Three barrier closure system for medical liquid container

Abstract

A parenteral liquid bottle with a three barrier closure system that (1) has first and second barriers that withstand pressure differentials of 10 psi (0.70 Kg/cm.sup.2) during and after steam sterilization and (2) all three barriers open easily with manual force. The first barrier is a puncturable diaphragm hermetically sealing off on inner portion of an opening through an inner closure of the bottle. The second barrier is a peelable foil hermetically sealing off an outer portion of the opening through the inner closure. The third barrier is a tortuously vented outer cap that fits over the first two hermetic barriers and is secured to the bottle by a series of manually frangible webs.

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 supplied to the hospital in sealed sterilized containers. For many years these containers have been glass bottles. Recently efforts have been made to change to thermoplastic containers to reduce the problems of breakage, high freight costs, and the requirement for an air inletting system with a rigid glass bottle. The Applicant has invented an improved collapsible plastic bottle which is the subject of a copending application entitled "THERMOPLASTIC BOTTLE WITH `CONTROLLED LATERAL COLLAPSE` AND METHOD OF DISPENSING LIQUID THEREFROM", Ser. No. 445,836 2-26-74. That application involves the structure of the bottle itself and its particular collapsing feature.

This application has to do with a novel dispensing closure system for this collapsible thermoplastic bottle. Previous closure systems for rigid glass bottles are not well suited for thermoplastic bottles. A typical glass bottle closure is shown in U.S. Pat. No. 2,665,024 and has a rubber stopper wedged into the neck of a glass bottle and held to the bottle by a crimped annular metal band. The forces exerted on a thermoplastic bottle neck by the compressed rubber stopper and crimped metal band could sufficiently deform the thermoplastic bottle neck with time to cause a crack or opening through which bacterial contamination could grow. To avoid excessive pressures tending to deform a thermoplastic neck frangible thermoplastic closures have been bonded directly to the thermoplastic bottle. One such closure system is described in U.S. Pat. No. 3,394,831 which is owned by the Assignee of the present application. In such a closure the outer cap formed a hermetic seal and was capable of withstanding pressure differentials of 10 psi between an inside surface and an outside surface of the outer cap during and after steam sterilization. The cap that would withstand such a pressure differential was sometimes hard to manually fracture to gain access to the bottle's inner closure.

SUMMARY OF THE INVENTION

In this invention a triple barrier system has been provided with first and second barriers that withstand pressure differentials during and after steam sterilization and a third barrier attached after steam sterilization, which third barrier protects the first two barriers. All three barriers are easy to open with manual force. In the present closure system there is an inner closure sealed across the neck of the thermoplastic bottle. This inner closure has a dispensing outlet tube with a first hermetic seal at an inner portion and a second hermetic seal at an outer portion. As used in this application, a hermetic seal is defined as a seal that will not pass either gas or liquid. These two hermetic barriers withstand pressure differentials of 10 psi (0.70 Kg/cm.sup.2) and are capable of withstanding steam sterilization without rupturing. The first and second barriers are easily opened with manual force because each barrier is a very small area, approximately one-half inch (1.27cm) diameter or less.

The third barrier is an enlarged cap, approximately 11/2 inch (3.81 cm) diameter that fits over the first two hermetic barriers and is sealed to the thermoplastic bottle without exerting any significant sealing pressure on the first and second hermetic seals. The third barrier includes a tortuous air vent system for equalizing pressure inside and outside the outer cap so that as temperature and atmospheric pressure change during storage, there is no pressure differential exerted between the outer caps interior and exterior surfaces. This outer cap has a series of very thin frangible webs extending across the tortuous air vents. The outer cap or third barrier does not form a hermetic seal and is not subjected to stresses from pressure differentials, and since the outer cap is spaced from the first two barriers, these two barriers do not exert an internal force on the outer cap. Thus the webs need be only strong enough to prevent accidental breaking of the cap during storing and handling. Immediately before use the outer cap is simply twisted or cocked to manually break it off to gain access to the two small diameter hermetic seals.

This triple barrier system provides a hermetically sealed closure that withstands pressure differentials of 10 psi and is also easy to open.

THE DRAWINGS

FIG. 1 is a front elevational view of the thermoplastic bottle as it is supplied to the hospitals;

FIG. 2 is an enlarged perspective view of the outer closure cap showing its vent structure;

FIG. 3 is a perspective view of a top portion of the bottle showing the outer cap removed from the bottle;

FIG. 4 is an enlarged view of a top portion of the bottle and closure system with the outer cap shown in cross-sectional view;

FIG. 5 is a further enlarged sectional view showing the vent structure of the outer cap;

FIG. 6 is a front elevational view of a top portion of the bottle closure system showing the outer cap being removed by a cocking motion; and

FIG. 7 is an enlarged sectional view of the dispensing tube with the second barrier opened to expose the first barrier.

