HK1040941B - Apparatus and method for filling an ampule of a needle-less injector - Google Patents

Description

This invention relates to devices and methods for filling an ampule of a needle-less injector prior to an injection.

Typically, injections are performed with syringes that pierce the skin with a needle to deliver medication to a desired location on a body. In a large number of cases the syringes are pre-filled with a medication. However, if the medication does not have a long shelf life, it must be added to the syringe prior to an injection to maintain potency. This requires the medication to be drawn into the syringe using needles or the like. After drawing in the medication, the injection is administered in a normal manner. But, after the injection there are one or more needles that need to be disposed of, increasing costs and increasing the potential health hazards from exposure to used needles.

As an alternative to needle delivery injections, needle-less medication injections have been performed with "permanent gun" instruments, generally referred to as "jet injectors". These devices use either a compression spring or a compressed inert gas to propel the fluid medication (via a push rod plunger) through a small orifice (an injector nozzle) which rests perpendicular to and against the injection site. The fluid medication is generally accelerated at a high rate to a speed of between about 800 feet per second (fps) and 1,200 fps (approximately 244 and 366 meters per second, respectively). This causes the fluid to pierce through the skin surface without the use of a needle, resulting in the medication being deposited in a flower pattern under the skin surface. These reusable jet injectors can accept pre-loaded medication cartridges, but again the cartridges must be pre-loaded just prior to an injection for certain medications with short shelf lives. The procedure is to again use a needle and a syringe to load the medication in the cartridge prior to an injection. After drawing in the medication, the needle-less injection is administered in a normal manner. But, after the injection there are again one or more needles that need to be disposed of, increasing costs and increasing the potential health hazards from exposure to used needles.

Single use needle-less jet injectors offer an alternative to multi-use, needle-less injectors, since they are low cost and can be pre-loaded at the point of manufacture. However, if the medication does not have a long shelf life, the preloading is impractical. Thus, single-use, needle-less injectors have not been usable with medications that must be loaded prior to injection.

The PCT patent specification WO 96/19252 discloses a needle-less injector provided with an ampule containing medication and a frangible syringe guide. The syringe guide receives a hypodermic syringe filled with a diluent which is injected into the ampule by insertion of the syringe needle into the ampule. After the medication has been mixed within the ampule the syringe guide (including syringe) is snapped off the injector. The frangible syringe guide is provided to address the problem of needle disposal by protecting the needle from exposure. However, once the syringe guide is snapped off the injector it is possible for jagged edges to remain on the surface of the injector providing a potential hazard to the recipient of an injection.

French patent application 2 749 169 discloses a method of mixing medication between two syringes. In one embodiment the syringes are connected together via a valve/tap arrangement to allow the transfer of medication between the syringes. Once mixed, the medication is distributed amongst a number of smaller conventional hypodermic syringes for subsequent delivery of the medication to a patient.

It is an object of the present invention to provide a method and apparatus that obviate the above-mentioned limitations.

According to a first aspect of the present invention there is provided a method of mixing liquid medication for an ampule of a needle-less injector suitable for injecting said liquid medication, the method comprising the steps of providing a needle-less injector ampule containing a reagent, providing a needle-less diluent holder containing a diluent, providing the diluent holder with a diluent plunger rod, coupling the ampule directly to the diluent holder to provide fluid communication between the ampule and the diluent holder and depressing the diluent plunger rod to load the diluent into the ampule to mix the reagent to produce the liquid medication.

According to a second aspect of the present invention there is provided apparatus for performing the above method, the apparatus comprising a needle-less injector ampule containing a reagent and a needle less diluent holder containing a diluent, said needleless diluent holder having a diluent plunger rod, and the ampule being adapted to be directly coupled to the diluent holder to provide fluid communication between the ampule and the diluent holder, wherein the diluent plunger rod can be depressed to load the diluent into the ampule to mix with the reagent to produce liquid medication.

In some embodiments, the ampule further includes an ampule plunger rod. After the ampule is loaded with the diluent, the ampule plunger rod is depressed to expel bubbles back into the diluent holder from the ampule of the needle-less injector. Preferably, the ampule is loaded with diluent just prior to injection of the medication due to a short shelf life of the medication. Also, the ampule of the needle-less injector is attached to the needle-less injector after filing with the diluent.

Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, various features of embodiments of the invention.

A detailed description of embodiments of the invention will be made with reference to the accompanying drawings, wherein like numerals designate corresponding parts in the several figures.

