Such bags have previously been made with tubular inserts sealed into an edge portion of the bag to form ports for insertion of needles and with sealed tear-off chambers outboard of the ports, as described in British Patent Specification No. 544811, for example.

In our co-pending British Patent Application No. 8138586, we have described and claimed a pouch-like bag for containing a liquid for medical or surgical use, the bag having two walls formed by respective plies of flexible plastics material sealed together around their periphery, wherein the bag is provided with an elongate insert of polymeric material which is capable of self-

sealing a puncture made transversely through the insert, the insert being sealed between the plies of flexible material so as to extend adjacent to a portion of the bag periphery, and extreme sealed peripheral portions of the plies of flexible material outboard of the insert forming a tearable tag which, when torn off the bag, exposes at least part of the length of the said insert, along a side face thereof, so as to allow an injection or dispensing needle access to penetrate transversely through the insert and into the bag.

European Patent Application No. 0038312 describes a package suitable for storage of preparations for paren- teral administration, e.g. intravenous infusion solutions, which is designed to protect the contents from the influence of light, microbial contamination and gas trans¬ port in either direction but which makes possible a visual control of the contents before the package is used. For these purposes, the package is made of a light-proof outer bag and a light permeable inner bag arranged inside the outer bag. The outer bag and the inner bag are each sealed at one of their ends and are bonded around their periphery close to their other end, and the two bags extend over this bond and are then commonly joined and , sealed. By opening one of the end seals in the outer bag, the inner bag can be turned out of the outer bag, and the contents of the package can be observed visually through the inner bag. A tapping device of conventional design may be arranged in the wall of the inner bag so as

to be accessible when the inner bag has been turned out of the outer bag.

It is an object of the present invention to provide an economical and effective construction of a bag for containing liquids for medical or surgical use, particu¬ larly a liquid for intravenous injection by means of a hospital drip feed system.

According to the present invention, a pouch-like bag for this purpose has two walls formed by respective plies of flexible plastics material sealed together around at least their top and side edges, and a third, folded ply of flexible plastics material which is dis¬ posed between the walls of the bag to form a gusset fold having opposed leaves sealed to the adjacent walls of the bag and which carries one or more elements for receiving a needle for making connection with the bag contents and which is closed below the element or elements to form a sealed compartment protecting the or each element from contamination, and is characterised in that the third or gusset ply is substantially smaller than the walls of the bag, so that when the sealed compartment is opened the gusset ply forms a substantially flat bottom of the bag and presents the element or elements substantially per¬ pendicular to the walls of the bag for insertion of a needle or needles without risk of accidental penetration of the walls.

In one construction of the bag, the seals between the leaves of the gusset ply and the adjacent walls of

the bag coincide with a peelable seal between the leaves of the gusset ply which closes the sealed compartment, and the leaves of the gusset ply and/or the walls of the bag extend below the coincident seals to form gripping means to enable the peelable seal to be opened. To ensure that the peelable seal can be peeled open, the material of the gusset ply or the nature of the sealing surfaces is selected or modified to ensure that the seal has the necessary relatively low strength. In a second construction, the sealed compartment is adapted to be opened by severance of a lower marginal portion of the 'bag along a severance line disposed below the seals between the opposed leaves of the gusset ply and the adjacent walls of the bag. The severance line is preferably disposed so that only two thicknesses of the flexible plastics material need to be torn to open the sealed compartment. For this purpose, either the walls of the bag do not extend as far as the severance line, which is formed in the leaves of the gusset ply above a seal between the leaves which closes the sealed compartment, or the leaves of the gusset ply do not ex¬ tend as far as the severance line, which is formed in the walls of the bag above a seal between the walls which closes the sealed compartment. Preferably the or each needle-rεcεiving element is of elastomeric material capable of making an hermetic and liquid-tight seal with a needle inserted therethrough. A peelable -protective strip may be attached to ^~ he gusset

ply within the gusset fold to provide temporary protection for the area of the gusset fold bottom of the bag adjacent one or more of said needle-receiving elements after the sealed compartment has been opened and before a needle is inserted. The or each element may be of any suitable shape, for example, circular, square or in the form of an elongate strip. It may be attached to the inner or outer surface of the gusset ply (in relation to the gusset fold) ; where the gusset ply has a plurality of layers, it may be located between those layers. It is preferably disposed to project from the gusset ply outwardly, but not inwardly, of the gusset fold, so as not to impede the leaves of the gusset ply from folding fully together.

