CA2210224A1

CA2210224A1 - Self-adhesive laminate

Info

Publication number: CA2210224A1
Application number: CA 2210224
Authority: CA
Inventors: Thomas Gilchrist; David Michael Healy
Original assignee: Individual
Current assignee: Giltech Ltd
Priority date: 1995-01-14
Filing date: 1996-01-12
Publication date: 1996-07-18
Also published as: WO1996021410A1; AU4353296A; GB9500716D0; EP0802777A1; JPH10511881A

Abstract

There is provided a laminate suitable for use as a wound dressing or as a transdermal medicament delivery system. The laminate is comprised of a carrier sheet sandwiched between a removable cover sheet and a removable backing sheet. The laminate has a cover sheet tab and a backing sheet tab, both tabs extending away from the carrier sheet. The laminate also comprises a holding portion. The holding portion and the two tabs facilitate application of the carrier sheet, which is normally in polyurethane film, to a surface of the patient and avoids stretching or wrinkling the carrier sheet. The carrier sheet will normally comprise a therapeutic agent, such as a bacteriostat and may be provided with an adhesive island to cover the wound.

Description

WO 96/21410 I'CT/GB96/00055 "SELF--ADHESIVE T.~MTN~E"

3 This invention relates to a laminate, and relates 4 particularly but not exclusively to a dressing which is self-adherent to body surfaces around a wound.

7 In recent years, laminates for use as wound dressings 8 have become available which are based on plastics 9 films, commonly polyurethane films. The film may contain or act as a carrier for substances which act as 11 bacteriostats or promote healing, for example, silver 12 salts or alginates.

14 Film dressings of this nature have considerable advantages. Firstly, they can readily be produced in 16 transparent form and thus allow the condition of a 17 wound to be monitored without removing the dressing.
18 Secondly, they can be produced in micro-porous forms 19 which allow movement of water vapour to the exterior of the dressing and movement of air to the interior of the 21 dressing while preventing movement of bacteria through 22 the dressing; this is of particular benefit in treating 23 exuding wounds such as burns.

To date, a disadvantage associated with known film l dressings has been that they can be difficult to apply 2 to a wound. It is usual for a film dressing to have an 3 adhesive layer for application to the skin of a user, 4 the adhesive layer being initially covered by a release paper. Once the release paper is removed from the 6 adhesive layer, the film is delicate and difficult to 7 handle. Stretching of the film can destroy its barrier 8 integrity, whilst a lack of tension during application 9 can lead to wrinkling. For these reasons, most film dressings currently used are provided with a stiffening ll edge or frame on the outer face, which stiffening must 12 be removed after the dressing has been applied. Known 13 arrangements of dressings can, however, be undesirably 14 complex to apply to a wound or other desired area.
16 According to a first aspect, the present invention 17 provides a laminate having an associated holding 18 portion, the laminate comprising a carrier sheet 19 sandwiched between a removable cover sheet and a removable backing sheet, the laminate further 21 comprising a cover sheet tab attached to the cover 22 sheet and extending away from the carrier sheet, a 23 backing sheet tab attached to the backing sheet and 24 extending away from the carrier sheet and wherein the holding portion is releasably connected to the carrier 26 sheet and is positioned so that it extends along a 27 substantially central portion of one edge of the 28 laminate.

The laminate may be provided as a dressing, for 31 example, a wound dressing, or a dressing intended to 32 release a medicament or therapeutic agent. In 33 particular the laminate may be suitable as a medium for 34 administration of an active ingredient in a controlled release manner over a relatively long period of time 36 (eg several days to weeks). The active ingredient will CA 022l0224 lgg7-o7-ll WO96/21410 PCT/G~9G/00055 1 normally be suitable for transdermal a~; n; ~tration.

3 The cover sheet tab and backing sheet tab preferably 4 facilitate removal of the cover sheet and backing sheet S respectively from the laminate to facilitate 6 application of the laminate to a wound or other area.

8 The holding portion is preferably attached to the 9 laminate at a substantially central portion of the edge at which it is positioned and/or on each side of that 11 substantially central portion.

13 Preferably, the holding portion extends substantially 14 along one edge of the laminate. The holding portion may be attached to the carrier sheet by means of one or 16 more lines of weakness which may be provided by 17 perforations. The holding portion may be a 18 continuation of the laminate.

