GB2289647A

GB2289647A - film construction for a disposable ostomy pouch

Info

Publication number: GB2289647A
Application number: GB9410058A
Authority: GB
Inventors: Graham Emery Steer; John Arthur Gooch Gent
Original assignee: ER Squibb and Sons LLC
Current assignee: ER Squibb and Sons LLC
Priority date: 1994-05-19
Filing date: 1994-05-19
Publication date: 1995-11-29
Also published as: GB9410058D0

Abstract

A WC-disposable ostomy pouch has laminated walls. The layers of the laminate may include (1) a layer such as a solvent deposited coating, e.g. acrylic, which loses its integrity in an aqueous medium having a pH of greater than 8.5 or less than 4.5 but which does not lose its integrity when exposed to aqueous media of pH 4.6 to 8.4 in 5 minutes at 38 degrees C, (2) cold water soluble polyvinyl alcohol, (3) adhesive, (4) a gas-barrier layer such as vacuum-deposited metal or glass, and (5) a layer e.g. containing polyvinylidene chloride or polyurethane which is weldable to itself or to a like layer to enable a pouch to be formed, resistant to aqueous media of pH 4.6 to 8.4 and releasable from a smooth polymer substrate. A layer (7), the same as layer (2), and a layer (8), the same as layer (1), may be laminated to layer (5) using a further adhesive layer (6). The ostomy pouch may be disposed of by placing in a bag which on contact by water releases a material which changes the pH of the aqueous medium immediately adjacent to the pouch to in excess of pH 8.5 or to less than 4.5.

Description

FILM CONSTRUCTION FOR A DISPOSABLE OSTOMY POUCH AND NETHOD OF MAKING SAME Ostomy pouches have been known for many years. A major disadvantage of the ostomy pouch is the method of disposal. The majority find their way into landfill, and some are incinerated.

Neither of these routes are environmentally friendly. It is therefore desired and has been for several years, that an alternative means of disposal be considered of which the preferred route is through the toilet flushing system.

It has been proposed, in European Patent No. 272 816, that a pouch should be encased in a slippery bag in order to facilitate flushing it down a W.C. It has been proposed in U.K. Patent No. (GB-B)2,083,762 that an ostomy pouch should be WC-disposable.

According to this patent a WC-disposable ostomy pouch comprises a front panel edge-sealed to a rear panel, the panels being formed of a composite sheet material having a mechanically weak, water-impermeable layer (e.g. PVDC) disposed inwardly and a mechanically strong, watersoluble or -disintegrable layer (e.g. PVOH) disposed outwardly. A karaya gum ring, for attachment to the peristomal areas, forms an access port and is sealed to one panel. Sample collection bags and bedpan liners may also be made from the WC-disposable material disclosed in this patent. Other proposals for disposal of ostomy pouches and like articles have been previously made in European Patent No. (EP-B)10171 (inventor Keifer), Galindo U.S. Patent No. 3,089,493, British Patent No. 1,271,424, and Wilkins U.S. Patent No. 3,762,454.

Instead of a karaya gum ring, the present applicants prefer to use a suitable medical grade adhesive ring (see for example British Patent No. 1 586 823 page 2 line 25 onwards).

The properties of a pouch film for a WC-disposable pouch should enable it to perform in a similar manner to that of a standard pouch film.

The properties of a standard pouch film include: 1. Mechanical strength such that the pouch does not fail in service due to tearing, creep, etc.

2. The film must be weldable in order to form a pouch. The resultant bond must have adequate strength to ensure that the pouch does not burst during usage.

3. It must provide an adequate barrier against odour emanating from body waste. These gases can escape by direct transmission through the film, whereas the preferred route is to pass through the deodorising filter.

4. It must be comfortable for the patient to wear, and essentially free of rustle characteristics, when the patient moves or sits.

To this list of properties for a disposable ostomy pouch film must be added: 5. The bag must degrade sufficiently when placed in the toilet and flushed after a short period of time, to enable it to release its body waste contents, and then the pouch must continue to degrade on its passage to the sewage works.

As mentioned above, there are products which have been developed, and which partially meet the last requirement by virtue of shape of pouch and lubricated surfaces. Also there are pouches in which an outer film dissolves in water, leaving an inner thin film which still retains the body waste contents, but which is flexible enough to pass through the toilet and reach the sewage works.

Although this suggestion offers advantages in terms of disposal, it does not meet the desired criteria given in property 5 above.

Also in the instances of pouches where the outer layer is dissolved in water, it is usual for this layer to provide the gas barrier property to the film. Since the barrier characteristics are significantly reduced by the presence of moisture within the polymer structure, there is a risk of poor performance with respect to gas barrier characteristics, when the pouch is worn for extended periods.

