Jet Injector Druckstrahlinjektor Injecteur a Pression

Europäisches Patentamt *EP000973567B1* (19) European Patent Office

Office européen des brevets (11) EP 0 973 567 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Date of publication and mention (51) Int Cl.7: A61M 5/30 of the grant of the patent: 02.04.2003 Bulletin 2003/14 (86) International application number: PCT/DK97/00562 (21) Application number: 97949987.8 (87) International publication number: (22) Date of filing: 11.12.1997 WO 98/028029 (02.07.1998 Gazette 1998/26)

(54) JET INJECTOR DRUCKSTRAHLINJEKTOR INJECTEUR A PRESSION

(84) Designated Contracting States: (72) Inventor: POULSEN, Jens, Ulrik AT BE CH DE DK ES FI FR GB GR IE IT LI LU NL DK-2830 Virum (DK) PT SE (74) Representative: Hansen, Einar Tronier et al (30) Priority: 20.12.1996 DK 148896 Novo Nordisk A/S, Health Care Patents, (43) Date of publication of application: Novo Allé 26.01.2000 Bulletin 2000/04 2880 Bagsvaerd (DK)

(73) Proprietor: NOVO NORDISK A/S (56) References cited: 2880 Bagsvaerd (DK) WO-A-95/03844 WO-A-95/27523

Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 0 973 567 B1

Printed by Jouve, 75001 PARIS (FR) 1 EP 0 973 567 B1 2

Description poule through a nozzle 5 at the end of a hollow needle 6 which pierces the rubber membrane 3 to make the [0001] The invention relates to injectors comprising a nozzle communicate with the interior of the ampoule 2 changeable cylinder ampoule containing medicine for a when the nozzle by a hub 7 is mounted on a receiving number of injections into which cylinder ampoule a pis- 5 part at the outlet end of the ampoule. Figure 2 shows in ton is pressed by a piston rod driven by a cocked and an enlarged scale the outlet end of the ampoule with the releasable spring to dispense a dose of medicine mounted hub 7. through a nozzle as a high speed jet which penetrates [0007] Further the injector comprises a proximal part the skin and dose setting means by which the distance forming a power unit comprising a housing 8 in which a which the piston is moved into the cylinder ampoule by 10 piston rod 9 is mounted to be moved axially between a the spring driven piston rod during an injection can be proximal and a distal position. In figure 1 the piston rod set in advance of each release of the spring, the cylinder 9 is in its proximal position in which it is held against the ampoule being accommodated by a distal part and the force of a spring 10 which positioned between an inward spring and the piston rod being accommodated in a flange 11 in the housing 8 and a ring shaped flange 12 proximal part. 15 on the piston rod 9 forces the said piston rod in a distal [0002] Unless the injector is delivered as a one shot direction. The piston rod is held in its proximal position disposable device which is filled with a medicine dose, by a number of hooks 13 provided on flexible arms 14 an injector has to be filled through its outlet immediately at the proximal end of the piston rod. Said arms 14 before use., e.g. as described in WO 96/19252. This is projects through an opening left in the centre of the in- an inconvenient process, and consequently a jet injector 20 ward flange 11 so that the hooks grips behind this flange. which is designed to be used for several injections and The hooks present collectively a conical surface on which do not request a filling procedure in advance of which the edge of an inner bore in a release button 15 each injection Is preferred can act when the release button is pressed to press [0003] From WO-A-95/03844 is known such an injec- hook 13 and the arms inward towards the axis of the tor comprising a changeable cylinder ampoule contain- 25 piston rod 9 until the hooks loose their grip over the ing medicine for a number of injections into which cylin- flange 11 and can be drawn through the opening at the der ampoule a piston is pressed by a piston rod driven centre of said flange 11 when the piston rod 9 by the by a cocked and releasable spring to dispense a dose spring is forced to its distal position which is defined by of medicine through a nozzle as a high speed jet which the ring shaped flange 12 on the piston rod abutting a penetrates the skin, and dose setting means by which 30 second inward flange 16 in the housing 8. the distance which the piston is moved into the cylinder [0008] From its distal position the piston can be re- ampoule by the spring driven piston rod during an injec- turned to its proximal cocked position by a cocking de- tion can be set in advance of each release of the spring. vice comprising a not shown pin which mounted through When cocked the spring can expand sufficiently to inject a hole 17 which runs through the piston rod 9 perpen- the whole content of the cylinder ampoule. During the 35 dicularly to the longitudinal axis of this piston rod and use of the injection device the spring is incrementally which through slots in the housing 8 projects from the released to inject doses corresponding to set incre- outer side of this housing. The ends of this pin can be ments. gripped and manually drawn in a proximal direction to [0004] An improvement of the injector described in the return the piston rod 9 to its proximal position. During opening paragraph is according to the invention char- 40 this movement of the piston rod 9, the hooks 13 will be acterised in that the distal and the proximal parts are moved through the opening at the centre of the inward provided with threads so that one of these parts can suc- flange 11 an will due to the flexibility of the arms snap cessively be screwed into the other to set a dose to be outward and grip behind the flange 11 to lock the piston delivered by the device. rod in its proximal position. [0005] In the following the invention is described in 45 [0009] The distal part 1 of the injector containing the further details with references to the drawing, wherein ampoule 2 is at its proximal end provided with an outer thread which engage an inner thread in the tubular distal Figure 1 schematically shows a sectional view of an end of the housing 8 of the proximal part so that the distal injector according to the invention. part can be screwed into the proximal part of the injector. 50 This screw connection allows the parts to be screwed Figure 2 shows in enlarged scale the ampoule end apart to allow a changing of the ampoule and to be and a mounted injection member. screwed successively into each other to allow a setting of a dose to be injected. [0006] The injector shown in figure 1 comprises a dis- [0010] When a dose is going to be injected, the pro- tal part 1 accommodating an ampoule 2 which is at an 55 cedure is the following starting with the piston rod in its outlet end closed by a rubber membrane 3 and at its distal position: other end closed by a piston 4 which can be forced into the ampoule to press out some of the content of the am- A hub 7 with a nozzle 5 is mounted on the receiving

