Injection site for sterile medical liquid container

Abstract

An injection site for a parenteral liquid bottle with an improved structure and assembly method for securing a puncturable diaphragm to a closure of the bottle. The closure is formed with an integral upstanding tube that has an internal flange at its outer end. A rubber diaphragm and a tubular retainer are telescopically inserted into the upstanding tube from the tube's inner end before the closure is assembled to the bottle. The retainer squeezes the diaphragm against an undersurface of the flange to form a seal and the retainer is locked in this position. After the closure is joined to the bottle, the entire joint between the upstanding tube and the retainer is inside the bottle and protected from external bacterial contamination.

Description

BACKGROUND

Sterile medical liquid such as parenteral solution is commonly infused into a patient's vein from a container hanging above the patient. The sterile liquid flows by gravity through a tubular administration set connected at one end to the container and at an opposite end to a venous needle in the patient.

Sterile parenteral solutions, such as 5% dextrose, normal saline, etc. are frequently supplied to the hospital in sealed sterilized containers. These containers are partially filled with liquid and have sterile air occupying the remainder of their volume. This is so that additive medication can be added to the air space of the container and mixed with the liquid of the bottle prior to administering to the patient. Many of the sterile medical liquid containers include what is termed as a "injection site" through which these additive medications can be injected. The injection site includes a rubber diaphragm through which a hypodermic needle of a syringe or a pointed hollow spike of an additive container can be inserted. After withdrawal of the needle or spike the diaphragm reseals.

In the past these rubber diaphragms have been secured to the containers by a series of external clamping structures. These external clamps which included crimped metal rings, tape bands, etc., compressively sealed the edges of the rubber diaphragm to the container structure.

When these external clamp members were not sufficiently crimped or tightened a small liquid seepage could occur at the edge of the puncturable rubber diaphragm. Such a small seepage in this area could be beneath the external clamp and hidden from view. Although many scientific tests are performed to determine there is no leakage or seepage in this area, it would be a definite advantage to have an additional visual test of any seepage.

SUMMARY OF THE INVENTION

The present invention provides an improved injection site which requires no separate external clamping devices which might cause cracks, crevices, seams, etc. and where liquid seepage would be hidden from view. This invention provides an injection site structure that includes a rigid upstanding thermoplastic tube integrally formed with a thermoplastic inner closure of the bottle. This rigid tube has an integral inwardly extending thermoplastic flange at its outer end. Before the inner closure is assembled to the bottle a puncturable rubber diaphragm and a tubular retainer are pre-assembled. This diaphragm and retainer are telescopically inserted into an inner end of the upstanding tube and the retainer squeezingly compresses the rubber diaphragm against an under surface of the tube's integral flange to form a hermetic seal. With this structure the inner closure presents a homogenous mass of thermoplastic material of the inner closure, integral upstanding tube, and integral flange that externally supports the rubber diaphragm. There is no seam, cracks or crevices between the flange and upstanding tube. If there were any liquid seepage around the edge of the rubber diaphragm it would be readily visible on a top surface of the diaphragm. While such liquid seepage would be extremely rare, it is a definite advantage to visually see such seepage.

Other advantages of the improved injection site include three important structural advantages. First, the tubular retainer confines substantially all compressive forces against the rubber diaphragm in a direction parallel to the longitudinal axis of the upstanding tube so there is no substantially hoop compression on the edges of the diaphragm. Hoop compression used to seal prior rubber diaphragms to injection sites sometimes cause additional binding on the hypodermic needle puncturing the diaphragm. Secondly, the tubular retainer has a rigid puncture support collar that supports an underside of the diaphragm surrounding its principle puncturing target to prevent excessive downward deflection of the diaphragm during puncture. This prevents excessive distortion stresses from being transferred to the peripheral sealed area of the diaphragm. Thirdly, the puncture support collar fits into a recess on the underside of the diaphragm for aligning the diaphragm and the retainer prior to insertion of this preassembled unit into the rigid tube of the injection site.

THE DRAWINGS

FIG. 1 is a front elevational view of the medical liquid container as it is supplied to the hospitals;

FIG. 2 is an enlarged perspective view of an upper end of the container showing its outer cap removed;

FIG. 3 is a top plan view of a puncturable resealable diaphragm portion of the injection site;

FIG. 4 is a sectional view taken along line 4--4 of FIG. 3.

