GB2249266A

GB2249266A - Wound dressing pack

Info

Publication number: GB2249266A
Application number: GB9123279A
Authority: GB
Inventors: David Fitzgerald Webster
Original assignee: Smith and Nephew PLC
Current assignee: Smith and Nephew PLC
Priority date: 1990-11-02
Filing date: 1991-11-04
Publication date: 1992-05-06
Anticipated expiration: 2011-11-04
Also published as: GB9123279D0; GB2249266B

Abstract

The pack comprises a wound dressing foam sheet 2 and a core 3 on which the sheet is wound in the form of a roll, one end margin 5 of the wound-facing side of the sheet being releasably secured to the core by a skin adhering adhesive 4. The other end margin of the wound-facing side may be releasably attached to the roll or may be held on the roll by a sleeve or overlapping wrap of material. The dressing sheet may comprise a hydrophilic polyurethane foam having a backing layer of moisture vapour transmitting film and a wound-facing layer of conformable polymer net. <IMAGE>

Description

DRESSING PACKS The invention relates to dressinc packs and processes for their preparation.

Dressings for use on extensive exuding wounds such as leg ulcers or burns usually comprise wound dressing sheet of general rectangular shape. Such a dressing sheet can have a length or width dimension of up to 100cm or more and is often packaged flat and unfolded within a flat pack. The dressing sheet in use is removed from the pack, preferably under sterile conditions, applied to the wound area and held in place on the patient by bandages, tapes or other suitable fastening means. It has been found, however, that flat packs containing larger dressing sheets can be awkward to store and handle. Furthermore, it has also been found that dressing sheets which comprise a resilient layer such as a conformable foam layer, after application to wound area, tend to "spring" away from the wound or skin area before the bandage, tape or other fastening means can be applied.United States Patent No. 3491753 discloses a dressing pack which comprises a large medical dressing for burns comprising a rectangular foam sheet which is in the form of a roll and which in use can be applied around a limb or torso of a patient and secured by fastening together outwardly extending portions of the foam sheet in a face to face relationship. A foam sheet and in particular a resilient foam sheet of such a dressing pack, however, may be difficult to manufacture in roll form. Furthermore the foam sheet does not have a means to anchor the dressing over the wound area to thereby prevent the foam sheet lifting or "springing" away from.

the wound area after application thereto but prior to being fastened. A dressing pack has now been found which overcomes the problems of prior art dressing sheets.

Accordingly the present invention provides a dressing pack which comprises a wound dressing sheet of general rectangular, oval or other suitable shape and a core on which the sheet is wound in the form of a roll wherein one end margin of the wound facing side of the sheet is releasably secured to the core by a skin adhering adhesive.

The dressing pack of the invention thus comprises a wound dressing sheet which is roll form. The pack will normally have a cylindrical shape. Such a pack containing a larger dressing sheet will therefore be more compact and easier to store and handle than a flat pack containing a dressing sheet of a similar size.

When the dressing pack of the invention is used to treat a wound, the wound dressing sheet roll of the pack can be unrolled, applied to the wound area and held in place on the patient by a conventional taping or bandaging or other suitable fastening means.

The end margin of dressing sheet roll used in the invention, however, is attached to the core by a releasable skin adhering adhesive. Such an end attachment fixes one end of the sheet within the roll and thereby advantageously allows the rolled dressing sheet to be unrolled in a controlled manner from the core.

Furthermore, releasable skin adhering adhesive on the end margin of the dressing sheet allows the core to be removed from the sheet and in use the dressing sheet at that end margin, to be adhered to skin adjacent to the wound area so that the dressing sheet can be anchored over the wound area prior to its being held on the patient by a conventional bandaging or taping fastening procedure. The dressing sheet and in particular a resilient conformable dressing sheet, such as a foam sheet as hereinafter mentioned, can be held in contact with the wound area prior to being fastened by attaching the non-attached end of the dressing sheet for example using adhesive tape, to the skin or to the back of a portion of the sheet, which is wrapped around a limb or torso of the patient.

It is preferred, however, that the dressing sheet used in the invention has a skin adhering adhesive on the end margin of the wound facing side thereof which is not attached to the core. The adhesive on this end margin can be covered by a removable protector such as a release-coated film, paper or plastics coated paper.

