Patent Application
20160296710
The present disclosure relates to a drive assembly for a drug delivery device and a drug delivery device comprising a drive assembly. In particular, the drug delivery device may be configured to deliver variable user selectable doses of a medicinal product. The drug delivery device may be spring driven. As an example, the drug delivery device may be an autoinjector, in particular a semi-automatic autoinjector.
It is an object of the present invention to disclose a drive assembly having improved properties.
According to a first aspect, a drive assembly for a drug delivery device is provided. The drive assembly comprises a dose setting member for setting a dose of a drug and an indicator for indicating the size of the set dose.
As an example, the dose setting member may be rotated for setting a dose of a drug. The amount of rotation of the dose setting member may determine the size of the set dose. In particular, a user may vary the size of the set dose by operating the dose setting member. The indicator may comprise numbers and/or graduations for indicating the size of the set dose. During a dose setting operation, the indicator may move such that a number or graduation corresponding to the currently set dose is displayed to a user.
The drive assembly may comprise a spring member. The spring member may provide a force for dispensing the set dose. In particular, the drive assembly may comprise a piston rod, wherein the spring member is configured to drive the piston rod towards a dispensing end of a drug delivery device during a dose dispense operation. The spring member may be a compression spring or a torsion spring, for example. The spring member may be tensioned during a dose setting operation. Alternatively, the spring member may be configured such that a tensioning before the first use of the device is sufficient to deliver all doses. In this case, a further tensioning during dose setting may not be required. The spring member may relax during a dose dispensing operation.
According to an embodiment, the indicator of the drive assembly may be configured to move towards an initial position during dose dispense. An initial position of the indicator may be a position in which the indicator indicates a zero size of a dose. Accordingly, the indicator indicates that no dose is set.
The drive assembly may comprise a piston rod. As an example, the piston rod may be configured as a lead screw or a toothed rack. The piston rod may be rigid or flexible. The piston rod may be configured to act on a piston in a cartridge, in particular to move the piston during a dose dispense operation. The piston rod may comprise or may be connected to a bearing, wherein the piston rod may act on the piston via the bearing.
During dose dispensing, the indicator may be coupled to the piston rod. The indicator may be coupled to the piston rod via a coupling member. In particular, “coupling” may mean that a movement of the piston rod results in a movement of the indicator. Due to the coupling, the indicator may be moved to its initial position when the piston rod moves in a dose dispense operation. Thereby, the indicator is automatically reset to its initial position when the set dose has been dispensed.
In one embodiment, an operation of the dose setting member may cause a decoupling of the indicator from the piston rod. In particular, the indicator may be releasably coupled to a reversing member coupled to the piston rod. The indicator may be decoupled from the reversing member by an operation of the dose setting member. As an example, the drive assembly may be configured such that the dose setting member has to be depressed before a dose can be set. A depression of the dose setting member may cause the decoupling. In particular, the depression may move the coupling member, which may be permanently connected to the indicator, out of engagement with the reversing member. The reversing member may be coupled to the piston rod, in particular permanently coupled to the piston rod. The coupling may be directly or via a further member, for example a drive control member which controls the movement of the piston rod. After the operation of the dose setting member, the indicator may be re-coupled to the piston rod, in particular re-coupled to the reversing member.
In a further embodiment, the drive assembly may comprise an actuator for initiating a dispensing of a dose, in particular after a dose has been set. In particular, the indicator may be coupled to a reversing member coupled to the piston rod. An operation of the actuator may cause a coupling of the indicator to the piston rod. As an example, the actuator may result in an engagement of a coupling member, which may be connected to the indicator, with the reversing member. The reversing member may be coupled to the piston rod, in particular engaged with the piston rod, and may be driven by the piston rod during a dose dispense operation. After the operation of the actuator member, the indicator may be decoupled from the piston rod, in particular decoupled from the reversing member.
Furthermore, during dose setting the indicator may be coupled to the dose setting member. Thereby, a movement of the dose setting member may result in a movement of the indicator. The indicator may be permanently connected to the dose setting member. Alternatively, during dose dispensing the indicator may be decoupled from the dose setting member. As an example, an operation of an actuator may cause the decoupling.
According to an embodiment, the drive assembly comprises a dispense stop for limiting a movement of a piston rod and/or a movement of the indicator during dose dispense. By limiting the movement of the piston rod, the dispense stop may ensure that the correct amount of the dose, i.e. the amount of the set dose, is dispensed. By limiting the movement of the indicator, the dispense stop may ensure that the indicator returns to its initial position.
The dispense stop may comprise a stop feature. The stop feature may be configured to move, in particular rotate, during dose setting. Thereby, an end stop position of the stop feature may be set. The end stop position of the stop feature may define the end stop position of the indicator and/or the piston rod. The stop feature may be connected to the indicator, in particular permanently connected to the indicator. As an example, the stop feature may be an integral part of the indicator. Alternatively, the stop feature may be coupled to the indicator during dose setting. As an example, the stop feature may be connected to a further member, which may be coupled to the indicator during dose setting. The further member may be decoupled from the indicator during dose dispensing.
The stop feature may be fixed during dose dispensing. In particular, the stop feature may be fixed relative to a housing of the drive assembly.
The drive assembly may comprise a further stop feature. The movement of the piston rod and/or the indicator may be stopped by an abutment of the stop feature and the further stop feature. The further stop feature may be connected to, in particular be an integral part of, a member coupled to the piston rod during dose dispense. As an example, the further stop feature may be connected to a drive control member, which controls the movement of the piston rod. Alternatively, the further stop feature may be connected to the housing of the drive assembly, for example may be an integral part of the housing.
The further stop feature may be configured to move during dose dispensing and may be fixed during dose setting, in particular fixed to the housing. Alternatively, the further stop member may be permanently fixed to the housing. In particular, when the stop feature is enabled to move, the further stop feature may be disabled from moving and vice versa.
According to a further aspect, a drug delivery device comprising a drive assembly is provided. The drive assembly may be the drive assembly disclosed above such that every structural and functional feature disclosed with respect to that drive assembly may also be present in the drug delivery device.
The drug delivery device may further comprise a cartridge comprising a piston wherein the drive assembly is adapted to provide a force on the piston such that the piston is moved in the distal direction further into the cartridge. Thereby, a drug may be expelled from the cartridge.
The term “distal end” may describe an end of the device or a part thereof which is closest to a dispensing end of the device. The term “proximal end” may describe an end of the device or a part thereof which is furthest away from the dispensing end of the device. Analogously, the term “distal direction” may describe a direction towards a dispensing end of the device and the term “proximal direction” may describe a direction away from the dispensing end of the device.
The drug delivery device may be an injection device. The medicament may be delivered to a user by means of a needle. The drug delivery device may be configured for multiple dose applications. The drug delivery device may be a pen-type device. The drug delivery device may be disposable. The term “disposable” means, that the drug delivery device cannot be reused after an available amount of a medication has been delivered from the drug delivery device. The drug delivery device may be configured to deliver a liquid medication. The medication may be, for example, insulin.
