WO1999017820A9

WO1999017820A9 - Improved dual chamber syringe apparatus

Info

Publication number: WO1999017820A9
Application number: PCT/US1998/020909
Authority: WO
Inventors: Nicholas Bachynsky
Original assignee: Texas Pharm Inc; Nicholas Bachynsky
Priority date: 1997-10-03
Filing date: 1998-10-05
Publication date: 1999-07-08
Also published as: AU9785598A; WO1999017820A1

Abstract

A dual chamber syringe apparatus (10) provides an improved configuration that can be adapted to commercially available smooth bore cylindrically-shaped syringe barrels. The apparatus includes in the preffered embodiment a plunger (20) that has a reservoir for containing a diluent fluid, the lower end of the plunger (20) having a valving portion (26) that automatically dispenses diluent into the syringe barrel chamber (12) that contains a dry drug product to be reconstituted. As the user moves the plunger rod (20) from a retracted position to an extended position, diluent fluid is transmitted from the plunger rod (20) into the chamber (12) of the syringe barrel (11) for mixing with the dry drug product. Once the plunger rod (20) reaches a full extended position, all diluent has been discharged therefrom, and mixed with the dry drug product. The user then depresses the plunger rod (20) for dispensing the reconstituted dry product to the patient.

Description

TITLE OF THE INVENTION

"IMPROVED DUAL CHAMBER SYRINGE APPARATUS" INVENTOR: Nicholas Bachynsky, A U.S. citizen, of San Antonio, TX. CROSS-REFERENCE TO RELATED APPLICATIONS

In the U.S., this is a continuation of U.S. Patent Application Serial No. 08/943,423, filed 3 October 1997, and incorporated herein by reference. Also incorporated by reference are U.S. Patent No. 5,267,963, U.S. Patent Application Serial No. 09/005,221, filed 9 January 1998, and U.S. Patent Application Serial No. 08/895,161, filed 16 July 1997.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable REFERENCE TO A "MICROFICHE APPENDIX" Not applicable BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to syringes, and more particularly to an improved smooth bore dual chamber syringe apparatus that includes an initially dry chamber that is separated from a diluent chamber by a transverse piston portion of a plunger wherein in one embodiment, the plunger carries the diluent chamber in a cylindrically-shaped reservoir and automatically valves diluent flow to the dry drug when the plunger is pulled to an extended position.

2. General Background of the Invention

It is known that many drugs cannot be administered by the oral route because of gastrointestinal intolerance, irregularity in absorption, and metabolic breakdown in the gut wall and liver (first pass effects). In particular, first pass loss abolishes oral bioavailability of all poly- peptide and protein medications (e.g. growth hormone, tumor necrosis factor receptor, insulin, glucagon. alteplase. erythropoietin, alglucerase (glucocerebrosidase-B-glucosidase), etc.). This necessitates their administration through various parenteral routes, i.e., intravenous, intramuscular, subcutaneous, intrathecal, etc. Further, parenteral delivery of such drugs will expand with future mapping and functional understanding of the human genome. Pharmaceutical recombinant DNA synthesis of new peptide-protein moieties will concomitantly increase, and make a cost-contained, safe, effective and simple to use delivery device essential for both patients and medical professionals.

Functionally, stability of an injectable drug may be defined as its capability to retain chemical, sterile, toxicological and therapeutic specifications within 90% of its original potency. By tradition, expiration dates denote the last day of a month and year a particular preparation retains such stability under recommended conditions. In case of a dry or lyophilized medication to be reconstituted prior to use, expiration dates are designated for both the dry and reconstituted product. When compared to drug solutions ready for injection, dry soluble medications ready to be reconstituted with solvent just prior to use are well known to have greater stability and longer expiration dates.

Time related deterioration in ready to use parenteral drug preparations include interactions between combined active, and between active and inactive ingredients. Aqueous solvents in particular, potentiated by heat and radiation, initiate or accelerate time dependent degradation through oxidation, reduction, hydrolysis, racemization, decarboxylation, photolysis, and, autooxidative free radical chain reactions.

Notwithstanding such chemical breakdown, buffers, antioxidants, preservatives and other stabilizers oftentimes cannot be used in formulations containing water because of their reactivity with the active ingredient(s) or, direct patient hypersensitivity. Moreover, water itself has a profound effect on hydrolysis and denaturation of drugs possessing ester or amide chemical bonds, e.g. tetracaine, physostigmine, growth hormone, benzylpenicillin, calcitonin, epoetin alfa, menotropins, placental gonadotropin, interferons, pituitary releasing hormones (gonadorelin, cosyntropin, etc.) and numerous others.

