# US 12,214,170 B2 · Auto-injector

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- Number: US 12,214,170 B2
- Document ID: US12214170B2
- Status: Granted
- Kind: B2
- Application number: 18/754,728
- Filed: 2024-06-26
- Published: 2024-10-17
- Granted: 2025-02-04
- Earliest claimed: 2011-02-18
- Assignees: Sanofi-Aventis Deutschland GmbH
- Applicants: Sanofi-Aventis Deutschland GMBH
- Inventors: Simon Francis Brereton; Thomas Kemp; Rosie Burnell; Matthew Ekman
- Web page: https://patentgrep.com/patent/US12214170B2

## CPC

- A61M 5/31501: {Means for blocking or restricting the movement of the rod or piston (A61M5/5013 takes precedence)}
- A61M 5/20: Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically (A61M5/142 takes precedence)
- A61M 5/2033: {Spring-loaded one-shot injectors with or without automatic needle insertion (multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287)}
- A61M 5/3157: {Means providing feedback signals when administration is completed (A61M5/20 takes precedence)}
- A61M 5/3158: {the component being manually operated or triggered by an axially moving actuator operated by user, e.g. an axially movable injection button}
- A61M 5/322: {Retractable needles, i.e. disconnected from and withdrawn into the syringe barrel by the piston (devices for protecting guide needles in combination with catheters A61M25/0612)}
- A61M 5/326: {Fully automatic sleeve extension, i.e. in which triggering of the sleeve does not require a deliberate action by the user}
- A61M 5/46: having means for controlling depth of insertion
- A61M 5/206: {with automatic needle insertion}
- A61M 2005/208: {Release is possible only when device is pushed against the skin, e.g. using a trigger which is blocked or inactive when the device is not pushed against the skin}
- A61M 2205/581: by audible feedback
- A61M 2205/582: by tactile feedback
- A61M 2205/583: by visual feedback
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}

## Abstract

An auto-injector for administering a dose of a liquid medicament (M) is present having a tubular chassis telescopable in a tubular case, a carrier subassembly comprising a tubular carrier slidably arranged relative to the chassis inside the case, where the carrier is adapted to contain a syringe with a hollow injection needle. The injector also has a drive spring and a plunger for forwarding load of the drive spring to a stopper of the syringe, wherein the syringe is lockable for joint axial translation with the carrier. A control spring is arranged around the carrier for translating the carrier in a proximal direction (P) for insertion of the needle through the chassis into an injection site.

## Claims

### Claim 1

An auto-injector comprising:
a housing;
a sleeve disposed within the housing, the sleeve comprising a retaining surface located on a distal end of the sleeve;
a compression spring disposed within a distal section of the sleeve and having a distal end engaged to the distal end of the sleeve;
a plunger rod disposed within the housing, the plunger rod comprising
a flange portion engaged to a proximal end of the compression spring;
a proximal portion extending from a proximal side of the flange portion and having a proximal end configured to engage a stopper of a syringe,
a distal portion extending distally from a distal side of the flange portion to a distal end of the plunger rod, the distal portion having a sidewall extending from a proximal region of the distal portion, through a central region of the distal portion, and to a distal region of the distal portion,
wherein an inner surface of the sidewall and an inner portion of the distal side of the flange portion define a central opening of the plunger rod that extends through the distal portion,
wherein a diameter of an outer surface of the sidewall is largest in the proximal region compared to the central and distal regions, and is substantially constant throughout the central region, wherein at least a portion of the outer surface in the distal region has a reduced diameter compared to the diameter throughout the central region,
wherein the outer surface, in the distal region, defines a first opening for axially coupling the plunger rod to the retaining surface of the sleeve, the first opening extending radially inward from the outer surface,
wherein the distal end of the plunger rod comprises a second opening that extends proximally from the distal end of the plunger rod and has a proximal end that is distal to the first opening, wherein the portion of the outer surface in the distal region having the reduced diameter at least partially defines the second opening,
wherein the auto-injector has (i) a first state in which the first opening and the retaining surface are engaged to one another to hold the plunger rod in a distal position within the housing and (ii) a second state in which the retaining surface has disengaged from the first opening by a radially inward deflection to release the plunger rod from being held in the distal position within the housing,
wherein the inner surface of the sidewall defines a third opening that extends radially outward from the inner surface, the third opening being located proximal to the first and second openings,
wherein the central opening intersects the second and third openings,
wherein the proximal portion has a proximal region and a distal region, an outer dimension of the proximal region of the proximal portion being larger than an outer dimension of the distal region of the proximal portion, and the proximal and distal regions of the proximal portion being substantially centered about a longitudinal axis of the housing,
wherein an axial length of the proximal portion of the plunger rod is longer than an axial length of the distal portion of the plunger rod, and
wherein the compression spring is disposed around at least the proximal and central regions of the distal portion of the plunger rod,
a button disposed at a distal end of the housing, the button comprising a proximally-extending protrusion, the auto-injector configured such that a relative axial movement between the proximally-extending protrusion and the plunger rod allows the auto-injector to change from the first state to the second state by allowing the radially inward deflection to release the plunger rod from being held in the distal position within the housing;
a second spring biasing the sleeve in a distal direction relative to the housing such that the sleeve distally moves relative to the housing during needle retraction, a diameter of the second spring being larger than a diameter of the compression spring,
a first collar disposed within the housing;
a second collar disposed within the housing and distal to the first collar, wherein the auto-injector is configured such that a predetermined relative movement between the second collar and the sleeve allows the sleeve to be released from being held in an initial position and move distally for needle retraction; and
a cap removably attached to a proximal end of the housing, the cap comprising an inner sleeve comprising a barb configured to engage a needle shield removably attached to the syringe, the auto-injector being configured such that removal of the cap from the housing removes the needle shield from the syringe when the syringe is disposed within the housing without proximally moving the syringe relative to the housing.