According to an embodiment, the drive assembly comprises a last dose stop for preventing a setting of a dose larger than an available amount of the drug.
In particular, the last dose stop may prevent a further operation of the dose setting member in a dose setting direction when the available dose has been set. However, in this state, the last dose stop may allow a movement of the dose setting member in a dose cancelling direction in order to decrease the size of the set dose. The dose cancelling direction may be opposite to the dose setting direction. Furthermore, when the available dose has been set, dispensing a last dose may be enabled.
The last dose stop may comprise a last dose stop member. The last dose stop member may be configured to move towards an end position during the setting of a dose. When the last dose stop member is at the end position, a further increase of the size of the set dose may be prevented. In particular, in the end position, a movement of the last dose stop member in at least one direction may be prevented. Thereby, also a movement of the dose setting member in the dose setting direction may be prevented.
During dose setting, the last dose stop member may be coupled to the dose setting member such that an operation of the dose setting member results in a movement of the last dose stop member. As an example, the last dose stop member may be coupled to the dose setting member via further members of the drive assembly. During a movement of the dose setting member in a dose cancelling direction, for example when decreasing or fully cancelling a set dose, the last dose stop member may move towards a start position. Thereby, the available dose always corresponds to the position of the last dose stop member. During a dose dispensing operation, the last dose stop member may be decoupled from the dose setting member.
The drive assembly may comprise a housing. The last dose stop member may be rotationally fixed to the housing. In particular, the last dose stop member may be rotationally fixed to the housing both during dose setting and dose dispensing operations. A translational movement of the last dose stop member relative to the housing may be allowed.
The drive assembly may comprise a last dose stop drive member. In particular, the last dose stop member may be engaged, for example threadedly engaged, with the last dose stop drive member. The last dose stop drive member may be configured to drive the last dose stop member, in particular cause a movement of the last dose stop member during a dose setting operation and/or a dose cancelling operation.
The last dose stop drive member may be translationally fixed to a housing, in particular permanently translationally fixed to the housing. During a dose setting operation, a rotational movement of the last dose stop drive member may be enabled. In particular, the last dose stop drive member may be configured to rotate during a dose setting operation. Thereby, the last dose stop member may be moved along the last dose stop drive member. During a dose dispensing operation, the last dose stop drive member may be rotationally and translationally fixed to the housing. Thereby, any movement of the last dose stop member may be prevented.
Furthermore, a setting of a dose larger than an available amount of the drug may be prevented by an interaction of the last dose stop member with the last dose stop drive member. In particular, the last dose stop member may comprise a stop face and the last dose stop drive member may comprise a stop face. When the stop faces abut, a further setting of a dose may be prevented. In particular, the position of the stop faces during an abutment may define an end position of the last dose stop member.
The terms “medicinal product”, “medication” or “drug”, as used herein, preferably mean a pharmaceutical formulation containing at least one pharmaceutically active compound,
wherein in one embodiment the pharmaceutically active compound has a molecular weight up to 1500 Da and/or is a peptide, a proteine, a polysaccharide, a vaccine, a DNA, a RNA, an enzyme, an antibody or a fragment thereof, a hormone or an oligonucleotide, or a mixture of the above-mentioned pharmaceutically active compound,
wherein in a further embodiment the pharmaceutically active compound is useful for the treatment and/or prophylaxis of diabetes mellitus or complications associated with diabetes mellitus such as diabetic retinopathy, thromboembolism disorders such as deep vein or pulmonary thromboembolism, acute coronary syndrome (ACS), angina, myocardial infarction, cancer, macular degeneration, inflammation, hay fever, atherosclerosis and/or rheumatoid arthritis,
wherein in a further embodiment the pharmaceutically active compound comprises at least one peptide for the treatment and/or prophylaxis of diabetes mellitus or complications associated with diabetes mellitus such as diabetic retinopathy,
wherein in a further embodiment the pharmaceutically active compound comprises at least one human insulin or a human insulin analogue or derivative, glucagon-like peptide (GLP-1) or an analogue or derivative thereof, or exendin-3 or exendin-4 or an analogue or derivative of exendin-3 or exendin-4.
Insulin analogues are for example Gly(A21), Arg(B31), Arg(B32) human insulin; Lys(B3), Glu(B29) human insulin; Lys(B28), Pro(B29) human insulin; Asp(B28) human insulin; human insulin, wherein proline in position B28 is replaced by Asp, Lys, Leu, Val or Ala and wherein in position B29 Lys may be replaced by Pro; Ala(B26) human insulin; Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) human insulin.
Insulin derivates are for example B29-N-myristoyl-des(B30) human insulin; B29-N-palmitoyl-des(B30) human insulin; B29-N-myristoyl human insulin; B29-N-palmitoyl human insulin; B28-N-myristoyl LysB28ProB29 human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin; B30-N-myristoyl-ThrB29LysB30 human insulin; B30-N-palmitoyl-ThrB29LysB30 human insulin; B29-N-(N-palmitoyl-Y-glutamyl)-des(B30) human insulin; B29-N-(N-lithocholyl-Y-glutamyl)-des(B30) human insulin; B29-N-(ω-carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(ω-carboxyhepta-idecanoyl) human insulin.
Exendin-4 for example means Exendin-4(1-39), a peptide of the sequence H His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu- Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro- Pro-Pro-Ser-NH2.
Exendin-4 derivatives are for example selected from the following list of compounds:
H-(Lys)4-des Pro36, des Pro37 Exendin-4(1-39)-NH2,
H-(Lys)5-des Pro36, des Pro37 Exendin-4(1-39)-NH2,
des Pro36 Exendin-4(1-39),
des Pro36 [Asp28] Exendin-4(1-39),
des Pro36 [IsoAsp28] Exendin-4(1-39),
des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),
des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),
des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),
des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),
des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),
des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39); or
des Pro36 [Asp28] Exendin-4(1-39),
des Pro36 [IsoAsp28] Exendin-4(1-39),
des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),
des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),
des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),
des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),
des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),
des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39),
wherein the group -Lys6-NH2 may be bound to the C-terminus of the Exendin-4 derivative;
or an Exendin-4 derivative of the sequence
des Pro36 Exendin-4(1-39)-Lys6-NH2 (AVE0010),
H-(Lys)6-des Pro36 [Asp28] Exendin-4(1-39)-Lys6-NH2,
des Asp28 Pro36, Pro37, Pro38Exendin-4(1-39)-NH2,
H-(Lys)6-des Pro36, Pro38 [Asp28] Exendin-4(1-39)-NH2,
H-Asn-(Glu)5des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-NH2,
des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,
H-(Lys)6-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,
H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,
H-(Lys)6-des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39)-Lys6-NH2,
H-des Asp28 Pro36, Pro37, Pro38 [Trp(O2)25] Exendin-4(1-39)-NH2,
H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-NH2,
H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-NH2,
des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
H-(Lys)6-des Pro36 [Met(O)14, Asp28] Exendin-4(1-39)-Lys6-NH2,
des Met(O)14 Asp28 Pro36, Pro37, Pro38 Exendin-4(1-39)-NH2,
H-(Lys)6-desPro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,
H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,
des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
H-Asn-(Glu)5 des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
H-Lys6-des Pro36 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-Lys6-NH2,
H-des Asp28 Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25] Exendin-4(1-39)-NH2,
H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,
H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-NH2,
des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(S1-39)-(Lys)6-NH2,
H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2;
or a pharmaceutically acceptable salt or solvate of any one of the afore-mentioned Exendin-4 derivative.
