CA2150253C - Injection cartridge - Google Patents
Injection cartridge Download PDFInfo
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- CA2150253C CA2150253C CA002150253A CA2150253A CA2150253C CA 2150253 C CA2150253 C CA 2150253C CA 002150253 A CA002150253 A CA 002150253A CA 2150253 A CA2150253 A CA 2150253A CA 2150253 C CA2150253 C CA 2150253C
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- barrel
- grooves
- lands
- cartridge according
- injection cartridge
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/00491—Surgical glue applicators
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
- A61C5/00—Filling or capping teeth
- A61C5/60—Devices specially adapted for pressing or mixing capping or filling materials, e.g. amalgam presses
- A61C5/62—Applicators, e.g. syringes or guns
- A61C5/64—Applicators, e.g. syringes or guns for multi-component compositions
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
- A61M5/178—Syringes
- A61M5/24—Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic
- A61M5/2422—Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic using emptying means to expel or eject media, e.g. pistons, deformation of the ampoule, or telescoping of the ampoule
- A61M5/2429—Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic using emptying means to expel or eject media, e.g. pistons, deformation of the ampoule, or telescoping of the ampoule by telescoping of ampoules or carpules with the syringe body
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F33/00—Other mixers; Mixing plants; Combinations of mixers
- B01F33/50—Movable or transportable mixing devices or plants
- B01F33/501—Movable mixing devices, i.e. readily shifted or displaced from one place to another, e.g. portable during use
- B01F33/5011—Movable mixing devices, i.e. readily shifted or displaced from one place to another, e.g. portable during use portable during use, e.g. hand-held
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F33/00—Other mixers; Mixing plants; Combinations of mixers
- B01F33/50—Movable or transportable mixing devices or plants
- B01F33/501—Movable mixing devices, i.e. readily shifted or displaced from one place to another, e.g. portable during use
- B01F33/5011—Movable mixing devices, i.e. readily shifted or displaced from one place to another, e.g. portable during use portable during use, e.g. hand-held
- B01F33/50112—Movable mixing devices, i.e. readily shifted or displaced from one place to another, e.g. portable during use portable during use, e.g. hand-held of the syringe or cartridge type
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
- B01F35/71—Feed mechanisms
- B01F35/713—Feed mechanisms comprising breaking packages or parts thereof, e.g. piercing or opening sealing elements between compartments or cartridges
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
- B01F35/71—Feed mechanisms
- B01F35/716—Feed mechanisms characterised by the relative arrangement of the containers for feeding or mixing the components
- B01F35/7164—Feed mechanisms characterised by the relative arrangement of the containers for feeding or mixing the components the containers being placed in parallel before contacting the contents
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/00491—Surgical glue applicators
- A61B2017/00495—Surgical glue applicators for two-component glue
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
- A61M5/178—Syringes
- A61M5/19—Syringes having more than one chamber, e.g. including a manifold coupling two parallelly aligned syringes through separate channels to a common discharge assembly
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
- A61M5/178—Syringes
- A61M5/24—Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic
- A61M5/2448—Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic comprising means for injection of two or more media, e.g. by mixing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
- B01F35/30—Driving arrangements; Transmissions; Couplings; Brakes
- B01F35/32—Driving arrangements
- B01F35/32005—Type of drive
- B01F35/3202—Hand driven
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- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Surgery (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Hematology (AREA)
- Anesthesiology (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Vascular Medicine (AREA)
- Medical Informatics (AREA)
- Molecular Biology (AREA)
- Oral & Maxillofacial Surgery (AREA)
- Dentistry (AREA)
- Epidemiology (AREA)
- Infusion, Injection, And Reservoir Apparatuses (AREA)
- Containers And Packaging Bodies Having A Special Means To Remove Contents (AREA)
- Dental Tools And Instruments Or Auxiliary Dental Instruments (AREA)
Abstract
An injection cartridge (1) of the dual-chamber type has a bypass connection (12) between its two chambers (9, 10) which is arranged such that the interior wall of the cartridge is modified in a predetermined area in such a way that the movable wall (11) between the two chambers does not seal completely against the interior wall in said area. According to the invention, the modification of said wall is arranged as a plurality of lands and grooves (12) which have a direction that is inclined in relation to the longitudinal axis of the cartridge barrel.
Description
WO 95/11051 ~ PCT/SE94/00949 Injection cartridge The preser:~ invention refers to an injection cartrid-ge of the duel-chamber type. In more detail, the in-vention refers to an injection cartridge of the dual-chamber type which has an improved arrangement of by-pass means fcr the liquid component.
Injection cartridges of the dual-chamber type are well-known and have found a wide use. Such cartridges are primarily intended to be used when the liquid phar-maceutical composition to be injected is not stable for any extended period of time. In such cases, the compo-sition to be injected is provided as two separate com-ponents, one solid component comprising the active pharmaceuticGl component in a dry state, and one liquid component comprising a solvent or dispersing agent for the solid component. These two components are enclosed in an injection cartridge of the dual-chamber type, such that the solid component is usually enclosed in a front chamber, while the liquid component is enclosed in a rear chamber. (In the following specification and claims, the expressions "front" and "rear" are to be .
regarded in relation to the direction in which the injectable composition is transported when an injection is administered.) The two components are separated by a movable wall which seals against the interior wall of the cartridge.
The rear chamber, which contains the liquid component, is also closed at its rear end by a piston which seals against the interior wall of the cartridge.
At its front end, the cartridge is usually closed by a rubber septum which is held into place by a metal capsule. This metal capsule has a central opening which exposes the rubber septum. Through this opening, a hollow needle may be inserted through this the septum to give a connection with the interior of the cartrid-ge.
For conducting the liquid component over to the solid ~,: .~iQ 5 component for dissolution or dispersion, conventional dual-chamber injection cartridges are provided with at least one bypass channel in the wall of the cartridge.
When the movable wall which separates the two chambers is at a suitable position, the bypass channel is , exposed, so that the liquid component may flow around said movable wall and be mixed with the solid compo-nent.
When the cartridge is to be readied for the admini-stering of one or more injections, pressure is applied to the rear piston to urge it forward. This pressure will be transmitted through the liquid phase, which is largely incompressible, so that also the movable wall, which separates the two chambers, is urged forward.
When front movable wall has been moved forward a deter-mined length, it will be situated at the bypass chan-nel, such that a flow of liquid from the rear chamber to the front chamber becomes possible. Further forward movement of the rear piston will now push the liquid from the rear chamber into the front chamber, while the movable wall remains essentially stationary.
When all the liquid has been expelled from the rear chamber, the rear piston will abut the movable wall, and further pressure forward will move the two walls together, to act like a single piston. The rubber sep-tum closing the front end of the cartridge should now have been pierced by a hollow needle, which makes it possible to expel the ready-mixed preparation from the front chamber to be administered to a patient.
The dual-chamber injection cartridges described above have a number of important advantages and have found a wide use. One important use is in injection devices which are intended to be used by the patient to admini-ster injections to himself. It is easy for the patient to prepare the injectable preparation from the two components immediately before the administering, and the risk of contamination is greatly reduced.