FIG. 5 is an enlarged sectional view showing the method of assembling the injection site;

FIG. 6 is an enlarged sectional view of the injection site that has been assembled;

FIG. 7 is a further enlarged sectional view of the upper portion of the injection site showing the compressed edge of the diaphragm; and

FIG. 8 is a further enlarged sectional view of a lower portion of the injection site showing the means for locking the tube and retainer together.

DETAILED DESCRIPTION

Referring to these drawings bottle 2 is shown in FIG. 1 having a neck 4 with an external flange 6. Secured to flange 6 is an outer cap 8 which houses the injection site. The bottle 2 is supported by a series of feet such as 10 and 12 at its lower end. Between feet 10 and 12 is a recess 14 that contains a hinged hanger 16. A front of the bottle has a label 21c located between calibrations 21a and 21b.

Within the bottle is a sterile liquid 18 and a sterile gas 19, such as air. It is into this air space 19 that an additive medication can be injected immediately prior to administering the liquid 18. It is to such an injection site that this invention relates.

In FIG. 2, the perspective view shows the outer cap 8 removed from the bottle to expose the inner cap and the injection site. This outer cap is shown frangibly connected to the bottle by a series of frangible webs. The precise details of this outer cap are described in my copending application entitled, "Three Barrier Closure System for Medical Liquid Container," Ser. No. 445,834. Alternatively, this outer cap could be a frangible cap such as disclosed in a copending application entitled, "Frangible Closure System for Medical Liquid Container and Method of Making Same," Ser. No. 338,685, invented by Pradip Choksi.

The inner closure of FIG. 2 includes a transverse wall 22 that is joined to an upstanding collar 24 which is permanently sealed to container neck collar 26. Integrally formed with the inner closure transverse wall 22 is an upstanding rigid thermoplastic tube 28 that has an outlet structure for connecting to an administration set through which liquid is dispensed to the patient. Also integrally formed with transverse wall 22 is a rigid upstanding tube 30 that forms a portion of the injection site structure which is indicated generally at 20.

Hermetically sealing off the outer end of both rigid tubes 28 and 30 is a thermoplastic metal foil 32 which is shown in FIG. 2. This foil 32 is preferably in two portions so that the foil can be peeled back from either tube without interfering with the foil's seal to the other tube. This foil on rigid tube 30 is peeled back immediately before use to expose a puncturable resealable diaphragm 34.

The puncturable resealable diaphragm 34, shown in the enlarged top view of FIG. 3, includes a peripheral sealing portion 36 and a central puncture portion 38. Puncture portion 38 is surrounded by an upstanding target ring 40 that acts as a guide for locating the hypodermic needle or puncturing spike on the diaphragm. As shown in FIG. 4, the central puncturing area 38 is offset upwardly from peripheral sealing portion 36 and thus forms a recess 42 in a bottom side of the diaphragm. The purpose of recess 42 and its relationship to a tubular retainer and puncturing support section will be explained later.

The construction of the injection site and method of assembly is shown in more detail in FIG. 5. Here, rigid tube 30 is clearly seen as have its lower end integrally formed with transverse wall 22 of the inner closure. There are no seams, cracks, crevices, etc. between rigid tube 30 and transverse wall 22. An upper end of the rigid tube has an integral inwardly extending thermoplastic flange 44. This flange also has no joints, cracks, crevices, etc. between the flange and rigid tube 20. The flange 44 has a beveled lead-in surface 46, a downardly directing sealing surface 48, and an inner surface 50. This inner surface 50 defines an opening through which the diaphragm can be punctured.

In the procedure for assembling the injection site the diaphragm 34 is fitted onto a rigid tubular retainer 52 to form a sub-assembly. An upper end 54 of the tubular retainer 52 engages peripheral portion 36 of diaphragm 34. The tubular retainer also includes a rigid puncture support collar 56 that is supported by transverse member 58. Above transverse member 58 is a recess 60 into which the squeezed peripheral portion 36 of the diaphragm is relieved when compressively sealed against under surface 48 of flange 44.

