Multi-layer absorbent wound dressing

Abstract

A multi-layer wound dressing comprising at least two absorbent layers, and materials for forming absorbent layers are provided. The absorbent layers have different absorbencies, with the layer closest to the wound having a lower absorbency than the layer furthest from the wound. The wound dressing typically contains additional non-absorbing layers, such as a backing film and wound-facing film. The dressing provides absorbency of wound exudates while preventing the absorbent material from entering the wound. In specific implementations the dressing is substantially transparent prior to application to a wound, as well as after application to the wound when body fluids have been absorbed.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a division of U.S. patent application Ser. No. 09 / 657,486, filed Sep. 8, 2000, now U.S. Pat. No. 6,903,243.FIELD OF THE INVENTION [0002] The present invention is directed to novel body fluid absorbing materials; and to absorbent articles used as wound dressings, including multi-layer absorbent articles having at least two absorbent layers. BACKGROUND OF THE INVENTION [0003] Proper wound dressings are an essential medical supply for treating injuries. Without dressings, the wound exudate accumulates and creates breeding grounds for harmful microorganisms. Each year, sterile wound dressings are applied to millions of wounds in order to absorb wound exudate while promoting sterility. [0004] Traditional wound dressings have included various cloth and fiber materials as exudates absorbents, such as cotton pads. Unfortunately, these traditional dressings provide relatively limited absorbency and must be changed frequently....

AI Technical Summary

Benefits of technology

[0008] The present invention is directed to multi-layer wound dressings. The multi-layer wound dressings allow for high absorbency of body fluids while providing good durability and minimal degradation during use. In addition, in specific implementations, the multi-layer wound dressings are transparent and remain transparent when wet; and the dressings can be cut by clinicians to conform to the shape and size of the wound being covered. Also described are novel compositions useful as body fluid absorbing materials.

[0009] The wound dressings of the invention include at least two absorbent layers: a first absorbent layer and a second absorbent layer. The first absorbent layer is typically more absorbent than the second absorbent layer, and can retain a greater volume of body fluids than the second absorbent layer. The second absorbent layer is positioned such that it is located between the first absorbent layer and the wound. This second absorbent layer provides integrity to the wound dressing and avoids transfer of the first absorbent layer into the wound.

[0013] The second absorbent layer functions as a “barrier” between the first absorbent layer (which may partially “disintegrate” when exudate is absorbed under some conditions) and the wound. Preferably the second absorbent layer has adhesive properties (or is a pressure sensitive adhesive) and functions to enhance the overall integrity of the wound dressing. In this regard, the second absorbent layer ties the first absorbent layer to a wound-facing layer (or to the wound itself). By having adhesive properties, this second absorbent layer not only aids in controlling the absorption of exudate, but also physically joins to other components of the dressing.

Problems solved by technology

Unfortunately, these traditional dressings provide relatively limited absorbency and must be changed frequently.

Their ability to preserve sterility is also limited, and scabs that form as the wounds heal tend to stick to the dressings.

After the dressings are removed, these scabs are also removed, which can be painful and interfere with healing.

However, these perforated films do nothing to improve on the absorbency of traditional absorbent materials used in dressings.

Unfortunately, some such dressings have the problem that the absorbent deforms and partially disintegrates upon swelling.

Specifically, as the absorbent takes in fluid, it often bends and buckles such that some of the absorbent material breaks away from the dressing and enters the wound.

This absorbent material can be left in the wound upon removal of the dressing, which is undesirable for cosmetic and therapeutic reasons.

In addition, such materials often have relatively high moisture content prior to application, which can limit their ability to absorb additional water after they are applied.

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