IP Library Granted Patent US 7,759,537
Granted Patent B2
US 7,759,537 · App. 11/055,931 · Granted Jul 20, 2010

Multi layered wound dressing

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Quick Facts
Patent No.
US 7,759,537
App. No.
11/055,931
Granted
Jul 20, 2010
Kind
B2
Abstract

A multi layered wound dressing for use on wounds producing high levels of exudate, the dressing comprising a transmission layer having a high MVTR; an absorbent core capable of absorbing and retaining exudates; and a wound contacting layer which transmits exudate to the absorbent core, the absorbent core and wound contacting layer limiting the lateral spread of exudate in the dressing to the region of the wound.

Claims (33)

1. A multi layered wound dressing for use on wounds producing high levels of exudate, the dressing comprising:

a transmission layer having an MVTR of at least 300 gm 2 /24 hours;

an adhesive;

an absorbent core comprising gel forming fibres and capable of absorbing and retaining exudates;

a wound contacting layer comprising gel forming fibres and which transmits exudate to the absorbent core; and

a keying layer positioned on the absorbent core and bonding the absorbent core to the wound contacting layer,

the transmission layer overlying the adhesive which overlies the absorbent core and

the absorbent core and wound contacting layer limiting the lateral spread of exudate in the dressing to the region of the wound.

2. The dressing according to claim 1 capable of handling at least 6 g of fluid per 10 cm 2 of dressing in 24 hours.

3. The dressing according to claim 2 capable of handling at between about 8 g and about 15 g of fluid per 10 cm 2 of dressing in 24 hours.

4. The dressing according to claim 1 in which the gel forming fibres of the wound contacting layer are chemically modified cellulosic fibres in the form of a fabric.

5. The dressing according to claim 4 in which the fibres are carboxymethylated cellulose fibres.

6. The dressing according to claim 1 in which the wound contact layer has a low lateral wicking rate from 5 mm per minute to 40 mm per minute.

7. The dressing according to claim 1 in which the wound contact layer has a fibre density between 25 gm 2 and 55 gm 2 .

8. The dressing according to claim 7 in which the wound contact layer has a fibre density of 35 gm 2 .

9. The dressing according to claim 1 wherein the absorbent core has an absorbency of exudate of at least 10 g/g.

10. The dressing according to claim 1 wherein the absorbent core has a rate of lateral wicking of less than 20 mm per minute.

11. The dressing according to claim 1 wherein the absorbent core is fibrous.

12. The dressing according to claim 11 wherein the fibre density in the absorbent core is between 150 gm 2 and 250 gm 2 .

13. The dressing according to claim 12 wherein the density is approximately 200 gm 2 .

14. The dressing according to claim 1 wherein the gel forming fibres of the absorbent core are sodium carboxymethylcellulose fibres.

15. The dressing according to claim 1 wherein the absorbent core is a blend of gel forming fibres and cellulosic fibres.

16. The dressing according to claim 15 wherein the absorbent core is a blend in the range of up to 25% cellulosic fibres by weight and 75% to 100% gel forming fibres by weight.

17. The dressing according to claim 15 wherein the blend is in the range of up to 50% cellulosic fibres by weight and 50% to 100% gel forming fibres by weight.

18. The dressing according to claim 17 wherein the blend is in the range of about 50% cellulosic fibres by weight and about 50% gel forming fibres by weight.

19. The dressing according to claim 1 wherein the keying layer is a polyamide web.

20. The dressing according to claim 1 wherein the transmission layer is a foam.

21. The dressing according to claim 1 wherein the transmission layer is a polyurethane foam laminated to a polyurethane film.

22. The dressing according to claim 1 including one or more layers selected from the group consisting of a soluble medicated film layer; an odour-absorbing layer; a spreading layer, and an additional adhesive layer.

23. The dressing according to claim 1 wherein the dressing is self-adhesive.

24. The dressing according to claim 1 wherein the dressing is non-self-adhesive.

25. The dressing according to claim 1 wherein the dressing is between 2 mm and 4 mm thick.

26. The dressing according to claim 1 wherein shrinkage of the dressing when wet is less than 25%.

Assignments (10)
RELEASE OF SECURITY INTEREST Recorded Oct 25, 2019
From: WILMINGTON TRUST (LONDON) LIMITED
To: CONVATEC TECHNOLOGIES INC.
Reel/Frame 050831/0001 →
SECURITY AGREEMENT Recorded Nov 3, 2016
From: CONVATEC INC.; CONVATEC TECHNOLOGIES INC.; 180 MEDICAL, INC.; PRN MEDICAL SERVICES, LLC
To: WILMINGTON TRUST (LONDON) LIMITED, AS COLLATERAL AGENT
Reel/Frame 040552/0227 →
RELEASE OF SECURITY INTEREST Recorded Nov 2, 2016
From: JPMORGAN CHASE BANK, N.A.
To: CONVATEC TECHNOLOGIES, INC.; CONVATEC LIMITED; UNOMEDICAL LIMITED; UNOMEDICAL A/S
Reel/Frame 040543/0357 →
SECURITY AGREEMENT Recorded Jan 6, 2011
From: CONVATEC TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A., AS COLLATERAL AGENT
Reel/Frame 025591/0856 →
RELEASE OF SECURITY INTEREST AT 021901/0419 Recorded Jan 4, 2011
From: J.P. MORGAN EUROPE LIMITED
To: CONVATEC TECHNOLOGIES, INC.
Reel/Frame 025580/0879 →
SECURITY AGREEMENT Recorded Dec 1, 2008
From: CONVATEC TECHNOLOGIES INC.
To: J.P. MORGAN EUROPE LIMITED
Reel/Frame 021901/0419 →
RELEASE OF SECURITY INTEREST Recorded Nov 28, 2008
From: J.P. MORGAN EUROPE LIMITED
To: CONVATEC INC.
Reel/Frame 021890/0786 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 29, 2008
From: BRISTOL-MYERS SQUIBB COMPANY; CONVATEC, INC.
To: CONVATEC TECHNOLOGIES INC.
Reel/Frame 021754/0611 →
SECURITY AGREEMENT Recorded Aug 12, 2008
From: CONVATEC INC.
To: J.P. MORGAN EUROPE LIMITED
Reel/Frame 021371/0796 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 5, 2005
From: BISHOP, STEPHEN M.; GRIFFITHS, BRYAN; LINNANE, PATRICK G.; LYDON, MICHAEL J.; SHAW, HELEN
To: BRISTOL-MYERS SQUIBB COMPANY
Reel/Frame 016010/0134 →