FIG. 5 shows how the rigid puncture support collar 56 fits within recess 42 of diaphragm 34 to align the diaphragm with opening 50 of the flange of rigid tube 30. The sub-assembly of diaphragm 34 and tubular retainer 52 is telescopically inserted into an inner end of the rigid tube 20 until the peripheral section 36 of the diaphragm is tightly gripped between an upper end 54 of the retainer and an under surface 48 of flange 44. When this occurs the diaphragm 34 takes on the configuration as shown in FIG. 6. Here the peripheral area 36 is tightly squeezed to form a hermetic seal and a portion of the squeezed diaphragm forms an annular bulge 62 that is relieved into annular recess 60 of the retainer. The diaphragm is sufficiently squeezed when the lower ends of the retainer and tube are in substantial alignment. At a lower end 64 of retainer 52 is an external recess 66. A portion 68 of the lower end of rigid tube 20 is deformed by heat and pressure to create an annular rib or flange that extends into recess 66. There is also some deformation of the retainer at its lower end as shown in FIG. 8. This construction locks the retainer 52 into rigid tube 30 to continually squeeze the diaphragm against the under surface 48 of flange 44.

At the top of FIG. 6 the operation of the rigid support collar 56 is shown during a needle puncture. Here the rigid support collar 56 supports an area of the diaphragm immediately outward of the target ring 40. Thus, when hypodermic needle 70 is forced through diaphragm 34, support collar 56 will prevent excessive strain and deflection of the diaphragm from being transmitted to the critical hermetic seal area 36. Also in FIG. 6 the compressive forces on area 36 of diaphragm 34 are substantially all in a direction parallel to a longitudinal axis 72 through the injection site. The diaphragm 34 in this construction is relieved of inwardly directed hoop forces tending to laterally compress the diaphragm 34 against cannular 70. Such hoop compression could cause the needle to bind as it passes through diaphragm 34. Some of the previous puncturable resealable diaphragms relied on a hoop compression around the peripheral of the diaphragm for making a seal with the closures.

FIG. 7 has a more detailed view that shows the compressed area 36 of diaphragm 34 that is tightly squeezed between surface 48 and surface 54 of the flange and retainer respectively.

In FIG. 8 the enlarged sectional view at the bottom end of the injection site shows in more detail how rib 68 is deformed into the annular recess to lock tubular retainer to the tube 30.

The method of assembling the unique injection site of this invention includes placing the diaphragm 34 on retainer 52 and aligning it with the rigid puncture support collar 56. Next the sub-assembly is telescopically inserted into a lower end opening of rigid tube 20 as shown in FIG. 5 and moved into tube 20 until peripheral section 36 of the diaphragm 34 is tightly compressed in a hermetic seal. Next the lower end of rigid tube 20 is deformed by heat and pressure to form a rib 68 that occupies at least a portion of groove 66 to lock retainer 52 to rigid sleeve 20. The inner closure, diaphragm 34 and retainer 52 forms a unit that is next connected to thermoplastic metal foil 32.

After the foil has been attached, the inner closure is fitted to the neck of a liquid containing bottle 2. Then the collar 24 and the inner closure 26 of the container are heat fused together. Finally the outer cap 8 is fitted over the inner closure and secured to the bottle flange by fusing a flange 9 of the closure to bottle flange 6.

It has been found that the above described invention works very well when the bottle, inner closure with integral tubes 28 and 30, and tubular retainer are all made of a propylene-ethylene thermoplastic. Preferably, the puncturable resealable diaphragm 34 is of natural or synthetic rubber.

In the above description a specific embodiment has been used to illustrate the invention. However, it is understood that persons skilled in the art can make modifications to this embodiment without departing from the spirit and scope of the invention.

Claims

I claim:

1. A container connected to a tube that has a puncturable resealable diaphragm secured within this tube, wherein the improvement comprises:

a container with a preformed opening therein; a closure with a rigid transverse wall spanning the container opening, with a periphery of the closure joined to the container at a hermetic seal; said transverse wall having an opening that is substantially smaller than the container opening and spaced from said hermetic seal; a rigid tube integrally formed with the transverse wall without any seam or joint therebetween, said tube having a passage communicating with the transverse wall opening; an inwardly extending flange integrally formed with the tube without any seam or joint therebetween; and a tubular retainer within said tube and spaced from said heremetic seal; said retainer, rigid tube, and flange combining to confine the diaphragm, and said retainer and flange engaging the diaphragm to form a hermetic seal whereby all external joints between the container and closure are remote from the diaphragm.