Hormones are for example hypophysis hormones or hypothalamus hormones or regulatory active peptides and their antagonists as listed in Rote Liste, ed. 2008, Chapter 50, such as Gonadotropine (Follitropin, Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin), Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin, Buserelin, Nafarelin, Goserelin.
A polysaccharide is for example a glucosaminoglycane, a hyaluronic acid, a heparin, a low molecular weight heparin or an ultra low molecular weight heparin or a derivative thereof, or a sulphated, e.g. a poly-sulphated form of the above-mentioned polysaccharides, and/or a pharmaceutically acceptable salt thereof. An example of a pharmaceutically acceptable salt of a poly-sulphated low molecular weight heparin is enoxaparin sodium.
Antibodies are globular plasma proteins (˜150 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.
The Ig monomer is a “Y”-shaped molecule that consists of four polypeptide chains; two identical heavy chains and two identical light chains connected by disulfide bonds between cysteine residues. Each heavy chain is about 440 amino acids long; each light chain is about 220 amino acids long. Heavy and light chains each contain intrachain disulfide bonds which stabilize their folding. Each chain is composed of structural domains called Ig domains. These domains contain about 70-110 amino acids and are classified into different categories (for example, variable or V, and constant or C) according to their size and function. They have a characteristic immunoglobulin fold in which two β sheets create a “sandwich” shape, held together by interactions between conserved cysteines and other charged amino acids.
There are five types of mammalian Ig heavy chain denoted by α, δ, ε, γ, and μ. The type of heavy chain present defines the isotype of antibody; these chains are found in IgA, IgD, IgE, IgG, and IgM antibodies, respectively.
Distinct heavy chains differ in size and composition; α and γ contain approximately 450 amino acids and δ approximately 500 amino acids, while μ and ε have approximately 550 amino acids. Each heavy chain has two regions, the constant region (CH) and the variable region (VH). In one species, the constant region is essentially identical in all antibodies of the same isotype, but differs in antibodies of different isotypes. Heavy chains γ, α and δ have a constant region composed of three tandem Ig domains, and a hinge region for added flexibility; heavy chains μ and ε have a constant region composed of four immunoglobulin domains. The variable region of the heavy chain differs in antibodies produced by different B cells, but is the same for all antibodies produced by a single B cell or B cell clone. The variable region of each heavy chain is approximately 110 amino acids long and is composed of a single Ig domain.
In mammals, there are two types of immunoglobulin light chain denoted by λ and κ. A light chain has two successive domains: one constant domain (CL) and one variable domain (VL). The approximate length of a light chain is 211 to 217 amino acids. Each antibody contains two light chains that are always identical; only one type of light chain, κ or λ, is present per antibody in mammals.
Although the general structure of all antibodies is very similar, the unique property of a given antibody is determined by the variable (V) regions, as detailed above. More specifically, variable loops, three each the light (VL) and three on the heavy (VH) chain, are responsible for binding to the antigen, i.e. for its antigen specificity. These loops are referred to as the Complementarity Determining Regions (CDRs). Because CDRs from both VH and VL domains contribute to the antigen-binding site, it is the combination of the heavy and the light chains, and not either alone, that determines the final antigen specificity.
An “antibody fragment” contains at least one antigen binding fragment as defined above, and exhibits essentially the same function and specificity as the complete antibody of which the fragment is derived from. Limited proteolytic digestion with papain cleaves the Ig prototype into three fragments. Two identical amino terminal fragments, each containing one entire L chain and about half an H chain, are the antigen binding fragments (Fab). The third fragment, similar in size but containing the carboxyl terminal half of both heavy chains with their interchain disulfide bond, is the crystalizable fragment (Fc). The Fc contains carbohydrates, complement-binding, and FcR-binding sites. Limited pepsin digestion yields a single F(ab′)2 fragment containing both Fab pieces and the hinge region, including the H—H interchain disulfide bond. F(ab′)2 is divalent for antigen binding. The disulfide bond of F(ab′)2 may be cleaved in order to obtain Fab′. Moreover, the variable regions of the heavy and light chains can be fused together to form a single chain variable fragment (scFv).
Pharmaceutically acceptable salts are for example acid addition salts and basic salts. Acid addition salts are e.g. HCl or HBr salts. Basic salts are e.g. salts having a cation selected from alkali or alkaline, e.g. Na+, or K+, or Ca2+, or an ammonium ion N+(R1)(R2)(R3)(R4), wherein R1 to R4 independently of each other mean: hydrogen, an optionally substituted C1 C6-alkyl group, an optionally substituted C2-C6-alkenyl group, an optionally substituted C6-C10-aryl group, or an optionally substituted C6-C10-heteroaryl group. Further examples of pharmaceutically acceptable salts are described in “Remington's Pharmaceutical Sciences” 17. ed. Alfonso R. Gennaro (Ed.), Mark Publishing Company, Easton, Pa., U.S.A., 1985 and in Encyclopedia of Pharmaceutical Technology.
Pharmaceutically acceptable solvates are for example hydrates.
Further features, refinements and expediencies become apparent from the following description of the exemplary embodiments in connection with the figures.
Like elements, elements of the same kind and identically acting elements may be provided with the same reference numerals in the figures.
A cartridge 118 is housed within a cartridge holder 117. The cartridge holder 117 is rigidly constrained to a housing 116. An actuator 120 is rotationally constrained to the cartridge holder 117. Between the actuator 120 and the cartridge holder 117, a reset member 121 is arranged. The reset member 121 may be, for example, a spring. An axial force of the reset member 121 is transmitted to and counteracted by the cartridge holder 117. A piston rod 102 is configured to abut a piston 119 which is arranged in the cartridge 118. The piston rod 102 is configured to move the piston 119 in a direction towards a distal end 111 of the device, in order to deliver a medication from the cartridge 118. The piston rod 102 will be described later in more detail.
The drug delivery device 101 further comprises an indicator 128, which is configured to indicate the amount of a set dose of a medication. The indicator 128 may be a number sleeve. The indicator 128 is coupled to a rotation member 123 by means of a coupling member 130. The rotation member 123 may be a sleeve. A window member 147 is placed over the indicator 128. The window member 147 comprises a transparent material. A last dose stop member 124 is engaged with the rotation member 123 by means of a thread. The last dose stop member 124 may be for example a lock nut. The last dose stop member 124 is configured to prevent the setting of a dose which is larger than the remaining amount of medication in the cartridge 118. A locking member 125 and a piston rod nut 126, which will be later described in more detail, are configured to engage with the piston rod 102. The piston rod nut 126 is configured as a drive control member. In particular, the piston rod nut 126 acts on the piston rod 102 for delivering a dose of medication. A spring member 127 is arranged between the piston rod nut 126 and a cap 131.The spring member 127 may be, for example, a coil spring. At a proximal end 112 of the device 101, a dose setting member 122 is arranged.
