PARTITIONED CARPULE, SYRINGE, AND SYSTEM THEREFOR, AND METHODS OF USE THEREOF

Abstract

Described is a mixing syringe for receiving a removable carpule partitioned to form two reservoirs independently containing anesthetic solution and buffering solution and having a mixing chamber for mixing the solutions during administration, and methods of using the mixing syringe.

Claims

1. A mixing cartridge syringe comprising: i) a syringe barrel for receiving a partitioned carpule, said carpule being partitioned longitudinally and asymmetrically to form a first reservoir for containing a drug solution and a second reservoir for containing a buffering solution; ii) a longitudinally slotted plunger stem forming two asymmetric plunger stem portions which separately and matingly engage a sliding cap on a distal end of each of the first and second reservoirs for expelling the contents therefrom; and iii) a mixing chamber for receiving and mixing the drug solution and the buffering solution expelled from the partitioned carpule, the mixing chamber containing a turbulence apparatus disposed therewithin, said turbulence apparatus being operable to facilitate mixing of the drug solution and the buffering solution within the mixing chamber before administering the drug solution and buffer solution to a patient.

2. The mixing cartridge syringe of claim 1, wherein the mixing chamber is in fluid communication with the first reservoir through a first conduit comprising a first piercing needle operable to traverse an end cap on the proximal end of the first reservoir and is in fluid communication with the second reservoir through a second conduit comprising a second piercing needle operable to traverse an end cap on the proximal end of the second reservoir.

3. The mixing cartridge syringe of claim 1, wherein each plunger stem portion of the slotted plunger stem comprises a harpoon on its proximal end.

4. The mixing cartridge syringe of claim 1, wherein the turbulence apparatus is distinct and separate from the mixing chamber.

5. The mixing cartridge syringe of claim 1, wherein the turbulence apparatus is formed from an inert material.

6. The mixing cartridge syringe of claim 5 wherein the inert material is steel wool.

7. The mixing cartridge syringe of claim 5 wherein the inert material is polymeric.

8. The mixing cartridge syringe of claim 5 wherein the inert material is plastic.

9. The mixing cartridge syringe of claim 1, further comprising an exit port connectable with a hypodermic transfer needle.

10. A method for mixing a local anesthetic drug solution and a buffer solution to form an anesthetic and buffer mixture immediately prior to administration of the anesthetic and buffer mixture to a patient, said method comprising: a) providing a mixing cartridge syringe of claim 1; b) loading into the barrel of the mixing cartridge syringe a longitudinally partitioned carpule containing anesthetic solution in the first chamber and buffer solution in the second chamber; and c) actuating the slotted plunger stem to expel and deliver the anesthetic solution and the buffer solution from the carpule into the mixing chamber whereby the anesthetic solution and buffering solution are mixed to form the anesthetic and buffer mixture, the anesthetic and buffer mixture being deliverable through a hypodermic transfer needle connected to the exit port and into a target tissue of the patient.

11. The method of claim 10, wherein said mixture of solutions is at a ratio ranging from about 6:1 anesthetic:buffer to about 10:1 anesthetic:buffer.

12. The method of claim 11, wherein said mixture is at a ratio of about 8:1 anesthetic:buffer.

13. The method of claim 10, further comprising the step of removing an expended carpule from the syringe and repeating steps a) to c).

14. A longitudinally and asymmetrically partitioned carpule operable for use in a mixing cartridge syringe having a slotted plunger stem, said carpule comprising: a first reservoir containing anesthetic solution and a second reservoir containing buffer solution, each solution provided in a predetermined amount for forming an anesthetic and buffer mixture at a predetermined ratio of anesthetic solution and buffer solution, without requiring mixing outside or remote from the syringe.

15. The asymmetrically partitioned carpule of claim 14, wherein the partition divides the reservoirs such that the anesthetic solution:buffer solution ratio is about 6:1 to about 10:1.

16. The asymmetrically partitioned carpule of claim 15, wherein the ratio of anesthetic solution:buffer solution is about 8:1.

17. The asymmetrically partitioned carpule of claim 14, wherein each reservoir comprises a stationary cap at a proximal end and a sliding cap at a distal end.

18. A system for mixing an anesthetic solution and a buffer solution to form and deliver to a patient in need thereof a buffered anesthetic solution from a single actuation of a syringe plunger, said system comprising: a) a mixing syringe of claim 1; and b) a carpule of claim 15 wherein the syringe and carpule are packaged or used together.