A cost effective, simple, self contained dual-chamber syringe which isolates dry- wet drug components and mixes them immediately prior to injection is highly desirable. Furthermore, such a device would eliminate extra standard syringes, medication and diluent containers required for mixing the individual drug constituents. The device would permit accurate drug reconstitution, eliminate waste and possible introduction of contaminants through human error.

Various types of two compartment injection syringes have been patented to address such concerns and are known: U.S. Patent No. 5,395,326 describes a medication jell-liquid two compartment syringe fitted with side-by-side chambers for mixing and injecting via a dilating O- ring piston assembly; U.S. Patent No. 4,983,164 utilizes a two chambered syringe barrel created by a non-movable, separating membrane which ruptures when displaced toward the plunger. Other patents, U.S. Patent No. 4,413,991, 4,202,314 and 4,214,584 either possess dual chambers interconnected with side openings through an injection needle, or two driving systems for mixing and injecting, or have concentric dual chambers which, upon manual rotation, untighten and permit mixing with subsequent standard injection. Dual chamber syringes are known for administering medicinal preparations wherein it is desired to isolate a first medicinal preparation from a second medicinal preparation until it is time to administer the combination of the two preparations to a patient.

An example of a device for administering such first and second medicinal preparations is seen in the Smirnov et al. Patent 4,214,584. The Smirnov device is provided for administering medicinal preparations that includes an isolated capsule divided into a chamber for a first medicinal preparation and a chamber for a second medicinal preparation. Coaxially inside the isolated capsule and concentrically therewith is the piston which bounds the chamber for the first medicinal preparation. Made fast on the piston is an injection needle having a hole located at the base of the piston. Provision is made in the device for a mechanical actuator of the piston, which is a spring-opposed pushrod located inside the housing which also accommodates the retaining member for the spring-opposed pushrod. The chamber for the second medicinal preparation is arranged concentrically with the chamber for the first medicinal preparation so as to embrace the latter. The isolated capsule is mounted traversably inside the housing, while communication between both of the chambers is established upon a positive extension of the isolated capsule from the housing outwards.

Another Smirnov patent is U.S. 4,202,314 entitled "Device For Injection Of Medicinal Preparations". The device for injection of medicinal preparations, comprises a changeable isolated capsule, an injection needle, and a drive to move pistons, made in the form of a spring- loaded pusher located inside the housing which supports the changeable isolated capsule. The housing has a stopping member to arrest said spring-loaded pusher. Inside said isolated capsule, installed coaxially therewith and with each other are a main piston closed by a partition on the side facing the chamber holding the first medicinal preparation and an additional piston. The partition is movable. The injection needle is installed inside the isolated capsule, fixed on the additional piston, and it in use passes through said partition, and has an aperture in the zone of the partition on the side of the chamber holding the first medicinal preparation. The additional piston is located in the channel of the main piston and limits the chamber for the second medicinal preparation. The drive of the pistons has an additional spring-loaded pusher interacting with the additional piston and is located coaxially with the spring-loaded pusher. The housing of the drive of the pistons has an additional stopping member for the additional spring- loaded pusher.

The Kamstra Patent 4,529,403, entitled "Automatic Injection Syringe", relates to a syringe for injecting two or more different injection liquids which may not be contact with each other for long periods of time. For that purpose, the ampoule between the piston and the needle connection includes one or more stoppers which keep the injection liquids separated from each other, while at a point a short distance before the needle connection a by-pass means is present through which the injection liquid or injection liquids present behind the stopper or stoppers can pass the stopper or stoppers during use of the syringe.

In the Hook Patent 4,983,164, an automatic two-chamber injector for mixing and injecting a medicinal solution is disclosed. The injector comprises a barrel having a first end with a receiving portion for an injection needle, that portion being sealed prior to use, and a second end with a displaceable plunger. The barrel comprises two chambers separated by a migration proof membrane, the membrane being adapted to rupture when the plunger is displaced towards the first end of the barrel. The ' 164 patent also discloses a method for mixing and injecting a solution by means of an automatic two-chamber injector and to a cartridge for a two- chamber injector.