WO 95/11051 ~~ PCT/SE94/00949 However, the conventional injection cartridges of the dual-chamber type also have certain shortcomings. The cartridges are often used in injection devices which more or less have the appearance of a fountain pen, and it is desirable that such a device should not be unduly thick or long. Thus, any measure which may make such a device slimmer and/or shorter is highly desirable.
The bypass channel in the wall of conventional car-tridges creates a longitudinal ridge in the outer wall of the cartridge, and makes it necessary to use an injection device having an undesirably thick barrel to make room for the cartridge. Furthermore, it is desi-rable to make the forward movement of the movable wall as short as possible, as this makes it possible to use an injection device having a shorter barrel.
The desirable improvements mentioned above are obtai-ned by the present invention. According to the inven-tion, an injection cartridge of the dual-chamber type is provided, which comprises a tubular barrel which at its front end is sealed by a closure which may be pe-netrated by an outlet conduit for a liquid preparation from the cartridge, at its rear end is closed by a piston which may be moved forward, and which comprises a movable transversal wall inside the barrel, said movable wall dividing the cartridge into two separate chambers, and a bypass connection between the two . chambers, said connection being openable by the dis-placement of said movable wall to permit a bypass flow of a liquid between the chambers. The connection be-tween the two chambers is arranged as a modification of the interior wall of said barrel along a determined area, such that said movable wall does not seal com-pletely against the interior wall of the barrel within said area. Said modified area extends completely around the circumference of the interior wall of the car-tridge, such that a flow of liquid is permitted around the complete circumference of the movable wall.
3a According to a broad aspect of the invention, there is provided an injection cartridge of the dual-chamber type, comprising a tubular barrel wherein said barrel has a front end, a rear end, interior wall and interior suzface, and wherein said front end is sealed by a closure which may be penetrated by an outlet conduit for a liquid preparation fxom the cartridge, said rear end is closed by a piston which may be moved forward, and a movable transversal wall inside said barrel, said movable transversal wall dividing l0 the cartridge into two separate chambers, and a bypass connection between the two separate chambers, said connection being openable by the displacement of said movable transversal wall to permit a bypas9 flow of liquid between the two separate chambers, whezein said bypass connection between the two separate chambers is arranged as a modification of the interior surface of the barrel along a predetermined area wherein said predetermined area extends completely around the circumference of said interior wall of the barrel, such that said movable transversal wall does not seal completely against said interior wall of the barrel within said axes, wherein said modification is arranged as a plurality of lands and grooves having an inclined direction in relation to the longitudinal axis of said barrel, said lands and grooves extending along all of said predetermined area, and wherein said tubular barrel has a nominal interior circumference and said lands extend inward from the nominal interior circumference of the tubular barrel.
WO 95/11051 r ~ PCT/SE94/00949 2150'53 What characterizes the invention is that the modifi-cation of the interior wall of the cartridge is ar-ranged as a plurality of lands and grooves in said , interior wall, said lands and grooves having an in-s clined direction in relation to the axial direction of the barrel and extending along all of said modified area. In a more preferred version of this embodiment, the lands extend inward from the interior wall of the cartridge such that the interior diameter between the lands is smaller than the nominal interior diameter of the cartridge.
In a further preferred embodiment of the invention, said axial lands and grooves are interrupted by essen-tially peripheral grooves having essentially the same depth as said axial grooves.
In a still further preferred embodiment, the modified area of the interior wall of the cartridge is divided into at least two circumferential areas, which have the same spacing as the distance between the same number of circumferential sealing ridges on the movable wall.
The depth of said grooves and the height of said lands is preferably between 0.06 and 0.6 mm from the interior wall of the cartridge.
Thus, the dual-chamber cartridge no longer contains a bypass channel, but a bypass area of modifications of the interior wall. Such an area affords a great number of shallow channels, which have at least the same flow capacity as one large channel. However, because of the shallow depth of the modifications, no exterior ridge or increased thickness of the cartridge wall will be necessary, and this makes it possible to use an injec-tion device having a slimmer barrel. The inclined ar-rangement of the lands and grooves in relation to the longitudinal axis of the cartridge also brings new and unexpected advantages in the manufacture of the car-tridge with its bypass area.
The grooves and lands cnay be embossed in the interior.
wall. of the cartridge barrel by means of a rotating embossing toot which works on the heat softened materi-al of the barrel. It has been found that when'the 5 grooves and lands are parallel to the axis of the bar-rel, the embossing action of the tool v.ill cause vibra~
tions which may lead to a distortion of the barrel. r~
the grooves and lands are instead embossed at an angle to the lcngitudirlal axis, no such vibratxor~s will oc-cur. This is an important and unexpected advantage of the invention, The angle between the grooves and the longitudiaal-axis of the cartridge can be from S to 45 degrees. A , pre f erred value is f ro~u 1 o . to 3 o degrees , and about degrees is especially preferred.
International patenC publication no. WO 1993/20868, which has not yet been published, discloses an iaj~ec-tion cartridge of the dua~.~chamber type, wherein a bypass area is arranged as a modification of .the inte..
2o rior cartridge wa~.l. ~iowever, nothing is mentioned about any inclxaed arrangement of grooves and lards.
.
The invention will now be described in closer dttail, with reference to the enclosed drawinga_ In the drawings, Figure 1 shows a dual-chamber injec-tion cartridge according to the invention. Figure 2 shows a sectional view of such a eartridge_ Figure 3 shows another embodiment of a du,ai-chaa~be~c injection cartridge of the invention, and Figure 4 shows the same cartridge xn the stage when the two components arm mix- ~~
~ ed_ Figure S shows a preferred embodibent of an injec-rio:~ cartridge of the invention, and Figure 6 shows a transverse sectional view of the same cartridge at the position of the piston_ Fa.gure 7 shows the same eaibodi-ment of the cartridge with the piston displaced from tn~ bypass zone, and Figure 8 shows a sectional view of the same cartridge at this position of the piston.In~
the fxguxes of the drawing, like parts have the same WO 95/11051 ~ ~ PCT/SE94100949 reference numbers. Furthermore, some of the details in the drawing are shown in an exaggerated scale for clarity.
Figure 1 shows a dual-chamber injection cartridge having 'a cylindrical barrel 1 and a neck portion 2 at .
its forward opening 3. This opening is closed by a sep-tum 4 of rubber or some similar material which has sealing properties, and the septum is held in place by a metal capsule 5, which is fastened around a flange 6 at the forward end of the neck portion 2. The capsule 5 has a central opening 7, where the septum is exposed and may be penetrated by a hollow needle when desired.
At its rear end, the barrel 1 of the cartridge is closed by a piston 8, which may be moved forward when the cartridge is to be readied for an injection.
The cartridge is divided into a front chamber 9, which usually contains the solid component of the in-jectable preparation, and a rear chamber 10, which usually contains the liquid component of said prepara-tion, by means of the movable wall 11. In the position shown in the figure, the movable wall seals against the interior wall of the cartridge, and nothing can pass between the two chambers.