The coupling member 130 is arranged concentrically around the distal end of the rotation member 123. During dose setting, the coupling member 130 is engaged with the rotation member 123. Furthermore, the coupling member 130 is engaged with an indicator 128. The indicator 128 is arranged concentrically around the coupling member 130. In particular, the coupling member 130 is rotationally fixed with respect to the rotation member 123 and with respect to the indicator 128 during the setting of a dose. During the dispense of a dose, the coupling member 130 is engaged with and rotationally locked to the locking member 125 and the indicator 128. The coupling member 130 is configured to cause a rotation of the indicator 128 during the setting and dispense of a dose. The coupling member 130 and the indicator 128 will be later described in more detail.
The piston rod nut 126 is in a threaded engagement with the piston rod 102. Furthermore, the piston rod nut 126 is rotationally fixed with respect to the rotation member 123. This is achieved by means of splines 137 of the piston rod nut 126, which engage in axial grooves 154 of the rotation member 123. In an alternative embodiment, the rotation member 123 and the piston rod nut 126 may be coupled by means of splines in the rotation member 123 and grooves in the piston rod nut 126. The piston rod nut 126 is axially moveable with respect to the rotation member 123 along the axial grooves 154 of the rotation member 123. The piston rod 102 is axially and rotationally fixed with respect to the housing 116 of the drug delivery device 101 during the setting and cancelling of a dose. This will be described in more detail in conjunction with
During the setting or cancelling of a dose, the piston rod nut 126 rotates together with the rotation member 123 with respect to the housing 116 of the drug delivery device 101, since the piston rod nut 126 is rotationally fixed with respect to the rotation member 123. Thereby, the piston rod nut 126 rotates with respect to the piston rod 102. Due to the threaded engagement of the piston rod nut 126 and the piston rod 102, the piston rod nut 126 is screwed along the piston rod 102. This results in the piston rod nut 126 moving axially relative to the rotation member 123 and the piston rod 102. In particular, the piston rod nut 126 is moved in a direction towards a proximal end 112 of the device during the setting of a dose, and in a direction towards a distal end of the device during the cancelling of a dose. Furthermore, a locking member 125 is engaged with the piston rod 102. In particular, the locking member 125 is in threaded engagement with the piston rod 102. The thread of the locking member 125 has an opposing helix direction to the piston rod nut 126. During the setting of a dose, the locking member 125 is rotationally fixed with respect to the housing. Thereby, a movement of the piston rod 102 is inhibited by the combination of constraints from the locking member 125 and the spline feature in the actuator 120 during the setting of a dose. During a dispense of a dose, the locking member 125 is enabled to rotate with respect to the housing. In particular, the piston rod 102 overhauls the locking member 125. The torque which is needed to cause the locking member 125 to overhaul the piston rod 102 is provided by the spring member 127.
Due to the second inner diameter 108 being larger than the first inner diameter 107, the piston rod 102 still has a sufficient mechanical stability.
The piston rod 102 further comprises axial splines, which are not shown in this figure for clarity reasons. The splines are configured as shown in
When the rotation member 123 is rotated during a setting or a cancelling of a dose, the coupling member 130 and the indicator 128 are also rotated. This is due to an engagement of the coupling member 130 with the rotation member 123, and an engagement of the indicator 128 with the coupling member, which is shown in more detail in
In particular, the coupling member 130 rotates the indicator 128 during both setting and dispensing of a dose to ensure that the correct dose is displayed through the indication window 129. The indication window 129 is a cut-out in the housing of the drug delivery device. Between the indicator 128 and the indication window 129 a window member 147 is arranged. The window member 147 may prevent an intrusion of dust or dirt into the housing of the drug delivery device and may magnify the dose numbers. In this embodiment a dose can be selected between zero and a pre-defined maximum in one unit increments. Any dose can be selected within this range. One unit is for example 0.01 ml.
The piston rod 102 moves in a direction towards a distal end 111 of the drug delivery device when a dose has been set and the actuator 120 is actuated. In particular, the spring member 127 exerts a force on the proximal face 134 of the piston rod nut 126. This force moves the piston rod 102 towards a distal end of the device. In particular, the piston rod 102 moves axially, but does not rotate with respect to the housing 116. When the piston rod 102 is moved in a direction towards a distal end of the device, the locking member 125 overhauls against a thread of the piston rod 102. During the dispensing of a medication, the indicator 128 is moved back to its initial position.
A section of the cartridge holder 117 and the indicator 128 are shown in
In
The ratchet interface between the dose setting member 122 and the housing 116 ensures that the torque from the spring member 127 does not return the device to a zero-unit position when a user releases the dose setting member 122 after a dose has been set. The zero-unit position is a position where no unit of a dose is set.
When the actuator 120 is further moved towards a distal direction as shown in
When the spring member 127 acts on the proximal surface of the piston rod nut 126, thereby moving the piston rod 102 in a distal direction, the flange 135 of the locking member 125 is pressed against the inner surface of the rotation member 123. Thereby, the rotation of the locking member 125 is impeded by friction. If the torque which is needed to overhaul the piston rod 102 is reduced, the force of the spring member 127 acting on the piston rod nut 126 will also reduce, and the locking member 125 is pressed against the inner surface of the rotation member 123 with less force. Thereby, the frictional losses at the interface between the flange 135 of the locking member 125 and the inner surface of the rotation member 123 can be reduced. This can be achieved by using a piston rod 102 wherein the inner diameter 107 of the first thread 103 is smaller than the inner diameter 108 of the second thread 104. Such a piston rod 102 is shown in
Since the coupling member 130 is in engagement with the splines 136 of the locking member 125, the coupling member 130 rotates together with the locking member 125. In particular, the coupling member rotates in a direction which is counter to the rotation of the coupling member 130 during the setting of a dose. Thereby, the coupling member 130 rotates the indicator 128 back to its initial position. Accordingly, the locking member 125 acts as a reversing member, as its movement causes a rotation of the indicator 128 via the coupling member 130 back to its initial position.
The reset member 121 reacts on a proximal face of the cartridge holder 117. It provides a return force in the proximal direction to return the actuator 120 to its initial position when a user releases the actuator 120.
The drive assembly 201 comprises a dose setting member 203, a drive control member 204, a secondary drive control member 205, a drive control member stop 206, a reversing member 207, a reversing member shaft 208, a coupling member 209, a last dose stop member 210, a last dose stop drive member 211, an actuator 212, a spring member 213 and a piston rod 214. The components of the drive assembly 201 will be discussed in detail in the following. The drive assembly 201 is configured to move a piston 218 further into the cartridge 202 in a distal direction 215.