Examples of materials which have virtually perfect gas barrier properties are metals and glass. However, unless these materials are exceptionally thin, that is to say thicknesses of less a few microns, they would be too rigid, and hence would not meet the requirements, notably comfort and noise aspects in addition to that of disposability. It has been suggested is possible to deposit thin films onto a smooth polymer film surface, to yield films used for packaging with good gas barrier characteristics. The two most commonly used materials are aluminium and glass (silicon dioxide), and the smooth film used is polyester. The disadvantages of the resulting so-called metallised polyester are that composite films made from these structures are rigid, noisy and not disposable through the toilet.

This invention is based on the concept of incorporating a thin deposited layer into a film to form an ostomy pouch having desirable characteristics. Within this concept, one utilises the barrier properties capable of being achieved with a thin coating of either a combination with other coatings and adhesives is bonded between two thicker cold water soluble films. On the exposed surfaces of the thick water soluble films there are disposed coatings which are readily dissolvable in aqueous acid or alkali.

In accordance with one aspect of the invention, there is provided a film for an ostomy pouch which is W.C.-disposable, said film having at least four layers and having a total thickness of 25 to 250 microns, said film comprising: an outer first layer or coating which loses its integrity in an aqueous media having a pH of greater than 8.5 or less than 4.5, but which does not lose its integrity when exposed to aqueous media of pH 4.6 to 8.4 in 5 minutes at 38C, the said layer having a thickness of from 0.2 to 10 microns; an inner layer or layers which is or are soluble in aqueous media and has or have a total thickness of between 15 to 245 microns a layer or layers which constitute a barrier to the transmission of gases through the film, and having a total thickness of less than 10 microns, an outer second layer which is weldable to itself to enable a pouch to be formed, said outer second layer being resistant to aqueous media of pH 4.6 to 8.4, and having a thickness of between 0.2 and 10 microns.

In accordance with a second aspect of the invention, there is provided a film for an ostomy pouch which is W.C.-disposable and has a minimum of three layers a total thickness of 25 to 250 microns, said film comprising: a first outer layer which loses its integrity in an aqueous media having a pH of greater than 8.5 or less than 4.5, but which does not lose its integrity when exposed to aqueous media of Ph 4.6 to 8.4 in 5 minutes at 38C, the said outer layer having a thickness of between 0.2 and 10 microns; an inner layer which loses its integrity in aqueous media and has a thickness of between 15 and 245 microns; a second outer layer which is weldable to itself to enable the formation of a pouch, provides a barrier to the transmission of gases through the film, and further is resistant to aqueous media of pH 4.6 to 8.4.

In accordance with a third aspect of the invention there is provided a method of using a bag for assisting in the disposal of a used ostomy pouch prepared from films in accordance with any preceding claim; said method comprising placing said used pouch in said bag, and placing said bag in a W.C., said bag having embodied therein a component which upon being contacted by water releases a material which changes the pH of the aqueous media immediately adjacent to the pouch to in excess of pH 8.5 or to less than 4.5.

In accordance with a fourth aspect of the invention, there is provided a W.C.-disposable ostomy pouch each of whose walls is made from a plurality of laminated layers, of which at least one layer is a film of metal or glass not exceeding 1.5 microns in thickness and another layer is of cold-water soluble polyvinyl alcohol (PVOH).

In accordance with a fifth aspect of the invention, there is provided a method of making a film laminate for use as a wall of an ostomy pouch, comprising the steps of (i) forming a laminate consisting of a smooth polymer film and Layers 5 to 1 as herein defined in that order (ii) peeling off the smooth polymer film and (iii) laminating Layers 8 and 7 as herein defined to said Layers 5 to 1 using Layer 6 as herein defined.

The envisaged construction of composite film, usable to make the walls of an ostomy pouch, may contain 5 or 8 layers: Layer 1 Layer 2 Layer 3 Layer 4 Layer 5 Layer 6 Layer 7 Layer 8 Layers 6-8 are optional. Layer 1 and Layer 8 contain a high percentage of material which is soluble in either aqueous acid or aqueous alkali. Layer 1 must also be weldable to itself.

Layer 2 and Layer 7 form the strength components of the composite pouch film and are films such as cold water soluble polyvinyl alcohol (PVOH) readily soluble in cold water and in aqueous acid or aqueous alkali.

Layer 3 and Layer 6 are suitable adhesives to bond the adjacent layers together.

Layer 4 is a thin coating of metal or glass.

Layer 5 is a coating, such as a lacquer, which can be readily released from a polyester.

The thickness of the various layers which are useful in practice are those falling within the ranges stated in the claims herein.