In front of the movable wall 11, the interior wall of the barrel 1 of the cartridge is provided with modifi-cations 12, which cause that the movable wall 11 in this area does not seal completely against the interior wall. In the figures of the drawing, these modifica-tions are shown as shallow grooves extending at an angle to the longitudinal direction of the barrel 1.
This is also shown in Figure 2, which is a sectional view of the barrel 1 along the line A-A in Figure 1.
In Figure 2, it is shown how the barrel 1, which here encloses the front chamber 9, is provided with a plura-lity of shallow grooves 13. For clarity, the depth of these grooves is exaggerated in the drawing. The shal-low grooves are evenly distributed along the internal WO 95111051 ty ~~~ PCT/SE94/00949 circumference of the barrel. However, it is also possi-ble to have the grooves present in certain discrete areas only. What is important is that the grooves should together afford a passage that is sufficient for the flow of the liquid component from the rear chamber to the front chamber.
It is understood that the area of surface modifica-tions should have such an extension in the axial direc-tion that it is somewhat longer than the movable wall 11, to make it possible for a flow of liquid to bypass said movable wall.
It will also be seen that the grooves 13 can take up so much of the interior wall that the movable wall 11 is properly guided only by small ridges. This is usu-ally not a problem.
The inclined grooves 13 may also be broken by a number of peripheral grooves around the interior cir-cumference of the barrel 1. This may improve the flow of the liquid and will aid in removing air from the system.
Furthermore, it should be noted that it is not strictly necessary that the bypass area 12 is formed by grooves. Other modifications of the interior surface are also possible, such as small projections, and the like. In a preferred embodiment, such projections are shaped as lands extending at an angle to the axial direction. The height of such projections should also preferably be between 0.06 and 0.6 mm. The important feature is that in said area 12, the movable wall 11 should not seal completely against the barrel, but permit a bypass flow of the liquid component between ' the chambers.
When the cartridge is to be readied for injection, a forward-directed pressure is applied to the piston 8 at the rear of the cartridge. This pressure is transmitted through the essentially incompressible liquid in the rear chamber 10 and acts on the movable wall 11 to urge ....
it forward. Wher~~the movable wall has been moved for-, ward so far that it is in the area of the modified internal surface of the barrel 1, it will no longer seal completely against the interior wall of the bar-s rel, and it will be possible for the liquid component to flow from the rear chamber 10 into the front chamber 9, to be mixed with the solid component in this cham-ber. Further pressure on the rear piston 8 will expel all of the liquid from the rear chamber 10, until fi-=0 nally the rear piston will rest against the rear surfa-ce of the movable wall 11. At this stage, the movable wall 11 and the rear piston 8 will act together as one single piston.
Before the liquid component is made to flow over into .5 the front chamber 9, the septum 4 closing the front chamber 9 will usually have been pierced with a hollow needle which is connected to a needle for administering the injection, or which itself serves as such an injec-tion needle by means of its forward pointed end. This 20 prevents the build-up of an excessive overpressure in the front chamber 9. After all of the liquid component has been made to flow over into the front chamber 9 and has been thoroughly mixed with the solid component, further pressure on the combined rear piston 8 and 25 movable wall 11 will serve to expel the mixed injec-table preparation through the hollow needle for admini-stering to a patient.
Before the cartridge is readied for injection, it is placed in a suitable holder device. Such devices are 30 known for carrying out the mixing of the two components and for subsequent administering of the injectable preparation. In many cases, they also comprise means for metering out predetermined amounts of the prepara-tion to be injected. There are a number of such devices 35 commercially available, which are arranged such that a patient may himself make the cartridge ready for injec-tion, and administer the injections to himself by means °~~3 of such a device .
Figures 3 and 4 show a preferred embodiment of the invention. The arrangements at the front and rear ends of the cartridge are the same here as shown in Figure 1.
However, the area of modification of the internal wall of the barrel 1 ~ here divided into at least two areas 15 and 16. Thes-- areas are arranged as spaced bands 15 and 16, which each contain the same types of inclined surface modificationshas those mentioned in connection with Figures 1 and 2. A sectional view along the lines A-A in Figure 3 will show exactly the same as Figure 2 in connection with Figure 1.
The movable wall 11_is composed of a central part having a smaller diameter than the interior diameter of the barrel 1, and at least two circumferential sealing ridges 17 and 18 at the front and rear end of the mo-vable wall, respectj,vely. This gives a space 19 defined by the two sealing ridges 17 and 18, the part of the movable wall having a smaller diameter, and the inte-rior wall of the barrel 1.
The spacing between the two sealing ridges 17 and 18 is the same as the spacing between the two bands 15 and 16 of surface modifications of the interior wall. These bands also have a somewhat greater axial length than the axial length of each of the sealing ridges 17 and 18, such that a flow of liquid around said sealing ridges becomes possible.
In the initial stage, before the cartridge has been readied for injection, the movable wall is in such a position inside the barrel 1 of the cartridge that the front sealing ridge 17 lies between the two bands of modification 15 and 16. The reax sealing ridge 18 should lie behind the rear band ~.6. In this way. a complete seal between the front and rear chambers is assured.
When the cartridge is to be readied for injection, pressure is applied on the rear piston 8, as described previously. This will bring about that the movable wall 11 is urged forward, until it is in the position shown in Figure 4. It will be seen that the two sealing rid-5 ges are now positioned opposite the bands of modifica-tion 15 and 16, and a liquid flow is now possible from the rear chamber 10 around the rear sealing ridge 18, into the space 19, and around the front sealing ridge 17 into the front chamber 9.
10 The advantage of this embodiment is that the movable wall 11 will only have to be moved the short distance corresponding approximately to half the spacing between the two bands 15 and 16. This makes it possible to use a shorter cartridge and a shorter injection device for housing the cartridge. For injection devices which are to be carried around by the patient himself, this can be of considerable importance.
It is also possible to use more than two areas of surface modification and corresponding sealing ridges of the movable wall. This gives a more secure seal, but the construction becomes more complicated and therefore also more expensive.
In Figures 5 to 8 is shown an especially preferred embodiment of an injection cartridge according to the invention. In these figures, only the part of the car-tridge around the bypass area and the front piston is shown, while the arrangements at the front and rear ends of the cartridge are the same as shown in the previous figures.
Figure 5 shows the barrel of the cartridge 20 with the piston 21 positioned in the bypass area 22. Figure 6 is a sectional view along A-A in figure 5 (in a larger scale for the sake of clearness) which shows the shape of the cartridge wall in the bypass area and of the piston therein. It will be seen that the interior wall of the cartridge 20 is provided with inclined lands 23 and grooves 24, and that the piston 21 has m -been deformec to adapt to the lands 23 and grooves 24 - ~ in this bypass area. This adapti,on is not complete, however, and axial channels 25 are foamed between the bottoms of ti:e grooves 24 and the deformed piston 2a.
S These ehanne~s 25 afford the bypass for the liquid from the rear char,~ber to the flout chamber of the cartridge.
