Hydrocolloid adhesive composition including acrylic fibers

Abstract

An adhesive composition for adhering a skin-adhering device to skin includes an adhesive component, a hydrocolloid component, and straight-cut acrylic fibers. The hydrocolloid component and the straight cut fibers are dispersed in the adhesive component.

Description

HYDROCOLLOID ADHESIVE COMPOSITION INCLUDING ACRYLIC FIBERSBACKGROUND

[0001] The present subject matter relates to the technical field of adhesive compositions for skin-adhering devices such as medical dressings and ostomy products adapted to be adhesively secured to skin surfaces of users. In particular, the adhesive compositions disclosed herein include a hydrocolloid adhesive composition that absorbs fluids and swells to provide a moisture barrier to skin and that includes fibers that provide a support structure to the hydrocolloid adhesive.

[0002] A hydrocolloid adhesive utilized, for example, to secure a skin-adhering device, such as an ostomy appliance or wound dressing, to skin also acts as a skin barrier that protects the skin from exposure to moisture, for example, perspiration, internal fluids (e.g., from a cut in the skin if the skin-adhering device is a wound dressing or leakage from a stoma if the skin-adhering device is an ostomy device), external fluids such a spills, bathing water, and precipitation, and the like. Continuous exposure to such moisture may damage the skin and / or interfere with wound healing.

[0003] Such hydrocolloid adhesive should have certain important yet conflicting features such as liquid absorbency, moldability, surface tack, and cohesive strength. For instance, hydrocolloid materials in the hydrocolloid adhesive composition may absorb moisture and thereby protect the skin from such moisture. However, the hydrocolloid material may expand (swell) when exposed to moisture and such expansion may interfere with or otherwise degrade the adhesion properties of the adhesive.

[0004] Further, a hydrocolloid adhesive composition that has low viscosity favors adhesion to the skin, since a pressure-sensitive adhesive phase must be able to wet the skin and provide an adhesive bond. In addition, the hydrocolloid adhesive composition with low viscosity also tracks movement of the skin and maintains adhesion thereto as the skin surface stretches and flexes. However, a low-viscosity hydrocolloid adhesive composition utilized to form a skin adhering device may exhibit cold flow during storage of such device. That is, the low-viscosity hydrocolloid adhesive composition applied to a substrate of the device may flow beyond an acceptable region of the substrate or even beyond a perimeter of such substrate and create difficulties in packaging and use of the device. Such flow may be more pronounced when the device is stored for an extended period of time or is exposed to elevated temperatures during storage. In addition,hydrocolloid adhesive compositions containing low viscosity pressure-sensitive adhesives may exhibit undesirably low cohesive strength.

[0005] Moldability of the hydrocolloid adhesive allows such adhesive to closely follow skin contours and thereby promotes strong adhesion of the adhesive to the skin. Moldability requires flow of the adhesive with sufficient cohesive strength to maintain the physical integrity of the adhesive when and while it is stretched. Additionally, the moldable hydrocolloid adhesive should maintain its new shape after molding, without demonstrating “shape memory” that drives the adhesive to return to its original shape. In general, a hydrocolloid adhesive may be deficient in moldability if such adhesive is too stiff to easily flow when stretched, have insufficient cohesive strength to maintain integrity when stretched, and / or have shape memory, tending to return to their original shape after stretching.

[0006] Moldability, viscosity or flowability, surface tack, cohesive strength, and liquid absorbency are all affected by the liquid-absorbing and swellable hydrocolloid content of a skin adhesive. A higher hydrocolloid content may provide greater absorbency but may reduce cohesive strength, surface tack, viscosity and / or moldability.

[0007] Taylor, U.S. Patent No. 7,767,291 discloses hydrocolloid containing adhesive compositions for medical use that contain a fluid-absorbing and swellable hydrocolloid component and fibrillated polymeric fibers. The fibrillated polymeric fibers form a fibrous three-dimensional network through the adhesive composition. The fibrillated polymeric fibers are fibers of polyolefin or another polymer that are highly branched with hair-like fibrils and the fibrils increase the surface area of the fiber and provide strength and integrity to the network formed thereby.SUMMARY

[0008] According to one aspect, a hydrocolloid adhesive composition for securing a skinadhering device to skin includes an adhesive component, a hydrocolloid component, and straightcut acrylic fibers dispersed in the adhesive component.