European Patent Application No. 0 072 057 relates to an automatic syringe for injecting two or more different injection liquids which may not be in contact with each other for longer periods of time. For that purpose the ampoule between piston and needle connection comprises one or more stoppers which keep the injection liquids separated from each other, while at a short distance before the needle connection a by-pass means is present past which the injection liquid or injection liquids present behind the stopper or stoppers can pass the stopper or stoppers during use of the syringe.

One of the problems with dual chamber syringes is that of achieving a complete mixture of the medicinal components while at the same time perfecting a complete and total dispensing of the combined medicinal portions into the patient after mixing has been completed.

The syringes disclosed in the above-discussed patents do not reseal the mixture of the two medicinal components after mixture in the syringe barrel so as to expel all of the reconstituted pharmaceuticals.

Many of the above-discussed prior art patents are highly complex structures comprising multiple interlocking and telescoping portions, some requiring springs for operation. The present invention is an improvement over these prior art patents. Unlike prior art dual chamber syringes, the apparatus of the present invention has only two moving parts, each being a piston sliding within a single one piece smooth bore syringe barrel. Yet the present invention effectively isolates first and second medicinal portions before use, perfects mixture immediately prior to administration, and contains the mixed medicinal components below a lower piston in the syringe barrel to ensure complete discharge of the mixed medicinal components during administration to the patient. BRIEF SUMMARY OF THE INVENTION The present invention provides an improved dual chamber syringe apparatus construction that can be used with commercially available syringe barrels that are typically smooth bore syringes having a uniform cylindrically-shaped open ended bore that receives a plunger rod having a piston. In one embodiment, the plunger rod fits within the barrel and carries a diluent reservoir. The rod has a lower end portion with a piston or valving member thereon. A dry drug product is positioned within the barrel bore next to the needle end of the barrel, the dry drug being contained in between the barrel and the piston valving member before mixing and reconstituting.

The valving member enables liquid diluent to flow through the valving member to the dry drug product when the plunger rod moves from the retracted initial position to an extended position. The plunger rod and barrel can be of corresponding uniform cylindrical shapes.

The valving member can be in the form of a flexible member such as flexible disk. At least one flow opening extends through the circular end wall of the syringe and the valving member closes the flow opening when the plunger rod is moved from the retracted to the extended position. A flow channel is provided in the plunger rod through which diluent flows from the reservoir into the barrel bore when the plunger rod moves from the retracted position to the extended position. In a second embodiment, the valving member is in the form of a ball that is held in a closed position on a valve seat with a spring member. When the plunger is moved from the retracted to the extended position, fluid flow moves from the diluent chamber forcing the ball valve from its seat and into the syringe chamber so that the diluent fluid mixes with the dry drug product. In a third embodiment, the plunger rod is a solid member with the diluent chamber and dry drug chamber being both positioned in the syringe chamber with a piston separating the two components to be reconstituted.

In a fourth embodiment, a closed needle arrangement provides a block that covers the dispensing end of the needle to prevent air flow from entering the mixture during reconstituting of the dry drug with liquid diluent. The third embodiment also uses a plunger rod construction that cooperates with commercially available automatic syringe gun mechanisms and with a copending patent application Serial No. 08/895,161, filed 15 July 1997, entitled "Rotary Cam Syringe", and incorporated herein by reference.

A fifth embodiment uses a plunger rod construction that is hollow providing a puncture stem deliver arrangement that fits the hollow bore of the plunger rod. The lower end of the stem carries dry medication. In order to mix the dry drug product with the liquid diluent contained in the syringe chamber, the puncture stem is pushed through a piston that initially separates the dry drug from the diluent. Once the puncture stem is pushed through the piston so that the dry drug can mix with the diluent, reconstitution takes place and the plunger rod can be used to dispense the reconstituted mix through the needled and into the patient. BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:

Figure 1 is an exploded sectional elevational view of the preferred embodiment of the apparatus of the present invention;

Figure 2 is a sectional elevational view of the preferred embodiment of the apparatus of the present invention prior to a mixing of the dry and diluent contents;

Figure 3 is a sectional elevational view of the preferred embodiment of the apparatus of the present invention shown during a mixing of the dry and diluent contents; Figure 4 is a sectional elevational view of the preferred embodiment of the apparatus of the present invention immediately prior to a dispensing of the reconstituted drug;

Figure 5 is a sectional exploded elevational view of a second embodiment of the apparatus of the present invention;

