Hypodermic Syringe Assembly

Abstract

Prefilled cartridges assembled and packaged for mixing of dual ingredient hypodermic injections immediately prior to injection. Package may also be employed for prefilled cartridge of single ingredient.

Description

This invention relates to hypodermic syringe assemblies employing sterile prefilled cartridges containing measured dosages of medicines to be administered as a hypodermic injection. More particularly, this invention relates especially to such assemblies comprising a plurality of ingredients which are maintained in separate sterile cartridges for mixing just prior to injection.

To satisfy both governmental control measures and the internal quality controls of drug manufacturers, the prefilling in sterile cartridges of medicinal dosages intended to be administered by hypodermic injection has been widely adopted. When the medicine is a single ingredient or may be mixed from several ingredients and thus safely stored, it has also become a standard practice to package the prefilled dosage in disposable hypodermic syringes, rather than the physician's or patient's reusable syringe. Such single-case disposable syringes provide the opportunity for optimum sterility, accuracy of dosage, comfort of injection (due to the absence of dulling the needle through reuse), and, by saving the time of the physician or patient in resterilizing reused syringes, economy is also obtained.

It is an object of the invention to provide a syringe assembly so that the foregoing advantages may be obtained for dosages of ingredients which cannot be packaged and stored as a single dosage but must be mixed at or administered shortly after mixture. Many of the newer medicines, particularly many antibiotics, are most safely or conveniently stored in a form which prevents them from being administered until mixed with another ingredient or diluent; thereafter, they will deteriorate if not administered promptly.

It is also an advantage of this invention that, in achieving the above object, one may use standard cartridges of the separated ingredients and the manipulation to mix and inject the dosage are ones which are familiar and similar to the manipulation of conventional syringes in administering hypodermic injections.

It is another object and advantage of this invention to provide for sterile packaging of the entire assembly which may be used advantageously for a single-component syringe assembly as well as a duel-component assembly.

Other objects and advantages of this invention will be apparent from the following specification, claims, and drawings in which:

FIG. 1 is a cross section of a preferred dual-cartridge syringe assembly made according to the invention and packaged for shipping and storage.

FIG. 2 is a view similar to FIG. 1, but showing the assembly removed from its package and at a first stage of assembly for preparing for mixing.

FIG. 3 is a view similar to FIG. 2, but showing the final stage of assembly for mixing.

FIG. 4 is a view showing the syringe containing the mixed dosage ready for injection.

As shown in FIG. 1, the complete package for a dual component, premeasured dosage, prepared for shipping and storage, employs a primary cartridge 10 made up of a vial 11, preferably provided with a manipulating flange 12. The dosage of one ingredient A, usually a liquid in the primary cartridge, is sterilely packed in the vial 11 between a sealing plunger 13 and puncturable diaphragm 14, both usually of rubber. The diaphragm 14 is held on the neck of the vial 11 by a crimped metal band 15. As thus described, the cartridge 10 is of a standard type, approved by governmental agencies for sterile packaging of hypodermically administered dosages when packaged under approved conditions with approved equipment.

The plunger 13 is provided with a threaded or other connection 16 to a plunger stem 17 having a diameter which permits reciprocation of the stem in the vial 11 with a guiding and sliding fit. The outer end of the stem 17 has a cap 18, preferably molded integrally with the stem and having a flanged recess 19 (See FIGS. 2--4). To lock the plunger and stem 17 to prevent accidental dislodgement during shipment and handling prior to intensive manipulating for administration, the stem 17 is provided with notches 51 located in the stem according to the volume of the ingredient A so that, when packaged as in FIG. 1, the notches 51 will be just outside the flange 12. A U-shaped clip 50 having an extended finger 52 located at the base of the U and bent in a plane perpendicular to the plane of the U, is snapped onto the assembled plunger stem and flange so that the flange is engaged by the finger 52 while the stem is engaged by the clip 50, received in the notches 51. As indicated in FIGS. 3 and 4, the notches 51 may be formed by a circumferential groove in the stem 17.

