MXPA97004576A - Filling device for an injector cartridge without ag - Google Patents

Abstract

The present invention relates to an adapter for allowing a fluid to be introduced from a outlet of a filling device (8) into an orifice of a needleless injector cartridge (2), comprising a first portion (3) for coupling with the cartridge, and a second device coupling portion (22) for coupling with the filling device, whereby it maintains the outlet of the filling device in fluid communication with the cartridge orifice, characterized in that the first and second portions are connected to each other by a frangible connection (1

Description

FILLING DEVICE FOR AN INJECTOR CARTRIDGE WITHOUT NEEDLE The present invention relates generally to hypodermic injection devices and is for use with particular needleless injectors. Needle injectors are used as an alternative to hypodermic syringes to deliver liquid drugs and medications directly through the patient's skin and into tissues without using a needle. Such injectors consist of a piston pump, spring or gas driven, which expels the drug through a small discharge orifice at a speed and pressure sufficient to cut the skin and enter the tissue through the hole thus formed. In WO 95/03844, a needleless injector is described which uses sufficient energy storage and delivery means to provide a very compact and easy to use device, and the present invention is intended primarily for use with that device, although of course could be adapted for use with alternative injectors. Ideally, a needleless injector would be provided pre-filled with the drug for the end user, self-energized and ready for immediate use. Pre-filling of the injector would preferably be done by the drug manufacturer, thus ensuring sterility, correct dosage and compliance with the approved specification.

However, while this is perfectly feasible for , stable liquid drugs such as heparin and some vaccines, for example, many drugs consist of two components, for example a lyophilized drug and its solvent. These drugs have a short storage life in liquid forms and must be reconstituted and used immediately. Other drugs, which may already be in liquid form, are supplied in bulk to a pharmacy for example, and the pharmacist may be required to load the drug into the injector. There is an old requirement for a single dose disposable needle injector that can be filled externally and many inventions are intended to provide external loading methods, for example WO 89/08469 (Parsons). Many such devices are more complicated and expensive and are inconvenient to use. With the current trend towards disposable needleless injectors, the filling device must be very simple to use, and economical enough so that it can be discarded with the injector. Another Lindmayer invention, US-A-4518385, is for a disposable syringe that is filled by the user in a conventional manner. After filling, the hollow filling needle is removed and broken, and the body of the syringe is inserted into the energy unit. The syringe body becomes the needleless delivery member, and therefore the syringe has a double function. Although US-A-4518285 does something to simplify the charging process, there is still a substantial requirement for the user to exercise his skill and judgment in the use of the device. In addition, the syringe is intended for use with a multi-purpose or multi-purpose power unit, which is complex and expensive. The present invention seeks to overcome the limitations of prior art injectors and provides a simple adapter for use with a standard hypodermic syringe, which adapter can be removed after filling the injector with the syringe. After use, the adapter covers the end of the needle to avoid or reduce the likelihood of biting the user. Therefore, in accordance with a first aspect of the invention, an adapter is provided to allow a fluid to be introduced from an outlet of a filling device into an orifice of a needleless injector cartridge, comprising a first portion. for coupling with the cartridge, and a second device coupling portion for coupling with the filling device, while maintaining the output of the filling device in fluid communication with the cartridge orifice, the first and second portions being connected to each other by a detachable connection. According to a second aspect of the invention there is provided a needleless injector cartridge in combination with an adapter for allowing a fluid to be introduced from an outlet of a filling device into an orifice of the cartridge, wherein the adapter comprises a portion of device coupling by means of which it maintains the output of the filling device in fluid communication with the cartridge orifice, the first and second portions being connected to each other by means of a detachable connection. With the syringe assembled to the needleless injector, the injectable substance can be transferred into the cartridge from the syringe, through the discharge port in the cartridge, to thereby move the discharge piston by hydraulic pressure. Preferably stop means are provided to limit the displacement of the plunger, so that the amount of injectable substance transferred within the injector cartridge is predetermined. Another aspect of the invention is to provide the reconstitution of a lyophilized drug. In a preferred embodiment, the lyophilized drug is stored in the drug cartridge between the discharge orifice and the plunger, so that the discharge orifice and the piston, so that the introduction of a liquid solvent through the orifice will dissolve the lyophilized drug and moves the plunger by hydraulic pressure to a predetermined stop. The connection between the syringe guide and the drug cartridge or the drug container is preferably provided by a brittle connection or other detachable connection. After transferring the injectable substance, the syringe is given a sharp lateral lever which causes the syringe guide to break from the cartridge or its container in the brittle joint. Preferably the needle is protected by remaining within the elastic seal, which remains itself attached to the syringe guide. The invention in its various aspects is capable of providing very safe, simple and convenient means of filling a pre-assembled needleless injector, auto-energized to a predetermined volume, with the subsequent safe disposal of the filling syringe. The safety aspect is improved if the hypodermic syringe is blunt. A preferred embodiment will be described with reference to the accompanying drawings, in which. Figure 1 shows a cross section through a needleless injector containing a lyophilized drug and the hypodermic syringe assembled to the injector; Figures 2a and 2b show an elastic seal, in plan view and longitudinal section, respectively; Figure 3 shows a cross section through a needleless injector with a hypodermic syringe attached, to fill the injector with a liquid drug, which can be reconstituted; Figure 4 shows a drug cartridge of the needleless injector with the integral syringe guide; and Figures 5a and 5b are general views of an injector before and after filling.