### Claim 2 (depends on 1)

The auto-injector of claim 1, wherein the first opening extends completely through the sidewall of the distal portion.

### Claim 3 (depends on 1)

The auto-injector of claim 1, wherein the third opening extends completely through the sidewall of the distal portion.

### Claim 4 (depends on 1)

The auto-injector of claim 1, comprising the syringe disposed within the housing, the syringe containing a medicament comprising a glucagon-like peptide-1 (GLP-1) or an analogue or derivative thereof.

### Claim 5 (depends on 1)

The auto-injector of claim 1, wherein the distal portion of the plunger rod is substantially concentric to the longitudinal axis of the housing.

### Claim 6

An auto-injector comprising:
a housing;
a sleeve disposed within the housing, the sleeve comprising a retaining surface located on a distal end of the sleeve;
a compression spring disposed within a distal section of the sleeve and having a distal end engaged to the distal end of the sleeve;
a plunger rod disposed within the housing, the plunger rod comprising
a flange portion engaged to a proximal end of the compression spring;
a proximal portion extending from a proximal side of the flange portion and having a proximal end configured to engage a stopper of a syringe,
a distal portion extending distally from a distal side of the flange portion to a distal end of the plunger rod, the distal portion having a sidewall extending from a proximal region of the distal portion, through a central region of the distal portion, and to a distal region of the distal portion,
wherein an inner surface of the sidewall and an inner portion of the distal side of the flange portion define a central opening of the plunger rod that extends through the distal portion,
wherein a diameter of an outer surface of the sidewall is largest in the proximal region compared to the central and distal regions, and is substantially constant throughout the central region,
wherein the outer surface, in the distal region, defines a first opening for axially coupling the plunger rod to the retaining surface of the sleeve, the first opening extending radially inward from the outer surface,
wherein the auto-injector has (i) a first state in which the first opening and the retaining surface are engaged to one another to hold the plunger rod in a distal position within the housing and (ii) a second state in which the retaining surface has disengaged from the first opening by a radially inward deflection to release the plunger rod from being held in the distal position within the housing,
wherein an axial length of the proximal portion of the plunger rod is longer than an axial length of the distal portion of the plunger rod, and
wherein the compression spring is disposed around at least the proximal and central regions of the distal portion of the plunger rod,
a button disposed at a distal end of the housing, the button comprising a proximally-extending protrusion, the auto-injector configured such that a relative axial movement between the proximally-extending protrusion and the plunger rod allows the auto-injector to change from the first state to the second state by allowing the radially inward deflection to release the plunger rod from being held in the distal position within the housing; and
a second spring biasing the sleeve in a distal direction relative to the housing such that the sleeve distally moves relative to the housing during needle retraction, a diameter of the second spring being larger than a diameter of the compression spring.