The piston rod 214 comprises a bearing 217 arranged at the distal end of the piston rod 214. The bearing 217 is adapted to provide a force on the piston 218 arranged in the cartridge 202 such that the piston 218 is moved in the distal direction 215 further into the cartridge 202. Thereby, a medicinal product is expelled from the cartridge 202.
The drive assembly 201 comprises a main axis 219. The main axis 219 of the drive assembly 201 corresponds to a longitudinal axis of the cartridge 202. The piston rod 214, the spring member 213, the reversing member 207 and the reversing member shaft 208 are located on the main axis 219 of the drive assembly 201.
Further, the drive assembly 201 defines a second axis 220. The second axis 220 is perpendicular to the main axis 219. In particular, the second axis 220 is defined by a shaft 221 of the dose setting member 203. In the drive assembly 201, the dose setting member 203, the secondary drive control member 205, the drive control member 204 and the coupling member 209 are arranged coaxially on the second axis 220.
The drive assembly 201 is configured to be located in a housing of the drug delivery device. In
Moreover, the drive assembly 201 may comprise a safety member which is not shown in
Moreover, the piston rod 214 is flexible such that it can be wound around other elements of the drive assembly 201. In particular, as shown in
The piston rod 214 comprises a main part 222 extending in the proximal direction 216 from the bearing 217. The main part 222 has an upper main surface 223 and a lower main surface 224. In the assembled drive assembly 201, as shown in
The piston rod 214 comprises teeth 225. The teeth 225 extend along the main part 222 of the piston rod 214. In particular, the teeth 225 cover more than half of the lower main surface 224 of the main part 222 of the piston rod 214. The teeth 225 are adapted to engage the piston rod 214 with the inner small diameter pinion gear 227 of the drive control member 204. In particular, the teeth 225 are configured to prevent the piston rod 214 from moving, unless the drive control member 204 is enabled to rotate.
The spring member 213 comprises a coil spring. During assembly of the drive assembly 201, the spring member 213 is compressed between the first spring seat 261 and a second spring seat 262. The housing part 221 forms the second spring seat 262. A second end of the spring member 213 abuts the second spring seat 262, as shown in
Further, the spring member 213 is configured such that it is capable of delivering all the required doses from the cartridge 202 without being further compressed during a dose setting or a dose dispensing operation. In particular, in its compressed state, the spring member 213 exerts a force on the first spring seat 261 of the piston rod 214. Accordingly, when a locking of the piston rod 214 is released, this force tends to move the piston rod 214 in the distal direction 215. In particular, the spring member 213 exerts the force on the first spring seat 261 formed by the bearing 217 which moves the piston 218 in the distal direction 215 and results in expelling a medicinal product from the cartridge 202.
Further, the drive control member 204 comprises teeth 229 located on its outer perimeter. The teeth 229 face in a direction away from the second axis 220. The teeth 229 arranged at the outer perimeter of the drive control member 204 are configured to engage with splines 230 on the actuator 212. The splines 230 in the actuator 212 are shown in
The drive control member 204 further comprises a set of crown gear teeth 231 which are arranged at its outer face 228 facing away from the dose setting member 203 in the assembled drive assembly 201. The set of crown gear teeth 231 are in permanent engagement with the reversing member 207.
The drive control member 204 also comprises a stop feature 232 which is configured to abut a corresponding stop feature 233 of the secondary drive control member 205 shown in
Further, the secondary drive control member 205 comprises a perimeter surface 237 which faces away from the second axis in the assembled drive assembly 201. The perimeter surface 237 has a stepped form. In particular, the perimeter surface 237 has an inner area 238 and an outer area 239 wherein the inner area 238 has a slightly smaller diameter than the outer area 239.
On the perimeter surface 237 of the secondary drive control member 205, two sets of gear teeth 240, 241 are arranged. In particular, on the perimeter surface, an inner set of gear teeth 240 and an outer set of gear teeth 241 are arranged. The inner set of gear teeth 240 are arranged on the inner area 238 and the outer set of gear teeth 241 is arranged on the outer area 239.
The inner set of gear teeth 240 is releasably engaged with teeth 242 of the drive control member stop 206 shown in
The outer set of gear teeth 241 is configured to engage with the dose setting member 203 during dose dialing.
The dose setting member 203 further comprises an indicator 243 arranged at its outer surface facing away from the drive control member 204. On the indicator 243, dial numbers and graduations are printed. In particular, the housing comprises a pointer 252, which is shown in
The outer perimeter of the dose setting member 203 is held in the housing of the drug delivery device. In particular, the indicator 243 is held at its perimeter. Further, the axial translation of the dose setting member 203 is limited by features (not shown) on the housing of the drug delivery device and by the secondary drive control member 205.
Further, at an inner surface of the dose setting member 203 facing towards the secondary drive control member 205, gear features 244 are arranged. The gear features 244 of the dose setting member 203 provide a connection with the secondary drive control member 205 when the dose setting member 203 is translated axially to enable dose setting. In particular, the gear features 244 of the dose setting member 203 are configured to engage with the outer set of gear teeth 241 of the secondary drive control member 205.
The inner surface of the dose setting member 203 also acts on the drive control member stop 206 when translated axially during dose setting. In particular, the inner surface of the dose setting member 203 abuts the drive control member stop 206 such that the drive control member stop 206 follows an axial displacement of the dose setting member 203 during dose setting.
The drive control member 204 and the secondary drive control member 205 are located on the shaft 221 integrally formed by the dose setting member 203.
Further, the coupling member 209 is rigidly fixed to an end 245 of the shaft 221. The end 245 of the shaft 221 has a non-circular cross-section rigidly fixing the coupling member 209 to the shaft 221.
The coupling member 209 comprises teeth 264. The teeth 264 may engage the reversing member 207. The reversing member 207 comprises teeth 265 arranged at its outer perimeter. The teeth 264 of the coupling member 209 may engage the teeth 265 of the reversing member 207.
As the coupling member 209 is rigidly fixed to the dose setting member 203, the coupling member 209 follows an axial movement of the dose setting member 203. Depending on the axial position of the dose setting member 203, the teeth 264 of the coupling member 209 are either engaged to the teeth 265 of the reversing member 207 or are arranged at a distance away from the teeth 265 of the reversing member 207. When the teeth 264 of the coupling member 209 are engaged with the teeth 265 of the reversing member 207, a rotation of the coupling member 209 around the second axis 220 results in a rotation of the reversing member 207 around the main axis 219 and vice versa.
The drive control member stop 206 comprises teeth 242, as shown in
An axial movement of the dose setting member 203 causes the drive control member stop 206 to disengage from the secondary drive control member 205, allowing the secondary drive control member 205 to rotate and a new dose end stop to be set.
The actuator 212, shown in
The last dose stop drive member 211 comprises a set of gear teeth 248 which are engaged with the secondary drive control member 205. Accordingly, a rotation of the secondary drive control member 205 results in rotating the last dose stop drive member 211 relative to the housing.