DETAILED DESCRIPTION

Referring to the above drawings FIG. 1 shows the bottle 1 that has been sterilized and in the condition it is supplied to the hospital. In this Figure the bottle 1 is standing upright on a series of feet, two of which are shown as 2 and 3. A recess 4 in a base of the bottle between feet 2 and 3 houses a hinged hanger 5. At an upper end of the bottle 1 is neck 6 with an external flange 7. An outer cap 8 is connected to this flange 7. Sealed within the bottle is a sterile medical liquid 9 and sterile air 10. A front of the bottle has a label 60c located between calibrations 60a and 60b.

The outer cap 8 is shown in more detail in FIG. 2. Here the cap has a top wall 11, a cylindrical side wall 12 and a laterally protruding external brim 13. Around the side wall 12 are a series of ribs 14 that aid in gripping the cap during its removal. At a juncture between side wall 12 and brim 13 are a series of circumferential vents 15 and 16. Between these vents are a series of frangible web sections, two of which are shown as 17 and 18.

After the bottle has been received by the hospital and is ready for use, the nurse or physician grasps the outer cap 8 and with either a twisting motion or a cocking motion breaks off the outer cap 8. This break occurs at the frangible webs, two of which are shown at 17 and 18. When this occurs the brim 13 which is fused to flange 7 remains with the bottle. Cap 8 can then be lifted from the bottle as shown in FIG. 3 to expose an inner cap structure of the closure. This inner cap structure includes a transverse wall 20 with an upstanding collar portion 21 sealed to a neck of the bottle in a hermetic fusion joint. Integral with the transverse wall 20 and extending upwardly therefrom is a dispensing tube 22 and an additive tube 23. The outer ends of these two tubes are hermetically sealed by a peelable thermoplastic-metal foil 24.

The structure of the triple barrier closure system is shown in more detail in FIG. 4. The triple barrier system will first be described relative to dispensing tube 22. Here the dispensing outlet tube, shown generally at 22, includes two tubular sections. First there is an outer tubular support section 32 that is secured at its lower end to transverse wall 20 and secondly there is a sleeve section 30 disposed within and spaced from tubular support section 32. The tubular sleeve section and the tubular support section are integrally joined at their upper ends to combine and form the dispensing outlet tube 22. The sleeve section 30 is laterally expandible and tapers inwardly to grip a spike of an administration set as it proceeds toward a lower end of sleeve section 30. This lower end is sealed off by an integral puncturable first barrier 31 of a non-resealable thermoplastic material which is exposed to the liquid contents within the bottle. As shown in FIG. 7, the sleeve section 30 has an inner flange at its upper end that seals to tapered spike 50 prior to puncture of diaphragm 31, so that no liquid will leak from the container.

A second hermetic barrier is comprised of the laminated thermoplastic-metal foil 24 that seals off the upper end of dispensing tube 22. The thermoplastic portion of foil 25 is peelably bonded to the outlet tube. Preferably the foil 24 is severed into a first section sealed to the outlet tube 22 and a second section 30 of the dispensing tube 22 contains a given mass of air. There is also a mass of air within the bottle below puncturable diaphragm 31. Both the first barrier 31 and the second barrier foil 24, are hermetic seals that can withstand pressure differentials of at least 10 psi (0.70Kg/cm.sup.2) without rupturing or forming a bacterial leak.

The third barrier in FIG. 4 is an enlarged outer cap 8. As previously described this outer cap 8 has a top wall 11, a cylindrical sidewall 12 and a brim 13 that is fused to flange 7. The tortuous vent 15 at a juncture between the sidewall and brim allows air to pass freely in and out of the outer cap as pressures change during storage. This equalizes pressure inside anad outside outer cap 8, so that no extraordinary strain is placed on frangible webs 17 and 18 during the pressure changes. Also since the top wall 11 of outer cap 8 is spaced from the first and second hermetic seals there is no strain placed on frangible webs 17 and 18 by the first and second hermetic seals. Thus the web as illustrated by 17 and 18 can be very thin with each having a cross-sectional area less than 0.0004 in.sup.2 (0.0026 cm.sup.2). The webs need be only strong enough to resist premature breakage during handling and storage. They do not need to withstand pressure differentials during steam sterilization, as do the first and second barriers.