The carrier sheet may be formed of a polymeric film 21 material. Preferably, the carrier sheet is 22 substantially porous to vapour and air but is 23 substantially impermeable to particles of dirt or other 24 contaminants, to micro-org~n; ~m~ and pathogens; the carrier sheet may be comprised wholly or partially of 26 polyurethane or of compositions containing 27 polyurethane.

29 The carrier sheet may comprise (for example be impregnated or coated with) a medicament or a 31 therapeutic agent (for example, an antibiotic ~ 32 antiseptic, antibacterial, a bacteriostat), a substance 33 which is intended to promote healing (for example by 34 stimulation of cell growth) or by an absorbent. The carrier sheet may be impregnated with a silver compound 36 or an alginate. The carrier sheet may be provided with CA 02210224 1997-07-ll PCT/GB9G/OOo~i!;

1 an absorbent island, for example an alginate pad, which 2 may cover the area to be treated.
4 A surface of the carrier sheet may be wholly or partially coated with a pressure sensitive adhesive to 6 facilitate its attachment and retention to the area to 7 be treated. The pressure sensitive adhesive may be a 8 skin friendly acrylic adhesive.

The cover sheet tab may be provided by a tab secured to 11 the cover sheet. The cover sheet tab is preferably 12 positioned at the laminate adjacent to the holding 13 portion. The cover sheet tab may extend across the 14 width of the laminate and may be of a similar length to the holding portion.

17 Positioning the cover sheet tab adjacent to the holding 18 portion may facilitate removal of the cover sheet from 19 the laminate in use.
21 Preferably, the holding portion can be held by the user 22 in one hand and the cover sheet tab is pulled away from 23 the holding portion (thus removing the cover sheet from 24 the laminate) by the user using his or her other hand.
26 The backing sheet tab may be provided as an extension 27 of the backing sheet; it may extend beyond a periphery 28 of the carrier layer of the laminate. The backing 29 sheet tab may extend substantially along one edge of the laminate. Preferably, the backing sheet tab 31 extends along a side of the laminate which is opposite 32 the holding portion. The backing sheet tab may be 33 formed of a flexible tape, for example a polypropylene 34 tape; other self-adhesive pressure sensitive tapes are also suitable.

1 The backing sheet may be secured to the laminate by 2 means of adhesion between the material of the backing 3 sheet and the material of the carrier sheet;
4 alternatively, it may be held on the carrier sheet by a separate adhesive material.

7 The backing sheet is preferably affixed to the rear 8 face of the carrier sheet with an adhesiveness which is 9 less than the adhesiveness between the front face of the carrier sheet and the cover sheet or, when the 11 laminate has been affixed to a surface, between the 12 carrier sheet and the surface (for example, where the 13 laminate is a dressing the surface will be the wound to 14 which it is applied).
16 The backing sheet may have instructions for use of the 17 laminate printed on it; it may have a pattern printed 18 on it.

One or more of the carrier sheet, the cover sheet and 21 the backing sheet may be translucent or substantially 22 transparent; this may facilitate visual alignment of 23 the laminate over a wound site when it is to be 24 applied. Where the carrier sheet is substantially transparent, this may facilitate visual inspection of a 26 wound covered by the laminate, when the laminate is in 27 the form of a dressing, without necessitating removal 28 of the dressing from the wound.

The cover sheet tab and/or the backing sheet tab may be 31 coloured and/or have a pattern and/or indications 32 printed on it to identify the tab region to a user.

34 According to a second aspect, the present invention provides a method of applying a laminate in accordance 36 with the first aspect of the invention, in which:

CA 02210224 1997-07-ll 1 a) a user grips the holding portion in one hand and 2 removes the cover sheet from the laminate by 3 holding the cover sheet tab and pulling the cover 4 sheet tab away from the holding portion to detach the cover sheet from the carrier sheet;
6 b) the exposed surface of the carrier sheet is then 7 applied over a wound or other desired area using 8 the holding portion to grip and position the g dressing;
c) the backing sheet is removed from the laminate by 11 gripping the backing sheet tab and pulling the 12 backing sheet tab away from the carrier layer to 13 detach the backing sheet from the carrier sheet;
14 and d) the holding portion is then removed from the 16 positioned carrier sheet.

18 According to a third aspect, the present invention 19 provides a method of manufacturing a laminate in accordance with the first aspect of the invention, said 21 method comprising the following steps:
22 a) providing a laminate having a carrier sheet 23 sandwiched between a cover sheet and a backing 24 sheet;
b) forming a backing sheet tab;
26 c) forming a cover sheet tab; and 27 d) providing said carrier sheet with an associated 28 holding portion.

