WO2008098860A1

WO2008098860A1 - Container for a medical device

Info

Publication number: WO2008098860A1
Application number: PCT/EP2008/051415
Authority: WO
Inventors: Victor Kronestedt; Istvan Bartha
Original assignee: Shl Medical Ab
Priority date: 2007-02-14
Filing date: 2008-02-05
Publication date: 2008-08-21

Abstract

The present invention relates to a container intended to be used in a medical delivery device, which medical delivery device is capable of exerting pressure inside said container, the container comprising a housing of generally tubular shape, a stopper arranged movably in said housing, a plug fixedly attached to one end of said housing and a passage opening arranged in said plug, through which passage a liquid medicament can be expelled from said housing, wherein the interior surface of said plug is shaped so as to direct air entrapped in the container through said passage when pressure is applied to the medicament via said medical delivery device.

Description

CONTAINER FOR A MEDICAL DEVICE Technical Field

[0001] The present invention relates to an arrangement for a medical device and in particular pressurized compartments containing medicament to be expelled to deliver a dose to a patient.

Background Art

[0002] There exists a number of different devices on the market that are capable of delivering metered doses of medicament, where the delivered medicament is injected or taken up by the lungs for further administration via the circulatory system. These devices for wherein said medicament is taken up by the lungs so called inhalers comprise aerosol, powder and nebulizers.

[0003] The nebulizers have a function such that medicament in liquid form is pressurized in a container and forced through a nozzle having a plurality of very small passages, in the region of μm. This causes the liquid to form a "mist" of very small droplets, which are inhaled by a patient. Often conventional containers for injecting devices are used, which containers usually have a tubular body of glass, a stopper slidable in the body for expelling medicament and a needle attached to one end of the body. The needle attachment is often a metal cap pressed onto a neck of one end of the body. The centre of the metal cap is arranged with a passage covered with rubber, through which the needle projects.

[0004] There are a few drawbacks to use that type of container in nebulizers. One is that the pressure inside the container for creating the mist of droplets is much higher than the pressure used for injecting the medicament, which could be 3 to 5 times higher, or even more. Since the containers are not intended for such high pressures, there is a risk of damage and leakage. One is that the cap may be pushed off the body, which has led to that a specially designed cap holder has been developed for holding it in place against the pressure force. However, even if the cap is held in place, it has been shown that the rubber at the centre of the cap is bulged and even pushed out of the opening due to the pressure. [0005] Another drawback with the above mentioned container is that the needle projects through the rubber and a certain distance into the container. There is almost always a certain amount of air entrapped in the container because it is very difficult to completely fill the container and then close it. This entrapped air uses to be positioned around the projection of the needle into the rubber. Further, this amount of air is a problem within the application of injectors and especially within the application of nebulizers because the air bubble and the high pressures cause a resiliency that negatively affect the forming of the mist of droplets. Because the needle projects into the container the air bubbles will not be expelled through the needle, but will rather be entrapped around the needle during the whole process of emptying the container. The air bubbles may even disturb the forming of droplets to such an extent that the amount of medicament entering the lungs are much smaller than the expelled dose, where the rest instead causes a drooling from the device.

[0006] There is thus a need for caps or closures of containers for in particular nebulizers and their specific conditions and requirements since the quality of the "mist" is dependent of the pressure exerted inside the container.

[0007] Document US 5,803,284 discloses a closure for a medicament containing container or vial. The closure is arranged with an elastomeric closure for sealing an opening of a medicament container, including a plug which is pushed into the opening and a flange that rests on the upper surface of the container. The plug is held in place by a washer and a crimp cap which surrounds a vial rim.

[0008] However the vial is not intended to be under pressure and there is no information regarding the holding strength of the crimp cap. Further the plug is arranged with a conical surface where air could be entrapped.

[0009] Regarding the entrapment of air, document US 2,666,434 discloses a disposable manual syringe having a medicament compartment where the front end is arranged tapered towards a central opening, in which a hollow needle is attached. The tapering prevents any air inside the compartment from being trapped.