Figure 6 is a sectional elevational view of the second embodiment of the apparatus of the present invention;

Figure 7 is a sectional elevational view of the third embodiment of the apparatus of the present invention showing the mixing of dry and diluent contents; Figure 8 is a sectional elevational view of the second embodiment of the apparatus of the present invention after dispensing of the reconstituted drug therefrom;

Figure 9 is a partial sectional elevational view of the second embodiment of the apparatus of the present invention showing an alternate construction of the valve portion thereof; Figure 10 is a sectional elevational view of a third embodiment of the apparatus of the present invention showing the dry drug and liquid diluent prior to mixing;

Figure 11 is a sectional elevational view of the third embodiment of the apparatus of the present invention shown during mixing of the dry drug and liquid diluent;

Figure 12 is a sectional view of the third embodiment of the apparatus of the present invention shown after the dry and liquid contents have been reconstituted;

Figure 13 is a sectional elevational view of the third embodiment of the apparatus of the present invention shown during a dispensing of the reconstituted drug;

Figure 14 is a sectional elevational view of a fourth embodiment of the apparatus of the present invention prior to a mixing of the dry drug and liquid diluent; Figure 15 is a sectional elevational view of the fourth embodiment of the apparatus of the present invention shown during a mixing of the dry drug and liquid diluent;

Figure 16 is a sectional elevational view of the fourth embodiment of the apparatus of the present invention shown during a mixing of the dry and liquid contents and immediately prior to dispensing; Figure 17 is a sectional elevational view of the fourth embodiment of the apparatus of the present invention shown during a dispensing of the reconstituted drug;

Figure 18 is a top view of a fourth embodiment of the apparatus of the present invention shown with the cap removed;

Figure 19 is a sectional elevational view of a fifth embodiment of the apparatus of the present invention shown prior to a reconstitution of the dry drug product with liquid diluent;

Figure 20 is a sectional elevational view of a fifth embodiment of the apparatus of the present invention shown during a reconstitution of the dry drug product with liquid diluent; and

Figure 21 is a sectional elevation view of a fifth embodiment of the apparatus of the present invention shown during a dispensing of the reconstituted drug. DETAILED DESCRIPTION OF THE INVENTION

Figures 1-4 show the preferred embodiment of the apparatus of the present invention designated generally by the numeral 10. Syringe apparatus 10 has a generally cylindrically- shaped barrel 11 with a smooth bore to provide a smooth cylindrically-shaped internal chamber or reservoir 12. The chamber 12 is surrounded by cylindrical side wall 13. One end of the barrel 11 is provided with a circular end wall 14 having a dispensing opening 15 that communicates with connector fitting 16. The connector fitting 16 would thus provide a flow path for fluid that is to be dispensed from chamber 12 through opening 15 and fitting 16 to needle 19 for dispensing. Fittings such as connecting fitting 16 are well known in the art.

Syringe barrel 11 has an open end 17 that receives hollow plunger rod 20. Plunger rod 20 fits opening 17 and can be forced into chamber 12 by a user that grips annular flange 18 at the upper end of barrel 11 and pushes on plunger 20 at annular shoulder 33.

Hollow plunger rod 20 includes a cylindrical side wall 21 surrounding a diluent chamber 30. Plunger rod 20 includes a circular end wall 22 having a central larger opening 23 and one or more flow channels 24 that are spaced radially from and circumferentially about the central opening 23. The flow channels 24 provide a path for fluid to travel from diluent chamber 30, through circular end wall 22, and into internal chamber 12 of syringe barrel 11 for mixing with dry drug 34 positioned in chamber 12 at end wall 14. Annular seal 25 extends about circular end wall 22 and beyond circular side wall 21 so that the seal 25 forms a fluid tight separation between plunger 20 and barrel 11 by engaging circular side wall 13 of barrel 11 during use. Thus, the only flow path for liquid diluent 35 contained in diluent chamber 30 is through the openings 24 when the syringe plunger rod 20 is pulled upwardly in the direction of arrows 37 as shown in Figure 3.

Initially, the plunger rod 20 is in a fully withdrawn, retracted position as shown in Figure 2, with valving member 26 in a closed position sealing the flow openings 24 and forming a seal in between the dry drug product 34 that is in between valving member 26 and circular end wall of barrel 11.