• FIG. 1 is a side plan view of a transparent reagent holder not forming part of of the present invention;
• FIG. 2 is a side plan view of an ampule for a rieedle-less injector not forming part of of the present invention.
• Fig. 3 is an end plan view of the ampule shown in Fig. 2.
• Fig. 4 is a side plan view of a diluent plunger rod.
• Fig. 5 is a side plan view of the ampule of Figs. 2 and 3 combined with the plunger rod shown in Fig. 4.
• Fig. 6 is a cross-sectional view of the ampule and plunger rod as shown along the line 6-6 in Fig. 5.
• Fig. 7 is a cross-sectional view of the reagent holder, as shown along line 7-7 in Fig. 1 coupled to the ampule and plunger rod as shown in Fig. 6, prior to mixing the reagent and the diluent in the reagent holder.
• Fig. 8 is a cross-sectional view of the reagent holder and ampule, shown in Fig. 7, after the diluent plunger rod has been depressed to load the diluent into the reagent for mixing.
• Fig. 9 is a cross-sectional view of the reagent holder and ampule, shown in Fig. 8, after the medication has been mixed and the reagent plunger rod is depressed to reload the mixed reagent and diluent in the ampule for an injection.
• Fig. 10 is a partial cross-sectional view and side plan view of an ampule that is to be mated to a needle-less injector not forming part of of the present invention.
• Fig. 11 is a side plan view of the assembled needle-less injector of Fig. 10 prior to administering an injection.
• FIG. 12 is a side plan view of a transparent diluent holder in accordance with an embodiment of the present invention;
• FIG. 13 is a side plan view of an ampule and a needle-less injector in accordance with an embodiment of the present invention.
• Fig. 14 is a cross-sectional view of the diluent holder coupled to the ampule reagent holder and the needle-less injector prior to mixing the reagent and the diluent in the reagent holder.
• Fig. 15 is a cross-sectional view of the diluent holder coupled to the ampule reagent holder and the needle-less injector after the diluent plunger rod has been depressed to load the diluent into the reagent for mixing.
• Fig. 16 is a cross-sectional view of the diluent holder coupled to the ampule reagent holder and the needle-less injector after the medication has been mixed and the diluent plunger rod is withdrawn to remove air from the mixed reagent and diluent in the ampule reagent holder.
• Fig. 17 is a cross-sectional view of a diluent holder coupled to the ampule reagent holder and needle-less injector prior to removal to permit an injection.
• Fig. 18 is a partial cross-sectional and side plan view of the assembled needle-less injector prior to administering an injection in accordance with another embodiment of the present invention.

As shown in the drawings for purposes of illustration, the invention is embodied in a device and method for filling an ampule of a single-use needle-less injector with medication prior to administration of an injection. Preferably, the device is used in conjunction with, or are attached to, a single-use disposable needle-less injector, such as that disclosed in United States Patent Nos. 5,730,723 and 5,851,198. However, it will be recognized that further embodiments of the invention may be used to fill an ampule in multiple-use needle-less injectors.

Figs. 1-11 illustrate a filling apparatus 10 not forming part of the present invention. The filling apparatus 10 includes a diluent holder 12 and a reagent holder 14.

The diluent holder 12 is sized to contain a diluent for producing a medication prior to injection. The diluent holder 12 may be an ampule for use on a needle-less injector 1000 (see Fig. 11), or may be another receptacle for loading diluent into another container, such as an ampule for a multiple-use needle-less injector, syringe or the like. The diluent holder 12 includes a housing 16 that forms an interior chamber 18 for holding the diluent. The diluent is preferably sterile water, saline, buffered solution or other solvent that is mixed with a reagent to form a liquid medication. One end of the housing 16 includes threads 20 and an orifice 22 for mating with corresponding threads and opening on the reagent holder 14 to provide fluid communication between the diluent holder 12 and the reagent holder 14. Another end of the housing 16 includes threads 24 and an opening 26 for mating with corresponding needle-less injector 1000. The ends of the diluent holder 12 may however be formed with other attachment structures, such as snaps, bars, friction fits or the like.

The diluent holder 12 also includes a piston 28 for maintaining the diluent in the interior chamber 18 and substantially prevent leakage out of the opening 26 of the housing 16. The piston 28 maintains the diluent in the interior chamber 18 so that it does not leak out of the orifice 22. As shown in Figs. 5-6, the diluent holder includes a diluent plunger 30 and a support bushing 32 having an opening 34 that allows passage of the diluent plunger rod 30 through the support bushing 32 to expel diluent

The reagent holder 14 is sized to contain a reagent for producing a medication prior to injection when mixed with the diluent of the diluent holder 12. The reagent holder 14 includes a housing 56 that forms an interior chamber 58 for holding the reagent. The reagent or other reagent is needed to produce a liquid medication. One end of the housing 56 includes threads 60 and an opening 62 for mating with corresponding threads 20 and orifice 22 on the diluent holder 12 to provide fluid communication between the diluent holder 12 and the reagent holder 14. Alternatively the end of the reagent holder 14 may be formed with other attachment structures, such as snaps; bars, friction fits or the like. Another end of the housing 56 includes a reagent plunger 64 and an opening 66 for receiving the reagent plunger 64.