[0009] According to some aspects, the adhesive component includes one or more pressuresensitive adhesives based on natural rubber, synthetic rubber, a styrene block copolymer, polyvinyl ether, poly(meth) acrylate, polyisobutylene, and other polyolefins.

[0010] According to some aspects, the hydrocolloid component comprises one or more of a pectin, carboxymethyl cellulose, and a superabsorbent polymer. Further, in some cases, the superabsorbent polymer comprises poly(acrylic acid). In other cases, the hydrocolloid component comprises one or more of calcium carboxymethyl cellulose, carboxymethyl starch, alginate, gelatin, synthetic gum, and natural gum.

[0011] According to some aspects, the straight-cut acrylic fibers comprise polyacrylonitrile fibers.

[0012] According to some aspects, the straight-cut acrylic fibers have an average diameter of between 15 microns and 29 microns.

[0013] According to some aspects, the straight-cut acrylic fibers have an average length of between 1 millimeter and 12 millimeters.

[0014] According to some aspects, the straight-cut acrylic fibers have an average diameter of between 15 and 29 microns and a length of between 1 millimeter and 12 millimeters.

[0015] According to some aspects, the straight-cut acrylic fibers are not water-soluble and do not swell when exposed to moisture.

[0016] According to some aspects, the straight-cut acrylic fibers withstand heating of greater than 135 degrees Celsius without damage thereto.

[0017] According to some aspects, the straight-cut acrylic fibers are completely free of fibrils.

[0018] According to some aspects, a skin-adhering device comprises a substrate and the hydrocolloid adhesive composition applied to the substrate. In some cases, the skin-adhering device is an ostomy appliance.

[0019] Other aspects and advantages will become apparent upon consideration of the following detailed description and the attached drawing.BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. l is a perspective view of an ostomy wafer including a hydrocolloid adhesive of the present disclosure according to an embodiment;

[0021] FIG. 2 is a cross-sectional view of the ostomy wafer of FIG. 1 taken along line A-A; and

[0022] FIG. 3 is schematic view of an ostomy pouch system including the ostomy wafer of FIG. 1 according to an embodiment.DETAILED DESCRIPTION

[0023] The present disclosure discloses a hydrocolloid adhesive composition for securing a skin-adhering device, e.g., a medical device or appliance, to skin according to various embodiments. The hydrocolloid adhesive composition may include an adhesive component, a hydrocolloid component, and straight-cut acrylic fibers. The hydrocolloid component and straightcut acrylic fibers may be dispersed in the adhesive component. The hydrocolloid component may be configured to absorb moisture and swell, and the straight-cut fibers may be configured to provide reinforcement to the adhesive to reduce degradation when the hydrocolloid component absorbs moisture and swells. The straight-cut fibers may improve erosion resistance of hydrocolloid adhesives form from the composition.

[0024] The adhesive component of the hydrocolloid adhesive composition may be any material that has pressure-sensitive adhesive properties. Such component may comprise a single pressure-sensitive adhesive or a combination of two or more pressure-sensitive adhesives. Adhesives suitable for the adhesive component may include, for example, adhesives based on natural rubbers, synthetic rubbers, styrene block copolymers, polyvinyl ethers, poly(meth) acrylates including acrylates and methacrylates, polyisobutylene and other polyolefins, and other materials with similar properties and apparent to one having ordinary skill in the art.

[0025] Suitable materials for the hydrocolloid component may include, but not limited to, carboxymethyl cellulose and its derivatives (e.g., sodium carboxymethyl cellulose, croscarmellose sodium, etc.), carboxymethyl starches, alginates, pectin, gelatin, superabsorbents, guar gum, locust bean gum, gum karaya, carbomer, and the like. In an embodiment, the hydrocolloid component may include pectin and carboxymethyl cellulose. In another embodiment, the hydrocolloid component may include a superabsorbent polymer (SAP) / carbomer system, for example poly(acrylic acid) and carbomer.