Valving member 26 is formed as shown in Figure 1 of a circular flexible disk 27, a narrow neck portion 28, and an enlarged retainer 29. Upon assembly, the narrow neck 28 fits opening 23 so that retainer 29 is on the inside of diluent chamber 30 as shown in Figure 2. The circular disk 27 is on the outside of diluent chamber 30. As packaged, the syringe apparatus 10 thus takes the configuration shown in Figure 2 with the dry drug 34 being contained at the extreme lower end of barrel 11 chamber 12 at end wall 14 and with circular disk 27 of valving member 26 being positioned closely thereto and in communication therewith to separate the dry drug 34 from liquid diluent 35.

When plunger 20 is in a fully retracted position as shown in Figure 2, the circular disk

27 of valving member 26 closely engages the dry drug product 34 and also forms a seal over the openings 24. Because the syringe barrel 11 is a cylindrically-shaped barrel having a cylindrical side wall 13 of generally uniform diameter, this enables a commercially available standard syringe barrel to be retrofitted with the plunger 20 construction shown in Figures 1-4. This converts that standard syringe barrel 11 having fittings 16 and needle 19 into a dual chamber syringe. The dry drug contents 34 are placed in the barrel 11 chamber 12 against circular end wall 14. Plunger 20 and its valving member 26 are then placed within the barrel 11 chamber 12 after the reservoir or diluent chamber 30 have been filled with the selected liquid diluent 35.

A moving seal member 32 is used to close the open end 31 of plunger 20 as shown in

Figures 1 and 2. Moving seal member 32 is held within diluent chamber 30 by annular shoulder

39. Shoulder 39 prevents removal of moving seal member 32 from open end 31 during use. The desired liquid diluent 35 is mixed with the dry drug 34 when the user pulls the plunger rod 20 in the direction of arrows 37 as shown in Figure 3.

Arrows 36 in Figure 3 indicate the flow of fluid from diluent chamber 30 through openings 24 and around the periphery of disk 27 of valving member 26 and into chamber 12 of barrel 11. This occurs immediately as the hollow plunger rod 20 is pulled upwardly. The user simply grips the annular shoulder 33 at the upper end of plunger 20 and pulls in the direction of arrows 37 (Figure 3).

When the plunger rod 20 is in a full extended position as shown in Figure 3, the liquid diluent 35 has been completely discharged and dispensed from diluent chamber 30 into chamber 12 of syringe barrel 11. The diluent 35 mixes with and reconstitutes dry drug product 34. In Figure 4, the reconstituted drug product can then be dispensed by the user pressing on the upper end of plunger rod 20 at annular shoulder 33 to force the plunger rod 20 downwardly as shown by arrow 38 in Figure 4. This dispenses the reconstituted drug product via opening 15 through connector fitting 16 and needle 19 into the patient.

During downward movement of the plunger 20 relative to the barrel 11 in the direction of arrow 38, valving member 26 forms a seal against flow openings 24. Further, as the liquid diluent 35 is dispensed from diluent chamber 30, moving seal 32 travels downwardly responsive to the removal of such diluent 35 from chamber 30 until it engages retainer 29.

Figures 5-9 show a second embodiment of the apparatus of the present invention designated generally by the numeral 40 in Figures 1-8. Syringe apparatus 40 includes a barrel 11 and hollow plunger rod 41. The barrel 11 is of the same construction as with the preferred embodiment of Figures 1-4. Barrel 11 includes a smooth bore internal chamber 12, cylindrical side wall 13, circular end wall 14 having opening 15, and connector fitting 16. In the embodiment of Figures 5-9, hollow plunger rod 41 has a generally cylindrically-shaped side wall 41 to provide a smooth cylindrical bore. Plunger rod 41 includes circular end wall 43 that carries sleeve 44 mounted on circular end wall 43.

Sleeve 44 has spring chamber 45 that carries ball valve 46 and coil spring 47. Sleeve 44 has an annular shoulder 48 that surrounds flow opening 49. A valve seat 50 is positioned at annular shoulder 48 and about flow opening 49. When ball valving member 46 is in a closed position, it is urged by spring 47 to engage valve seat 50 forming a flow closure.

A flow channel 51 is provided in hollow plunger rod 41 at sleeve 44 so that fluid can flow via opening 49 and flow channel 51 into chamber or bore 12 of syringe barrel 11. A retainer 52 holds the spring 47 and ball valve 46 within spring chamber 45 and flow channel 51. As the syringe plunger rod 41 is moved from the retracted to the extended position in the direction of arrows 37 in Figure 7, arrows 53 indicate the flow of fluid from diluent chamber 30 into the bore 12 of syringe barrel 13. In Figure 7, the liquid diluent 35 has mixed with and reconstituted the dry drug 34.