The skin adhering adhesive on this end margin of the dressing sheet can advantageously allow the anchored dressing sheet to be adhered to the skin adjacent to the other side of the wound area or to be adhered to the back of an overlapped portion of the sheet wrapped around a limb or torso of the patient so that dressing sheet is held in contact with the wound area prior to its being held on the patient by the normal fastening procedure.

The non-attached end of the dressing sheet roll used in the dressing pack of the invention is preferably fixed to the roll by a fastening means to inhibit the end lifting where the pack is opened. Such fastening means can include an adhesive tape or an adhesive on the end margin of the sheet which releasably adheres the end to the back of the dressing.

However, when the dressing sheet comprises a surface layer as hereinafter described which can be damaged or ripped by pulling of a releasable adhesive, it is preferred that the unattached end of the dressing sheet is held on the roll by a sleeve or overlapping wrap of material such as paper or plastics fili.

The overlapped end of the overwrap can be sealed by any convenient means such a heat-sealing or adhesive. The other end of the wrap can be held by interleaving the end portion of the wrap within the outer layers of the dressing sheet roll.

The core of the dressing pack can have a length which is similar to that of the width of the dressing sheet so that the ends of the core are coterminus with the roll edges. It is preferred, however, that the core extends beyond one or both edges of the roll to provide the core with a handle or handle portions to facilitate handling of the roll in use. Such a handle or handle portions can suitably have a length of 1 to locum and can preferably have a length of 2.5 to 7.5cm for example 5cm.

The diameter of the core can be adapted in size to the length and width of the dressing sheet. A core diameter of 1.5cm to 3cm has to be suitable for a sheet of lengths of at least lm, aptly upto Zm and typically about 2 or 3m and widths of upto 40cm cr more eg. upto 50cm.

The core can be made of the rigid materials used for surgical adhesive tape cores such as cardboard or plastics providing that core outer surface allows adhesion and release of the adhesive without contamination of the surface thereof.

The wound dressing sheet of the pack of the invention will normally comprise of a conformable absorbent material.

Highly suitable absorbent materials for use in the invention are conformable hydrophilic foams.

Favoured conformable hydrophilic foams are hydrophilic polyurethane foams. Suitable hydrophilic foams for use in the invention are disclosed in European Patent No.

0059049.

The hydrophilic foam material can suitably have a thickness of 0.5mm to 20mm, more suitably 0.8mm to 15mm and preferably lmm to 12mm for example 1.5mm to 6mm.

The wound dressing sheet used in the invention can comprise a continuous moisture vapour transmitting conformable film. The film can favourably be a backing or an outer layer of the dressing sheet such as a dressing sheet which comprises a conformable hydrophilic foam as herein before described.

Such a continuous moisture vapour transmitting backing or outer layer may be used to regulate the moisture loss from a wound area under the dressing and also act as a barrier to bacteria on the outside of the dressing penetrating to the wound area. Suitable continuous moisture vapour transmitting conformable films which have a moisture vapour transmitting rate of 300 to 5000g/m2/24 hours at 370 at 100t to 10% relative humidity difference (measured in an upright position by the Payne cup method) are disclosed in European Patent No. 0059049.

The dressing sheet used the invention is preferably relatively non-adherent to wounds. A dressing sheet which comprises a hydrophilic foam material can favourably have a wound facing layer which comprises of a non-adherent layer of conformable net, such a net of elastomeric polymer. Suitable nets of this type are disclosed in the herein abovementioned European Patent.

Favoured dressings sheets used in this invention are low adherency wound dressing sheet which comprise of a wound facing layer of conformable elastomeric polymer net, an intermediate absorbent ayer of conformable hydrophilic foam and an outer layer of conformable moisture vapour transmitti=g film. Such dressing sheets and methods for their preparation are described in the herein above mentioned European Patent No. 0059049. Suitable wound dressing sheets of this type are known as Allevyn (Trade mark cf Smith and Nephew Associated Companies plc).

The skin adhering adhesive on one or both end margins of the dressing sheet used in the invention can be any of the pressure sensitive adhesives conventionally used on adhesive wound dressings. Such pressure sensitive adhesives can releasably attach an end margin of the dressing to the core.