[0010] However, the syringe of US 2,666,434 has a container made in one piece by moulding in plastic, preferably polystyrene in order to reduce the cost. This makes it unsuitable for use in nebulizers where the interior of the containers are subjected to very high pressures.

Brief Description of the Invention

[0011] The aim of the present invention is to provide a container which is capable of ensuring that any air enclosed in the container is expelled during the dose deliveries and also is capable of withstanding high pressures.

[0012] This aim is obtained by the features of the independent claim 1. Preferable embodiments of the invention form the subject of the dependent claims.

[0013] According to a main aspect of the invention it is characterised by a container intended to be used in a medical delivery device, which medical delivery device is capable of exerting pressure inside said container, the container comprising a housing of generally tubular shape , a stopper arranged movably in said housing, a plug fixedly attached to one end of said housing and a passage opening arranged in said plug, through which passage a liquid medicament can be expelled from said housing, wherein the interior surface of said plug is shaped so as to direct air entrapped in the container through said passage when pressure is applied to the medicament via said medical delivery device.

[0014] According to a further aspect of the invention, said means for directing air entrapped in the container comprises a portion of said passage opening widening towards the inner surface of the housing.

[0015] Said portion of said passage opening could be shaped as a funnel.

[0016] According to another aspect of the invention, said passage is arranged in a plug inserted in the housing and attached to the same.

[0017] According to yet an aspect of the invention, the exterior surface of said plug is arranged with a sealing membrane.

[0018] According to yet an aspect of the invention, said passage is arranged in a body of a passage creating member which is insertable in said plug.

[0019] Further, said body is arranged with a central passage divide in two openings and with a pointed end capable of piercing said sealing membrane.

[0020] Preferably the pointed end, when said body is inserted in said plug, is arranged in said air directing means, and wherein said central passage openings are arranged in the surface of said pointed end.

[0021] There are several advantages with the container according to the present invention. Because the passage for expelling medicament from the container is arranged with means shaped as for directing possible air entrapped in the container, it is ascertained that air is removed during the initial dose delivery. Air is then effectively prevented from being entrapped in the container, which otherwise could affect the function negatively.

[0022] Preferably the inner part of the passage widens towards the inner walls of the container housing, thereby reducing the surfaces that could block the air from entering the passage. A preferred form of the widening is a funnel-shape.

[0023] The front part of the container with the passage could be formed as a separate plug that is attached fixedly to the container housing, capable of withstanding the high pressures inside the container when delivering a dose of medicament.

[0024] According to one embodiment of the invention, the plug is arranged with a protective sealing membrane for ensuring the quality and sterility of the medicament before the container is used. Said protective sealing membrane being an adhesive membrane that can be removed or a membrane of material such as rubber that must be broken or pierced.

[0025] In this case a passage creating member is used for breaking or piercing the protective sealing membrane by a pointed end. Thus the medicament could be stored for long periods and the container be opened and a passage created just before the first use of the container.

[0026] The plug is preferably made of a rather stiff and non-elastic material, for reducing the resiliency inside the container when high pressures are applied to the medicament. In order to ensure a proper function and especially dose accuracy, the plug is preferably arranged with sealing means for preventing medicament under high pressure from leaking out.

[0027] These and other aspects of and advantages with the present invention will become apparent from the following detailed description and from the accompanying drawings. Brief Description of the Drawings

[0028] In the following detailed description of the invention, reference will be made to the accompanying drawings, of which

[0029] Fig. 1a is a side view of a medical delivery device comprising the present invention,

[0030] Fig. 1 b is an end view of the device of Fig. 1 ,

[0031] Fig. 2 is a longitudinal cross-section of the device of Fig. 1a,

[0032] Fig. 3 shows a longitudinal cross-section of one embodiment of a container according to the present invention,

[0033] Fig. 4a shows a longitudinal cross-section of another embodiment of a container according to the present invention,

[0034] Fig. 4b shows a longitudinal cross-section taken 90^° in relation to Fig. 4a,

[0035] Fig. 5 shows a longitudinal cross-section of yet an embodiment of a container according to the present invention, and

[0036] Fig. 6 shows a variant of a plug used with the present invention.