In Figure 9, an alternate configuration of the ball valve 59 and spring 58 is shown. In Figure 9, the lower half of the syringe barrel 11 of Figures 5-8 is designated by the numeral 54. It should be understood that the upper portion of the syringe barrel 11 is configured as with the embodiment of Figures 5-8. Syringe barrel 54 has a cylindrical wall 55 that communicates with circular end 56. A sleeve 57 carries spring 58 and ball valving member 59. Valve seat 60 is provided with a flow opening 62 through which diluent flows when the plunger rod is moved from a retracted position such as in Figure 6 to an extended position such as in Figure 7.

Figures 10-13 show a third embodiment of the apparatus of the present invention designated generally by the numeral 70 in Figures 10-13. Syringe apparatus 70 includes a barrel 71 having a cylindrical barrel wall 72 and a circular end wall 73. An opening 74 is provided in circular end wall 73 for dispensing the contents of barrel 70 through connector fitting 75 and into needle 76. The end portion of barrel 71 opposite connector fitting 75 is an open end 77 into which a plunger rod 80 can be placed. Barrel 71 has an annular flange 79 adjacent open end 77 as shown in Figures 10-11. Plunger rod 80 has an enlarged upper end 81 that can be manipulated by a user to move the plunger rod 80 between extended and retracted positions. A retracted position is shown in Figure 10. A fully extended position is shown in Figure 12. Plunger rod 80 has an enlarged lower end portion that carries flexible piston 83. The piston 83 is a valving member that can flex enabling fluid to flow from diluent chamber 78 around enlarged end 82 and the periphery of flexed piston 83 A as shown in Figure 11. Arrows 84 in Figure 11 indicate the flow of diluent fluid around valving member 83 and more particularly around the flexed valving member 83A shown in Figure 11. This mixing and reconstituting of the dry drug contained within chamber 85 as shown in Figures 11 and 12. In Figure 12, the mixed drug and diluent is indicated by the numeral 87.

Arrows 88 in Figures 12-13 indicate the direction of travel of plunger rod 80 when it moves from the extended position of Figure 12 to the retracted position of Figure 13 such as occurs during an administration of the reconstituted mixed drug and diluent 87 into the patient.

An annular shoulder 89 retains moving seal member 90. Moving seal member 90 has a central opening 91 that conforms to piston rod 80 as shown in Figures 10-13.

Figures 14-18 show a fourth embodiment of the apparatus of the present invention designated generally by the numeral 100 in Figures 14-17. The syringe apparatus 100 is a closed needle arrangement wherein the needle 106 has a seal block 107 thereon that prevents air from entering the needle 106 when the plunger rod 112 is moved from the retracted position of Figure 14 to the extended position of Figure 16.

Syringe apparatus 100 includes a barrel 101 having a cylindrical wall 102 and a circular end wall 103. A dispensing opening 104 is formed in the circular end wall 103 through which fluid can flow into dispensing connector fitting 105 and then into needle 106. The barrel 101 is open at open end portion 108 that is opposite circular end wall 103. Barrel 101 has a cylindrically-shaped bore or chamber 109 that contains diluent for reconstituting and mixing with the dry drug 111 contained below flexible piston 83.

The embodiment of Figures 14-18 is preferably for use with a syringe gun mechanism that would utilize the apparatus 100 shown in Figures 14-18 as a cartridge. Such a pre-packaged cartridge would be supplied with a seal cap 115 and with a seal block 107 so that liquid is prevented from leaking. Further, the seal cap prevents operation of the device until it is ready to be loaded into a syringe gun apparatus. Such automatic dispensing devices for use with syringe cartridges are known in the art and are commercially available. Another such gun type dispenser is disclosed in copending patent application serial number 08/895,161, filed 16 July 1997, and entitled "Rotary Cam Syringe".

Barrel 101 has an upper end portion 110 that surrounds open end 108. The upper edge 1 10 receives protective cap 115 as shown in Figure 14 when the plunger rod 112 is in a fully retracted position of Figure 14. The plunger 112 has an upper end portion 113 with a fitting 114 thereon that would be configured to mate with an actuator portion of a commercially available syringe gun or the gun of copending U.S. Patent Application Serial No. 08/895,161, filed 16 July 1997.

