <NUM>, whereby a dose is set by turning the dial knob <NUM> in a predetermined direction about the longitudinal axis A. Alternatively, the medicament delivery device <NUM> may be configured for administering a fixed dose of the medicament M without having to turn the dial knob <NUM>.

The medicament cartridge <NUM> is coupled to the case <NUM> with respect to movement in the proximal direction P and the distal direction D. The medicament cartridge <NUM> may be releasably connected to or retained fixed to the case <NUM>.

The medicament cartridge <NUM> comprises a cartridge body <NUM> that may be made from glass and adapted to contain the medicament M, e.g. high concentrated insulin. The cartridge body <NUM> is designed as a generally tubular barrel with a not shown open proximal end and a distal end <NUM>. <NUM>, e.g. defined by an inwardly converging shoulder <NUM>. In an exemplary embodiment, a small diameter neck <NUM>. <NUM> projects distally from the shoulder <NUM>. <NUM> and is provided with a large diameter annular bead <NUM>. <NUM> extending circumferentially. A pierceable septum <NUM>. <NUM> extends across the open distal end <NUM>. <NUM> defined by the neck <NUM>. The septum <NUM>. <NUM> is held in place by a ferrule <NUM>. <NUM> which is crimped around the annular bead <NUM>. <NUM> at a distal end of the neck <NUM>.

The medicament M is pre-filled into the cartridge body <NUM> and is retained therein by a stopper <NUM>. The stopper <NUM> is slidably movable within an inner wall of the cartridge body <NUM>, wherein the inner wall of the cartridge body <NUM> is coated with a sliding layer <NUM> that may comprise silicon oil to enable an easy sliding of the stopper <NUM> on the inner wall of the cartridge body <NUM>.

The stopper <NUM> comprises a rigid body <NUM>. <NUM> with a proximal end <NUM>. <NUM>, a distal end <NUM>. <NUM> and a length that extends along the longitudinal axis A. A diameter of the rigid body <NUM>. <NUM> is smaller than an inner diameter of the cartridge body <NUM>, thus the rigid body <NUM>. <NUM> alone cannot seal against the inner wall of the cartridge body <NUM>. The rigid body <NUM>. <NUM> is made from a hard plastic material such as polypropylene, polyethylene, polyoxyethylene, polyamide or cycloolefin-copolymer.

The stopper <NUM> further comprises a soft sealing component <NUM>. <NUM> that slides on the inner wall of the cartridge body <NUM> during an injection process. In the shown exemplary embodiment, the soft sealing component <NUM>. <NUM> comprises two sealing portions <NUM>. <NUM>, <NUM>. <NUM>, each forming a ring around the circumference of the rigid body <NUM>. <NUM>, wherein the sealing portions <NUM>. <NUM>, <NUM>. <NUM> are spaced from each other in the direction of the longitudinal axis A. Alternatively, the soft sealing component <NUM>. <NUM> comprises only one of the sealing portions <NUM>. <NUM>, <NUM>. <NUM> or more than two sealing portions <NUM>. <NUM>, <NUM>.

The sealing portions <NUM>. <NUM>, <NUM>. <NUM> are made from a resilient material such as natural rubber or synthetic rubber for a fluid-tight engagement of the stopper <NUM> within the cartridge body <NUM>.

The provided two-component stopper <NUM> requires low injection force, particularly when delivering high concentrated medicaments M, and high elasticity of the stopper <NUM> for a fluid-tight engagement of the stopper <NUM> within the cartridge body <NUM>.

The medicament delivery device <NUM> further comprises a piston rod <NUM> that is movable along the longitudinal axis A with respect to the cartridge body <NUM> and that is coupled to the stopper <NUM> for moving the stopper <NUM> in the distal direction D within the cartridge <NUM>, thus dispensing the medicament dose through a hollow needle <NUM> into a patient. Therefore, the piston rod <NUM> is coupled to the dial knob <NUM> that transfers a movement to the piston rod <NUM> when a user presses the dial knob <NUM> into the distal direction D. In case of using Insulin as the medicament, the movement of the piston rod <NUM> and consequently the stopper <NUM> for single dose increments could be less than <NUM>,<NUM>.

The needle <NUM> is pierced through the septum <NUM>. <NUM> and comprises a proximal tip <NUM> and a sharp distal tip <NUM>. The proximal tip <NUM> is in fluid communication with the medicament M contained in the cartridge body <NUM>, wherein the sharp distal tip <NUM> has to be inserted into a patient's skin for medicament delivery.

The stopper <NUM> may likewise be applied in a medicament cartridge <NUM> arranged as a syringe with a fixed injection needle <NUM>.

<FIG> shows a schematic longitudinal section of an exemplary embodiment of a stopper. Also shown is an example placement of the soft sealing component. Groove <NUM>. <NUM> holds the soft sealing components in their place but allows some movement for said components. This is to allow the said components to adjust to the actual friction between sliding layer <NUM> and sealing portions <NUM>. <NUM> and <NUM>. The bottom of groove <NUM>. <NUM> has a slope <NUM>. <NUM> which is an additional means to keep the friction constant during gliding.

Hormones are for example hypophysis hormones or hypothalamus hormones or regulatory active peptides and their antagonists as listed in Rote Liste, ed. <NUM>, Chapter <NUM>, such as Gonadotropine (Follitropin, Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin), Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin, Buserelin, Nafarelin, Goserelin.

Antibodies are globular plasma proteins (-<NUM> kDa) that are also known as immunoglobulins which share a basic structure. As they have sugar chains added to amino acid residues, they are glycoproteins. The basic functional unit of each antibody is an immunoglobulin (Ig) monomer (containing only one Ig unit); secreted antibodies can also be dimeric with two Ig units as with IgA, tetrameric with four Ig units like teleost fish IgM, or pentameric with five Ig units, like mammalian IgM.

Claim 1:
Medicament delivery device (<NUM>), comprising
- a medicament cartridge (<NUM>) adapted to contain a medicament (M) and
- a stopper (<NUM>) slidably arranged within the cartridge (<NUM>),
wherein the stopper (<NUM>) comprises a rigid body (<NUM>.<NUM>) that is enclosed partially by a soft sealing component (<NUM>.<NUM>),
characterised in that the soft sealing component (<NUM>.<NUM>) comprises at least two sealing portions (<NUM>.<NUM>, <NUM>.<NUM>), each forming a ring around the circumference of the rigid body (<NUM>.<NUM>),
- wherein the sealing portions (<NUM>.<NUM>, <NUM>.<NUM>) are spaced from each other in the direction of a longitudinal axis (A) of the cartridge (<NUM>),
- wherein each of the sealing portions is arranged in a groove (<NUM>.<NUM>),
- wherein said groove (<NUM>.<NUM>) comprises a groove bottom,
- wherein said groove bottom exhibits a slope (<NUM>.<NUM>) with respect to the longitudinal axis (A) of the cartridge (<NUM>) and
- wherein the slope (<NUM>.<NUM>) rises from a distal end (<NUM>.<NUM>) of the stopper (<NUM>) to a proximal end (<NUM>.<NUM>) of the stopper (<NUM>).