Detailed Description of the Invention

[0037] The present invention will now be described in connection with a medical delivery device of the type capable of dispensing the medicament as very small droplets, normally called nebulizers.

[0038] Such a device is shown in figures 1 and 2 where the outer housing has been removed for clarity. The device comprises a front part 10, to the left in the figures, where the medicament delivery takes place and a rear part 30. The front part comprises a medicament container holder 12 arranged with an elongated tubular space. This space can receive a medicament container or cartridge14, which will be explained in detail below. The front part of the container holder is arranged with a neck part 16 arranged with external threads. A cap 18 arranged with internal corresponding threads is threaded onto the neck. The cap is arranged with a central opening, into which an end plug 20 of the container is placed. The end plug is arranged with a circumferential ledge 22, which rests against the inner surface of the cap around the central opening. The cap is also arranged with a central opening, in which a nozzle 24 is placed. The nozzle is arranged with a plurality of very small passages, which are capable of creating very small droplets when a liquid is pushed through the passages. The nozzle is held in place by a washer 26 attached to the cap by screws 28.

[0039] The rear part 30 of the device comprises dose setting and drive means. The rear part of the container holder is arranged with internal threads which mate with external threads of a front tubular part 32 of a holder. The holder then widens to a larger diameter tubular part 34. On the inside of the wider tubular part a nut 36 is attached with screws. The nut is arranged with a central threaded passage. A plunger rod 38 is threaded into the nut, where the front end of the plunger rod is in contact with a stopper 40 arranged in the container. Adjacent the nut a locking member 42 is arranged, having a central opening through which the plunger rod extends. The plunger rod is arranged with longitudinally extending cut-outs and the central opening has a corresponding shape, whereby the plunger rod is rotationally locked in relation to the locking member, but movable in the longitudinal direction.

[0040] The locking member is arranged with externally arranged grooves 44 directed in the longitudinal direction of the device. The grooves mate with corresponding grooves arranged on the inner surface of a release member 46. The release member is arranged with outwardly extending arms 48, which are placed in grooves of the holder. A ring 50 is attached to the arm. The function of the release member will be described below. The release member is held in a meshing position with the locking member by a compression spring 52. A dose setting member 54 having a generally tubular shape is arranged around the plunger rod, having a front part in contact with the locking member. The mating surfaces of the front part of the dose setting member and the locking member are arranged with saw-tooth shaped protrusions (not shown), whereby the dose setting member can be rotated in relation to the locking member in only one direction, as will be described below. The dose setting member is rotatably attached to a dose setting knob 56, protruding to the rear of the device. The dose setting member is however axially movable to the dose setting knob.

[0041] A flat spiral spring 58 is arranged in a spring housing 57, which in turn is attached to the base structure of the device. The outer end of the spiral spring is attached to the spring housing, and the inner end of the spiral spring is attached to the dose setting member 54.

[0042] The device is intended to function as follows. A container 14 is inserted in the container holder 12, which in turn is threaded onto the rear part 32 of the device. When the device is to be used, the dose setting knob 56 is turned. This causes the dose setting member 54 to turn and because the spiral spring 58 is attached to the dose setting member, the spring is tensioned. The dose setting member is turned in relation to the locking member 42 because this is held rotationally fixed by the cooperating grooves 44 of the dose release member 46. The saw-toothed protrusions of the dose setting member and the locking member act to allow rotation in one direction and to prevent the dose setting member from rotating back when a certain dose has been set.

[0043] When a dose is to be delivered the release member 46 is moved towards the back of the device whereby the cooperating grooves 44 of the locking member and the release member are moved out of contact with each other. The locking member 42, connected to the dose setting member, is now free to rotate, and due to the force of the spiral spring 58 acting on the dose setting member 54, the locking member is rotated. Because of the rotational lock between the locking member 42 and the plunger rod 38, the latter will also rotate and because of the threads of the plunger rod co-acting with the threads of the nut 36, the plunger rod is moved forward. This forward movement causes the stopper 40 to be moved forward, building up a pressure inside the container. This pressure causes the medicament to be pressed through the very small passages of the nozzle 24, thereby creating a "mist" of very fine droplets. The delivery of medicament is terminated when the dose setting member has rotated back to its original position.