For purposes of simplicity, similar parts were given the same numbers.

Referring to Figure 1, a needleless injector body 1 contains a drug cartridge 2 retained by a sleeve 3 having a threaded flange 18. The cartridge 2 contains a lyophilized drug 5, preferably made to closely fit the inner container of the drug. drug cartridge and held firmly in place by a plunger 4, adjacent to a discharge orifice 23. A syringe guide 23 is frangibly attached by a brittle connection 10 to the holding sleeve 3. The syringe guide 22 is preferably tubular, open at one end to receive a syringe 8 and having a partial end wall 24. Inserted into a concentric hole in the end wall 24 is an elastic seal 6 (see also Figures 2a and 2b) that is biased to form a hydraulic seal around the discharge hole of the cartridge 2. Referring to Figure 2, the elastic seal 6 has a hole 11 for sealingly receiving the a hypodermic shield 7 (Figure 1) of syringe 8 and, may have circumferential ribs 12 to improve sealing efficiency on cartridge 2. A tapered inlet port 14 helps guide the needle into port 11. Preferably, the tapered orifice 14 is sealed with a brittle diaphragm 15, which can be made from a laminate of aluminum foil and plastic or other material that is impervious to water vapor and capable of withstanding a pressure differential of up to 900 mbar. The retaining lip 25 serves to hold the seal 6 in the end wall 24 of the syringe guide 22 (Figure 1).

Referring to Figures 1 and 2, the filling syringe 8 is loaded into the open end of the syringe guide 22; the guide is long enough to align the syringe body so that the needle 7 is approximately concentric with the conical hole 14 in the seal 6. By driving the syringe body, the needle 7 breaks the frangible diaphragm 15 and, is guided by the conical hole 14 to enter the hole 11. The syringe body comes to rest on a flange 19, which extends axially from the end wall 24 of the syringe guide 22. The flange 19 can also house the seal 6, of so that the end of the needle 7 just touches the hole 23 in the cartridge 2. The hole of the needle 7 is now in hydraulic contact with the inside of the drug cartridge 2 by means of the hole 23, and by actuating the plunger of the syringe 8, the solvent 9 will be transferred into the drug cartridge 2. The hydraulic pressure created within the syringe 8 causes the piston 4 to move in the cartridge 2 until it stops in the position 4a against a splice 16 formed in the body of the injector. During this time, the turbulence of the affluent solvent 9 will agitate the lyophilized drug 5, helping to dissolve it. An agitator (not shown) can be preloaded with the drug 5, so that stirring the needleless injector after filling will result in rapid dissolution of the drug 5.