In this invention the large diameter outer cap, approximately 11/2 inch (3.81 cm) in diameter, does not need to be broken loose about its entire circumference. Only the very thin webs, such as 4 to 6 in number, need to be broken for removal of the cap. Thus the opening forces are greatly reduced from a non-vented cap structure, so the nurse or physician can easily break off the outer cap to gain entrance to the two hermetic seals. The hermetic seals 31 and 34 are very small in area, each less than one-half inch (1.27 cm) in diameter, so that manual rupturing forces at these barriers are concentrated at a precise location. This makes the critical hermetic seals much easier to open than if they were of a large diameter, such as the diameter of the outer cap.

The tortuous vent of the outer closure is shown in more detail in the enlarged view of FIG. 5. The torous nature of this vent resists bacterial transmission, because bacterial growth or movement does not readily progress through a series of sharp angled turns. While the third barrier of the outer cap is not a hermetic barrier it does provide protection for the first and second hermetic seals and greatly reduces the chance of airborne or water borne bacteria coming in contact with the second hermetic seal (foil 24) prior to opening the outer cap.

The details of the air path through tortuous vent 15 is shown in FIG. 5. Here the cylindrical sidewall 12 is spaced slightly from an upstanding collar portion to provide an air path. A brim portion 13 of an outer closure 8 is fused to flange 7 at a fusion joint 21. The tortuous vent, shown generally by numeral 15, is formed by a recess 42 that extends partially through sidewall 12. Preferably, sidewall 12 has a slight clearance space 43 for air passage as shown in the dotted line. However, if the bottom area of the cylindrical wall 12 does contact flange 7 this would not be an air tight seal and air could still pass cylindrical wall 12 for equalizing pressure inside cap 8 with the air outside of cap 8.

The outer cap remains secured to the flange 7 by webs such as 17 and 18 until ready for use. Immediately before use the outer cap is removed by either a twisting motion or a cocking motion. FIG. 6 shows the preferred cocking motion that tends to break the frangible webs one at a time reducing the force required. This makes opening slightly easier for the nurse or physician. A twisting motion tends to fracture all of the webs at once.

After the outer cap 8 (third barrier) has been removed, the foil 24 (second barrier) is peeled back from outlet tube 22. This exposes sleeve section 30 of the outlet tube with its tapered inner wall surface that receives a tubular spike of an administration set. Such tubular spike 50, shown in dotted line, punctures the end wall diaphragm 31 (first barrier) after the spike 50 has formed a seal with the inner flange at a top of the sleeve section 30. For ease of molding barrier 31 it can be formed with a protrusion 51 formed by a gate in the mold through which plastic is injected into the mold. Protrusioon 51 can be located in a center portion of puncturable wall 31 so as not to intefere with a pointed puncturing section of spike 50 in dotted line shown engaging a left edge portion of diaphragm 31 in FIG. 7. To strengthen the joint between the diaphragm 31 and tubular sleeve 30 and prevent premature breakage in this area is an integral annular rib that extends below diaphragm 31.

After the spike 50 of an administration set has been connected, the bottle is inverted and hung from its hinged hanger 5 for draining the sterile liquid contents in the bottle through the administration set.

In the above description the three barrier closure system has been described relative to the outer tube 22. The additive tube 23 also forms a three barrier closure system with the outer cap 8 being the third barrier. With additive tube 23 a puncturable resealable diaphragm 25 forms the first hermetic barrier, and the foil 24 sealed to the outer end of additive tube 23 forms the second hermetic barrier. There is a sealed air chamber between diaphragm 25 and foil 24.

It has been found that this invention with the triple barrier closure system works very well with the collapsible thermoplastic bottle, the inner closure, and the outer cap all made of a propyleneethylene copolymer thermoplastic. The foil 24 is a laminate of a thermoplastic material and an aluminum foil with the thermoplastic material fused to the dispensing outlet tube.

In the foregoing specification a specific example has been used to describe the invention. However it is understood by those skilled in the art that certain modifications can be made to this example without departing from the spirit and scope of the invention.

Claims

I claim:

1. In a thermoplastic steam sterilizable medical liquid container, having a flange on a neck portion and an inner closure and an outer closure, the improvement of: a tube on the inner closure with a passage therethrough; a first hermetic seal closing the passage; a second hermetic seal closing the passage externally of the first hermetic seal; said outer closure encloses the first and second hermetic seals; said outer closure having an outwardly extending brim fused to said flange and includes a vent that equalizes pressure inside and outside the outer closure, so that the outer closure is relieved of differential pressure stresses.

2. The combination as set forth in claim 1, wherein the first hermetic seal remains closed when subjected to a pressure differential of 10 psi (0.70 Kg/cm) exerted across the first hermetic seal.