[0044] The above described device utilizes a container according to the present invention, where one embodiment is shown in figures 2-3. It comprises a generally tubular body 60 with a stopper 40 in the rear end, as mentioned above. According to one embodiment, the stopper could be made of a rather stiff, non-elastic material for reducing the resiliency of the container when pressure is built up inside. The stopper is arranged with a number of sealing means 62 arranged around the circumference of the stopper, such as rubber O-rings for ensuring a tight seal between the stopper and the housing. Moreover, the stopper can alternatively be covered with a sealing rubber cap (not shown). Further, the interior of the rigid stopper can be shaped to receive the rotating plunger rod of the device in order to decrease the friction between said plunger rod and said stopper.

[0045] The front end of the container is arranged with a specially designed plug 64. This may also be made of a rather stiff, non-elastic, material, for the same reason as for the stopper. This plug is also arranged with a number of sealing means 66 arranged around the circumference of the plug. The plug is arranged with a central passage 68 extending through the plug from the interior of the container to the front surface of the plug. At the inner end of the plug, the passage is designed with a funnel-like shape 70, i.e. the passage diameter at the inner surface of the plug is larger, and is reduced as the passage extends towards the front end. This design ensures that any air entrapped in the container when it is delivered to the patient is directed through the passage and removed during the first delivery of medicament, i.e. there are no spaces where the air can be trapped during use. Further, the exterior surface of said plug 64is arranged with an adhesive sealing membrane 67. This is the state that the medicament container is stored and delivered to a patient, where the adhesive sealing membrane ensures the quality of the medicament. When the container is to be positioned into the container holder of the device, then the patient removes said adhesive sealing membrane. The plug is held in place on the container by the cap 18, Fig. 2, threaded onto the container holder of the device, thereby ensuring that the plug is held in place even during very high pressures in the container.

[0046] Figures 4a and 4b show another embodiment of the present invention. Also here the plug 80 is preferably made of a rather stiff, non-elastic material. However there are no sealing means arranged around the circumference of the plug. Instead in this embodiment the plug is further arranged with an outer cap 82, where the lower part of the inner surface of the cap is arranged with an inwardly directed circumferential ledge 84, which has a bevelled surface. Further the container housing is arranged with a circumferential groove 86 into which the ledge fits when the plug with the cap is pressed onto the front end of the container holder of the device. A seal ring 88 is arranged between the front surface of the housing and the plug 80. This seal ring is compressed to allow a proper sealing when the circumferential ledge enters the groove of the housing. The bevelled surface of the ledge facilitates the mounting of the plug 80 on the housing. The plug 80 is arranged with a passage 90 having a certain shape, as will be described below.

[0047] Outside the plug 80 a sealing cap 92 is attached, by for example threads or adhesive or any other suitable means. The sealing cap has a central opening 94 and on the inner surface facing the plug 80, an annular spacer 96. Inside the spacer 96 and covering the central opening of the sealing cap, a sealing membrane 98 is arranged. This could comprise a resilient, medicament safe, material such as rubber. This is the state that the medicament container is stored and delivered to a patient, where the sealing cap with the membrane ensures the quality of the medicament.

[0048] When a patient is to use the container for dose delivery, the membrane is broken by a passage creating member 100. Said member 100 is arranged with a pointed tip end 102 capable of piercing or rupturing the membrane 98, when pushed through the central opening 94 of the sealing cap 92. Said passage creating member 100 comprises also a body 104 having a conical shape, wherein said shape corresponds to the conical shape of the passage 90 of the plug 80, such that when the member 100 is pushed further into the plug 80, a wedge-like sealing action is obtained between the body 104 and the passage 90. The tip 102 is now placed in the inner part of the passage 90 of the plug 80, which inner passage has a funnel-like shape 91 as the previous embodiment, thus ensuring that no air can be entrapped inside the container.