The secondary cartridge 20 is comprised of a vial 21, in this case preferably but not necessarily flangeless, which carries a dosage of the second ingredient B sterilely packaged between a plunger 23 and a diaphragm 24 sealed by a band 25 similar to the corresponding elements 13, 14, and 15 in the primary cartridge 10. In the secondary cartridge, however, the stem 26, connected at its inner end to the plunger 23, is provided with a longitudinal needle-receiving bore 22 provided, at its outer end, with a pair of needle-coupler engaging ridges 27 and 28 extending inwardly into the bore 22. The stem is preferably molded of a slightly elastic plastic with an enlarged integral flange 29.

As indicated in FIG. 1, the cartridges 10 and 20 are coupled for packaging and shipping by a needle-bearing coupler 30 comprised of a barrel 31 closed at its inner end, which is provided with an extending shank 32. A needle 33 is molded and permanently secured in the shank 32, a relatively short outer portion extending into the barrel 31 of the coupler and relatively long inner portion extending through the bore 22 of the stem 26 up to the plunger 23. The interior of the barrel 31 is provided with a snap ridge 35, which engages the inner end of the sealing band 15 as the neck of the vial 11 is inserted in the barrel 31. The barrel 31 preferably receives the vial 11 with a fairly firm frictional fit so that the ridge 35 serves as a firm (though not positive) stop when the cartridges are assembled, as in FIG. 1. The shank 32 is provided with grooves 38 which receives the ridge 28 of the stem 26 so that the innermost end of the shank 32 is received between the ridges 27 and 28 and, thereby, is held firmly but not positively in the bore 22 of the stem 26, as shown in FIG. 1.

It will be noted in FIG. 1 that the radius of the plunger stem flange 29 is about equal to the radius of the vial stem 12 plus the thickness of the finger 52 of the clip 50 and the diameter of the flange 29 is just slightly less than the diameter of the recess 19 of the cap 18 on the primary plunger stem 17. So proportioned, the assembly of the cartridges 10 and 20 is adapted to be received in a closed end packing tube 53 which closely fits on the recess 19 of the plunger cap 18; this fit may be frictional but is preferably provided with a seal which maintains the sterility of the assembly within the tube 53 and which would be ruptured when the assembly is removed for use. The assembly is thus supported and centered within the packing tube 53 by the cap 18, the clip 50 and, at the center, by the flange 29. Due to the firm fit of the coupler barrel 31 upon the vial 11 and the firm latching of the coupler shank 32 in the bore 22, the assembly will withstand rough handling in shipping and storage up to loads which the tube 53 can withstand. A small packing ring (not shown) may be placed in the tube 53 adjacent its closed end to receive the neck of the vial 20, but this appears to be a surplusage.

To manipulate and administer an admixture of dosages A and B, the assembled vials are removed from the shipping tube 53, and, with the clip 50 still in place, the flange 29 is held while pressure is applied to the cap 18. This will push the vial 11 into the barrel 31 of the coupler 30, snapping the ridge 35 over the band 15 to a locking position between the band and the neck of the vial 11, as shown in FIG. 2. Abrupt configurations of the mating surfaces of the band 15 and ridge 35 can make this position a substantially permanently locked arrangement which is difficult to dislodge without rupturing the assembly and, in any event, an assembly adequate to withstand any normal loads which might thereafter tend to dislodge the cartridge 10 from the coupling 30 during use. The significance of the lock secured by the coupler 30 on the cartridge 10 is that the movement of the vial 11 into the barrel 31 drives the outer end of the hypodermic needle 33 through the diaphragm 14 and into the dosage A; thus the lock of the coupler 30 on the cartridge 10 substantially permanently affixes the needle 33 to the cartridge to and in communication with the interior of the vial 11.

Simultaneously with the coupling of the coupler 30 on the cartridge 10, or quickly following it, the same longitudinal force which locks the coupler 30 on the cartridge 10 forces the shank 33 further into the bore 22 of the stem 26, disengaging the ridge 28 from the groove 38 and telescoping the shank into the bore 22 until the ridge 27 snaps into the groove 38 to effect a removable latching of the stem 26 on the shank 32 while the inner end of the needle 33 pierces the plunger 23 and enters the volume of the cartridge 20 containing the dosage B.

With the assembly held in the same manner as it is held to force the coupling of the cartridges 10 and 20 with the coupler 30, as indicated in FIG. 2, the clip 50 is removed. Continued pressure on the cap 18 thereby forces the contents of the primary cartridge 10 into the secondary cartridge 20, causing the plunger 23 and stem 26 to move outwardly of the vial 21 and mixing dosages A and B within the vial 21.