After filling the injector, the syringe 8 and the guide 22, while still assembled together, can be detached from the retaining sleeve 3 in a brittle connection 10, pulling sharply laterally in the X direction relative to the injector, as shown in Figure 5b. Referring to Figure 3, a construction similar to that described is shown, except that the drug container 2 does not contain at this stage any drug (for example lyophilized drug) and the plunger 4 is molded to closely conform to the internal profile of the end. Discharging the container 2. This method is for use with a hypodermic syringe, as before, although the drug to be transferred is premixed. A further improvement shown in Figure 3 and, applicable to all modalities, is an elastic projection 26 extending from the inner wall of the guide 22, which serves to prevent the removal of the syringe 8 from the guide 22 after insertion. In the embodiments described, the drug cartridge is a separate component and can be made from glass, metal or plastic. In order to withstand the high pressure produced during injection, the holding sleeve 3 can act as a reinforcing member for the drug cartridge 2, which can then be of a lighter configuration than otherwise possible. In Figure 4 there is shown an additional embodiment, in which the drug cartridge 2 is made with the thread 18 for screwing directly onto the injector body 1. This embodiment is preferably made of a plastic material and, the syringe guide 22 can be conveniently molded integrally with the cartridge 2, with the brittle connection 10 between the two elements. If the strength of the material is too low for a reasonable wall thickness for the cartridge, the cartridge will be fitted with a reinforcing sleeve 17 either after molding or as an insert during molding. The splice 16 can be molded conveniently on the cartridge 2, either as a continuous ring or as small projections. Alternatively, the splice may be an interference fit ring in the cartridge 2 to achieve the same purpose of limiting the stroke of the plunger 4. The plunger 4 is configured to fit closely to the inner profile of the discharge end of the cartridge 2. To avoid undue difficulties in molding, the elastic seal 6 may be retained on a separate support 20, which may be an interference fit or retained by co-operating projections on the guide 22, to deflect the seal 6 to form a hydraulic seal on the discharge end of the cartridge 2. This embodiment may be adapted to contain a lyophilized drug, similar to the embodiment shown in Figure 1 and the plunger 4 may be shaped with a flat end face. A feature of all the above described embodiments is that the hypodermic syringe 8 and its guide 8 are separated together after the filling of the injector and, the seal 6 remains in place in the guide 22 to reduce the risk of injury to the end of the needle 7. This risk can be further reduced by having a rounded or blunt end for the needle instead of the usual sharp tip. Of course, it may be that a commercial hypodermic syringe is inconvenient, if, for example, more than one needleless injector is to be filled from a large filled syringe. Such procedures may be necessary in hospitals and pharmacies, where the injector is to be used in a short time of filling. In those cases, the guide 22 is left in place and the hole 11 in the seal 6 can be closed after the removal of the filling needle 7, in order to maintain at least the short-term sterility of the drug contained in the injector. When the injector is required for use, the guide 22 is separated as previously described, bearing the seal 6 therewith. For all embodiments, the preferred material for the plunger 4 is PTFE or similar fluoropolymer having a compressive strength that is highly dependent on the force application ratio at room temperature. Therefore, the piston 4 can be easily deformed when pushed past the splice 16 (Figure 4) and jumps back to seal on the walls of the cartridge 2, although when the injection force is applied in a high relation towards the piston 4, has enough time to deform and maintain its sealing properties through injection. While the described embodiments specify threading means for retaining screw of the drug cartridge on the injector body, it would be equally feasible to use snap-fit retaining means. In addition, the retaining means may use cuts or other mechanical locking means to ensure proper coupling of the drug cartridge to the body of the injector. It is preferred that the drug cartridge is not easily removed from the injector power unit after an injection, except by means of a tool. Many variations of the basic invention are possible. For example, the injector and the syringe can be supplied as part of a kit with which the user can reconstitute a lyophilized drug for self-administration. The syringe containing the solvent can be pre-inserted into the syringe guide, so that the user only has to push the syringe slightly into the guide to break the seal and operate the syringe plunger until the solvent stops. to be transferred, that is, when the injector plunger reaches the junction in the cartridge. It can be seen therefore that the present allows a needleless injector to be filled with the absolute minimum of skill, using a very common and inexpensive hypodermic syringe or similar device.