19. The system of claim 18 wherein the system is self-contained whereby prior or remote mixing of the anesthetic and buffer solutions is not required.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG. 1 is a perspective exploded view of an embodiment of a syringe device and system in accordance with the subject invention, illustrating a plunger comprising a slotted plunger stem and cross-sectional view of a partitioned carpule.

[0043] FIG. 2A is a perspective view of an embodiment of a plunger removed from the syringe body, as used in a syringe according to the subject invention, illustrating a plunger stem comprising a longitudinal slot along its length, forming two asymmetric plunger stem portions. FIG. 2B is a detailed perspective view of the proximal end of the slotted plunger stem, showing the semicircular cross-sectional shape of each plunger stem portion and illustrating the presence of a grasping implement or “catch” provided on the proximal end of each plunger stem portion.

[0044] FIG. 3A is a perspective view of an embodiment of a partitioned carpule in accordance with the subject invention, illustrating its standard shape and size for use in a conventionally configured syringe barrel. FIG. 3B is a cross-sectioned perspective view of a carpule of FIG. 3A, illustrating the partition disposed therewithin forming dual, asymmetric reservoirs within the carpule.

[0045] FIG. 4A is a plan view of the distal end of a partitioned carpule used in accordance with the subject invention, illustrating a partition provided along the length of the carpule to form dual, asymmetric reservoirs within the carpule. FIG. 4B is a plan view of the stoppered distal end of a partitioned carpule of FIG. 4A in accordance with the subject invention. FIG. 4C is a plan view of a proximal end of a partitioned carpule according to the subject invention, illustrating the asymmetric partition disposed along the length of the carpule to form dual, asymmetric reservoirs within the carpule. FIG. 4D shows illustrates a capped-end embodiment of the carpule of FIG. 4C.

[0046] FIG. 5 is a detailed view of a mixing chamber provided with a mixing syringe according to the subject invention.

[0047] The drawings presented in this application are not to scale.

DETAILED DESCRIPTION OF THE INVENTION

[0048] The subject invention concerns a partitioned carpule and a system for mixing and delivering buffered anesthetic to a patient without requiring remote mixing of the anesthetic and buffer prior to administration. The invention includes use of the carpule in a conventional cartridge syringe, preferably a conventional aspiration cartridge syringe, or can employ a modified cartridge syringe.

[0049] The delivery system according to the subject invention comprises a carpule partitioned to provide dual, asymmetric reservoirs within the carpule, each reservoir respectively containing a drug solution and a buffering solution. The partitioned carpule can include a longitudinally divided chamber.

[0050] The invention can employ a conventional cartridge syringe or can employ a syringe modified to comprise a mixing chamber for receiving and mixing the drug solution and buffering agent expelled from the partitioned carpule and containing therewithin the mixing chamber, a turbulence apparatus. In an embodiment comprising a longitudinally partitioned carpule, a syringe of the invention can include a longitudinally slotted plunger stem forming two asymmetric plunger stem portions which separately, but simultaneously engage a sliding cap on a distal end of each carpule reservoir for plunging each reservoir of the partitioned carpule simultaneously and expelling the contents therefrom into the optional mixing chamber.

[0051] In one embodiment, the partitioned carpule of the invention comprises a partition disposed along the entire length of the carpule forming dual, asymmetric reservoirs within the single carpule, each reservoir comprising a sliding cap at its distal end and a stopper at its proximal end. Advantageously, the partition within the carpule forming the reservoirs does not divide the carpule into equal-volume reservoirs; rather, the partition is offset from the longitudinal midline, forming asymmetrical reservoirs proportionately dividing the carpule reservoirs according to the desired and predetermined amounts and ratios of anesthetic solution and buffering solution when mixed and administered.

[0052] The subject syringe device and system includes a plunger stem comprising a slot formed along its length. Although the slotted plunger stem can be divided along its entire length, effectively forming two half stems wherein each adjoin to a thumbpiece at their respective distal ends, the plunger stem preferably comprises a slot along a portion of its length, i.e., the slot does not extend the entire length of the plunger stem, and forms an intact distal segment that is adjoined and is not slotted.

[0053] In a preferred embodiment, the slot along the length of the plunger stem forms two plunger stem portions which are separate from one another at their proximal ends and adjoin at their distal ends and form a single plunger stem for that adjoined segment. Thus, in the preferred embodiment, the plunger comprises a slotted stem segment along most, between 50-99%, of its length, and has an adjoined, single-stem segment for the remaining portion of its length. Although not limited except for practical purposes, this distal unslotted segment typically can measure about 0.5 mm to about 10 mm from the distal end, where the unslotted segment adjoins or is formed integral with the thumbpiece.