Figure 7 shows the cartridge 20 after the piston~21 has been moved further forward of the bypass area 22, and figure.8 shows a sectional view (in a larger scale) 1o along A-A in figure 7. Yt will be seen that the piston 21 has now adapted to the staooth interior wah of the . cartridge 20 and completely seals against said interior wall. .
It is important feature of the embodi~aent shown in 1.5 f figures 5 to a , especially then is f~.gure 6 , that the inclined lands 23 extend inward from the nominal inte-rior c~.rcumference of the cartridge 20, while the grooves 24 extend outvrard fro~a said nom~.nal circumfer-ence. The nominal interior circumference aad:interior 2o diameter of the cartridge are defiaed as the interior circu~uference and interior diameter, respectively, of the smooth-wa3.led portion of the cartridge and said -~
circum$erence xs symbolized by the-dashed line 26 in figure G_ The height of the lands 23 and the depth of 25 the grooves 29;, as well as their muaber, should be .
correlated to each ether such that the piston 21 has the sa~ae cross-sectional area when it is in the bypass part as when it is in the smooth-walled parts of the ca=tridge.
30 . When the pisCon 21 is in the smooth-walled part of the cartridge, it has to be compressed to a certain ex~ent to seal securely against the interior wall of the cartridge_ This compression of the piston will make its length increase to some extent_ The compression of 35 the piston will also ~.ncrease its resistance against . movement in the axial direction. A suitable degree of xesi.stance can be obtained by the selection of an WO 95/11051 : ' . PCT/SE94/00949 ,. ~.', ,; :~ :. ...
.:~ 210 appropriate degree of compression, as well as by a suitable treatment of the interior wall of the car-tridge, such as siliconizing. A siliconizing treatment, .
however, may also cause contamination of the product in the cartridge.
When the piston 21 has been moved to the bypass area 22, parts of it will be further compressed by the lands 23 extending inwards from the nominal circumference 26, while other parts of it are allowed to expand into the grooves 24, without filling up said grooves completely.
. It is an important feature of this embodiment of the invention that this further compression and expansion should balance each other out, such that the cross-section area of the piston in the bypass part will be essentially the same as the cross-section area of the piston=ihy.the smooth-walled part of the cartridge. This will mean that the length of the piston 21 will be essentially unchanged, as a consequence of which the resistance against axial displacement of the piston will also be essentially unchanged. This is an important advantage, as the constant resistance contri-butes to an increased accuracy in the mixing and metering out of the product in the cartridge.
In the bypass areas of the prior art, the diameter is usually somewhat greater than in the smooth-walled parts of the cartridge. Thus, the resistance against axial displacement of the piston is less in the bypass area, and the change in resistance may be rather abrupt. This may cause a user pushing the piston for-ward to move the piston too fast in the bypass area, so that the piston will pass over the bypass area before all the liquid in the rear chamber has been transferred to the front chamber. The risk of this occurring is greater when the piston is moved forward by manual pressure instead of by the use of a screw mechanism.
Thus, the interaction between the piston and the interior wall of the cartridge in the bypass area is a WO 95/11051 ,2~' PCT/SE94100949 critical feature for obtaining a correct and accurate mixing of the liquid and the solid components in the cartridge. Through this embodiment of the present in-vention, the risk of errors in the mixing process is greatly diminished.
The lands and grooves in the interior wall of the cartridge can be manufactured by a mechanical treatment of the interior wall while the cartridge barrel is in a softened state. Thus, the cartridge barrel, which is usually made of glass or a thermoplastic material, is heated to a suitable degree of softness, and a wheel having a circumferential shape corresponding to the profile desired for the interior wall is inserted into the barrel and is rolled around the circumference of the interior wall at the place of the bypass area. The wheel will then emboss the interior wall with the desired pattern. The wave form shown in figure 6 has turned out to be advantageous, but other shapes of the lands and grooves are also possible. An essential fea-ture is that the dimensions of the lands and grooves should be such that the piston in its deformed state in the bypass part should have essentially the same cross-section area as in the smooth-walled portion of the cartridge barrel, while affording bypass channels in the bottoms of the grooves.
When the lands and grooves are arranged at an angle to the longitudinal axis of the cartridge, this will mean that the projections on the embossing wheel will strike the interior wall of the cartridge barrel gradu-ally, and not abruptly, as is the case when grooves are embossed which are parallel to the longitudinal axis.
This gradual process will give rise to less vibrations and a lessened risk that the heat softened cartridge barrel will be deformed.
It goes without saying that the preferred embodiment shown in figures 5 to 8 may be combined with the embodiment shown in figures 3 and 4, where the modifi-WO 95/11051 . .~ ; v cation of the interior wall in the bypass area is divided into at least two separate areas.
The injection cartridge of the invention is especial-ly.advantageous to use together with sensitive prepara-tions, such as growth hormones and other proteins. Such preparations have to be reconstituted under very mild conditions, as there is otherwise a risk that they will be denatured. Through the present invention, where the risk of deformation has been lessened, an even liquid flow around the whole circumference of the movable wall is arranged, and this makes possible a mixing of the two components under very mild conditions. This type of liquid flow also aids in removing trapped air from the composition.
The manufacture of the injection cartridges according to the present invention does not present any difficul-ties to a person skilled in the art. The modifications of certain areas of the interior wall may be carried out by the use of a suitable grinding tool, or as described in the foregoing for the preferred embodi-ment. In all other respects, the preparation and filling of the cartridges are carried out in the same way as for conventional injection cartridges of the dual-chamber type.
The injection cartridge of the invention may be manufactured from conventional materials, such as glass or suitable plastic materials. Such materials are well-known to those skilled in the art.
Injection cartridges of the dual-chamber type are well-known and have found a wide use. Such cartridges are primarily intended to be used when the liquid phar-maceutical composition to be injected is not stable for any extended period of time. In such cases, the compo-sition to be injected is provided as two separate com-ponents, one solid component comprising the active pharmaceuticGl component in a dry state, and one liquid component comprising a solvent or dispersing agent for the solid component. These two components are enclosed in an injection cartridge of the dual-chamber type, such that the solid component is usually enclosed in a front chamber, while the liquid component is enclosed in a rear chamber. (In the following specification and claims, the expressions "front" and "rear" are to be .
regarded in relation to the direction in which the injectable composition is transported when an injection is administered.) The two components are separated by a movable wall which seals against the interior wall of the cartridge.
The rear chamber, which contains the liquid component, is also closed at its rear end by a piston which seals against the interior wall of the cartridge.
At its front end, the cartridge is usually closed by a rubber septum which is held into place by a metal capsule. This metal capsule has a central opening which exposes the rubber septum. Through this opening, a hollow needle may be inserted through this the septum to give a connection with the interior of the cartrid-ge.
For conducting the liquid component over to the solid ~,: .~iQ 5 component for dissolution or dispersion, conventional dual-chamber injection cartridges are provided with at least one bypass channel in the wall of the cartridge.
When the movable wall which separates the two chambers is at a suitable position, the bypass channel is , exposed, so that the liquid component may flow around said movable wall and be mixed with the solid compo-nent.
When the cartridge is to be readied for the admini-stering of one or more injections, pressure is applied to the rear piston to urge it forward. This pressure will be transmitted through the liquid phase, which is largely incompressible, so that also the movable wall, which separates the two chambers, is urged forward.