3. The combination as set forth in claim 1, wherein the second hermetic seal remains closed when subjected to a pressure differential of 10 psi (0.70 Kg/cm.sup.2) exerted across the second hermetic seal.

4. The combination as set forth in claim 1, wherein the vent is a tortuous passage through the outer closure.

5. The combination as set forth in claim 1, wherein the outer closure has a manually frangible section for opening the outer closure to gain access to the first and secoind hermetic seal means on the inner closure.

6. The combination as set forth in claim 5, wherein the manually frangible section includes an annular venting opening about the outer closure with one or more frangible webs integral with the outer closure and extending across the vent opening.

7. The combination as set forth in claim 1, wherein the tube is a dispensing outlet tube and includes a spike gripping tubular sleeve.

8. The combination as set forth in claim 7, wherein the spike gripping sleeve has an inner wall that tapers inwardly toward an interior of the container.

9. The combination as set forth in claim 8, wherein the spike gripping sleeve is laterally expandable for grippingly receiving a tubular administration spike.

10. The combination as set forth in claim 9, wherein the first hermetic seal in puncturable thermoplastic diaphragm formed integrally with and closing off a passage through the tubular spike gripping sleeve.

11. The combination as set forth in claim 10, wherein the spike gripping sleeve has an integral annular rib extending below the diaphragm.

12. The combination as set forth in claim 10, wherein the tube includes an annular support section with the spike gripping sleeve disposed within and integrally formed with this annular support section.

13. The combination as set forth in claim 12, wherein the tube includes an annular space between the annular support section and the spike gripping sleeve disposed therein.

14. The combination as set forth in claim 1, wherein the second hermetic seal is a manually peelable thermoplastic-metal foil bonded to an outer end of the tube.

15. The combination as set forth in claim 1, wherein the outer closure is a cap having a diameter substantially greater than a diameter of the tube section, whereby forces to open the first and second hermetic seals are concentrated in areas substantially smaller than the outer closure.

16. The combination as set forth in claim 1, wherein the tube is an outlet tube and the inner closure also includes an additive port closed by a puncturable resealable diaphragm separate from the outlet tube and additive medication can be added to the container through this additive port.

17. The combination as set forth in claim 16, wherein the puncturable resealable diaphragm is externally sealed off by a hermetic barrier disposed within the outer closure.

18. The combination as set forth in claim 17, wherein the puncturable resealable diaphragm is disposed in an additive tube integrally formed with the inner closure.

19. The combination as set forth in claim 18, wherein the additive tube section has hermetic barrier external of the puncturable resealable diaphragm.

20. The combinationn as set forth in claim 19, wherein the hermetic barrier is a thermoplastic-metal foil.

21. The combination as set forth in claim 1, wherein the outer closure is a thermoplastic cap and is secured to the container by a plurality of webs each of which has a cross-sectional area less than 0.0004 in.sup.2 (0.0026 cm.sup.2) for easy manual breakage by twisting or cocking the outer cap relative to the container.

22. The combination as set forth in claim 1, wherein the inner closure has an additive tube, the first hermetic barrier is a puncturable resealable diaphragm, and the second hermetic barrier is a metal-thermoplastic laminate foil, both of which are sealed to the additive tube.

23. For handling and dispensing a sterile medical liquid the combination of: a thermoplastic bottle having a neck with an outlet passage therethrough; an integral thermoplastic flange integral with this neck; an inner closure permanently sealed to the container neck; said inner closure having an outlet tube formed by an annular support section and a spike gripping tubular sleeve integral with and disposed within the annular support section; a puncturable diaphragm integrally formed with the spike gripping sleeve and forming a first hermetic barrier to a dispensing passage that extends through the spike gripping sleeve; a thermoplastic-metal foil having a thermoplastic surface bonded to an outer end of the dispensing tube forming a second hermetic barrier across the dispensing passage through the spike gripping sleeve; an additive tube integrally formed with the inner closure; a puncturable resealable diaphragm sealing off a passage through the additive tube through which additive medications can be injected into the bottle; a hermetic seal across the additive tube externally of the puncturable resealable diaphragm, said hermetic barrier being a thermoplastic-metal foil; a third barrier in the form of a cap having a top wall, a tubular sidewall, and a laterally extending brim fitting over and enclosing both the outlet tube and the additive tube; said cap brim being permanently bonded to the bottle neck flange and supporting the outer cap's top wall a distance above the thermoplastic-metal foil; said outer closure having a tortuous vent at a juncture between the tubular side wall and the cap brim; and a series of manually frangible web sections connecting the sidewall to the flange of the outer closure.