The reagent holder 14 also includes a piston 68 coupled to the end of the reagent plunger 64 for maintaining the reagent in the interior chamber 58 and to substantially prevent leakage out of the opening 66 of the housing 56. The piston 68 maintains the reagent in the interior chamber 58 so that it does not leak out of the opening 62.

As shown in Figs. 1-11, the reagent holder 14 stores the reagent and is configured for sterile docking (or coupling) with the diluent holder 12 containing the diluent. When the diluent holder 12 is docked with the reagent holder 14, the diluent plunger 30 is pushed through the bushing 32 on the diluent holder 12 to transfer and load the diluent into the reagent holder 14, by moving the diluent plunger 30 and piston 28 towards the orifice 22. As the diluent enters the reagent holder 14, the diluent and reagent are mixed together to produce the medication. Once the medication is produced, the reagent plunger 64 and piston 68 are moved towards the opening 62 in the housing 56 of the reagent holder 14 to reload the mixed medication back into the diluent holder 12. The diluent holder 12 may be the ampule for a needle-less injector or the like. After reloading the diluent holder 12, the diluent plunger 30 and the bushing 32 are removed and discarded from the diluent holder 12. The diluent holder, if an ampule, is then threaded onto the body of a needle-less injector 1000. Once seated, the reagent holder 14 is removed from the end of diluent holder 12, and final tightening is performed on the diluent holder 12. A needle-less injection is then performed in a normal manner.

If the diluent holder 12 is not an ampule for a needle-less injector, the reagent holder 14, may be removed after receiving the diluent, and then coupled to an ampule for filling with the mixed medication. The diluent holder 12 may however be an ampule for a multi-use needle-less injector, syringe or the like.

Figs. 12-18 illustrate a filling apparatus 100 in accordance with an embodiment of the present invention. The filling apparatus 100 includes a diluent holder 112 and a reagent holder 114 which is an ampule for use on a needle-less injector 1000. The filling apparatus 100 is similar to the apparatus 10 described above; however, the filling apparatus 100 contains the reagent in the ampule for a needle-less injector. This removes one step of reloading the ampule after mixing the reagent and diluent to produce the medication.

The ampule 114 is sized to contain a reagent for producing a medication prior to injection. The ampule 114 includes a housing 116 that forms an interior chamber 118 for holding the reagent. The reagent is mixed with a diluent to form a liquid medication. One end of the housing 116 includes threads 120 and an orifice 122 for mating with corresponding threads and opening on the diluent holder 112 to provide fluid communication between the diluent holder 112 and the ampule 114. Another end of the housing 116 includes threads (not shown) and an opening 126 for mating with corresponding needle-less injector 1000. In alternative embodiments, the ends of the reagent holder 114 may be formed with other attachment structures, such as snaps, bars, friction fits or the like.

The ampule 114 also includes a piston 128 for maintaining the reagent in the interior chamber 118 and substantially prevent leakage out of the opening 126 of the housing 116. The piston 128 maintains the reagent in the interior chamber 118 so that it does not leak out of the orifice 122. As shown in Figs. 13-18, the ampule 114 is attached to the needle-less injector 1000. In alternative embodiments, the ampule 114 is filled separately from the needle-less injector 1000 and includes a reagent plunger and a support bushing having an opening that allows passage of the reagent plunger rod through the support bushing to adjust the piston 128 after receipt of the diluent, in a manner and structure similar to that described in relation to Figs. 1 - 11.

The diluent holder 112 is sized to contain a diluent for producing a medication prior to injection when mixed with the reagent of the ampule 114. The diluent holder 112 includes a housing 156 that forms an interior chamber 158 for holding the diluent. In preferred embodiments, the diluent is sterile water, saline, buffered solution or other solvent that is mixed with a reagent to form a liquid medication. One end of the housing 156 includes threads 160 and an opening 162 for mating with corresponding threads 120 and orifice 122 on the ampule 114 to provide fluid communication between the diluent holder 112 and the reagent holder 114. In alternative embodiments, the end of the diluent holder 112 may be formed with other attachment structures, such as snaps, bars, friction fits or the like. Another end of the housing 156 includes a diluent plunger 164 and an opening 166 for receiving the diluent plunger 64.