When front movable wall has been moved forward a deter-mined length, it will be situated at the bypass chan-nel, such that a flow of liquid from the rear chamber to the front chamber becomes possible. Further forward movement of the rear piston will now push the liquid from the rear chamber into the front chamber, while the movable wall remains essentially stationary.
When all the liquid has been expelled from the rear chamber, the rear piston will abut the movable wall, and further pressure forward will move the two walls together, to act like a single piston. The rubber sep-tum closing the front end of the cartridge should now have been pierced by a hollow needle, which makes it possible to expel the ready-mixed preparation from the front chamber to be administered to a patient.
The dual-chamber injection cartridges described above have a number of important advantages and have found a wide use. One important use is in injection devices which are intended to be used by the patient to admini-ster injections to himself. It is easy for the patient to prepare the injectable preparation from the two components immediately before the administering, and the risk of contamination is greatly reduced.
WO 95/11051 ~~ PCT/SE94/00949 However, the conventional injection cartridges of the dual-chamber type also have certain shortcomings. The cartridges are often used in injection devices which more or less have the appearance of a fountain pen, and it is desirable that such a device should not be unduly thick or long. Thus, any measure which may make such a device slimmer and/or shorter is highly desirable.
The bypass channel in the wall of conventional car-tridges creates a longitudinal ridge in the outer wall of the cartridge, and makes it necessary to use an injection device having an undesirably thick barrel to make room for the cartridge. Furthermore, it is desi-rable to make the forward movement of the movable wall as short as possible, as this makes it possible to use an injection device having a shorter barrel.
The desirable improvements mentioned above are obtai-ned by the present invention. According to the inven-tion, an injection cartridge of the dual-chamber type is provided, which comprises a tubular barrel which at its front end is sealed by a closure which may be pe-netrated by an outlet conduit for a liquid preparation from the cartridge, at its rear end is closed by a piston which may be moved forward, and which comprises a movable transversal wall inside the barrel, said movable wall dividing the cartridge into two separate chambers, and a bypass connection between the two . chambers, said connection being openable by the dis-placement of said movable wall to permit a bypass flow of a liquid between the chambers. The connection be-tween the two chambers is arranged as a modification of the interior wall of said barrel along a determined area, such that said movable wall does not seal com-pletely against the interior wall of the barrel within said area. Said modified area extends completely around the circumference of the interior wall of the car-tridge, such that a flow of liquid is permitted around the complete circumference of the movable wall.
3a According to a broad aspect of the invention, there is provided an injection cartridge of the dual-chamber type, comprising a tubular barrel wherein said barrel has a front end, a rear end, interior wall and interior suzface, and wherein said front end is sealed by a closure which may be penetrated by an outlet conduit for a liquid preparation fxom the cartridge, said rear end is closed by a piston which may be moved forward, and a movable transversal wall inside said barrel, said movable transversal wall dividing l0 the cartridge into two separate chambers, and a bypass connection between the two separate chambers, said connection being openable by the displacement of said movable transversal wall to permit a bypas9 flow of liquid between the two separate chambers, whezein said bypass connection between the two separate chambers is arranged as a modification of the interior surface of the barrel along a predetermined area wherein said predetermined area extends completely around the circumference of said interior wall of the barrel, such that said movable transversal wall does not seal completely against said interior wall of the barrel within said axes, wherein said modification is arranged as a plurality of lands and grooves having an inclined direction in relation to the longitudinal axis of said barrel, said lands and grooves extending along all of said predetermined area, and wherein said tubular barrel has a nominal interior circumference and said lands extend inward from the nominal interior circumference of the tubular barrel.
WO 95/11051 r ~ PCT/SE94/00949 2150'53 What characterizes the invention is that the modifi-cation of the interior wall of the cartridge is ar-ranged as a plurality of lands and grooves in said , interior wall, said lands and grooves having an in-s clined direction in relation to the axial direction of the barrel and extending along all of said modified area. In a more preferred version of this embodiment, the lands extend inward from the interior wall of the cartridge such that the interior diameter between the lands is smaller than the nominal interior diameter of the cartridge.
In a further preferred embodiment of the invention, said axial lands and grooves are interrupted by essen-tially peripheral grooves having essentially the same depth as said axial grooves.
In a still further preferred embodiment, the modified area of the interior wall of the cartridge is divided into at least two circumferential areas, which have the same spacing as the distance between the same number of circumferential sealing ridges on the movable wall.
The depth of said grooves and the height of said lands is preferably between 0.06 and 0.6 mm from the interior wall of the cartridge.
Thus, the dual-chamber cartridge no longer contains a bypass channel, but a bypass area of modifications of the interior wall. Such an area affords a great number of shallow channels, which have at least the same flow capacity as one large channel. However, because of the shallow depth of the modifications, no exterior ridge or increased thickness of the cartridge wall will be necessary, and this makes it possible to use an injec-tion device having a slimmer barrel. The inclined ar-rangement of the lands and grooves in relation to the longitudinal axis of the cartridge also brings new and unexpected advantages in the manufacture of the car-tridge with its bypass area.
The grooves and lands cnay be embossed in the interior.
wall. of the cartridge barrel by means of a rotating embossing toot which works on the heat softened materi-al of the barrel. It has been found that when'the 5 grooves and lands are parallel to the axis of the bar-rel, the embossing action of the tool v.ill cause vibra~
tions which may lead to a distortion of the barrel. r~
the grooves and lands are instead embossed at an angle to the lcngitudirlal axis, no such vibratxor~s will oc-cur. This is an important and unexpected advantage of the invention, The angle between the grooves and the longitudiaal-axis of the cartridge can be from S to 45 degrees. A , pre f erred value is f ro~u 1 o . to 3 o degrees , and about degrees is especially preferred.
International patenC publication no. WO 1993/20868, which has not yet been published, discloses an iaj~ec-tion cartridge of the dua~.~chamber type, wherein a bypass area is arranged as a modification of .the inte..
2o rior cartridge wa~.l. ~iowever, nothing is mentioned about any inclxaed arrangement of grooves and lards.
.
The invention will now be described in closer dttail, with reference to the enclosed drawinga_ In the drawings, Figure 1 shows a dual-chamber injec-tion cartridge according to the invention. Figure 2 shows a sectional view of such a eartridge_ Figure 3 shows another embodiment of a du,ai-chaa~be~c injection cartridge of the invention, and Figure 4 shows the same cartridge xn the stage when the two components arm mix- ~~
~ ed_ Figure S shows a preferred embodibent of an injec-rio:~ cartridge of the invention, and Figure 6 shows a transverse sectional view of the same cartridge at the position of the piston_ Fa.gure 7 shows the same eaibodi-ment of the cartridge with the piston displaced from tn~ bypass zone, and Figure 8 shows a sectional view of the same cartridge at this position of the piston.In~
the fxguxes of the drawing, like parts have the same WO 95/11051 ~ ~ PCT/SE94100949 reference numbers. Furthermore, some of the details in the drawing are shown in an exaggerated scale for clarity.