### Claim 7 (depends on 6)

The auto-injector of claim 6, wherein the inner surface of the sidewall defines a third opening that extends radially outward from the inner surface.

### Claim 8 (depends on 7)

The auto-injector of claim 7, wherein the third opening is located proximal to the first opening.

### Claim 9 (depends on 7)

The auto-injector of claim 7, wherein the central opening intersects the third opening.

### Claim 10 (depends on 6)

The auto-injector of claim 6, wherein the proximal portion has a proximal region and a distal region, an outer dimension of the proximal region of the proximal portion being larger than an outer dimension of the distal region of the proximal portion.

### Claim 11 (depends on 10)

The auto-injector of claim 10, wherein the proximal and distal regions of the proximal portion are substantially centered about a longitudinal axis of the housing.

### Claim 12 (depends on 6)

The auto-injector of claim 6, wherein the auto-injector is configured such that a predetermined relative movement between a collar and the sleeve allows the sleeve to be released from being held in an initial position and move distally for needle retraction.

### Claim 13 (depends on 6)

The auto-injector of claim 6, comprising a cap removably attached to a proximal end of the housing, the auto-injector being configured such that removal of the cap from the housing removes a needle shield from the syringe when the syringe is disposed within the housing without proximally moving the syringe relative to the housing.

### Claim 14 (depends on 6)

The auto-injector of claim 6, wherein at least a portion of the outer surface in the distal region of the distal portion of the plunger rod has a reduced diameter compared to the diameter throughout the central region of the distal portion of the plunger rod.

### Claim 15 (depends on 14)

The auto-injector of claim 14, wherein the distal end of the plunger rod comprises a second opening that extends proximally from the distal end of the plunger rod and has a proximal end that is distal to the first opening.

### Claim 16 (depends on 15)

The auto-injector of claim 15, wherein the portion of the outer surface in the distal region of the proximal portion having the reduced diameter at least partially defines the second opening.

### Claim 17

An auto-injector comprising:
a housing;
a sleeve disposed within the housing, the sleeve comprising a retaining surface located on a distal end of the sleeve;
a compression spring disposed within a distal section of the sleeve and having a distal end engaged to the distal end of the sleeve;
a plunger rod disposed within the housing, the plunger rod comprising
a flange portion engaged to a proximal end of the compression spring;
a proximal portion extending from a proximal side of the flange portion and having a proximal end configured to engage a stopper of a syringe,
a distal portion extending distally from a distal side of the flange portion to a distal end of the plunger rod, the distal portion having a sidewall extending from a proximal region of the distal portion, through a central region of the distal portion, and to a distal region of the distal portion,
wherein an inner surface of the sidewall and an inner portion of the distal side of the flange portion define a central opening of the plunger rod that extends through the distal portion,
wherein the distal region defines a first opening for axially coupling the plunger rod to the retaining surface of the sleeve, the first opening extending radially inward from an outer surface of the distal portion,
wherein the auto-injector has (i) a first state in which the first opening and the retaining surface are engaged to one another to hold the plunger rod in a distal position within the housing and (ii) a second state in which the retaining surface has disengaged from the first opening by a radially inward deflection to release the plunger rod from being held in the distal position within the housing,
wherein the inner surface of the sidewall defines a third opening that extends radially outward from the inner surface, the third opening being located proximal to the first opening,
wherein an axial length of the proximal portion of the plunger rod is longer than an axial length of the distal portion of the plunger rod, and
wherein the compression spring is disposed around at least the proximal and central regions of the distal portion of the plunger rod,
a button disposed at a distal end of the housing, the button comprising a proximally-extending protrusion, the auto-injector configured such that a relative axial movement between the proximally-extending protrusion and the plunger rod allows the auto-injector to change from the first state to the second state by allowing the radially inward deflection to release the plunger rod from being held in the distal position within the housing; and
a second spring biasing the sleeve in a distal direction relative to the housing such that the sleeve distally moves relative to the housing during needle retraction, a diameter of the second spring being larger than a diameter of the compression spring.

### Claim 18 (depends on 17)

The auto-injector of claim 17, wherein the distal end of the plunger rod comprises a second opening that extends proximally from the distal end of the plunger rod and has a proximal end that is distal to the first opening.

