WO1998001166A1

WO1998001166A1 - Treatment of wounds

Info

Publication number: WO1998001166A1
Application number: PCT/GB1997/001813
Authority: WO
Inventors: Trisha Grocott; Simon Ashley Dixon; Martyn Edward Leat; Nada Walker; Duncan Gilding
Original assignee: Innovative Technologies Limited
Priority date: 1996-07-04
Filing date: 1997-07-04
Publication date: 1998-01-15
Also published as: GB9614034D0; AU3626697A

Abstract

A kit for the treatment of chronic wounds (e.g. fungating carcinomas) of an irregular 3D nature comprising a breathable film which is of increased MVTR capability in the presence of liquid water as compared to moisture vapour only and an agent for infection contact.

Description

TREATMENT OF WOUNDS

The present invention relates to the treatment of chronic wounds of an irregular 3D nature. The invention relates more particularly (but not exclusively) to the treatment of fungating carcinomas, i.e. cancers that erupt tluough the skin causing a continuous breakdown of surface tissues either by cancerous undermining or excess exudate levels eroding the periphery. All of these wounds are heavily colonised, predisposed to infections and malodorous. The wounds degrade the life of both the patient and the carer.

Patients affected with fungating carcinomas spend their full time in palliative care with a life expectancy of 12 to 48 months. There are currently around 2000-2500 such patients in the U.K.

According to a first aspect of the present invention there is provided a kit for the treatment of irregular 3D wounds comprising a breathable film which is of increased MVTR capability in the presence of liquid water as compared to moisture vapour only, and an agent for infection control.

The agent for infection control serves not only to control infection but also limit odour.

Examples of wounds to which the kit of the present invention is applicable include fungating carcinomas and diabetic ulcers.

In one preferred embodiment of the invention, the breathable film is preformed so as to be contoured to the portion of the body and/or the shape of the wound to which the dressing is to be applied. Such contoured dressings may be formed, for example, by a dipping process using a former corresponding to the desired "shape" of the dressing and provide a convenient way of dressing an irregular 3D wound.

For heavily exuding wounds (e.g. fungating carcinomas) it is preferred that such contoured dressings include two apertures (e.g. upper and lower apertures) such that exudate may be drained from one aperture and treatment agents introduced to the wound through the other aperture. Exudate drainage may be by means of a tube attached to the film. The tube may drain into a bag or the like. Conveniently there is a collar, flange or the like (e./g. a (lal annular ring) located around the drainage aperture for the purpose of mounting the tube in position. Alternatively, the bag may be mounted directly onto the film such that exudate passes through the aperture directly into the bag. Examples of treatment agents which may be introduced through the other aperture (which may also be surrounded by a collar, flange or the like) include further infection control agent or iodine to clean the wound.

As an alternative to the use of pre-contoured films the kit of the invention may include

(i) an absorbent wound packing material to pack the wound and absorb fluid;

(ii) a gel or gel forming agent to fill the wound cavity and absorb fluid;

(iii) in-situ space forming agents to act as a plug.

The components (i)-(iii) may be used for filling or packing the wound so as to provide a more regular "structure" to which a flat breathable film may be applied. It is however also possible to incorporate one or more of components (i) to (iii) in a kit incorporating a pre-contoured film dressing.

Examples of (i) include absorbent fibrous materials such as alginates in any of a variety of formats, e.g. ropes, felt or wool. Preferred examples of (I) comprise alginate fibres co-spun with at least one other polysaccharide as disclosed in WO-A- 96/10106 (Innovative Technologies). A particular example of (ii) is an alginate gel. Preferred examples of (ii) are compositions as disclosed in WO-A-96/13285 (Innovative Technologies) and our copending U.K. Patent Application No. 9609474. examples of (iii) include foams and gels.

Alternatively or additionally the kit may incorporate a polysaccharide which may be applied as a spray (e.g. from an aerosol) to fill the wound.

The purpose of the film is lo cover the wound and block out odour. The film also vents fluid from the wound, protects clothing from wound fluid and prevents ingress of dirt, bacteria and other micro-organisms into the wound. The film may be provided with an adhesive (e.g. a patterned adhesive) which allows passage of moisture vapour tlirough the adhesive layer. There may be a greater density of adhesive around the peripheral region of the dressing than in the central region. In fact, a relatively thick layer of adhesive may be required around the periphery of films to be used as dressings for fungating carcinomas in view of the very high levels of exudate.