The moving seal member 90 and valving member in the form of flexible piston 83 would function as with the embodiments of Figures 10-13. Thus, in Figure 14 the apparatus 100 is in a retracted position. In Figure 16, an extended position is shown so that the push rod 112 has been retracted with the automatic syringe gun mechanism (not shown). Because such automatic gun mechanisms are designed to use cartridges of a certain size and shape, they automatically pull the push rod 112 the exact proper amounts so that withdrawal of the push rod 112 from the barrel 101 is not typically a problem.

Figures 19-21 show a fifth embodiment of the apparatus of the present invention designated generally by the numeral 120. Syringe apparatus 120 includes a smooth bore cylindrically-shaped barrel 121 having a cylindrical side wall 122 and an internal cylindrically- shaped chamber 123 of generally uniform cross sectional configuration. Thus, the syringe barrel 121 can be a commercially available smooth bore syringe barrel. Syringe barrel 121 has an end wall 124 with an opening 15 through which a reconstituted dry product can be dispensed to connector fitting 16 and needle 19. Syringe barrel 121 includes an upper annular edge 125 through which piston 126 can be inserted and its connected plunger rod 127.

Plunger rod 127 is a hollow plunger rod having a longitudinally extending open ended bore 129 that receives puncture stem delivery member 130. In Figure 19, the delivery member

130 extends into but not all the way through piston 126 as shown. The lower end of delivery member 130 at 131 carries a desired amount of a dry drug product to be reconstituted with diluent 133.

In Figure 2, the dry drug product 131 and liquid diluent 133 are mixed when the user forces the delivery member 130 downward and through piston 126 so that the lower end carrying dry drug 131 extends through piston 126 at a punctured opening 132 as shown in Figure 20.

Once this occurs, the users can agitate the entire syringe apparatus 120 to mix the dry drug product 131 with liquid diluent 133 until the drug is fully reconstituted.

After the drug has been reconstituted with liquid diluent 133, the user presses the plunger rod 127 downwardly in the direction of arrows 134 to dispense the reconstituted drug product through opening 15, connector fitting 16, and needle 19 into the patient. The upper end of barrel 121 provides an upper annular edge 125 with upper seal 135 fitted to the chamber 123 of syringe barrel 121 at upper annular edge 125 as shown in Figures 19-21. Annular flange 136 can be provided on syringe barrel 121 at upper annular edge 125 for purposes of enabling a user to more easily manipulate the syringe apparatus 120 such as during dispensing of the reconstituted mixture as shown in 121 or during movement of the delivery member 130 as shown in Figures 19 and 20.

The following table lists the parts numbers and parts descriptions as used herein and in the drawings attached hereto.

PARTS LIST Part Number Description 10 syringe apparatus

11 barrel

12 internal chamber

13 cylindrical side wall

14 circular end wall 15 opening

16 connector

17 open end

18 annular flange

19 needle 20 hollow plunger rod

21 cylindrical side wall

22 circular end wall

23 opening

24 flow channel 25 retainer seal

26 valving member

26A valving member 27 flexible circular disk

28 neck

29 retainer

30 diluent chamber 31 open end

32 moving seal member

33 annular shoulder

34 dry drug

35 liquid diluent 36 arrows

37 arrows

38 arrow

39 annular retaining shoulder

40 syringe apparatus 41 hollow plunger rod

42 cylindrical side wall

43 circular end wall

44 sleeve

45 spring chamber 46 ball valve

47 spring

48 annular shoulder

49 opening

50 valve seat 51 flow channel

52 retainer

53 arrow

54 barrel

55 side wall 56 end wall

57 sleeve

58 spring 59 ball valve

60 valve seat

61 spring support

62 flow opening 70 syringe apparatus

71 barrel

72 cylindrical barrel wall

73 circular end wall

74 opening 75 connector

76 needle

77 open end

78 diluent chamber

79 annular flange 80 plunger rod

81 enlarged upper end

82 enlarged lower end

83 flexible piston

83A flexible piston (flexed)

84 arrows

85 dry drug chamber

86 arrow

87 mixed drug and diluent

88 arrows 89 annular shoulder

90 moving seal member

91 opening

100 syringe apparatus

101 barrel 102 cylindrical wall

103 circular end wall

104 dispensing opening 105 connector fitting

106 needle

107 seal block

108 open end 109 bore

110 annular rim

111 dry drug

112 plunger rod

113 upper end 114 fitting

115 cap

120 syringe apparatus

121 barrel

122 side wall 123 chamber

124 end wall

125 upper annular edge

126 piston

127 hollow plunger rod 128 enlarged lower end

129 bore

130 puncture stem delivery member

131 dry drug

132 punctured opening 133 liquid diluent

134 arrows

135 upper seal

136 annular flange

The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.