2. The combination as set forth in claim 1, wherein there is a locking means maintaining the retainer in a fixed relationship to the flange.

3. The combination as set forth in claim 2, wherein said tube and retainer are rigid, and one of the tube and retainer has an annular groove and the other has a deformed section extending into said groove forming the locking means.

4. The combination as set forth in claim 3, wherein the retainer has one end portion that compressingly engages the puncturable resealable diaphragm and has an annular groove at an opposite end of the retainer, and said tube has an annular deformed bead extending into said groove.

5. The combination as set forth in claim 4, wherein the closure including the tube has an inner surface adjacent the groove in the retainer; and said retainer has an inner end surface adjacent said groove, whereby alignment of the two inner surfaces insures a proper compression of the diaphragm between the flange and retainer.

6. The combination as set forth in claim 1, wherein the rigid tube extends outwardly from the transverse thermoplastic wall.

7. The combination as set forth in claim 6, wherein the rigid tube has an outer end and the flange is adjacent this outer end.

8. The combination as set forth in claim 7, wherein the closure's transverse wall, outwardly extending rigid tube, and internal flange are formed of a homogeneous mass of thermoplastic material.

9. The combination as set forth in claim 1, wherein the retainer includes a rigid puncture support member for a central portion of the puncturable resealable diaphragm.

10. The combination as set forth in claim 9, wherein the rigid puncture support member includes an annular collar engaging an inner surface of the diaphragm and the diaphragm has a peripheral area extending outwardly from the annular puncture support collar, and this peripheral area is hermetically sealed between the tube's flange and the retainer.

11. The combination as set forth in claim 10, wherein the retainer has an annular recess between the rigid puncture support and an end portion of the retainer that compressingly squeezes the diaphragm against the flange, whereby the diaphragm can at least partially deform into said recess when its peripheral area is under compression.

12. The combination as set forth in claim 11, wherein the diaphragm has an upwardly offset central portion, and this offset portion is supported on its under surface by the rigid puncture support collar.

13. The combination as set forth in claim 12, wherein the puncturable resealable diaphragm has an indicia indicating the location of a center passage through the rigid puncture support collar of the retainer.

14. The combination as set forth in claim 13, wherein the indicia is an upstanding ring on an outer surface of the diaphragm.

15. The combination as set forth in claim 1, wherein the flange is located at an outer end of the rigid tube and includes an inwardly beveled approach surface of the flange.

16. The combination as set forth in claim 1, wherein the puncturable resealable diaphragm is rubber.

17. The combination as set forth in claim 1, wherein the compressive forces on the puncturable resealable diaphragm are in a direction parallel to a longitudinal axis through the rigid tube.

18. The combination as set forth in claim 17, wherein the diaphragm is free of any substantial hoop compression.

19. An injection site structure connected to a sterile medical liquid container comprising: a rigid thermoplastic inner closure having a transverse wall hermetically sealed to an opening of the container; a rigid upstanding thermoplastic tube integrally formed with the transverse wall and extending upwardly from said transverse wall; an inwardly extending thermoplastic flange integrally formed with an upper end portion of the upstanding tube, said flange having a beveled lead-in surface and an under surface; a rubber puncturable resealable diaphragm having an upwardly offset center portion and a peripheral sealing portion fitting within said tube and having an upper annular peripheral surface in abutting engagement with the under surface of said flange; a rigid thermoplastic tubular retainer fitting within said rigid upstanding tube and compressingly squeezing an annular peripheral portion of the rubber diaphragm into hermetic sealing engagement with the under surface of said flange; a rigid thermoplastic tubular retainer fitting within said rigid upstanding tube and compressingly squeezing an annular peripheral portion of the rubber diaphragm into hermetic sealing engagement with the under surface of the flange; a locking means securing the retainer in a fixed position within said upstanding tube; a peelable foil secured to an outer end of said upstanding tube; and an outer cap fitting over said upstanding tube and foil, said outer cap being frangibly secured to the bottle.