Further, the last dose stop drive member 211 comprises a threaded portion 249. The last dose stop member 210 comprises a corresponding thread at its inner surface. The last dose stop member 210 runs on the threaded portion 249 of the last dose stop drive member 211. The last dose stop drive member 211 is constrained to the housing such that it can only rotate relative to the housing, but is prevented from moving axially along a linear axis parallel to the second axis 220 relative to the housing.
The last dose stop member 210 is threadedly engaged with the threaded portion 249 of the last dose stop drive member 211. The last dose stop member 210 is engaged by a spline feature 250 with the housing such that the last dose stop member 210 is prevented from rotating relative to the housing. Moreover, the last dose stop member 210 comprises a stop face. The stop face is configured to engage with the last dose stop drive member 211 when the permitted total number of doses has been selected.
In the rest state, the drive control member stop 206 is engaged with the secondary drive control member 205. Thereby, the secondary drive control member 205 is rotationally locked such that it can not rotate relative to the drive control member stop 206 or the housing of the drug delivery device.
Further, the splines 230 of the actuator 212 are engaged with the drive control member 204. Thereby, the drive control member 204 is rotationally locked such that it can not rotate relative to the actuator 212 and the housing of the drug delivery device. As the drive control member 204 is further engaged to the teeth 225 of the piston rod 214, the piston rod 214 is prevented from moving in a distal direction 215.
The stop feature 232 of the drive control member 204 is in abutment with the stop feature 233 of the secondary drive control member 205.
On the dose setting member 203, the “0” mark is in alignment with the pointer 252 of the housing.
The reversing member 207 is in toothed engagement with the drive control member 204 and the coupling member 209. In particular, the set of crown gear teeth 231 of the drive control member 207 are engaged with the teeth 265 of the reversing member 207. Further, the teeth 265 of the reversing member 207 are engaged with the teeth 264 of the coupling member 209.
As the drive control member 204 is prevented from rotating relative to the housing due to the engagement of the drive control member 204 with the splines 230 of the actuator 212, the coupling member 209 is also prevented from rotating relative to the housing. Thereby, the dose setting member 203 is prevented from rotating relative to the housing, as the coupling member 209 is further rigidly fixed to the end 245 of the shaft 221 of the dose setting member 203.
When the dose setting member 203 is pushed inwards, this drives the drive control member stop 206 axially along the second axis 220. Thereby, the drive control member stop 206 is disengaged from the secondary drive control member 205. Due to the disengagement from the drive control member stop 206, the secondary drive control member 205 is now allowed to rotate. Simultaneously, the secondary drive control member 205 engages the dose setting member 203 by an engagement of the inner set of gear teeth 240 of the secondary drive control member 205 engaging the gear features 244 of the dose setting member 203.
Moreover, in the ready-to-set state of the drive assembly 201, i.e. when the drive control member 204 has been pushed inwards, the coupling member 209 being rigidly fixed to the drive control member 204 is moved axially along the second axis 220 and is thereby disengaged from the reversing member 207. Due to the disengagement of the coupling member 209 from the reversing member 207, it is prevented that a rotation of the dose setting member 203 results in translating the piston rod 214.
However, as the coupling member 209 is disengaged from the drive control member 204 in the ready-to-set state, the coupling member 209 is now enabled to rotate relative to the housing. Thereby, the dose setting member 203 which is engaged to the coupling member 209 is also enabled to rotate relative to the housing in the ready-to-set state, i.e. after it has been pushed inwards.
Moreover, the drive control member stop 206 follows the axial movement of the dose setting member 203. Accordingly, in the ready-to-set state, the drive control member stop 206 abuts the splined end of the actuator 212, thereby preventing the actuator 212 from being moved axially in a direction towards the dose setting member 203. Accordingly, the actuator 212 cannot be depressed in the ready-to-set state.
Moreover, the drive control member 204 is prevented from rotating relative to the housing due to its engagement with the splines 230 of the actuator 212 in the ready-to-set state.
To set a new dose, a user rotates the dose setting member 203 whilst it is pushed inwards.
Compared to the ready-to-set state shown in
As there is no spring to compress during the dose setting operation, setting of the dose requires very little torque input.
In this new dose set position, the stop feature 233 of the secondary dose control member 205 has moved to provide a new end stop for the drive control member 204. The secondary drive control member 205 has been relocked in rotation by an engagement with the drive control member stop 206.
As the dose setting member 203 has been rotated, the indicator 243 of the dose setting member 203 has been rotated as well. The set dose is now displayed on the indicator 243 of the dose setting member 203. The set dose can be viewed through the window 251 of the housing. Only a small group of printed numbers is visible through the window 251. A magnifying lens may be arranged in the window 251. Alternatively, the window may comprise a simple cutout in the housing. The pointer 252 on the housing points to the number corresponding to the set dose.
During dose setting, the drive control member 204 is rotationally fixed relative to the housing by its engagement to the actuator 212. The actuator 212 is configured such that the actuator 212 cannot be depressed while a dose setting operation is carried out. In particular, the drive control member stop 206 abuts the splined end of the shaft 247 of the actuator 212 such that the actuator 212 is prevented from moving in a direction along the second axis 220. Accordingly, a dose cannot be accidently delivered during dose setting as the dose delivery operation has to be initiated by depressing the actuator 212 which is prevented during dose setting.
After the dose setting operation has been completed, the user releases the dose setting member 203. The dose setting member 203 returns via a spring (not shown) to its original outward position, along with the drive control member stop 206. Now, the drive control member stop 206 does not abut the actuator 212 any more such that the actuator is not locked against an axial movement and can now be depressed by a user.
Before the actuator 212 is depressed by a user, i.e. before a dose dispensing operation is initiated, the set dose can be amended, i.e. it can be increased or decreased. To do this, the user has to depress and rotate the dose setting member 203 again.
In order to dispense a dose, the actuator 212 is pressed. This causes the actuator 212 to translate parallel to the second axis 220 and releases the splined connection between the actuator 212 and the drive control member 204. When the drive control member 204 is released, it is driven rotationally. In particular, the spring member 213 exerts a force on the piston rod 214. Specifically, the spring member 213 exerts a force on the first spring seat 261 formed by the bearing 217 of the piston rod 214. As the drive control member 204 is not locked against a rotation, the spring member 213 is enabled to expand. This results in a translation of the piston rod 214 in the distal direction 215. As the teeth 225 of the piston rod 214 are engaged to the inner small diameter pinion gear 227 of the drive control member 204, the drive control member 204 is thereby rotated.
The axial translation of the piston rod 214 allows the bearing 217 to drive the piston 218 forward in a distal direction 215 further into the cartridge 202, thus delivering the dose of the medicinal product.
The drive control member 204 is rotated until its stop feature 232 reaches the new end stop position set by the stop feature 233 of the secondary drive control member 205. The end of the rotation of the drive control member 204 corresponds to the delivery of the dose being finished. When the stop feature 232 reaches the new end stop position, the drive control member 204 is prevented from rotating further relative to the housing. The engagement of the drive control member 204 with the piston rod 214 prevents a further translation of the piston rod 214 in the distal direction, thereby preventing the piston rod 213 from expelling more of the medicinal product from the cartridge 202.