[0054] More specifically, the length of the slot in the plunger stem is formed at least the distance required to fully expel the contents of the reservoirs of the partitioned carpule, with the remainder of the plunger stem being adjoined. Typically, a conventional carpule is about 5-8 cm in length. Accordingly, the length of the slot is at least about 5 cm along the length of the plunger stem and up to about 10 mm in length but less than the entire length of the plunger stem. Therefore, the length of the slot is dependent on the travel distance required to traverse the length of the carpule partition.

[0055] The slotted plunger stem portions are preferably semicircular in cross-section, corresponding to the partitioned carpule reservoirs which are also semicircular in cross-section. Thus, the slotted plunger stem portions matingly slide into the carpule reservoirs to efficiently push the reservoir caps distally, toward the distal reservoir stopper or stoppers to expel the contents of the reservoirs into the mixing chamber and then to the delivery port and transfer needle for injection and administration to the patient.

[0056] When the plunger is actuated, the slot of the plunger stem traverses the length of the partition to engage and push the sliding cap at the distal end of each carpule reservoir the entire length of the carpule until it meets the stopper disposed at the proximal end of the carpule to permit expelling a portion and up to the entire contents of the carpule chambers through a conduit comprising two piercing needles positioned proximal to the carpule and distal to the mixing chamber. The piercing needles provide for fluid communication between the carpule reservoirs and the mixing chamber.

[0057] In addition, each proximal end of the slotted plunger stem portions can include a grasping implement or harpoon protruding from their proximal ends which can engage the sliding distal end caps of the partitioned carpule to allow for pulling or drawing back of the tip in the opposite direction for aspiration (testing whether the needle has entered a blood vessel.) These harpoons are conventional in the art.

[0058] In an embodiment of a mixing syringe of the subject invention, the proximal end of each plunger stem portion comprises a harpoon whereby, depression or actuation of the plunger thumbpiece pushes the slotted plunger stem to engage the distal carpule reservoir caps. The stabs are not permanently, rather removably engaged with the partitioned carpule caps, and can be removed for disengaging the partitioned carpule from the mixing syringe barrel.

[0059] One embodiment of the invention provides a mixing syringe which comprises a mixing chamber positioned between, and in fluid communication with, the syringe barrel and the delivery port. The mixing chamber is capable of receiving the anesthetic solution and buffering solution from a single, partitioned carpule for mixing of the solutions. A wall separates the mixing chamber from the syringe barrel, but includes two piercing needles, each piercing needle traversing a stopper in the proximal end of a carpule having dual reservoirs so that, when engaged, the contents in the dual reservoirs of the carpule are in fluid communication with the mixing chamber. The piercing needles can be separate, where each piercing needle delivers solution to the mixing chamber from each of the respective reservoirs of the carpule, or can adjoin into a single conduit such that the contents from each dual reservoir are delivered to the mixing chamber via the single conduit.

[0060] The mixing chamber preferably comprises a turbulence apparatus disposed therewithin which serves to create turbulent flow of the solutions entering the mixing chamber from the partitioned carpule reservoirs, resulting in thorough mixing of the solutions immediately prior to administration of the buffered anesthetic solution through the delivery port and hypodermic transfer needle.

[0061] In one preferred embodiment, the turbulence apparatus is an inert material separate and distinct from the mixing chamber, and is not formed as an integral part of the mixing chamber, i.e., it is a distinct apparatus that is not etched or formed into the wall of the mixing chamber. A preferred turbulence apparatus can be made of plastic or metal which does not interact chemically or physically with the buffered anesthetic solution and can be provided in a twisted or convoluted or highly porous configuration, e.g., steel wool, to facilitate turbulent flow and mixing of the solutions. Alternatively, the turbulence apparatus can be a finned disc or turbine which can facilitate mixing of the solutions by a rotational motion activated by fluid passing by the apparatus. The mixing chamber comprising the turbulence apparatus preferably provides a substantially homogeneous mixture of buffer and anesthetic solutions.

[0062] The subject invention further comprises a method of administering a mixture of anesthetic solution and buffering solution, forming a mixed, buffered anesthetic solution by employing a novel syringe as described and shown herein.