Embodiments of the present invention will now be 31 described, by way of example only, with reference to 32 the accompanying drawings, of which:-34 Fig. 1 is a plan view of a first embodiment of a laminate in the form of a wound dressing embodying 36 the present invention, prior to use of the PCT/~D3C~O&~

1 dressing;
2 Fig. 2 is a cross-section of Fig. 1;
3 Fig. 3 is a cross-section of a second embodiment 4 of a laminate in the form of a wound dressing embodying the present invention;
6 Fig. 4 is a cross-section of a third embodiment of 7 a laminate in the form of a wound dressing 8 embodying the present invention; and g Fig. S is a cross-section of a fourth embodiment of a wound dressing embodying the present 11 invention.

13 The laminate of the dressing 1 shown in Fig 1 comprises 14 a carrier sheet 10 in the form of a transparent and permeable polyurethane film. A front face of the film 16 lo (the lower face as viewed in Fig 2) is coated with 17 an adhesive layer 12 which may be of any adhesive 18 material suitable for medical or veterinary use; in 19 this embodiment the material is a pressure-sensitive solvent-based acrylic compound. The adhesive material 21 of the layer 12 and the polyurethane carrier sheet 10 22 may comprise a bacteriostatic silver compound such as a 23 soluble glass containing silver orthophosphate. The 24 layer 12 is covered by a cover sheet 14 which is a transparent polymer sheet held in place by the adhesive 26 layer 12.

28 The right edge of the cover sheet 14 (as viewed in Fig 29 2) is provided on its outer edge with a holding portion 14a which is an extension of the laminate, releasably 31 connected to the carrier sheet 10. Immediately in from ~ 32 the holding portion 14a, the cover sheet 14 is also 33 provided with a pull tab 15 having a free-standing 34 extension flap 15a. The holding portion 14a extends along a substantially central portion of the edge of 36 the dressing 1. The holding portion 14a may thus be W096/21410 PCT/~ OQ~

1 held at the central portion of this edge to facilitate 2 handling of the dressing 1 and removal of the cover 3 sheet 14. In this embodiment, the holding portion 14a 4 extends along the entire length of the edge of the dressing 1. The pull tab 15 extends across the entire 6 width of the dressing 1 adjacent to the holding portion 7 14a.

9 A rear face of the carrier sheet 10 (the upper face as viewed in Fig 2) is covered by a backing sheet 16 which 11 adheres to the sheet 10 with an adhesiveness which is 12 lower than that between the sneet 10 and the layer 12.
13 The relatively lower tack between the rear face of the 14 carrier sheet 10 and the backing sheet 16 ensures that when the dressing is applied, with the cover sheet 14 16 removed, from the front face of the sheet 10, to a 17 surface of a patient's body and the backing sheet 16 is 18 pulled, the backing sheet 16 separates from the sheet 19 10 while the relatively higher tack of the adhesive in the layer 12 continues to hold the carrier sheet 10 on 21 to the body tissue of the patient. The backing sheet 22 16 is of a transparent polymer film, but other 23 materials such as siliconised paper may alternatively 24 be used for the backing sheet.
26 The laminate of the cover sheet 14, the carrier sheet 27 10 and the backing sheet 16 as described above is 28 available in manufactured strip form from, for example, 29 the Rexham division of Bowater plc.
31 One edge of the dressing 1 (the left edge as viewed in 32 Fig 2) is cut away through the cover sheet 14, the 33 adhesive layer 12 and the carrier sheet 10, but leaving 34 the backing sheet 16 intact across its original width.
This partially cut-away edge of the dressing 1 forms a 36 backing sheet tab 2. The backing sheet tab 2 is an CA 022l0224 lgg7-o7-ll 1 extension of the backing sheet 16 and extends from the 2 backing sheet away from the carrier sheet 10. The 3 backing sheet tab 2 extends substantially along one ., 4 edge of the dressing 1 opposite the edge provided with the holding portion 14a.

7 A score line 20 is formed through the cover sheet 14 8 adjacent and parallel to the edge of the dressing 1 g between the holding tab 14a and the pull tab 15 (avoiding the pull tab extension flap 15a). A line of 11 perforations 21 is formed completely through the 12 dressing 1 below the score line 20 from the same 13 (lower) face of the dressing 1 as the score line 20 is 14 formed. It is to be noted that the relative thicknesses of the various layers shown in the 16 accompanying drawings are not necessarily to scale.