Claims (19)

1. CLAIMING IS 1 . An adapter for allowing a fluid to be introduced from an outlet of a filling device into an orifice of the needleless injector cartridge, comprising a first portion for coupling with the cartridge and, a second portion of coupling device for coupling with the filling device, by means of which it maintains the outlet of the filling device in fluid communication with the cartridge orifice, the first and second portions being connected to each other by a detachable connection. An adapter according to claim 1, wherein the first portion comprises a sleeve in which the cartridge is received. An adapter according to claim 1 or 2, wherein the first portion carries a screw thread for coupling with a coupling thread on an injector. 4. A needleless injector cartridge in combination with an adapter for allowing a fluid to be introduced from an outlet of a filling device into an orifice of the cartridge, wherein the adapter comprises a device coupling portion by means of which it maintains the output of the filling device in fluid communication with the orifice of the cartridge, the first and second portions being connected to each other by a brittle connection. 5. A cartridge / adapter combination according to claim 4, further comprising a reinforcing sleeve surrounding at least part of the cartridge. A cartridge / adapter combination according to claim 4 or 5, wherein the cartridge comprises a cartridge body with a plunger longitudinally slidable therein and wherein a splice is provided within the cartridge body to limit movement the plunger away from the cartridge hole. A cartridge / adapter combination according to any one of claims 4 to 6, wherein the cartridge carries a screw thread for coupling with a coupling thread on an injector. An adapter according to any one of claims 1 to 3, or cartridge / adapter combination according to any one of claims 4 to 7, comprising seal means for effecting a seal between the outlet of the filling device and the hole in the cartridge. An adapter or cartridge / adapter combination according to claim 8, wherein the sealing means comprises a sealing member having respective conically tapered passages at opposite ends thereof and means communicating the passages to each other. 10. An adapter or cartridge / adapter combination according to claim 8 or 9, wherein the sealing means are transported by the support means connected to the device coupling portion. 11. An adapter or cartridge / adapter combination according to claim 10, wherein the support means comprises means for engaging the distal end of the filling device to align the outlet of the filling device with the cartridge orifice. 12. An adapter or cartridge / adapter combination according to any preceding claim, wherein the device coupling portion comprises means for preventing removal of the filling device from the device coupling portion. An adapter or cartridge / adapter combination according to claim 12, wherein the prevention means comprises an elastic projection adapted to engage behind a distal portion of the filling device. 14. An adapter or cartridge / adapter combination according to any preceding claim, wherein the detachable connection is a brittle connection. 15. An adapter or combination of cartridge / adapter in accordance with any previous claim, adapted for use when the filling device is a syringe. 16. An adapter or cartridge / adapter combination according to any preceding claim, wherein the device coupling portion comprises a sleeve in which the filling device is received. 17. A method for reconstituting a lyophilized drug, wherein the drug is stored in a cartridge comprising a cartridge body having an outlet orifice at one end thereof and a longitudinally movable plunger, the drug being located between the piston and the exit orifice, and a liquid solvent is introduced into the cartridge through the exit orifice to dissolve the lyophilized drug. 18. A method according to claim 17, wherein the introduction of the solvent causes the piston to move longitudinally. 19. A method according to claim 18, wherein the longitudinal movement of the plunger is limited by detent means. SUMMARY A needleless injection supply cartridge is filled through its discharge port with the drug to be injected by the use of an adapter. The filling means, for example a hypodermic syringe, are separated from the needleless injector cartridge after use and, the cannula remains covered by the adapter. The adapter may comprise a pair of sleeves, or not from which the cartridge receives and the other receives the end of the syringe. Alternatively, the role of the first of these sleeves can be assumed by the cartridge body itself.