[0063] Advantages of the present invention include convenience of use and greater efficiency in a clinical setting for injectable drugs, such as anesthetics, which are commonly remotely mixed with another solution immediately prior to administration. This advantage is achieved by providing a dispensing device in accordance with the subject invention comprising a syringe barrel adapted to receive a single, asymmetrically partitioned carpule having dual reservoirs for containing anesthetic solution in a first reservoir and a buffering solution in a second reservoir.

[0064] A mixing cartridge syringe and partitioned carpule of the subject invention can be a self-contained anesthetic/buffer solution mixing and delivery system which does not require pre-mixing of the anesthetic and buffer prior to loading the syringe with anesthetic or buffer solution, nor does it require mixing to be conducted remotely or outside the syringe or system of the invention.

[0065] Turning to the drawings provided herewith, FIG. 1 shows an exploded view of an embodiment of a mixing syringe and system 100 according to the subject invention. Shown is the thumbpiece 101 at a distal end of the syringe device. Affixed or integral with the thumbpiece is a plunger stem comprising a slot formed therein to provide a slotted plunger stem comprising two plunger stem portions 102a and 102b. The proximal end of each plunger stem portion comprises a stab 103. The slotted plunger stem and plunger stem portions slidingly engage the syringe barrel 103, having at its distal end at least one flange 105 forming a fingerhold. Illustrated in FIG. 1 is a mixing syringe comprising two flanges 105 to form two fingerholds.

[0066] The mixing syringe barrel 103 comprises an opening 106 or aperture in its side wall to provide for insertion and removal of a carpule containing injectable solutions. In accordance with the subject invention, a mixing syringe system includes a partitioned carpule 107, shown in cross-section in FIG. 1 to illustrate the partition asymmetrically disposed along the length of the carpule and forming dual, asymmetric reservoirs 108 and 109 therewithin.

[0067] Proximal to the mixing syringe barrel is mixing chamber 110, having a turbulence apparatus 111 disposed therein. For fluid communication between the carpule reservoirs and the mixing chamber, piercing needles 112 and 113 are provided as conduits to deliver the anesthetic and buffer solutions from the partitioned carpule into the mixing chamber. Each penetrating needle 112 and 113 can be independent from one another to deliver the solutions to the mixing chamber, or they can adjoin, proximal to the carpule reservoirs to form a single conduit for delivery of both solutions into the mixing chamber.

[0068] The mixing chamber connects proximally to a delivery port 114, which is adapted to receive and removably engage a standard hypodermic transfer needle 115, which is typically provided with a safety cap 116.

[0069] An embodiment of the unique slotted plunger stem 200 of the invention is further illustrated in FIG. 2. FIG. 2A shows a perspective view of the slotted plunger stem isolated from the syringe barrel. As shown, slot 201 is formed along the length of the stem, forming divided plunger stem portions 202a and 202b, which can adjoin at their distal ends to provide a single intact plunger stem section 202. The slotted plunger stem adjoins a thumbpiece 203 at the extreme distal end, and each plunger stem portion 202a and 202b has a stab 204 at its proximal end.

[0070] FIG. 2B is a detailed view of the proximal ends of the slotted plunger stem portions 202a and 202b. Specifically illustrated is the asymmetric configuration of plunger stem portions 202a and 202b, where slot 201 is offset from the central axial plane. FIG. 2B also illustrates the semicircular cross-sectional shape of the plunger stem portions. Stabs 204a and 204b, provided on a proximal end of each plunger stem portion are also shown, illustrated in a conventional arrowhead shape.

[0071] FIGS. 3 and 4 illustrate the configurations of a carpule used in accordance with the subject invention. FIG. 3A illustrates an outer, perspective view of a partitioned carpule 300, showing its standard shape and size for use in the mixing syringe system of the subject invention. The partitioned carpule of the invention comprises a stopper 302 at its proximal end. FIG. 3B illustrates a sectioned perspective view of a carpule 300 of the invention, showing a partition 303 asymmetrically disposed along the length of the carpule, forming asymmetric dual reservoirs 304 and 305 within the carpule. Each reservoir 304 and 305 separately and independently contains either an anesthetic solution or a buffering solution.

[0072] FIG. 4A is a plan view of the distal end of a partitioned carpule 400, without sliding caps, further illustrating the asymmetric configuration, and positioning of partition 401 to form asymmetric reservoirs 402 and 403 within the carpule. FIG. 4B shows the same view as FIG. 4A, illustrating the reservoir caps positioned onto the distal end of the carpule. FIG. 4C shows a plan view of a distal end of a carpule of the invention, illustrating an embodiment comprising two stoppers respectively provided on the proximal ends of each reservoir in a partitioned carpule. FIG. 4D shows an embodiment of a partitioned carpule comprising a single stopper for both reservoirs of the carpule.