18 In use, the dressing is supplied sterile in a sealed 19 pouch (not shown). At the time and place of use of the dressing 1, the pouch is opened and the dressing 1 is 21 removed from the pouch. The dressing is grasped by the 22 holding portion 14a, and bent around the score line 20, 23 which raises an adjacent edge of the main portion of 24 the cover sheet 14 under the tab 15. The extension flap 15a is gripped by the user who can then peel the 26 cover sheet 14 away from the adhesive layer 12 while 27 holding the tab 14a on the opposite edge.

29 Once the cover sheet 14 has been removed, the dressing 1 is then applied over the wound or other application 31 site and pressed into place on the body tissue around 32 the wound. During this operation, the backing sheet 16 33 maintains the carrier sheet 10 in a dimensionally 34 stable and readily handled condition, allowing the dressing to be secured to the body tissue around the 36 wound or other application site without creasing or CA 022l0224 1997-07-ll 1 stretching of the carrier sheet 10.

3 Thereafter, the backing sheet tab 2 is gripped by the 4 user and is used to peel the backing sheet 16 away from the carrier sheet 10.

7 The holding portion 14a is then removed from the film 8 10 by tearing along the perforations 21 after g application of the main portion of the dressing 1 to the patient, the overlying edge of the carrier sheet 10 11 subsequently being smoothed down onto the body tissue 12 of the patient.

14 The carrier sheet 10 conforms well to the underlying tissue surface because the dressing 1 is flexible in 16 two directions, ie length and width. The act of 17 peeling the cover sheet 14 away from the carrier sheet 18 10 automatically takes the user's hands away from the 19 face of the dressing 1 which will be applied to the patient's tissue, thus avoiding potentially 21 contaminating contact to the wound. As an alternative 22 to removing the holding portion 14a by tearing along 23 the perforations 21, this edge of the dressing 1 could 24 be cut off with scissors after application of the main portion of the dressing 1 to the patient.

27 The dressing 1 may be readily manufactured. It is 28 known to make film dressing material in bulk by 29 laminating polyurethane film with adhesive and release layers. A dressing of the present invention can be 31 made by removing a strip of the carrier sheet 10, 32 adhesive layer 12 and cover sheet 14 along one edge of 33 the dressing 1 to form the backing sheet tab 2, cutting 34 the score line 20 and perforations 21 (for example y using a rotary knife) and cutting the resulting strip 36 across its width at suitable intervals to form CA 022l0224 lgg7-07-ll l individual dressings.

3 An example of a bulk film dressing material consists of 4 a lamination of:-~.
6 sPETl/PUf/PSA/sPET2 8 where:-9 sPETl and sPET2 = siliconised polyethylene terephthalate having different ll silicone linearisations;

13 PUf = polyurethane film;
14 PSA = pressure sensitive adhesive.
16 The PUf (polyurethane film) may be impregnated with a 17 silver-releasing product, for example, a bacteriostat.

l9 A grid pattern (not illustrated) may be printed onto the backing sheet 16 for monitoring wound size. After 2l application of the carrier sheet lO but prior to 22 removal of the backing sheet 16, the outline of the 23 wound can be traced onto the backing sheet. The area 24 of the wound can subsequently be calculated from the outline on the grid, which is also suitable to be 26 retained as a record as it is not cont~;n~ted by 27 contact with the wound, having been spaced from the 28 wound by the intervening polyurethane carrier sheet lO.

Instructions for use of the dressing can be printed on 31 the tabs 2, 14a and 15, as can advertisements and/or ~ 32 other messages.

34 Islands of alginate or other absorbent materials can be pre-located in the centre of the dressing l as an aid 36 to healing.

CA 022l0224 lgg7-o7-ll 1 The embodiments shown in Fig 3, Fig 4 and Fig 5 are 2 generally similar to that shown in Fig 1 and Fig 2.
3 For clarity, the layers of the laminate forming the 4 dressing are shown separated although, in practice, adjacent layers are in contact.

7 In the embodiment of Fig 3, the backing sheet tab 2 is 8 extended by a distance x away from the carrier sheet 10 9 with respect to the previously described embodiment.
Increasing the distance that the backing sheet tab 2 11 extends away from the carrier sheet 10 may permit the 12 user to bend the tab 2 towards the body of the carrier 13 sheet 10 before beginning to peel the backing sheet 16 14 from the carrier sheet 10. This may make the backing sheet 16 easier to peel away without lifting the 16 carrier sheet 10 from the surface to which it has been 17 applied.