Figure 1 shows a dual-chamber injection cartridge having 'a cylindrical barrel 1 and a neck portion 2 at .
its forward opening 3. This opening is closed by a sep-tum 4 of rubber or some similar material which has sealing properties, and the septum is held in place by a metal capsule 5, which is fastened around a flange 6 at the forward end of the neck portion 2. The capsule 5 has a central opening 7, where the septum is exposed and may be penetrated by a hollow needle when desired.
At its rear end, the barrel 1 of the cartridge is closed by a piston 8, which may be moved forward when the cartridge is to be readied for an injection.
The cartridge is divided into a front chamber 9, which usually contains the solid component of the in-jectable preparation, and a rear chamber 10, which usually contains the liquid component of said prepara-tion, by means of the movable wall 11. In the position shown in the figure, the movable wall seals against the interior wall of the cartridge, and nothing can pass between the two chambers.
In front of the movable wall 11, the interior wall of the barrel 1 of the cartridge is provided with modifi-cations 12, which cause that the movable wall 11 in this area does not seal completely against the interior wall. In the figures of the drawing, these modifica-tions are shown as shallow grooves extending at an angle to the longitudinal direction of the barrel 1.
This is also shown in Figure 2, which is a sectional view of the barrel 1 along the line A-A in Figure 1.
In Figure 2, it is shown how the barrel 1, which here encloses the front chamber 9, is provided with a plura-lity of shallow grooves 13. For clarity, the depth of these grooves is exaggerated in the drawing. The shal-low grooves are evenly distributed along the internal WO 95111051 ty ~~~ PCT/SE94/00949 circumference of the barrel. However, it is also possi-ble to have the grooves present in certain discrete areas only. What is important is that the grooves should together afford a passage that is sufficient for the flow of the liquid component from the rear chamber to the front chamber.
It is understood that the area of surface modifica-tions should have such an extension in the axial direc-tion that it is somewhat longer than the movable wall 11, to make it possible for a flow of liquid to bypass said movable wall.
It will also be seen that the grooves 13 can take up so much of the interior wall that the movable wall 11 is properly guided only by small ridges. This is usu-ally not a problem.
The inclined grooves 13 may also be broken by a number of peripheral grooves around the interior cir-cumference of the barrel 1. This may improve the flow of the liquid and will aid in removing air from the system.
Furthermore, it should be noted that it is not strictly necessary that the bypass area 12 is formed by grooves. Other modifications of the interior surface are also possible, such as small projections, and the like. In a preferred embodiment, such projections are shaped as lands extending at an angle to the axial direction. The height of such projections should also preferably be between 0.06 and 0.6 mm. The important feature is that in said area 12, the movable wall 11 should not seal completely against the barrel, but permit a bypass flow of the liquid component between ' the chambers.
When the cartridge is to be readied for injection, a forward-directed pressure is applied to the piston 8 at the rear of the cartridge. This pressure is transmitted through the essentially incompressible liquid in the rear chamber 10 and acts on the movable wall 11 to urge ....
it forward. Wher~~the movable wall has been moved for-, ward so far that it is in the area of the modified internal surface of the barrel 1, it will no longer seal completely against the interior wall of the bar-s rel, and it will be possible for the liquid component to flow from the rear chamber 10 into the front chamber 9, to be mixed with the solid component in this cham-ber. Further pressure on the rear piston 8 will expel all of the liquid from the rear chamber 10, until fi-=0 nally the rear piston will rest against the rear surfa-ce of the movable wall 11. At this stage, the movable wall 11 and the rear piston 8 will act together as one single piston.
Before the liquid component is made to flow over into .5 the front chamber 9, the septum 4 closing the front chamber 9 will usually have been pierced with a hollow needle which is connected to a needle for administering the injection, or which itself serves as such an injec-tion needle by means of its forward pointed end. This 20 prevents the build-up of an excessive overpressure in the front chamber 9. After all of the liquid component has been made to flow over into the front chamber 9 and has been thoroughly mixed with the solid component, further pressure on the combined rear piston 8 and 25 movable wall 11 will serve to expel the mixed injec-table preparation through the hollow needle for admini-stering to a patient.
Before the cartridge is readied for injection, it is placed in a suitable holder device. Such devices are 30 known for carrying out the mixing of the two components and for subsequent administering of the injectable preparation. In many cases, they also comprise means for metering out predetermined amounts of the prepara-tion to be injected. There are a number of such devices 35 commercially available, which are arranged such that a patient may himself make the cartridge ready for injec-tion, and administer the injections to himself by means °~~3 of such a device .
Figures 3 and 4 show a preferred embodiment of the invention. The arrangements at the front and rear ends of the cartridge are the same here as shown in Figure 1.
However, the area of modification of the internal wall of the barrel 1 ~ here divided into at least two areas 15 and 16. Thes-- areas are arranged as spaced bands 15 and 16, which each contain the same types of inclined surface modificationshas those mentioned in connection with Figures 1 and 2. A sectional view along the lines A-A in Figure 3 will show exactly the same as Figure 2 in connection with Figure 1.
The movable wall 11_is composed of a central part having a smaller diameter than the interior diameter of the barrel 1, and at least two circumferential sealing ridges 17 and 18 at the front and rear end of the mo-vable wall, respectj,vely. This gives a space 19 defined by the two sealing ridges 17 and 18, the part of the movable wall having a smaller diameter, and the inte-rior wall of the barrel 1.
The spacing between the two sealing ridges 17 and 18 is the same as the spacing between the two bands 15 and 16 of surface modifications of the interior wall. These bands also have a somewhat greater axial length than the axial length of each of the sealing ridges 17 and 18, such that a flow of liquid around said sealing ridges becomes possible.
In the initial stage, before the cartridge has been readied for injection, the movable wall is in such a position inside the barrel 1 of the cartridge that the front sealing ridge 17 lies between the two bands of modification 15 and 16. The reax sealing ridge 18 should lie behind the rear band ~.6. In this way. a complete seal between the front and rear chambers is assured.
When the cartridge is to be readied for injection, pressure is applied on the rear piston 8, as described previously. This will bring about that the movable wall 11 is urged forward, until it is in the position shown in Figure 4. It will be seen that the two sealing rid-5 ges are now positioned opposite the bands of modifica-tion 15 and 16, and a liquid flow is now possible from the rear chamber 10 around the rear sealing ridge 18, into the space 19, and around the front sealing ridge 17 into the front chamber 9.
10 The advantage of this embodiment is that the movable wall 11 will only have to be moved the short distance corresponding approximately to half the spacing between the two bands 15 and 16. This makes it possible to use a shorter cartridge and a shorter injection device for housing the cartridge. For injection devices which are to be carried around by the patient himself, this can be of considerable importance.
It is also possible to use more than two areas of surface modification and corresponding sealing ridges of the movable wall. This gives a more secure seal, but the construction becomes more complicated and therefore also more expensive.
In Figures 5 to 8 is shown an especially preferred embodiment of an injection cartridge according to the invention. In these figures, only the part of the car-tridge around the bypass area and the front piston is shown, while the arrangements at the front and rear ends of the cartridge are the same as shown in the previous figures.