Specific embodiments of the invention will now be described in more detail by way of example and with reference to the accompanying drawings, in which:-

Figure 1 is a diagrammatic elevation of a bag in accordance with the invention,

Figure 2 is a diagrammatic cross-section on line II-II of Figure 1,

Figure 3 is a cross-sectional view similar to Figure 2 showing a modification,

Figure ^" 4 is a diagrammatic elevation of the lower part of a modified form of bag, Figure 5 is a diagrammatic sectional view on line V-V of Figure 4,

Figure 6 is a similar sectional view of a modification corresponding to that of Figure 3 ,

Figure 7 is a diagrammatic elevation of a lower part of another form of bag in accordance with the invention,

Figure 8 is a sectional view on line VIII-VIII of Figure 7, Figure 9 is a diagrammatic elevation of the lower part of yet another form of bag in accordance with the invention,

Figure 10 is a sectional view on line X-X of Figure 9, Figure 11 is a view similar to Figure 9 and showing the lower part of a further bag in accordance with the invention,

Figure 12 is a sectional view on line XII-XII of Figure 11 , Figure 13 is a cross-sectional view of the bag of Figures 11 and 12, showing the bag after cutting between the lower seals to expose the needle-insertion elements,

Figure 14 is a diagrammatic illustration of the production of the needle-insertion elements, and

Figure 15 illustrates the mounting of the needle- insertion elements on a ply of plastics material which is to form the gusset ply.

As shown diagrammatically in Figures 1 and.2, a bag has two walls 10,11 formed by respective plies of flexible plastics material sealed together at 12 around their top and side edges. A suspension hole 13 is punched in the

top seal and this area may be reinforced by including an insert of strengthening material, if desired. In the lower part of the bag, a third or gusset ply 14 of flexible plastics material folded along line 15 is disposed between the walls 10, , and each leaf 16,17 of the gusset ply 14 is heat-sealed to the adjacent wall 10,11 along line 18. The gusset ply 14 is also heat-sealed between the walls 10,11 at the edges of the bag as shown at 19,20. The gusset ply 14 is subst-antially smaller than the walls 10,11 and thus forms for the bag a gusset bottom which is closed at its top along the fold line 15 and closed along its sides by the seals 19,20.

The gusset ply 14 carries two elements 21,22 of elastomeric material, on opposite sides of the fold line 15 and outside the gusset fold (but within the bag interior) . The elastomeric elements are shown as flat circular discs secured to the gusset ply 14. Element 21 is designed to be capable of self-sealing a puncture made therethrough by a hypodermic needle, e.g. for inserting a drug into liquid contained in the bag. Element 22 is designed to be capable of sealing around an administration needle forced therethrough, and may be formed with a hole 28 for guiding the needle. Usually, as shown, the element 22 will be made of thicker material than the element 21 to provide adequate retention of the administration needle. ^• Below the elements 21,22 the two leaves 6,17 of the gusset ply 14 are additionally heat-sealed together at 27 so as to form the gusset fold into a sealed compartment in

which the access points of the needles 21,22 are disposed and protected from contamination. In the example illust¬ rated in Figures 1 and 2, the seal 27 between the leaves 16,17 coincides with the seals 18 between the respective walls 10,11 and the leaves 16,17.

In order to enable the sealed compartment to be opened to provide access to the elements 21,22 when required for insertion of a hypodermic or administration needle, the side seals 19,20 and bottom seal 27 between the leaves 16,17 are peelable, the material of the gusset ply 1 being chosen, or its surface being treated, so as to ensure that any seal made with itself is of sufficiently low strength to be peelable. To provide gripping means for peeling open the seals, the walls 10,11 and the leaves 6,17 are extended beyond the seal line 18, their extremi¬ ties being sealed together at 23,24. If desired, the gusset ply may be cut away locally, e. g. by notching, along the sides of the bag within the seals 19,20 so as to allow the walls 10,11 to be directly heat-sealed to- gεther in that locality. In this way the pεelability of the seals 19,20 may be limited to a transverse line lying below thε fold linε 15 of the gusset ply. When the sealed compartment has thus beεn opεnεd, thε gussεt ply 14 forms a substantially flat bottom of thε bag and presents the elements 21 ,22 substantially perpendicular to the walls of thε bag for Ins rtiδn of a needle or neεαlεs without risk of accidental pεnetration of the walls.