In a desirable embodiment of this invention, the preferred film will have only 5 layers namely Layers 1-5. In this instance it is an additional feature that Layer 5 would be a substrate suitable for attaching the filter.

In making such a composite film, the process used for Layer 1 and 8 would be a coating technique. Layer 2 and 7 are made by conventional extrusion casting or coating. Layers 3-5 are formed by a technique known as transfer coating. This technique is used in the production of metallised papers and board. A transfer coating technique employed in the present invention involves the following basic steps: 1. A suitable coating (Layer 5) is cast onto a smooth plastic film, e.g. a polyester film, using a suitable known technique such as gravure or reverse roll. The polyester or similar film serves as a temporary substrate.

2. Onto Layer 5 is deposited, using vacuum deposition, a thin coating (Layer 4) of a metal or glass.

3. Onto Layer 2 is coated Layer 1. This is carried out prior to the next step.

4. Onto Layer 4 is applied an adhesive (Layer 3) and this is bonded to Layer 2 (which already has Layer 1 applied to it).

The resultant complex laminate will then comprise, in order: - a smooth polymer film, e.g. polyester - Layer 5 - Layer 4 - Layer 3 - Layer 2 - Layer 1.

5. The smooth polymer film is then peeled from the surface of Layer 5. The resultant product has Layers 1-5, and may be used as an ostomy pouch wall.

If desired, then it is possible to laminate Layers 7 and 8 to Layer 5 using an adhesive (Layer 6).

The selection of the indicated materials for each layer will enable a disposable and degradeable ostomy pouch film to be formed, which exhibits the desired mechanical, weldability, gas barrier and comfort properties, in addition to that of disposability through a flushing WC.

The mechanism by which the pouch will degrade involves attack on Layers 2 and 7 by cold water, and by aqueous alkali (or acid) on Layers 1 and 8. In the case of Layer 1 this will lead to the weld failure and the release of the bag contents. The bag will continue to degrade whilst immersed in water and will gradually disintegrate.

Preferred Materials Layers 1 and 8 are both (typically) a solvent deposited acrylic which is soluble in aqueous alkali, having a dry thickness of approximately 2 microns.

Layers 2 and 7 are both cold water soluble polyvinyl alcohol (PVOH).

Layers 3 and 6 are suitable adhesives each of a thickness of approximately 2 microns.

Layer 4 is an aluminium layer deposited by vacuum deposition, preferably less than 3 microns thick.

Layer 5 is, as stated, a suitable coating which can be readily released from a polyester.

Alternative Embodiment In a variation of this invention, a used pouch may be inserted into a bag. The bag may be of a paper tissue which has been coated/impregnated with an alkali or an acid on the inner surface.

When the bag is placed in the WC, the water will penetrate the tissue dissolving the alkali/acid and providing a concentrated solution environment within the bag. In this environment, the pouch will rapidly degrade. By virtue of the alkali/acid solubility of Layer 1 the pouch will 'explode' open and release its contents. The flushing operation will break the tissue bag. The large volumes of water will then continue to dissolve Layers 2 and 7 of the pouch with the result that the pouch will have virtually completely broken down by the time it reaches the sewage works.

Properties, characteristics, and thicknesses of the various layers included are set out in the claims herein. The whole content of these claims is hereby incorporated into this description.

Claims

1. A film for an ostomy pouch which is W.C.-disposable, said film having at least four layers and having a total thickness of 25 to 250 microns, said film comprising: first outer layer or coating which loses its integrity in an aqueous media having a pH of greater than 8.5 or less than 4.5, but which does not lose its integrity when exposed to aqueous media of pH 4.6 to 8.4 in 5 minutes at 38C, the said layer having a thickness of from 0.2 to 10 microns; an inner layer or layers which is or are soluble in aqueous media and has or have a total thickness of between 15 to 245 microns a layer or layers which constitute a barrier to the transmission of gases through the film, and having a total thickness of less than 10 microns, second outer layer which is weldable to itself or to a like layer to enable a pouch to be formed, said outer second layer being resistant to aqueous media of pH 4.6 to 8.4, and having a thickness of between 0.2 and 10 microns.

2. A film according to claim 1 in which the barrier layer is a layer of a copolymer of vinylidene chloride.

3. A film according to claim 1 in which the barrier layer is a vacuum-deposited layer.

4. A film according to claim 3 in which the gas transmission barrier layer is initially vacuum deposited onto a coated smooth film and then the vacuum deposited layer plus the coating is removed from the smooth film and bonded to the other aforesaid layers.