Further mixing is achieved by withdrawing the plunger 13 to aspirate the mixed dosage in the vial 21 into the vial 11. The stem 26 is then pulled off the coupler 30 and the mixed dosage A and B is then ready to be administered hypodermically, as indicated in FIG. 4.

The above embodiment of this invention has been described in detail in its preferred form as an assembly for administering a mixed dosage of separately packaged ingredients. It is to be understood, of course, that the same principle may be applied in packaging for an admixture of three ingredients (or more) by adding a duplicate (or more) of the coupler 30 and cartridge 20 onto the coupler and cartridge as shown in FIG. 1. Further, without the vial 21, the stem 26 can serve as a needle cover for a single dosage packaged in the cartridge 10 which may carry the needle coupler 30.

Likewise the cartridge 10 and coupler 30 may be replaced with a conventional syringe in which the hypodermic needle, either held on the syringe neck by a close-fitting ferrule or permanently received in the glass neck of the syringe, is in communication with the inside of the syringe when it is assembled in the hollow stem 26. In such cases the length of the bore 22 is preferably proportioned with respect to the length of the needle so that the point of the needle is buried in the sealing plunger 23 but does not penetrate it until the stem 26 is further telescoped onto the needle. Contents of the syringe may then be expelled and mixed in a cartridge 20, as in FIG. 3 or other package, and the mixed contents may then be aspirated back into the syringe for injection after the stem 26 and cartridge vial have been removed and discarded.

Accordingly, this invention is not to be limited to the preferred embodiment disclosed; rather it may be varied to meet specific needs or conditions within the scope of the following claims.

Claims

I claim:

1. A hypodermic needle assembly comprising a first cartridge including a first-necked vial having a dosage sealed therein, said seal being effected by a rupturable diaphragm and an outer sealing band closing the vial neck and a stem-operated plunger within said vial; a stem member and a coupler comprising a barrel fitting over the necked end of said vial, an integral shank extending beyond said barrel, a hypodermic needle carried by said shank and having an end extending into said barrel, and detent means within said barrel, said detent means normally engaging said sealing band to space the end of said needle from said diaphragm but to lock said coupler onto said cartridge by engaging said band when the vial is forced past said detent means further into said barrel, including a longitudinal cylindrical plunger stem member having a bore extending throughout its length and receiving said shank and a protruding end of said needle, and means to normally restrain said stem member on said shank and space the same from said barrel while the protruding end of said needle is located substantially entirely in said bore.

2. A hypodermic needle assembly as defined in claim 1 including a secondary cartridge comprised of a vial and containing a dosage sealed in said vial by a plunger connected to said cylindrical stem member, whereby said needle may be forced into communication between the dosages of said first and second cartridges by telescoping said coupler on the vial of said first cartridge and said stem member onto said shank to pierce the diaphragm of the seal and of said first cartridge with one end of said needle and the plunger of said second cartridge with the protruding end of said needle.

3. A hypodermic needle assembly as defined in claim 2 including a stem connected to the plunger of said first cartridge, a flange on the vial of said first cartridge, and removable clip means to engage said stem and said flange simultaneously in order to fix the position of said plunger in said vial.

4. A hypodermic needle assembly as defined in claim 3 including a cap on said plunger stem of said first cartridge and a rigid packaging member surrounding said assembly as defined in claim 4 and closed by said cap, whereby the said assembly may be supported for shipping and stored in a sterile condition with said packaging member.

5. A packaged hypodermic needle assembly as defined in claim 5 in which said plunger stem member of said second cartridge is provided with a flange whose radius is substantially equal to the radius of said clip means and but slightly less than the radius of said cap, whereby said packaging means may be a tube closed at one end and adapted to be closed by said cap at its other end and said flange on said plunger stem member will support said assembly within said tube.

6. A spacer-plunger stem for hypodermic needle assemblies comprising a tubular member flanged at one end and provided at its other end with means connected to a plunger in a hypodermic dosage vial, the external surface of said stem having a sliding fit within said vial, and detent means on the interior of the bore of said tubular stem engaging a ferrule portion of means carrying a hypodermic needle having an overall length greater than the length of said bore but restrained by said detent means, when inserted into said bore at the flanged end of said stem, from penetrating through the plunger on said other end of said stem.