During the dose dispensing operation, the indicator 243 of the dose setting member 203 automatically travels back to its “0” position such that “0′” is displayed in the window 251 of the housing. This is achieved by an interaction of the coupling member 209 and the reversing member 207. During dose dispense, the reversing member 207 is rotated due to its toothed engagement with the drive control member 204.
When the dose setting member 203 is moved outward to its original position after the dose setting has been completed and before the dose dispense is started, the coupling member 209 follows this movement as the coupling member 209 is rigidly fixed to the dose setting member 203. Thereby, the coupling member 209 engages the reversing member 207. Accordingly, the coupling member 209 is coupled via the reversing member 207 to the drive control member 204 during the dose dispense operation. Further, the drive control member 204 is rotated during the dose dispense operation such that this rotation causes the coupling member 209, and hence the indicator 243, to rotate back to its zero display position.
Moreover, the drive assembly 201 comprises a last dose lockout assembly which is shown in
When the maximum number of doses available has been dialed, the last dose stop member 210 reaches the end of the threaded portion 249 and the stop face of the last dose stop member 210 contacts a similar stop face on the last dose stop drive member 211. This prevents a further rotation of the last dose stop drive member 211. Thereby, also a further rotation of the secondary drive control member 205 and of the dose setting member 203 is prevented such that it is not possible to dial a larger dose. However, the number of units available for the last dose is now shown on the indicator 243 in the normal way before the final units are dispensed. This allows splitting of the dose in two injections if required.
Furthermore, the drive assembly 201 comprises a safety member 253.
The safety member 253 is configured to prevent a movement of the piston rod 214 when the drive assembly 201 is damaged. The safety member 253 prevents the spring member 213 from automatically dispensing the remaining contents of the cartridge 202 when the drive assembly 201 is damaged, e.g. when the piston rod 214 is damaged.
The safety member 253 comprises a first safety member part 254 and a second safety member part 255. The first safety member part 254 comprises a strap 256. One end of the strap 256 is fixed to the bearing 217 of the piston rod 214 which corresponds to the first spring seat 261. The strap 256 runs parallel to the piston rod 214. In particular, the strap 256 is arranged to run along the upper main surface 223 of the piston rod 214.
The first safety member part 254 comprises a first engagement member 257 comprising teeth arranged on its surface facing away from the upper main surface 223 of the piston rod 214.
The second safety member part 255 comprises a spring arm 258 which is attached to the housing part 221. The housing part 221 corresponds to the second spring seat 262. The spring arm 258 comprises a second engagement member 259 and a spacer member 260. The spacer member 260 abuts the piston rod 214 with a light spring force. The second engagement member 259 is formed integrally with the spring arm 258. The second engagement member 259 comprises a protrusion which is configured to engage with the teeth of the first engagement member 257 of the first safety member part 254.
The strap 256 of the first safety member part 254 comprising the first engagement member 257 is connected to the first spring seat 261. Further, the second engagement member 259 of the second safety member part 255 is connected to the second spring seat 262. When the first and the second safety member parts 254, 255 are not engaged to each other in the undamaged state of the drive assembly 201, they do not provide a mechanical connection between the first and the second spring seat 262.
When the drive assembly 201 is undamaged, as shown in
Further,
For example, when the piston rod 214 breaks or is detached at either end, its tension loosens and the piston rod 214 becomes slack. In this condition, the spacer member 260 is enabled to overcome the now reduced tension of the piston rod 214. Accordingly, the spacer member 260 moves the piston rod 214 in a direction away from the first safety member part 254. This enables the first safety member part 254 to engage with the second safety member part 255. In particular, the teeth of the first engagement member 257 engage with the protrusion of the second engagement member 259.
The engagement of the first and the second safety member parts 254, 255 locks the spring member 213. In particular, the engagement of the first and the second safety member parts 254, 255 fixes the distance between the first and the second spring seat 262 such that the first and the second spring seats 261, 262 are prevented from moving relative to each other, as the first safety member part 254 is fixed to the first spring seat 261 formed by the bearing 217 and the second safety member part 255 is fixed to the second spring seat 262 formed by the housing part 221. When the distance between the spring seats 261, 262 is fixed, the spring member 213 is prevented from relaxing any further.
In particular, the first safety member part 254 is now prevented from moving in the distal direction 215 any further as it is engaged to the housing part 221 via the second safety member part 255. As the first safety member part 254 is fixed to the first spring seat 261 at one end, the first spring seat 261 can not move in the distal direction 215 when the first and the second safety member parts 254, 255 are engaged to each other. This prevents a further movement of the spring member 213 and thereby of the piston rod 214. Accordingly, a further dose dispensing is also prevented.
The drive assembly 301 is structurally and functionally similar to the drive assembly 201 according to the second embodiment as shown in
The drive assembly 301 comprises a dose setting member 303, a drive control member 304, a secondary drive control member 305, a drive control member stop 306, a reversing member 307, a reversing member shaft 308, a coupling member 309, a last dose stop 310, a last dose stop drive member 311 and an actuator 312, wherein these parts structurally and functionally correspond to the parts of the drive assembly 201 according to the second embodiment. In particular, the interactions of these parts with each other correspond to the interactions of the corresponding parts of the drive assembly 201 according to the second embodiment.
Furthermore, the drive assembly 301 comprises a spring member 313 and a piston rod 314, which are different from the spring member 213 and the piston rod 214 of the second embodiment. The spring member 313 is configured as a torsion spring. The spring member 313 has two free ends 322, wherein one of which is located in a through hole 323 in the drive control member 304 and the other one in a through hole 324 in the secondary drive control member 305.
The drive assembly 301 comprises a main axis 319. The main axis 319 of the drive assembly 301 corresponds to a longitudinal axis of the cartridge 302. The piston rod 314, extends along the main axis 319 of the drive assembly 301.
The piston rod 314 is configured as a rack and comprises a bearing 317 arranged at the distal end of the piston rod 314. The bearing 317 is adapted to provide a force on a piston 318 arranged in the cartridge 302 in order to expel a medicinal product from the cartridge 302. The piston rod 314 is axially and rotationally constrained in a housing of the drug delivery device so that it can only move in a linear fashion, in particular along the main axis 319 of the drive assembly 301. The position of the piston rod 314 along the main axis 319 is constrained by the drive control member 304. In particular, the teeth 325 of the piston rod are engaged with an inner small diameter pinion gear 327 of the drive control member 304.
Further, the drive assembly 301 defines a second axis 320. The second axis 320 is perpendicular to the main axis 319. In particular, the second axis 320 is defined by a shaft 321 of the dose setting member 303. In the drive assembly 301, the dose setting member 303, the secondary drive control member 305, the drive control member 304 and the coupling member 309 are arranged coaxially on the second axis 320.
The drive assembly 301 is configured to be located in a housing of the drug delivery device. In
In particular, the drive control member stop 306 is constrained to a housing of the drug delivery device such that it can only move parallel to the second axis 320. With no user input, teeth 342 of the drive control member stop 306 are engaged with an inner set of gear teeth 340 of the secondary drive control member 305. Thereby, the secondary drive control member 305 is rotationally locked such that it can not rotate relative to the housing of the drug delivery device.