Figure 5 shows the barrel of the cartridge 20 with the piston 21 positioned in the bypass area 22. Figure 6 is a sectional view along A-A in figure 5 (in a larger scale for the sake of clearness) which shows the shape of the cartridge wall in the bypass area and of the piston therein. It will be seen that the interior wall of the cartridge 20 is provided with inclined lands 23 and grooves 24, and that the piston 21 has m -been deformec to adapt to the lands 23 and grooves 24 - ~ in this bypass area. This adapti,on is not complete, however, and axial channels 25 are foamed between the bottoms of ti:e grooves 24 and the deformed piston 2a.
S These ehanne~s 25 afford the bypass for the liquid from the rear char,~ber to the flout chamber of the cartridge.
Figure 7 shows the cartridge 20 after the piston~21 has been moved further forward of the bypass area 22, and figure.8 shows a sectional view (in a larger scale) 1o along A-A in figure 7. Yt will be seen that the piston 21 has now adapted to the staooth interior wah of the . cartridge 20 and completely seals against said interior wall. .
It is important feature of the embodi~aent shown in 1.5 f figures 5 to a , especially then is f~.gure 6 , that the inclined lands 23 extend inward from the nominal inte-rior c~.rcumference of the cartridge 20, while the grooves 24 extend outvrard fro~a said nom~.nal circumfer-ence. The nominal interior circumference aad:interior 2o diameter of the cartridge are defiaed as the interior circu~uference and interior diameter, respectively, of the smooth-wa3.led portion of the cartridge and said -~
circum$erence xs symbolized by the-dashed line 26 in figure G_ The height of the lands 23 and the depth of 25 the grooves 29;, as well as their muaber, should be .
correlated to each ether such that the piston 21 has the sa~ae cross-sectional area when it is in the bypass part as when it is in the smooth-walled parts of the ca=tridge.
30 . When the pisCon 21 is in the smooth-walled part of the cartridge, it has to be compressed to a certain ex~ent to seal securely against the interior wall of the cartridge_ This compression of the piston will make its length increase to some extent_ The compression of 35 the piston will also ~.ncrease its resistance against . movement in the axial direction. A suitable degree of xesi.stance can be obtained by the selection of an WO 95/11051 : ' . PCT/SE94/00949 ,. ~.', ,; :~ :. ...
.:~ 210 appropriate degree of compression, as well as by a suitable treatment of the interior wall of the car-tridge, such as siliconizing. A siliconizing treatment, .
however, may also cause contamination of the product in the cartridge.
When the piston 21 has been moved to the bypass area 22, parts of it will be further compressed by the lands 23 extending inwards from the nominal circumference 26, while other parts of it are allowed to expand into the grooves 24, without filling up said grooves completely.
. It is an important feature of this embodiment of the invention that this further compression and expansion should balance each other out, such that the cross-section area of the piston in the bypass part will be essentially the same as the cross-section area of the piston=ihy.the smooth-walled part of the cartridge. This will mean that the length of the piston 21 will be essentially unchanged, as a consequence of which the resistance against axial displacement of the piston will also be essentially unchanged. This is an important advantage, as the constant resistance contri-butes to an increased accuracy in the mixing and metering out of the product in the cartridge.
In the bypass areas of the prior art, the diameter is usually somewhat greater than in the smooth-walled parts of the cartridge. Thus, the resistance against axial displacement of the piston is less in the bypass area, and the change in resistance may be rather abrupt. This may cause a user pushing the piston for-ward to move the piston too fast in the bypass area, so that the piston will pass over the bypass area before all the liquid in the rear chamber has been transferred to the front chamber. The risk of this occurring is greater when the piston is moved forward by manual pressure instead of by the use of a screw mechanism.
Thus, the interaction between the piston and the interior wall of the cartridge in the bypass area is a WO 95/11051 ,2~' PCT/SE94100949 critical feature for obtaining a correct and accurate mixing of the liquid and the solid components in the cartridge. Through this embodiment of the present in-vention, the risk of errors in the mixing process is greatly diminished.
The lands and grooves in the interior wall of the cartridge can be manufactured by a mechanical treatment of the interior wall while the cartridge barrel is in a softened state. Thus, the cartridge barrel, which is usually made of glass or a thermoplastic material, is heated to a suitable degree of softness, and a wheel having a circumferential shape corresponding to the profile desired for the interior wall is inserted into the barrel and is rolled around the circumference of the interior wall at the place of the bypass area. The wheel will then emboss the interior wall with the desired pattern. The wave form shown in figure 6 has turned out to be advantageous, but other shapes of the lands and grooves are also possible. An essential fea-ture is that the dimensions of the lands and grooves should be such that the piston in its deformed state in the bypass part should have essentially the same cross-section area as in the smooth-walled portion of the cartridge barrel, while affording bypass channels in the bottoms of the grooves.
When the lands and grooves are arranged at an angle to the longitudinal axis of the cartridge, this will mean that the projections on the embossing wheel will strike the interior wall of the cartridge barrel gradu-ally, and not abruptly, as is the case when grooves are embossed which are parallel to the longitudinal axis.
This gradual process will give rise to less vibrations and a lessened risk that the heat softened cartridge barrel will be deformed.
It goes without saying that the preferred embodiment shown in figures 5 to 8 may be combined with the embodiment shown in figures 3 and 4, where the modifi-WO 95/11051 . .~ ; v cation of the interior wall in the bypass area is divided into at least two separate areas.
The injection cartridge of the invention is especial-ly.advantageous to use together with sensitive prepara-tions, such as growth hormones and other proteins. Such preparations have to be reconstituted under very mild conditions, as there is otherwise a risk that they will be denatured. Through the present invention, where the risk of deformation has been lessened, an even liquid flow around the whole circumference of the movable wall is arranged, and this makes possible a mixing of the two components under very mild conditions. This type of liquid flow also aids in removing trapped air from the composition.
The manufacture of the injection cartridges according to the present invention does not present any difficul-ties to a person skilled in the art. The modifications of certain areas of the interior wall may be carried out by the use of a suitable grinding tool, or as described in the foregoing for the preferred embodi-ment. In all other respects, the preparation and filling of the cartridges are carried out in the same way as for conventional injection cartridges of the dual-chamber type.
The injection cartridge of the invention may be manufactured from conventional materials, such as glass or suitable plastic materials. Such materials are well-known to those skilled in the art.
Claims (20)
1. ~An injection cartridge of the dual-chamber type, comprising a tubular barrel wherein said barrel has a front end, a rear end, interior wall and interior surface, and wherein said front end is sealed by a closure which may be penetrated by an outlet conduit for a liquid preparation from the cartridge, said rear end is closed by a piston which may be moved forward, and a movable transversal wall inside said barrel, said movable transversal wall dividing the cartridge into two separate chambers, and a bypass connection between the two separate chambers, said connection being openable by the displacement of said movable transversal wall to permit a bypass flow of liquid between the two separate chambers, wherein said bypass connection between the two separate chambers is arranged as a modification of the interior surface of the barrel along a predetermined area wherein said predetermined area extends completely around the circumference of said interior wall of the barrel, such that said movable transversal wall does not seal completely against said interior wall of the barrel within said area, wherein said modification is arranged as a plurality of lands and grooves having an inclined direction in relation to the longitudinal axis of said barrel, said lands and grooves extending along all of said predetermined area, and wherein said tubular barrel has a nominal interior circumference and said lands extend inward from the nominal interior circumference of the tubular barrel.