[0049] Further the passage creating member 100 is arranged with a central passage 108. At the tip the central passage is divided in two obliquely arranged openings 110, which communicate with the funnel-shaped space. Thus a passage is created between the interior of the container and the front end of the passage creating member 100. When inserted in the medicament delivery device, the front end of the passage creating member is abutting fixed surfaces of the device (not shown), thereby ensuring that the pressure inside the container cannot push the passage creating member out of the plug 80. The central passage 108 of the passage creating member is in communication with the nebulizing nozzle for creating the mist of very small droplets. Further, it is also to be understood that the central passage 108 of the passage creating member can also be an injection needle.

[0050] It is to be understood that the front end of the container can be modified in many ways in order to ascertain the desired function of expelling entrapped air. Normally glass is used as material for medicament containers of this type, which material cannot react with or affect the medicament contained therein. However there are some plastic materials that have been developed that display the same properties as glass regarding not affecting the medicament. Thus it could be feasible to design a container, Fig. 5, having a front end integrated with the housing where the passage is arranged with a funnel-shaped inner part, for ensuring that air is expelled from the container during initial dispensing of medicament. The integrated front end will also have the necessary strength for handling the pressures that build up for these applications. Further, the outer surface of front end of said container can be arranged with threads or grooves that cooperate with threads or ledges of a cap (not shown) of the passage creating member 100.

[0051] It is also to be understood that not the entire inner part of the passage needs to be widening. For example, as shown in Fig, 6, that part could be arranged with funnel shaped grooves 120 capable of directing any entrapped air through the passage.

[0052] It is to be understood that the embodiments described above and shown in the drawings are to be regarded only as non-limiting examples of the invention and that it may be modified in many ways within the scope of the patent claims.

Claims

1. Container intended to be used in a medical delivery device, which medical delivery device is capable of exerting pressure inside said container, the container comprising a housing of generally tubular shape (60), a stopper (40) arranged movably in said housing, a plug (64; 80) fixedly attached to one end of said housing and a passage opening (68; 108a) arranged in said plug, through which passage a liquid medicament can be expelled from said housing, wherein the interior surface of said plug is shaped so as to direct air entrapped in the container through said passage when pressure is applied to the medicament via said medical delivery device.

2. Container according to claim 1 , wherein said interior surface comprises a portion of said passage opening widening towards the inner surface of the housing.

3. Container according to claim 1 , wherein said portion of said passage opening is shaped as a funnel (70; 91).

4. Container according to claim 3, wherein the exterior surface of said plug (64; 80) is arranged with a sealing membrane (67; 98)

5. Container according to claim 4, wherein said plug (64) comprises sealing means (66) arranged between said plug and said housing.

6. Container according to claim 4, wherein said plug (80) is arranged with an outer cap (82) surrounding a part of the outer surface of said housing and arranged with an annular ledge fitting into a groove an the outer surface of said housing.

7. Container according to claim 6, wherein it further comprises a sealing ring (88) arranged between the front surface of the housing and the plug (80).

8. Container according to claim 4, wherein the sealing membrane (98) is arranged inside an annular spacer (96) of a sealing cap (92) which is attached to the plug (80).

9. Container according to claim 8, wherein the passage (90) of the plug (80) has a shape that corresponds to a body (104) of a passage creating member (100) which is adapted to be insertable in said plug (80).

10. Container according to claim 9, wherein said body (104) is arranged with a central passage (108) and with a pointed end (102) capable of piercing said sealing membrane (98).

11. Container according to claim 10, wherein said pointed end (102), when said body (104) is inserted in said plug (80), is arranged in said air directing means, and wherein said central passage (108) is divided in at least two openings (110) arranged in the surface of said pointed end.

12. Container according to claim 11 , wherein said central passage (108) is arranged to be in contact with a nebulising nozzle for creating a mist of very small droplets.

13. Container according to claim 11 , wherein said central passage (108) is arranged to be an injection needle.

14. Container according to any of the preceding claims, wherein the stopper is arranged and designed to be non-elastic and arranged with sealing means.

15. Container according to claim 15, wherein the interior of said stopper can be shaped to receive a plunger rod of the medical delivery device.