Preferred pressure sensitive adhesives for use in the invention are moisture vapour transmitting as a continuous layer. Suitably adhesives of this type are disclosed in the aforementioned European Patent.

Favoured pressure sensitive adhesives for use in the invention comprise a polyvinyl ethyl ether or an alkyl acrylate acrylic acid copolymer.

The weight per unit area of adhesive on the end margins of the dressings sheet can suitably be 15g to 70g/m2 and can preferably be 20 to 409 m2 for example 25 to 30g/m2.

The width of adhesive on an end margin of the dressing sheet can suitably be 0.3mm to 20mm and preferably 4mm to 15mm for example 5mm to lOmm.

The dressing pack of the invention preferably comprises a dressing sheet which is sterile and within a bacteria proof pack. Suitable bacteria proof packs include heat sealable aluminium foil/plastics film laminates such as aluminium foil/polyester or polyamide laminates. Favoured wound dressing sheets of the dressing pack of the invention are highly suitable for use on exuding wounds such as burns or leg ulcers.

The size of these rectangular, oval or other suitably shaped dressing sheets can be adapted to the area of wound to be treated. Rectangular dressing sheets of sizes 10 x locum, 20 x 20cm, 40 x 20cm, 40 x 50cm and 100 x 40cm have been found suitable for treating leg ulcers or burns. Dressings which have been found more suitable have a width of greater than 40cm and a length of at least 100cm. Preferably the larger dimension of the dressing is less than 300cm.

In another aspect the invention provides a process for the preparation of the dressing pack of the invention, which comprises providing a releasable skin adhering adhesive at an end margin of the wound facing side of a dressing sheet of general rectangular shape, attaching a core to the adhesive and winding the sheet into a roll upon the core.

The process thus provides a simple and convenient method for forming the dressing sheet into a roll.

In the process of the invention adhesive can be provided at the end margin of the dressing sheet by any suitable conventional coating process such as solvent, an emulsion or hot melt coating process.

It is preferred, however, that the adhesive is provided on the end margin by a transfer coating process in which the adhesive for exanple as a strip is coated onto a release surface and then transferred onto the end margin of the dressing sheet by bringing the sheet in contact with the adhesive on the release surface. When the release surface is a release coated paper or plastics film the adhesive can conveniently be coated as a strip onto a slightly wider release strip of release coated paper or film and the coated release strip laminated to the end margin or of the dressing sheet. The release strip can then be removed to expose the adhesive for attachment to the core.

Adhesive on the end margin of the dressing sheet which is not attached to the core can provide by a similar process. When the adhesive is provided a transfer coating using a release strip of paper a film the release strip can conveniently be left in place to act as a protector.

After the roll has been formed the roll can be provided with an overwrap or sleeve or adhesive tape closure to hold the free end of the sheet in place.

The roll can then be sealed within a suitable bacteria proof pack and sterilised within the pack by a suitable sterilisation method such as ethylene oxide or gamma irradiation.

The invention will now be illustrated with reference to the following drawings in which: Fig 1. is an end cross section of a dressing pack of the invention.

Fig 2. is longitudinal cross section of a dressing sheet of the dressing pack of Fig 1 in unrolled form and ready for use.

Fig 3. is a longitudinal cross section of another dressing sheet similar to that of Fig 2.

Fig 4. is a elevated view of another dressing pack of the invention.

Fig 1 shows a dressing pack 1 of the invention which comprises a wound dressing foam sheet 2 of rectangular shape and a core 3 on which sheet 2 is wound in the form of a roll. Sheet 2 has skin adhering adhesive 4 on an end margin 5 of the wound facing side 6 thereof which releasably attaches sheet 2 to core 3.

Dressing pack 1 shown in Fig 1 has a bacteria-proof pouch 7 containing rolled sheet 2.

Fig 2 shows the dressing sheet 2 of Fig 1 in unrolled form. Dressing sheet 2 is shown in Fig 2 with core 3 removed and adhesive 4 on end margin 5 of the wound facing side 6 exposed ready for attachment to the skin of a patient.