### Claim 19 (depends on 18)

The auto-injector of claim 18, wherein at least a portion of the outer surface in the distal region has a reduced diameter compared to the diameter throughout the central region.

### Claim 20 (depends on 19)

The auto-injector of claim 19, wherein the portion of the outer surface in the distal region having the reduced diameter at least partially defines the second opening.

### Claim 21 (depends on 18)

The auto-injector of claim 18, wherein the central opening intersects the second and third openings.

### Claim 22 (depends on 17)

The auto-injector of claim 17, wherein the proximal portion of the plunger rod has a proximal region and a distal region, an outer dimension of the proximal region of the proximal portion of the plunger rod being larger than an outer dimension of the distal region of the proximal portion of the plunger rod.

### Claim 23 (depends on 22)

The auto-injector of claim 22, wherein the proximal and distal regions of the proximal portion of the plunger rod are substantially centered about a longitudinal axis of the housing.

### Claim 24 (depends on 17)

The auto-injector of claim 17, wherein the auto-injector is configured such that a predetermined relative movement between a collar and the sleeve allows the sleeve to be released from being held in an initial position and move distally for needle retraction.

### Claim 25 (depends on 17)

The auto-injector of claim 17, comprising the syringe containing a medicament comprising a glucagon-like peptide-1 (GLP-1) or an analogue or derivative thereof.

### Claim 26

An auto-injector comprising:
a housing;
a sleeve disposed within the housing, the sleeve comprising a retaining surface located on a distal end of the sleeve;
a compression spring disposed within a distal section of the sleeve and having a distal end engaged to the distal end of the sleeve;
a plunger rod disposed within the housing, the plunger rod comprising
a flange portion engaged to a proximal end of the compression spring;
a proximal portion extending from a proximal side of the flange portion and having a proximal end configured to engage a stopper of a syringe,
a distal portion extending distally from a distal side of the flange portion to a distal end of the plunger rod, the distal portion having a sidewall extending from a proximal region of the distal portion, through a central region of the distal portion, and to a distal region of the distal portion,
wherein the distal region defines a first opening for axially coupling the plunger rod to the retaining surface of the sleeve, the first opening extending radially inward from an outer surface of the distal portion,
wherein the proximal portion has a proximal region and a distal region, an outer dimension of the proximal region of the proximal portion being larger than an outer dimension of the distal region of the proximal portion, and the proximal and distal regions of the proximal portion are substantially centered about a longitudinal axis of the housing,
wherein the auto-injector has (i) a first state in which the first opening and the retaining surface are engaged to one another to hold the plunger rod in a distal position within the housing and (ii) a second state in which the retaining surface has disengaged from the first opening by a radially inward deflection to release the plunger rod from being held in the distal position within the housing,
wherein an axial length of the proximal portion of the plunger rod is longer than an axial length of the distal portion of the plunger rod, and
wherein the compression spring is disposed around at least the proximal and central regions of the distal portion of the plunger rod,
a button disposed at a distal end of the housing, the button comprising a proximally-extending protrusion, the auto-injector configured such that a relative axial movement between the proximally-extending protrusion and the plunger rod allows the auto-injector to change from the first state to the second state by allowing the radially inward deflection to release the plunger rod from being held in the distal position within the housing; and
a second spring biasing the sleeve in a distal direction relative to the housing such that the sleeve distally moves relative to the housing during needle retraction, a diameter of the second spring being larger than a diameter of the compression spring.

### Claim 27 (depends on 26)

The auto-injector of claim 26, wherein the auto-injector is configured such that a predetermined relative movement between a collar and the sleeve allows the sleeve to be released from being held in an initial position and move distally for needle retraction.

### Claim 28 (depends on 27)

The auto-injector of claim 27, comprising a cap removably attached to a proximal end of the housing, the auto-injector being configured such that removal of the cap from the housing removes a needle shield from the syringe when the syringe is disposed within the housing without proximally moving the syringe relative to the housing.

### Claim 29 (depends on 26)

The auto-injector of claim 26, wherein an inner surface of the sidewall defines a third opening that extends radially outward from the inner surface, the third opening being located proximal to the first opening.

### Claim 30 (depends on 26)

The auto-injector of claim 26, wherein the auto-injector is configured to deliver a medicament from the syringe, and the medicament comprises a glucagon-like peptide-1 (GLP-1) or an analogue or derivative thereof.