5. A film according to claim 3 or 4 in which the vacuum deposited layer is aluminium.

6. A film according to claim 3 or 4 in which the vacuum deposited layer is silicon dioxide.

7. A film according to claim 4 in which the smooth film is a polyester film.

8. A film according to any preceding claim in which the said inner layer, which is soluble in aqueous media, comprises at least 60 parts by weight of polyvinyl alcohol per 100 parts by weight total.

9. A film according to claim 8 which contains a water soluble alkali in an amount up to 10 parts by weight.

10. A film according to claim 8 which contains perfume in an amount up to 5 parts by weight.

11. A film according to claim 8 which contains a plasticiser in an amount up to 30 parts by weight.

12. A film according to claim 1 in which the said outer second layer is not resistant and will lose its integrity when exposed to aqueous media having a pH of less than 4.5 or greater than 8.5.

13. A film according to any preceding claim in which the thickness of the first outer or second outer layer lies between 0.5 and microns.

14. A film according to any preceding claim in which the layer soluble in the aqueous media has a thickness of between 20 and 8C microns.

15. A film according to any preceding claim in which the weldabie layer is a heat seal lacquer.

16. A film according to any of claims 1-14 in which the weldable layer is a polyurethane.

17. A film for an ostomy pouch which is- W.C.-disposable and has a minimum of three layers which have a total thickness of 25 to 250 microns, said film comprising: a first outer layer which loses its integrity in an aqueous media having a pH of greater than 8.5 or less than 4.5, but which does not lose its integrity when exposed to aqueous media of Ph 4.6 to 8.4 in 5 minutes at 38C, the said outer layer having a thickness of between 0.2 and 10 microns; an inner layer which loses its integrity in aqueous media and has a thickness of between 15 and 245 microns; a second outer layer which is weldable to a layer of like composition and properties to enable the formation of a pouch, provides a barrier to the transmission of gases through the film, and further is resistant to aqueous media of pH 4.6 to 8.4.

18. A film according to claim 17 in which the weldable layer contains at least 50 parts by weight of a copolymer of vinylidene chloride.

19. A film according to claim 17 or 18 in which the weldable layer contains up to 50 parts by weight of a polyurethane.

20. A method of using a bag for assisting in the disposal of a used ostomy pouch prepared from films in accordance with any preceding claim; said method comprising placing said used pouch in said bag, and placing said bag in a W.C., said bag having embodied therein a component which upon being contacted by water releases a material which changes the pH of the aqueous media immediately adjacent to the pouch to in excess of pH 8.5 or to less than 4.5.

21. A method according to claim 20 in which the bag comprises a coated tissue paper.

22. A method according to claim 20 or 21 in which the component released is sodium carbonate.

23. A method according to claim 20 or 21 in which the component released is triethanolamine.

24. A WC-disposable ostomy pouch each of whose walls is made from a plurality of laminated layers, of which at least one layer is a film of metal or glass not exceeding 1.5 microns in thickness and another layer is of cold-water soluble polyvinyl alcohol (PVOH).

25. A pouch according to claim 24 in which the layers include: Layer 1 namely a coating which is solvent-deposited and is soluble in aqueous alkali, having a dry thickness of under 2.5 microns; Layer 2 namely a cold water soluble polyvinyl alcohol (PVOH); Layer 3 namely an adhesive having a thickness of less than 2.5 microns; Layer 4 namely a layer of vacuum-deposited metal or glass of thickness less than 2 microns; and Layer 5 namely a coating which can be readily released from a smooth polymer substrate by peeling the coating of the substrate.

26. A pouch according to claim 25 in which Layer 1 is a solver,r- deposited acrylic.

27. A pouch according to claim 25 or 26 in which Layer 4 is aluminium.

28. A pouch according to claim 25 or 26 in which Layer 4 is a silicon dioxide.

29. A pouch according to claim 25 or any claim dependent thereon wherein Layer 5 is a lacquer of thickness less than 3 microns.

30. A pouch according to claim 27 or 28 in which Layer 4 has a thickness of less than 1.5 microns.

31. A pouch according to any of claims 24-30 in which Layers 6, 7 and 8 as herein defined are laminated to the said Layers 1-5.

32. A pouch according to claim 31 in which the thickness of Layer 6 is less than 2.5 microns.

33. A pouch according to claim 31 or 32 in which the thickness of Layer 7 is from about 20 to 70 microns.

34. A pouch according to claim 31, 32 or 33 in which the thickness of Layer 8 is less than 2.5 microns.

35. A method of making a film laminate for use as a wall of an ostomy pouch, comprising the steps of (i) forming a laminate consisting of a smooth polymer film and Layers 5 to 1 as herein defined in that order (ii) peeling off the smooth polymer film and, optionally, (iii) laminating Layers 8 and 7 as herein defined to said Layers 5 to 1 using Layer 6 as herein defined.