Fig 3 shows a dressing sheet 8 similar to that of Fig 2 except that the non-attached end margin 9 is provided with adhesive 10 and release protector 11 which can be removed to expose adhesive 10.

Fig 4 shows another dressing pack 12 of the invention similar to that of Fig 1 in which the core 3 has an extended portion 13 to facilitate handling of the rolled sheet 2 during use.

Dressings sheets 2 and 9 can be used as a dressing for wounds for example exuding wounds such as burns or leg ulcers by applying sheet 2 or 9 as a flat sheet as shown in Fig 2 and 3 to the wound area and adhering adhesive 4 at end margin 5 to the skin adjacent to the wound area so that the dressing covers the wound area. The other end of the sheet 2 or 9 can then be attached to the skin adjacent to the other side of the wound area or to the back of the dressing sheet by adhesive tape or adhesive 5 of sheet 9, when sheet 2 or 9 is wrapped around the affected limb or torso, to hold the dressing sheet against the wound area prior to being held in place on the patient by the usual bandaging or taping fastening means.

The dressing pack of the invention has several advantages over conventional dressing packs which comprise of absorbent wound dressing sheet within a flat pack. The wound dressing sheet within pack is in the form of roll which is more compact and therefore easier to handle and store than a flat pack. The dressing sheet has adhesive at one end which can be attached to a core to enable the sheet to be simply wound up into a roll. The adhesive attachment of the sheet to the core also fixes one end of the sheet within the roll to enable the sheet and in particular a resilient foam sheet to be unrolled from the core in a controlled manner. The adhesive at the end margin of the sheet enables the dressing sheet used in the invention to be anchored to the skin so that the dressing sheet can be held against in wound area prior to fixing by the conventional fastening means such as bandaging or taping.

Claims

1. A dressing pack which comprises a wound dressing foam sheet and a core on which the sheet is wound in the form of a roll wherein one end margin of the wound facing side of the sheet is releasably secured to the core by a skin adhering adhesive.

2. A dressing pack according to claim 1 wherein the end margin of the wound facing side of the wound dressing sheet which is not attached to the core is releasably attached to the roll by fastening means.

3. A dressing pack according to claim 2 in which the fastening means is an adhesive tape or an adhesive on the end margin.

4. A dressing pack according to claim 1 wherein the end margin of the wound facing sheet which is not attached to the core is held on the roll by a sleeve or overlapping wrap of material.

5. A dressing pack according to claims 1 to 4 wherein the core extends beyond one or both edges of the roll thereby providing the core with a handle or handle portions.

6. A dressing pack according to claims 1 to 5 wherein the dressing sheet comprises a conformable hydrophilic foam.

7. A dressing pack according to claim 6 wherein the sheet has a thickness of 0.5 to 20mm.

8. A dressing pack according to any of claims 1 to 7 wherein the dressing sheet comprises an outer continuous moisture vapour transmitting conformable film.

9. A dressing pack according to any of claims 1 to 8 wherein the wound dressing sheet comprises a non-adherent conformable net.

10. A dressing pack according to any of claims 1 to 9 wherein the adhesive is a'moisture vapour transmitting layer.

11. A dressing pack according to any of claims 1 to 10 wherein the adhesive is a continuous layer.

12. A dressing according to any of claims 1 to 11 wherein the adhesive is polyvinyl ethly ether or an alkyl acr4ylte acrylic acid copolymer.

13. A dressing pack according to any one of claims 1 to 12 wherein the width of adhesive on an end margin is in the range of 0.3mm to 20mm.

14. A dressing pack according to any one of claims 1 to 13 wherein the weight per unit area of adhesive is in the range of 15 to 70g/m2.

15. A dressing pack according to any one of claims 1 to 14 wherein the dressing pack is a bacteria-proof pack.

16. A dressing pack according to any one of claims 1 to 15 wherein the dressing pack comprises a heat sealable aluminium foil/plastics film laminate.

17. A process for the preparation of the dressing pack as claimed in any of claims 1 to 16 which comprises providing a releasable skin adhering adhesive at an end margin of the wound facing side of a dressing sheet, attaching a core to the adhesive and winding the sheet into a roll upon the core.

18. A dressing pack substantially as hereinbefore described with reference to the accompanying drawings.