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member at the outlet end of the ampoule 2, piston rod (9) during an injection can be set in advance of each release of the spring (10), the cylin- the distal part is screwed into the proximal part until der ampoule (2) being accommodated by a distal a visual inspection shows that medicine is pressed part (1) and the spring (10) and the piston rod (9) out through the nozzle, 5 being accommodated in a proximal part (8) of a housing, characterised in that the distal and the the power unit is cocked by drawing the piston in a proximal parts (1, 8) are provided with threads so proximal direction until the hooks 13 grips behind that one of these parts can successively be screwed the flange 11 (the end of the piston rod 9 now has into the other to set a dose to be delivered by the a distance to the piston 4 corresponding to the 10 device. stroke of the piston rod),

a dose is set by screwing the distal part into the Revendications proximal part a distance corresponding to the movement of the piston which is necessary to press 15 1. Injecteur comprenant une ampoule cylindrique in- out the wanted dose ( the distance between the end terchangeable (2) contenant un médicament pour of the piston rod 9 and the piston 4 now corresponds un certain nombre d'injections, dans laquelle am- to the stroke of the piston rod minus the distance poule cylindrique (2) est pressé un piston (4) par which the piston must be moved to inject the wanted une tige de piston (9) entraînée par un ressort armé dose), and 20 et libérable (10) pour délivrer une dose de médica- ment à travers une buse (5) sous la forme d'un jet the nozzle is held against the skin where the injec- à grande vitesse qui pénètre dans la peau, et un tion is wanted and the release button 15 is pressed moyen doseur par lequel la distance de déplace- ( the piston rod is now moved by the spring in the ment du piston (4) dans l'ampoule cylindrique (2) distal direction a distance corresponding to its 25 par la tige de piston entraînée par ressort (9) pen- stroke. During the last part of this movement the pis- dant une injection peut être réglée au préalable ton is moved into the ampoule a distance corre- avant chaque libération du ressort (10), l'ampoule sponding to the set dose). cylindrique (2) étant logée dans une partie distale (1) et le ressort (10) ainsi que la tige de piston (9) [0011] A counter may be installed to count units in ac- 30 étant logés dans une partie proximale (8) d'un boî- cordance with the extend of the screwing to set a dose. tier, caractérisé en ce que les parties distale et Further a detent may be provided so that the distal part proximale (1, 8) sont munies de filetages si bien can only be unscrewed from the proximal part when the qu'une de ces parties peut être vissée successive- detent is released either to allow a partly unscrewing to ment dans l'autre pour régler une dose à délivrer annul a wrongly set dose or a totally unscrewing to allow 35 par le dispositif. changing of the ampoule. [0012] The cocking of the injector may be performed by an build in motor which is powered either from a build Patentansprüche in battery or through an external connection to a power source. Also gas pressure from a build in or an external 40 1. Injektor umfassend eine auswechselbare Zylinder- gas cartridge may be used. ampulle (2), enthaltend eine Medizin für eine An- [0013] In the embodiment described the piston rod is zahl von Injektionen, in welche Zylinderampulle (2) driven by a cocked spring but the piston rod may also ein Kolben (4) durch eine Kolbenstange (9) ge- be driven by compressed gas, or by an electric motor, drückt wird, angetrieben durch eine gespannte und or by a carefully adapted charge of an explosive. 45 freigebbare Feder (10), um eine Medizinidosis durch eine Düse (5) als Hochgeschwindigkeits- strahl abzugeben, welcher die Haut penetriert und Claims Dosiseinstellungsmittel, durch welche die Distanz, welche der Kolben (4) durch die federangetriebene 1. An injector comprising a changeable cylinder am- 50 Kolbenstange (9) während einer Injektion in die Zy- poule (2) containing medicine for a number of injec- linderampulle (2) bewegt wird, können im voraus tions into which cylinder ampoule (2) a piston (4) is von jeder Freigabe der Feder (10) eingestellt wer- pressed by a piston rod (9) driven by a cocked and den, die Zylinderampulle (2) ist in einem distalen releasable spring (10) to dispense a dose of medi- Teil (1) untergebracht und die Feder (10) und die cine through a nozzle (5) as a high speed jet which 55 Kolbenstange (9) sind in einem proximalen Teil (8) penetrates the skin and dose setting means by eines Gehäuses untergebracht, dadurch gekenn- which the distance which the piston (4) is moved zeichnet, dass die distalen und proximalen Teile into the cylinder ampoule (2) by the spring driven (1, 8) mit einem Gewinde ausgestattet sind, sodass

3 5 EP 0 973 567 B1 6 eines dieser Teile sukkzessiv in das andere ge- schraubt werden kann, um eine Dosis einzustellen, die durch die Vorrichtung abgegeben wird.

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