[0073] FIG. 5 illustrates a detailed plan view of a mixing chamber 500 employed with the mixing syringe of the subject invention. Mixing chamber 500 comprises a housing 501 bounding a chamber 502 into which anesthetic solution and buffer solution are received for mixing. To facilitate mixing of the solutions, the mixing chamber comprises a turbulence apparatus 503. At its proximal end, mixing chamber 500 comprises an exit port 504 through which the mixed, buffered anesthetic solution is delivered to a delivery port 505 of the syringe. The delivery port 505 of the mixing syringe is configured to receive a standard, removable hypodermic transfer needle. Wall 506 formed at a proximal end of the housing includes two piercing needles 507 which traverse carpule stoppers 508 forming conduits in fluid communication with carpule reservoirs 509.

[0074] The first and second reservoirs are provided to respectively and discretely contain an anesthetic solution and a buffer solution, each reservoir independently containing a single content of either an anesthetic solution or a buffer solution.

[0075] The present invention provides advantages over prior devices in, at least the following ways: [0076] it allows for mixing and dispensing local anesthetic and buffering solution from a single syringe using prefabricated carpules dispensed in a single actuating step; [0077] it provides a method of mixing an anesthetic solution with a buffering solution which provides a convenient and all-in-one step of producing a thorough and precise mixture of buffered anesthetic solution; [0078] it does not require any activation step; therefore, it is better suited for practicality and efficiency in a clinical setting. [0079] it provides a method of mixing buffered local anesthetic solution which will obviate the necessity of any mixing steps prior to loading into a syringe for administration; [0080] it provides a dual-reservoir carpule having substantially standard size and shape which may be readily and easily inserted into a conventional syringe barrel for use, and readily and easily removed therefrom after use; [0081] it provides a disposable readily and easily inserted carpule comprising dual reservoirs prefilled with sodium bicarbonate solution local anesthetic solution readily available for mixing or dispensing; [0082] it provides a syringe assembly with a mixing chamber which facilitates dispensing of buffered local anesthetic solution instantly prior to administering the solution into the intended target tissue; [0083] it provides a syringe system for simultaneously transferring solutions in preset ratios and amounts from a dual-reservoir carpule directly into a mixing chamber; [0084] it provides a syringe with an autoclavable (sterilizable) mixing chamber; it provides a syringe with a reusable mixing chamber; [0085] it provides a syringe mixing chamber causing turbulence between the two solutions when the slotted plunger is actuated; [0086] it provides a syringe assembly with piercing needles for providing fluid transfer paths or conduits from each reservoir of the partitioned carpule into a common mixing chamber; and [0087] it provides a partitioned carpule assembly having the same length and where the diameter of a standard carpule but having one reservoir smaller than the other (8:1 ratio).

[0088] In use, a syringe of the subject invention is manipulated and utilized in a manner similar to a conventional carpule-holding syringe, except that the carpule is partitioned to have dual reservoirs, each loaded within the syringe barrel prior to administration of a medicament.

[0089] Specifically, the method comprises the steps of: [0090] a) providing a syringe having a syringe barrel capable of receiving a single partitioned carpule, a slotted plunger, and mixing chamber, as described herein; [0091] b) loading the carpule containing a drug solution and buffer solution into the syringe barrel; and [0092] c) actuating, in a single step, the slotted plunger to actuate each reservoir to expel and deliver anesthetic solution and buffering solution into a mixing chamber, whereby the anesthetic solution and buffering solution are mixed, preferably homogeneously, and delivered from the delivery port as a buffered anesthetic solution and through a hypodermic transfer needle into a target tissue.

[0093] The method can further include removing the expended carpules from the syringe barrel and repeating the above steps a) through c) as needed.

[0094] It is contemplated that the invention provides a significant role in ease-of-use and efficiency in administering local anesthetic buffered solution in a pH control fashion. The present invention provides optimal dosing control of freshly buffered local anesthetic solution at the fingertips of medical practitioners.

[0095] It is to be understood that certain descriptions of the invention have been simplified to focus on elements that are relevant for a clear understanding of the invention, while eliminating, for purposes of clarity, other elements that those of ordinary skill in the art will appreciate may also comprise a portion of the invention. While the present invention has been presented in accordance with several preferred and practical embodiments thereof, it is recognized that departures from and variants of the instant disclosure are contemplated as being fully within the spirit and scope of the invention.