The diluent holder 112 also includes a piston 168 coupled to the end of the diluent plunger 164 for maintaining the diluent in the interior chamber 158 and to substantially prevent leakage out of the opening 166 of the housing 156. The piston 168 maintains the diluent in the interior chamber 158 so that it does not leak out of the opening 162.

As shown in Figs. 12-18, the ampule 14 stores the reagent and is configured for sterile docking (or coupling) with the diluent holder 112 containing the diluent. When the diluent holder 112 is docked with the ampule 114, the diluent plunger 164 and piston 168 are moved towards the opening 162 in the housing 156 to load the diluent in the ampule 114. As shown in Fig. 16, after loading the ampule 114 with diluent, the diluent plunger 164 is withdrawn a distance along the interior chamber 158 to remove any air bubble, and then the diluent holder 112 is removed and discarded. In alternative embodiments, after loading the ampule 114 (that is not connected to a needle-less injector 1000) with diluent, the reagent plunger and the bushing are used to remove any air or bubbles, and then the diluent holder 112 removed and discarded from the ampule 114, in a manner and structure similar to that described above in relation to Figs. 1 - 11. The ampule 114, if an ampule that is separated from a needle-less injector 1000, is then threaded onto the body of a needle-less injector 1000. In further embodiments, the ampule 114 may be an ampule for a multi-use needle-less injector.

Claims (10)

1. A method of mixing liquid medication for an ampule of a needleless injector suitable for injecting said liquid medication, the method comprising the steps of:

   providing a needleless injector ampule (114) containing a reagent;

   providing a needleless diluent holder (112) containing a diluent;

   providing the diluent holder with a diluent plunger rod (164);

   coupling the ampule directly to the diluent holder to provide fluid communication between the ampule and the diluent holder; and

   depressing the diluent plunger rod (164) to load the diluent into the ampule to mix the reagent to produce the liquid medication.
2. A method in accordance with claim 1, wherein the reagent and the diluent are mixed just prior to injection of the liquid medication due to a short shelf life of the liquid medication.
3. A method in accordance with claim 1 or claim 2, further comprising the step of attaching the ampule (114) to a needleless injector (1000) after filling with the diluent.
4. A method in accordance with any preceding claim, further comprising adapting the diluent holder (112) to be matingly attached directly to the ampule (114) so as to define an unobstructed fluid-communication path between an interior chamber of the diluent holder (112) and an interior chamber of the ampule (114) upon attachment of the ampule (114) to the diluent holder (112) and prior to application of any pressure on the fluid plunger rod (164) to move the diluent out of the diluent holder (112).
5. A method in accordance with any preceding claim, wherein the ampule (114) further includes an ampule plunger rod, and wherein after the diluent is loaded into the ampule (114), the ampule plunger rod can be depressed to expel bubbles back into the diluent holder (112) from the filled ampule (114).
6. An apparatus for performing the method of claim 1, the apparatus comprising:

   a needleless injector ampule (114) containing a reagent; and

   a needleless diluent holder (112) containing a diluent, said needleless diluent holder having a diluent plunger rod (164), and the ampule (114) being adapted to be directly coupled to the diluent holder (112) to provide fluid communication between the ampule (114) and the diluent holder (112), wherein the diluent plunger rod (164) can be depressed to load the diluent into the ampule (114) to mix with the reagent to produce liquid medication.
7. An apparatus in accordance with claim 6, wherein the apparatus is adapted to allow the reagent and the diluent to be mixed just prior to injection of the liquid medication due to a short shelf life of the liquid medication.
8. An apparatus in accordance with claim 6 or claim 7, wherein the ampule (114) is adapted to be attached to a needleless injector (1000) after filling the ampule (114) with the diluent.
9. An apparatus according to claim 8, wherein the ampule (114) is adapted to be matingly attached directly to the diluent holder (112) so as to define a needleless, unobstructed fluid-communication path between an interior chamber of the diluent holder (112) and an interior chamber of the ampule (114) upon attachment of the ampule (114) to the diluent holder (112) and prior to application of any pressure on said diluent plunger (164) to move the diluent out of the diluent holder.
10. An apparatus according to any one of claims 6 to 9, wherein the ampule (114) comprises an ampule plunger rod and wherein after the diluent is loaded into the ampule (114) the ampule plunger rod can be depressed to expel bubbles back into the diluent holder (112) from the filled ampule (114).