Further, splines 330 of the actuator 312 are engaged with the drive control member 304. Thereby, the drive control member 304 is rotationally locked such that it can not rotate relative to the actuator 312 and the housing of the drug delivery device.
A stop feature 332 of the drive control member 304 is in abutment with a stop feature 333 of the secondary drive control member 305. Thereby, a pre-torque from the spring member 313 is prevented from being applied to the drive control member 322.
As can be seen in
As can be seen in
As can be seen in
When the dose setting member 303 is rotated to set a new dose, the secondary drive control member 305 is rotated, whereby the spring member 313 located in the through hole 324 of the secondary drive control member 305 is wound up.
When the user releases the dose setting member 303, it returns along second axis 320 under a force exerted by a spring (not shown) to its original outward position, along with the drive control member stop 306.
As can be seen in
As can be seen in
As can be seen in
In order to dispense a dose, the actuator 312 is depressed as indicated by an arrow. This causes the actuator 312 to translate parallel to the second axis 320 and release the splined connection with the drive control member 304. When released, the drive control member 304 is driven by the spring member 313, for example in a clockwise direction, until its stop feature 332 abuts the stop feature 333 of the secondary drive control member 305. Thereby, the stop features 332, 333 act as a dispense stop. In particular, the stop features 332, 333 limit the travel of the piston rod 314 and of the indicator 343.
The rotation of the drive control member 304 causes the piston rod 314 to move parallel to the main axis 319 and drive the piston 318 in the cartridge 302 forward, thus delivering the dose.
During dose dispensing, the dose setting member 303 and, thereby, the indicator 343 travels back to its initial position, i.e. the ‘0’ displayed position. A new dose can be set immediately afterwards if required. The interaction of the coupling member 309 and the reversing member 307 is used to achieve this. During dispense, the reversing member 307 is rotated due to its toothed engagement with the drive control member 304. Due to the toothed engagement of the reversing member 307 and the coupling member 309, this rotation also causes the coupling member 309 and hence the dose setting member 303 to rotate back to its ‘0’ display position.
When the maximum number of doses available has been dialed, the last dose stop 310 reaches the end of the threaded engagement with the last dose stop drive member 311. A stop face on the last dose stop 310 contacts a similar stop face on the last dose stop drive member 311, thereby preventing a setting of a dose larger than an available dose. When the stop faces abut, the last dose stop member is in its end position. The configuration of the last dose stop corresponds to the last dose stop shown in
Due to the curved shape of the piston rod 313, a shorter overall length of the drug delivery device can be achieved.
101 drug delivery device
102 piston rod
103 first thread
104 second thread
105 first pitch
106 second pitch
107 first inner diameter
108 second inner diameter
109 longitudinal axis of device
111 longitudinal axis of piston rod
111 distal end of device
112 proximal end of device
113 dose setting direction
114 dose cancelling direction
115 axial spline of piston rod
116 housing
117 cartridge holder
118 cartridge
119 piston
120 actuator
121 reset member
122 dose setting member
123 rotation member
124 last dose stop member
125 locking member
126 piston rod nut
127 spring member
128 indicator
129 indication window
130 coupling member
131 cap
132 first engagement feature of actuator
133 second engagement feature of actuator
134 proximal face of piston rod nut
135 flange of locking member
136 spline of locking member
137 spline of piston rod nut
138 bearing of cap
139 snap feature of cap
140 ratchet feature of dose setting member
141 ratchet arm of rotation member
142 housing ratchet feature
143 engagement means of coupling member
144 engagement means of indicator
145 maximum dose abutment of indicator
146 maximum dose abutment of window member
147 window member
148 thread of window member
149 end of dispense stop
150 distal direction
151 proximal direction
152 thread of locking member
153 extended spline of locking member
154 axial groove of rotation member
155 snap feature of actuator
156 engagement feature of coupling member
158 engagement means of window member
159 last dose stop face of last dose stop member
160 last dose stop face of rotation member
161 thread of rotation member
162 engagement features of dose setting member
163 feedback feature
164 arrow
165 arrow
167 protrusions of actuator
168 magnifying element
169 protrusion
170 stop feature of indicator
171 stop feature of cartridge holder
172 opening of actuator
173 indentation
175 constraint features of cap
176 protrusion of last dose stop member
177 axial groove of housing
178 small diameter bearing
179 radial face of ratchet arm
180 drive assembly
181 thread start
182 thread start
183 thread start
184 thread start
185 sloped face of ratchet arm
190 last dose stop drive member
191 main axis
201 drive assembly
202 cartridge
203 dose setting member
204 drive control member
205 secondary drive control member
206 drive control member stop
207 reversing member
208 reversing member shaft
209 coupling member
210 last dose stop member
211 last dose stop drive member
212 actuator
213 spring member
214 piston rod
215 distal direction
216 proximal direction
217 bearing
218 piston
219 main axis
220 second axis
221 shaft
222 main part
223 upper main surface
224 lower main surface
225 teeth of the piston rod
226 through hole
227 inner small diameter pinion gear
228 outer face
229 teeth
230 splines
231 set of crown gear teeth
232 stop feature
233 stop feature
234 inner face
235 through hole
236 outer face
237 perimeter surface
238 inner area
239 outer area
240 inner set of gear teeth
241 outer set of gear teeth
242 teeth of the drive control member stop
243 indicator
244 gear features
245 end of the shaft
246 button
247 shaft
248 set of gear teeth
249 threaded portion
250 spline feature
251 window
252 pointer
253 safety member
254 first safety member part
255 second safety member part
256 strap
257 first engagement member
258 spring arm
259 second engagement member
260 spacer member
261 first spring seat
262 second spring seat
263 housing
264 teeth of the reversing member
265 teeth of the coupling member
301 drive assembly
302 cartridge
303 dose setting member
304 drive control member
305 secondary drive control member
306 drive control member stop
307 reversing member
308 reversing member shaft
309 coupling member
310 last dose stop
311 last dose stop drive member
312 actuator
313 spring member
314 piston rod
315 distal direction
316 proximal direction
317 bearing
318 piston
319 main axis
320 second axis
321 shaft
322 free end of spring member
323 through hole in drive control member
324 through hole in secondary drive control member
325 teeth
326 through hole
327 inner small diameter pinion gear
328 outer face
329 teeth
330 splines
331 set of crown gear teeth
332 stop feature
333 stop feature
334 inner face
335 through hole
336 outer face
337 perimeter surface
338 inner area
339 outer area
340 inner set of gear teeth
341 outer set of gear teeth
342 teeth
343 indicator
344 gear features
345 end of the shaft
346 button
347 shaft
348 set of gear teeth
349 threaded portion
350 spline feature
351 window
352 pointer
353 housing
354 drug delivery device
| Number | Date | Country | Kind |
|---|---|---|---|
| 13182753.7 | Sep 2013 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2014/068648 | 9/3/2014 | WO | 00 |