[0026] In some embodiments, the straight-cut acrylic fibers dispersed in the adhesive may be formed from polyacrylonitrile (PAN). Examples of suitable straight-cut acrylic fibers may include Sterling CTF 326 fibers manufactured by Sterling Fibers, Inc. of Pace, Florida, and Goonvean AC2 / 15 fibers manufactured by Goonvean Fibres Ltd. of Cullompton, Devon, United Kingdom. The straight-cut acrylic fibers may have an average diameter between approximately 15 microns and approximately 29 microns. Further, the straight-cut acrylic fibers may have an average length between approximately 1 millimeter and approximately 12 millimeters. In an embodiment, the straight-cut acrylic fibers may have an average diameter of about 15 microns to about 29 microns and an average length of about 1 mm to about 12 mm.

[0027] Straight-cutting the acrylic fibers prevents the formation of fibrils and / or fraying and such lack of fibrils / fraying prevents agglomeration of the straight-cut acrylic fibers when such fibers are dispersed in the adhesive component. In some embodiments, the straight-cut acrylic fibers may be completely free of fibrils. Further, acrylic fibers can withstand higher temperatures compared to other polymeric fibers, such as polyethylene fibers. For example, acrylic fibers begin to decompose (rather than melt) when exposed to temperatures greater than approximately 280 degrees Celsius. In contrast, polyethylene fibers begin to melt at approximately 135 degrees Celsius. Such resistance to heat enables the use of higher-temperature processes during manufacture of the skin-adhering device having the hydrocolloid adhesive composition (e.g., during mixing of the adhesive, processing the adhesive from a bulk mix into a final shape by processes such as extrusion, and / or if the skin-adhering device includes parts that have to be heat- sealed, heat treated, or the skin-adhering device is otherwise exposed to heat after the hydrocolloid adhesive composition is applied thereto). Further, the straight-cut acrylic fibers are not water- soluble and do not swell when exposed to moisture. Thus, such fibers, when dispersed in a hydrocolloid adhesive, can reinforce the adhesive structure and improve erosion resistance of the adhesive when the hydrocolloid component absorbs water and swells.

[0028] In some embodiments, the straight-cut acrylic fibers (e.g., straight-cut PAN fibers) dispersed in the adhesive component may have a slight yellow or tan hue whereas polyolefin fibers tend to be white. Thus, the color of the straight-cut acrylic fibers may blend in better with the rest of the components of the hydrocolloid adhesive composition and may be less noticeable in use in comparison to polyolefin fibers. Further, the straight-cut acrylic fibers can be substantially lessexpensive than other types of fibers (e g., polyolefin and the like) and thus the cost of the hydrocolloid adhesive composition disclosed herein may be more favorable than that of other adhesives comprising other types of fibers dispersed in the adhesive.

[0029] The amount of the hydrocolloid component present in the hydrocolloid adhesive composition may be selected in accordance with a desired amount of fluid the hydrocolloid adhesive composition should be able to absorb. In some embodiments, such amount of the hydrocolloid component comprises between approximately 15-percent and approximately 55- percent by weight of the hydrocolloid adhesive composition. Further, the amount of straight cut acrylic fibers present in the hydrocolloid adhesive composition may be selected in accordance with a stiffness of the hydrocolloid adhesive composition that is desired. In one embodiment, the hydrocolloid adhesive composition comprises at least some straight cut acrylic fibers and up to approximately 8-percent straight cut acrylic fibers by weight. The hydrocolloid adhesive composition may include additional components that would be apparent to one who has ordinary skill in the art including, for example, tackifiers, thermoplastic elastomers, plasticizers, etc.

[0030] As discussed above, the hydrocolloid adhesive composition may be used to secure a skin-adhering device such as a wound dressing, an ostomy appliance, an ostomy appliance accessory, and the like to a user’s skin. In some embodiments, the formulation of the hydrocolloid adhesive composition may be varied in accordance with how the hydrocolloid adhesive composition is to be used with an ostomy appliance or accessory. For example, in some embodiments, the hydrocolloid adhesive composition may be formulated to have a high modulus (i.e., cohesive strength) to produce a skin barrier that is suitable for use with an ostomy appliance because, for example, such skin barrier may be weight bearing. Further, the hydrocolloid adhesive composition may be formulated to have a low modulus so that it is soft and pliable to produce a moldable seal that may be used in conjunction with the skin barrier to improve the fit between a stoma and the ostomy appliance. Referring to FIGS. 1-3, in one application, the hydrocolloid adhesive composition disclosed herein may be used in an ostomy wafer 10. The ostomy wafer 10 may include a layer of the hydrocolloid adhesive composition 12, a backing layer 14, a release liner 16, and an inlet opening 20 for receiving a stoma. Removing the backing layer 14 exposes one side of layer of the hydrocolloid adhesive composition 12 so that such layer 12 may be secured to a substrate 32 of an ostomy appliance 30 or to another layer of the hydrocolloid adhesivecomposition (not shown) already secured to the substrate. Removing the release liner 16 exposes a second side of the layer of the hydrocolloid adhesive composition 12 so that such second side may be secured to a user’s skin. Thus, the layer of hydrocolloid adhesive composition 12 facilitates securing the substrate 32 of the ostomy appliance 30 to the user’s skin and forms barrier to protect such skin from moisture as described above.