As indicated, the film is a breathable film which is increased MVTR capability in the presence of liquid water as compared to moisture vapour only. MVTR in the presence of liquid water may be measured by ASTM E96BW whereas MVTR in the presence of moisture vapour alone may be measured by ASTM E96B (water method). Preferably the value of the breathability in the presence of liquid water is at least twice and preferably at least three times that in the presence of moisture vapour alone. The value may be up to 30 or 40 times that for moisture vapour alone. Typically the film will be of a material which has an MVTR in the presence of moisture vapour alone (ASTM E96B) of 2,000 to 2,500 g m^"2 24hr^'' and an MVTR in the presence of liquid water (ASTM E96BW) in the range 6,000 to 30,000 g m^'2 24hr^"' (e.g. 600 to 10,000 g m^"2 24hr^"'). Typically the film will have a thickness of 30-70 microns more preferably 40-60 microns, e.g. about 50 microns.

The film may for example be of polyurethane. Suitable films are available from Innovative Technologies Limited under the designations B532. C542 and D562.

Preferably the agent for infection control comprises a solution or paste of a non-reducing sugar and iodine in a vehicle consisting essentially of a pharmacologically acceptable glycol and. optionally, water. Such a composition is disclosed in WO-A-94/1781 1 ( cConn-Stern) and is referred to herein as a composition of the kind defined. The principal use of the composition of the kind defined as disclosed in WO-A-94/1781 1 is in veterinary medicine, particularly the treatment of mastitis. Other applications disclosed in WO-A-94/1781 1 include treatment of deep varicose vein ulcers, burns, and decubitus ulcers in human patients. All compositions disclosed in WO-A-94/1781 1 may be used in the present invention. Alternatively the agent for infection control may be a debride ent enzyme such as PHM-101 (ex Phairson Ltd.).

The infection control agenl may, for example, be provided in the form of an ointment, e.g. in a table. However, irrespective of its exact chemical formulation or physical form the agent is applied to the exposed surfaces ofthe wound.

The kit in accordance with the invention may be used, for example, for the treatment of diabetic ulcers but is particularly suitable for treatment of fungating carcinomas for which purpose it is particularly preferred that the agent for infection control is a composition of the kind defined. The composition controls the infections and foul odour associated with fungating carcinomas without being toxic. Therefore according to a second aspect of the present invention there is provided the use of the composition of the kind defined for the manufacture of a medicament for the treatment of fungating carcinomas.

It will be appreciated that the wound treatment regimes contemplated by the present invention allow the treatment of fungating carcinomas by controlling the flow of fluid out of the wound, preventing further erosion of the wound, minimising ongoing infection and odour and controlling exudate flow. The kits allow treatment to be tailored to the requirements of a particular patient and are substantially cheaper than conventionally used dressings which cost about £ 10- 100/patients/day and are not entirely effective. The reason why the prior art dressings are not effective is that they tend to be flat rectangular sheets that do not have the conformability to fit the 3D structures of the fungating wound or the site, and leakage occurs around the edge. Disadvantages are overcome by the kits of the present invention.

Claims

1. A kit for the treatment of chronic wounds of an irregular 3D nature comprising a breathable film which is of increased MVTR capability in the presence of liquid water as compared to moisture vapour only and an agent for infection contact.

2. A kit as claimed in claim 1 wherein the breathable film is of a three- dimensionally contoured shape.

3. A kit as claimed in claim 2 wherein the film is provided with two apertures.

4. A kit as claimed in claim 3 wherein at least one of the apertures is surrounded by a collar, flange or the like.

5. A kit as claimed in claim 3 or 4 additionally provided with an exudate drainage table.

6. A kit as claimed in any one of claims 1 to 5 further comprising one or more of

(i) an absorbent wound packing material to pack the wound and absorb fluid;

(ii) a gel or gel forming agent to fill the wound cavity and absorb fluid;

(iii) in-situ space forming agents to act as a plug.

7. A kit as claimed in claim 6 which incorporates an absorbent wound packing material (i) and said packing material is an alginate. for example a rope, felt or wool.

8. A kit as claimed in claim 6 or 7 which incorporates a gel (ii) and said gel is an alginate gel.

9. A kit as claimed in any one of claims 1 to 8 wherein the agent for infection control is a composition of the kind defined.

10. A kit as claimed in any one of claims 1 to 8 wherein the agent for infection control is a wound debridement enzyme.

1 1. A kit as claimed in any one of claims 1 to 10 further comprising a polysaccharide to be applied to the wound as a spray to fill the wound.

12. A kit as claimed in any one of claims 1 to 1 1 wherein the film has an MVTR in the presence of water vapour alone of 2,000 to 2,500 g m^~2 24hr^"' and an MVTR in the presence of liquid water in the range of 6,000 to 30,000 g m^"2 24hf '.

13. A kit as claimed in any one of claims 1 to 12 wherein the film has a thickness of 30 to 70 microns.

14. The use of a composition of the kind defined in the manufacture of a medicament for the treatment of fungating carcinomas.

15. A method of treating a fungating carcinoma comprising using a therapeutically effective amount of a composition of the kind defmed.