Figure 3 illustrates a modification of the construe-

tion of Figures 1 and 2, in which the wall 10 and the corresponding leaf 6 are extended further than the walls 11 and leaf 17 to facilitate gripping of the respective leaves for peeling open the seal. Figures 4, 5 and 6 illustrate an embodiment similar to that of Figures 1,2 and 3, but in which the walls 10,11 do not extend beyond the seals 18,27. The leaves 16,17 extend beyond the seals 18,27 as before, and provide gripping means for peeling open the seals between them. Figures 7 and 8 illustrate an embodiment which is similar to those of Figures 1 to 6 except that thε extensions of the walls 10,11 and lεavεs 16,17 beyond the seal 27 are omitted, and the seal 27 is taken diagonally, at 26, across a bottom corner of the bag instead of following the seals 18 in that locality. Two free corner tabs 25 are thereby provided for the user to grasp when opening the bag.

Figures 9 to 12 illustrate alternative embodiments which are not intendεd for use with a peelable seal, but arε provided with a severance line for opening the sealed compartment.

In the embodiment of Figures 9 and 10, the lower extremities of the walls 10,11 are sealed to the respec¬ tive leaves 16,17 at seals 18 as before. The leaves 6 and 17 project below the seals 18 and are sealεd togεthεr at their lower extrεmitiεs at 27. To open the sealed compartment to provide needle access to the elements 21,22, the bag is torn or cut along a severance line 29 defined

by tear initiating formations 32 (cuts or notches) be¬ tween the seals 18 and 27.

Figures 11 and 12 illustrate a second εmbodimεnt having a sεvεrablε portion. In this case the walls 10,11 are continued below the seals 18, which arε madε with thε lowεr εxtrεmitiεs of the gusset ply 14. The walls 10,11 are themselves sealed together at 27 along their lower extremitiεs to form a sealed compartment with the gusset ply. Tear initiating formations 32 arε formed in the walls 10,11 below the seals 18 to assist the opening of this compartment for use.

In use of each of the bags shown in the drawings, the sealεd compartment formεd within the gusset fold is opened by the user by manually peeling the compartment open along the seals 27,19 and 20 or, as appropriate, by sevεring thε bag along line 29 as described. Figure 13 shows the bag of Figures 11 and 12 when opened, but it v/ill be under¬ stood that the other embodiments generally correspond. From Figure 13 it will be seen that the opening of the sealεd compartment allows freεdom for thε basε region of the bag to open out under the weight of the liquid contents, so that the gusset ply 14 genεrally adopts thε flat condition shown. The needle-insεrtion elements 21,22 are thεrεby presented side-by-sidε for εasy accεss by thεir rεspεctivε hypodermic and administration needles. As indicated at 33,34, the nεεdlεs are forced into the bag through the gusset ply material and thε appropriata εlεmεnt, in a diraction gεnεrally pεrpendicular to the gusset ply,

without risk of accidental penetration of the walls of the bag.

In those bags in which the gusset fold is still closed at its ends along the seals 19,20, the flat, εlεment- carrying part of the gusset ply will be surrounded by a - skirt. By suitable arrangement this skirt may serve as a standing edge on which the bag may be stood upright, with the gusset ply held clear of the supporting surface. If desired, additional inclined heat seals may be made .across the bag for improving the standing ability of the bag (when open) by controlling the shape adopted by the base region.

Figure 14 illustrates one way in which the elεmεnts 21,22 may be prepared. They may be made from an elasto¬ meric paste based on natural rubber or silicone rubber, being a single component or pre-mixed from a two part system including a cross-linking agent. They may be of any suitable shapε, circular εlεmεnts being illustrated as being generally most conveniεnt.

The thickness of rubber is selected to ensure that the injection neεdle elemεnt will self seal effectively when the needlε is withdrawn, and thε administration needle elemεnt will εxert sufficient grip on the admini¬ stration needle to grip it and retain it and prevent leakage during administration. The elεments may therefore be of differing formulations and differing thicknesses, e.g. 1 mm thick for the injection needle element and 3 mm for the administration needlε εlεmεnt. To produce the elements, a layer 35 of the elastomeric material is

applied by conventional coating means to a trεatεd surface of a polyolefin film 36 which is formulated so as to be heat sealable to the appropriate surface of the gusset web 14. Aftεr curing the elastomεr, thε elemεnts are punched out by a punch shown diagrammatically at 37 and hεat sεaled through their backing film 36 to the gussεt ply 14 as shown in Figurε 15, on either side of the cεntre line 15.