[0031] While particular embodiments of the present invention have been illustrated and described, it would be apparent to those skilled in the art that various other changes and modifications can be made and are intended to fall within the spirit and scope of the present disclosure. Furthermore, although the present disclosure has been described herein in the context of a particular implementation in a particular environment for a particular purpose, those of ordinary skill in the art will recognize that its usefulness is not limited thereto and that the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in view of the full breadth and spirit of the present disclosure as described herein.

[0032] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0033] The use of the terms “a” and “an” and “the” and similar references in the context of describing the embodiments disclosed herein (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the disclosure, and does not pose a limitation on the scope of the disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure.

[0034] Numerous modifications to the present disclosure will be apparent to those skilled in the art in view of the foregoing description. It should be understood that the illustrated embodiments are exemplary only and should not be taken as limiting the scope of the disclosure.

Claims

I / WE CLAIM:

1. A hydrocolloid adhesive composition for adhering a skin-adhering device to skin, comprising: an adhesive component; a hydrocolloid component; and straight-cut acrylic fibers, wherein the hydrocolloid component and the straight-cut acrylic fibers are dispersed in the adhesive component.

2. The hydrocolloid adhesive composition of claim 1, wherein the adhesive component comprises one or more pressure-sensitive adhesives based on natural rubber, synthetic rubber, a styrene block copolymer, polyvinyl ether, poly(meth) acrylate, polyisobutylene, and other polyolefins.

3. The hydrocolloid adhesive composition of claim 1 or claim 2, wherein the hydrocolloid component comprises one or more of a pectin, carboxymethyl cellulose, and a superabsorbent polymer.

4. The hydrocolloid adhesive composition of claim 3, wherein the superab sorb ent polymer comprises polyacrylic acid.

5. The hydrocolloid adhesive composition of claim 3, wherein the hydrocolloid component comprises one or more of carboxymethyl cellulose, carboxymethyl starch, carbomer, alginate, gelatin, synthetic gum, and natural gum.

6. The hydrocolloid adhesive composition of any one of claims 1 through 5, wherein the straight-cut acrylic fibers are formed from polyacrylonitrile.

7. The hydrocolloid adhesive composition of any one of claims 1 through 6, wherein the straight-cut acrylic fibers have an average diameter of between 15 microns and 29 microns.

8. The hydrocolloid adhesive composition of any one of claims 1 through 7, wherein the straight-cut acrylic fibers have an average length of between 1 millimeter and 12 millimeters.

9. The hydrocolloid adhesive composition of any one of claims 1 through 6, wherein the straight-cut acrylic fibers have an average diameter of between 15 and 29 microns and an average length of between 1 millimeter and 12 millimeters.

10. The hydrocolloid adhesive composition of any one of claims 1 through 9, wherein the straight-cut acrylic fibers are not water-soluble and do not swell when exposed to moisture.

11. The hydrocolloid adhesive composition of any one of claims 1 through 10, wherein the straight-cut acrylic fibers withstand heating of greater than 135 degrees Celsius without damage thereto.

12. The hydrocolloid adhesive composition of any one of claims 1 through 11, wherein the straight-cut acrylic fibers are completely free of fibrils.

13. The hydrocolloid adhesive composition of any one of claims 1 through 12 in combination with a skin-adhering device, wherein the skin-adhering device comprises a substrate and the hydrocolloid adhesive composition applied to the substrate.

14. The hydrocolloid adhesive composition and skin-adhering device of claim 13, wherein the skin-adhering device is an ostomy appliance or accessory.

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