Claims

CLAIMS L A dual chamber syringe apparatus comprising: a) a barrel having a cylindrically-shaped smooth bore of generally uniform diameter; b) a dispensing fitting on the barrel that enables a needle to be fitted to the barrel; c) a plunger rod that fits the barrel, the plunger being movable between retracted and extended portions; d) a diluent reservoir contained within the plunger rod holding a liquid diluent; e) the plunger rod having an end portion with a valving member thereon; f) a dry drug positioned within the barrel bore, the dry drug being contained in between the barrel and valving member portion of the plunger rod; g) wherein the valving member enables liquid diluent to flow through the valving member to the dry drug when the plunger rod moves from the retracted to the extended position.

2. The syringe apparatus of claim 1 wherein the plunger rod is generally cylindrically shaped.

3. The syringe apparatus of claim 1 wherein the plunger rod has a cylindrical wall and a circular end wall and the valving member is mounted on the circular end wall.

4. The syringe apparatus of claim 1 wherein the valving member is flexible.

5. The syringe apparatus of claim 4 wherein the valving member includes a flexible disk.

6. The syringe apparatus of claim 3 wherein there is at least one flow opening through the circular end wall and the valving member closes the flow opening when the plunger rod is moved from the retracted to the extended position.

7. The syringe apparatus of claim 1 further comprising a flow channel in the plunger rod through which diluent flows from the diluent reservoir into the barrel bore when the plunger rod moves from the retracted position to the extended position.

8. The syringe apparatus of claim 7 wherein the valving member is positioned to valve the flow channel.

9. The syringe apparatus of claim 8 further comprising a flow channel seat on the plunger rod at the flow channel and wherein the valving member includes a moving portion that seats upon the flow channel seat when the plunger rod is in the retracted position.

10. A dual chamber syringe apparatus comprising: a) a barrel having a cylindrically-shaped smooth bore of generally uniform diameter; b) a dispensing fitting on the barrel that enables a needle to be fitted to the barrel; c) a plunger rod that fits the barrel, the plunger being movable between retracted and extended portions; d) a diluent reservoir contained within the plunger rod holding a liquid diluent; e) the plunger rod having an end portion with a valving member thereon; f) a dry drug positioned within the barrel bore, the dry drug being contained in between the barrel and valving member portion of the plunger rod; g) a valved flow channel carried by the plunger rod that enables diluent to flow from the diluent reservoir into the barrel more and into communication with the dry drug.

11. The syringe apparatus of claim 10 wherein the valved channel is opened when the plunger rod is moved from the retracted position to the extended position.

12. The syringe apparatus of claim 10 wherein the valved channel includes a flow channel on the plunger rod, a valve seat on the plunger rod at the flow channel, and a valving member that moves between open and closed positions and that engages the valve seat when the valving member is in a closed position

13. The syringe apparatus of claim 10 wherein the plunger rod is generally cylindrically shaped.

14. The syringe apparatus of claim 10 wherein the plunger rod has a cylindrical wall and a circular end wall and the valving member is mounted on the circular end wall.

15. The syringe apparatus of claim 14 wherein the valving member is flexible.

16. The syringe apparatus of claim 10 further comprising a flow channel in the plunger rod through which diluent flows from the diluent reservoir into the barrel bore when the plunger rod moves from the retracted position to the extended position.

17. The syringe apparatus of claim 16 wherein the valving member is positioned to valve the flow channel.

18. The syringe apparatus of claim 10 further comprising a flow channel seat on the plunger rod at the flow channel and wherein the valving member includes a moving portion that seats upon the flow channel seat when the plunger rod is in the retracted position.

19. The syringe apparatus of claim 1 wherein the plunger rod has a moving seal member opposite the valving member that moves as the diluent reservoir is emptied.

20. The syringe apparatus of claim 10 wherein the plunger rod has a moving seal member opposite the valving member that moves as the diluent reservoir is emptied.