19 In the embodiment of Fig 4, the backing sheet tab 2 is formed from a tab member bend around, and secured to, 21 an extension 16a of the backing sheet 16. In this 22 embodiment, the tab 2 may be provided by a piece of 23 tape, for example, a polypropylene tape which may be 24 self adhesive for attachment to the backing sheet extension 16a.

27 In the embodiment of Fig 5, the backing sheet tab 2 is 28 attached to a surface of the backing sheet extension 29 16a by means of a layer of adhesive 3. The tab 2 may be provided in the form of a tape, for example, of 31 polypropylene.

33 As an alternative to a wound dressing, the invention 34 may be utilised as a transdermal medicament delivery system, for example as nicotine supply patches, or, as 36 a non-medical application in the electronics industry.

1 The above described embodiments of the present 2 invention provide a dressing having a number of 3 advantages:

5 - the dressing is easy to apply;

6 - the dressing is protected against stretching 7 during application;

8 - the dressing is protected against creasing during 9 application;

10 - the dressing is not touched by the user during 11 application, reducing problems of contamination;

12 - the amount of waste material is reduced;

13 - the dressing conforms well to uneven surfaces as 14 it is flexible in two directions, ie length and width;
16 - manufacture is simple and a wide range of sizes 17 can readily be produced; for example, the depth of 18 the score line once set provides accurately 19 repeatable performance;
20 - the whole of the dressing is transparent thus 21 allowing the user to see exactly where it is being 22 applied.

Claims

1. A laminate comprising a carrier sheet sandwiched between a removable cover sheet and a removable backing sheet, wherein a cover sheet tab is attached to the cover sheet and extends away from said carrier sheet, wherein a backing sheet tab is attached to said backing sheet and extends away from said carrier sheet, and wherein said laminate comprises an associated holding portion releasably connected to the carrier sheet and positioned so that it extends along a substantially central portion of one edge of said laminate.

2. A laminate as claimed in Claim 1 wherein the holding portion extends substantially along one edge of the laminate.

3. A laminate as claimed in either one of Claims 1 and 2 having perforations between said holding portion and said carrier sheet to facilitate removal of said holding portion.

4. A laminate as claimed in any one of Claims 1 to 3 wherein said carrier sheet is formed of a polymeric film material.

5. A laminate as claimed in any one of Claims 1 to 4 wherein said carrier sheet comprises a medicament or a therapeutic agent.

6. A laminate as claimed in any one of Claims 1 to 5 wherein said carrier sheet is provided with an absorbent island.

7. A laminate as claimed in any one of Claims 1 to 6 wherein said cover sheet tab is adjacent said holding portion.

8. A laminate as claimed in any one of Claims 1 to 7 wherein said backing sheet tab is an extension of said backing sheet or is attached to an extension of said backing sheet.

9. A laminate as claimed in any one of Claims 1 to 8 wherein one or more of said carrier sheet, said cover sheet and said backing sheet is translucent or substantially transparent.

10. A laminate as claimed in any one of Claims 1 to 9 wherein said backing sheet is affixed to the carrier sheet with an adhesiveness which is less than the adhesiveness between the carrier sheet and the cover sheet.

11. A method of applying a laminate as claimed in any one of Claims 1 to 10, in which:
a) a user grips the holding portion in one hand and removes the cover sheet from the laminate by holding the cover sheet tab and pulling the cover sheet tab away from the holding portion to detach the cover sheet from the carrier sheet;
b) the exposed surface of the carrier sheet is then applied over a wound or other desired area using the holding portion to grip and position the dressing;
c) the backing sheet is removed from the laminate by gripping the backing sheet tab and pulling the backing sheet tab away from the carrier layer to detach the backing sheet from the carrier sheet; and d) the holding portion is then removed from the positioned carrier sheet.

12. A method of manufacturing a laminate as claimed in any one of Claims 1 to 10, said method comprising the following steps:
a) providing a laminate having a carrier sheet sandwiched between a cover sheet and a backing sheet;
b) forming a backing sheet tab;
c) forming a cover sheet tab; and d) providing said carrier sheet with an associated holding portion.

13. The use of a laminate as claimed in any one of Claims 1 to 10 as a wound dressing.

14. The use of a laminate as claimed in any one of Claims 1 to 10 as a transdermal medicament delivery system.