2. Injection cartridge according to claim 1, wherein the grooves extend outward from said nominal circumference.
3. Injection cartridge according to claim 2, wherein the inclined direction of said lands and grooves and the longitudinal axis of the cartridge barrel forms an angle from 5 to 45 degrees.
4. ~The injection cartridge according to claim 3 wherein said angle is from 10 to 30 degrees.
5. ~The injection cartridge according to claim 3 wherein said angle is about 20 degrees.
6. ~Injection cartridge according to claim 2, wherein the depth of said grooves or the height of said lands or both is between 0.06 and 0.6 mm.
7.~Injection cartridge according to claim 6, wherein the angle between the direction of said lands and grooves and the longitudinal axis of the cartridge barrel is from to 45 degrees.
8. ~Injection cartridge according to claim 2, wherein the cartridge has a smooth-walled part and the height of the lands and the depth of the grooves, as well as their number, are correlated in such a way that the movable transversal wall has essentially the same cross-sectional area when it is positioned in the area of said lands and grooves as when it is positioned in a smooth-walled part of the cartridge.
9. ~Injection cartridge according to claim 8, wherein said modification of interior wall surface is divided into at least two spaced circumferential areas, and that the movable wall is provided with peripheral sealing ridges, said ridges and said areas having the same spacing wherein there are the same number of ridges as there are areas.
10. ~Injection cartridge according to claim 8, wherein the depth of said grooves or the height of said lands or both is between 0.06 and 0.6 mm.
11. ~Injection cartridge according to claim 8, wherein the inclined direction of said lands and grooves and the longitudinal axis of the cartridge barrel forms an angle from 5 to 45 degrees.
12. ~The injection cartridge according to claim 11 wherein said angle is from 20 to 3o degrees.
13. ~The injection cartridge according to claim 11 wherein said angle is about 20 degrees.
14. ~Injection cartridge according to claim 2, wherein said modification of said interior surface is divided into at least two spaced circumferential areas, and that the movable wall is provided with peripheral sealing ridges, said ridges and said areas having the same spacing wherein there are the same number of ridges as there are areas.
15. ~Injection cartridge according to claim 1, wherein said modification of said interior surface is divided into at least two spaced circumferential areas, and that the movable wall is provided with peripheral sealing ridges, said ridges and said areas having the same spacing wherein there are the same number of ridges as there are areas.
16. ~Injection cartridge according to claim 15, wherein the depth of said grooves or the height of said lands or both is between 0.06 and 0.6 mm.
17. ~Injection cartridge according to claim 15, wherein the angle between the direction of said lands and grooves and the longitudinal axis of the cartridge barrel is from to 45 degrees.
18. ~Injection cartridge according to claim 1 wherein the inclined direction of said lands and grooves and the longitudinal axis of the cartridge barrel forms an angle from 5 to 45 degrees.
19. The injection cartridge according to claim 18 wherein said angle is from 10 to 30 degrees.
20. The injection cartridge according to claim 18 wherein said angle is about 20 degrees.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE9303453-6 | 1993-10-20 | ||
| SE9303453A SE9303453D0 (en) | 1993-10-20 | 1993-10-20 | Injection cartridge |
| PCT/SE1994/000949 WO1995011051A1 (en) | 1993-10-20 | 1994-10-10 | Injection cartridge |
| EP00120455A EP1188455A1 (en) | 1993-10-20 | 2000-09-19 | Device for delivering the content of a sealed container filled with liquid, paste or gas |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2150253A1 CA2150253A1 (en) | 1995-04-27 |
| CA2150253C true CA2150253C (en) | 2006-04-25 |
Family
ID=26056722
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002150253A Expired - Lifetime CA2150253C (en) | 1993-10-20 | 1994-10-10 | Injection cartridge |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP1188455A1 (en) |
| CA (1) | CA2150253C (en) |
| DE (1) | DE20022899U1 (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8292619B2 (en) | 2004-02-27 | 2012-10-23 | 3M Deutschland Gmbh | Dose delivery system |
| WO2006058435A2 (en) * | 2004-12-03 | 2006-06-08 | Duoject Medical Systems Inc. | Cartridge, device and method for pharmaceutical storage, mixing and delivery |
| JP5230023B2 (en) * | 2007-01-25 | 2013-07-10 | ハイパーブランチ メディカル テクノロジー， インコーポレイテッド | Applicators and methods of use for multi-component formulations, etc. |
| RU2454271C1 (en) * | 2010-12-27 | 2012-06-27 | Владимир Антонович Шутиков | Method of producing gas mix |
| DE102011009187A1 (en) * | 2011-01-21 | 2012-07-26 | Heraeus Kulzer Gmbh | Applicator for a dental fluid |
| RU2461414C1 (en) * | 2011-03-15 | 2012-09-20 | Владимир Антонович Шутиков | Method of producing gas mix |
| US10952709B2 (en) | 2014-04-04 | 2021-03-23 | Hyperbranch Medical Technology, Inc. | Extended tip spray applicator for two-component surgical sealant, and methods of use thereof |
| EP3025744A1 (en) * | 2014-11-28 | 2016-06-01 | Sulzer Mixpac AG | Apparatus and methods for storing and mixing separate substances |
| EP3147034A1 (en) * | 2015-09-25 | 2017-03-29 | Sulzer Mixpac AG | Applicator for ejecting doses of a flowable component |
| DE102017122990A1 (en) * | 2017-10-04 | 2019-04-04 | Kulzer Gmbh | Micro applicator with application area for applying a liquid, such as a dental adhesive, or paste in a cavity of a natural tooth for use with dental adhesives |
| WO2019233546A1 (en) | 2018-06-04 | 2019-12-12 | Gemü Gmbh | Applicator |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5454792A (en) * | 1993-04-19 | 1995-10-03 | Hyproteck, Inc. | Linear slide valve for CVC access |
| GB9521287D0 (en) * | 1995-10-18 | 1995-12-20 | Smith & Nephew | Fluid delivery device |
| US5814022A (en) * | 1996-02-06 | 1998-09-29 | Plasmaseal Llc | Method and apparatus for applying tissue sealant |
-
1994
- 1994-10-10 CA CA002150253A patent/CA2150253C/en not_active Expired - Lifetime
-
2000
- 2000-09-19 EP EP00120455A patent/EP1188455A1/en not_active Withdrawn
- 2000-09-19 DE DE20022899U patent/DE20022899U1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| DE20022899U1 (en) | 2002-07-18 |
| CA2150253A1 (en) | 1995-04-27 |
| EP1188455A1 (en) | 2002-03-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKEX | Expiry |
Effective date: 20141010 |