A further way in which the elεmεnts 21 ,22 may bε prεparεd is to thεrmoform a web of the gusset ply 14 with shallow cavities, one for each elemεnt. Thε elemεnts thεmsεlves are then located in the cavities either as preformεd discs or mouldεd in situ from a suitable elasto¬ mer. The elements are therεaftεr εncapsulatεd within the cavities by a second web of material which is bonded to the first layer so as to close the cavitiεs and form a sεcond layer of the gusset ply. Prεfεrably, as with thε εmbodimεnts particularly dεscribεd above, the. elemεnts arε located to project outside the gusset ply (but within the bag interior) , so that they do not impedε the gusset leaves 16,17 from being folded fully together.

Manufacture of the bags describεd abovε with referε- ncε to the drawings is exemplified by the following description of a prefεrrεd mεthod of manufacturing bags of the particular form shown in Figures 11 and 12. Two continuous webs of plastics material to form the walls 10,11 arε fεd horizontally togεther on either side of a further, longitudinally folded web which is destined to

for the gusset plies 14 of the bags and which accordingly carries pairs of elements 2 , 2 at regular intervals along its length. Continuous heat seals 18 are then made between the outer webs and the lower extremities of the folded web while a plate is positioned within the folded web to pre¬ vent its leaves from being heat-sealed together. The threε webs then move together beyond the end of the plate, and a further continuous heat seal is made along the lower extrεmities of the outer webs to form the heat seals 27. Finally the webs are heat sealεd transversely at intervals between the pairs of elements 21,22, the tear-initiating formations 32 are formed, and the individual bags are separated from one another by severing the webs along the transverse seals. The bags are subsεquεntly fillεd with liquid, closed by top seals 30 (Figure 1), and suspension holes 13 punched within the seal closure area.

In order to maintain substantially aseptic conditions after it has beεn opεnεd, εach of the bags describεd abovε may have a peelablε strip attached to the interior surface of the gusset ply so as to provide a protectivε cover over the entry point of an administration and/or hypodermic needle until immediately before the needle is insertεd. One such strip is shown in Figures 11 to 13 in relation to administration needle element 22, and indicated by the ref rεnce numeral 41. Strip 41 is attached to the gusset ply 1_4 at a suitable time before the gusset ply is incor- poratεd into thε bag.

In a modification of each of the describεd bags, onε

-

or both of thε nεεdlε-insεrtion εlεmεnts is attachεd to thε innεr surface of the gusset ply and disposed to lie within the gusset fold. A protective strip as describεd in the precεding paragraph may than bε advantagεously provided as a separator between the elements.

A bag in accordance with the invention may have its walls 10,11 made of a single layer of plastics material or of laminated construction. In one possible wall structure an outer heat-rεsistant film such as nylon, a polyεstεr or polypropylεnε is bondεd to a heat-sealable inner ply, typically a polyolefin or modified polyolefin. The materials are clear and transparent and capable of withstanding steam stεrilisation. The gusset ply may be of a similar material, laminated or otherwisε, and may includε or bε formεd of a blend of polyolefins. In onε possiblε construction thε walls and thε gusset ply are intεgrally formεd from a singlε shεεt of plastics material folded longitudinally into W formation.

Although each of the bags particularly describεd has two nεεdlε-insεrtion εlεmεnts carriεd by the same gusset ply in mutual opposition, the invention also extends to bags having only one elεmεnt, for εxamplε in the form of an elongate strip on or in one of the leavεs of the gusset ply, and to bags having two or more elemεnts. "hεrε two ^or morε εlements are provided they may be disposed so as to bε spacεd apart (i.e. non-overlapping) in thε same gusset ply, or they may bε carriεd by sεparate gusset plies. In one such latter arrangε εnt a bag has two

gusset plies each carrying one elemεnt, thε pliεs bεing individually disposεd at the bottom corners of the bag so as to extend, at an inclination to the centre-line of the bag, from the bottom edgε to respective side edges of the bag.