Abstract:
The present invention relates to a wound care dressing and package assembly. The assembly includes a first package substrate or layer to which a wound care dressing is attached. The wound care dressing includes a backing layer and a contact layer. A release structure is in contact with the contact layer on a side of the contact layer opposite the wound care dressing. The release structure is supported by a second package substrate or layer. A seal interconnects the first and second package layers, forming a sealed volume in which at least the wound care dressing and the release structure is contained. The wound care dressing advantageously releases from the backing layer at low forces, e.g., less than about 1N/linear inch.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/734,847 filed Dec. 7, 2012, which is incorporated herein in its entirety by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to a wound care dressing. More particularly, a wound care dressing that can be placed on a wound using a reduced number of steps as compared to conventional wound dressings is provided. 
       BACKGROUND 
       [0003]    Conventional wound care dressings require multiple steps to apply. For example, a wound care dressing is typically placed within a sterile package or envelope. In order to apply the dressing, the packaging is broken to allow the dressing to be accessed. The dressing is then removed from the packaging. Often, a release liner then needs to be removed, before the dressing is placed on the wound. In the case of a thin film wound dressing, a frame carrying the dressing needs to be peeled off after the dressing is placed on the wound. Accordingly, multiple steps are typically required in order to apply a conventional thin film wound dressing. 
         [0004]    The production or manufacture of a conventional thin film wound dressing is also complex, and relatively expensive. For example, in order to form a typical thin film wound dressing, components of the dressing are formed using rotary die cutting techniques. The different components of the dressing must then be registered with one another, and assembled. In addition to requiring multiple precision forming and registration steps, conventional techniques can result in the creation of a relatively large amount of waste material. 
       SUMMARY 
       [0005]    In accordance with embodiments of the present disclosure, a wound care dressing that can be applied in a reduced number of steps, and that can be produced more economically than many conventional wound care dressings, is provided. More particularly, a wound care dressing assembly is provided that can include first and second package layers that are bonded to one another about a periphery of the first and second package layers by a seal, to form a sealed volume. A wound care dressing is located within the sealed volume. The wound care dressing can be interconnected to and/or formed on the first package layer. A release structure is formed on the second package layer. The release structure may be a continuous layer or may include multiple three-dimensional features or support elements that have the effect of reducing the surface area of the associated package layer. The wound care dressing can include a backing layer and a contact layer. The contact layer can cover all or a portion of the surface of the side of the backing layer facing the release structure. Moreover, the contact layer and/or a surface of the wound care dressing can be in contact with the release structure. 
         [0006]    Methods for applying a wound care dressing according to the present disclosure include separating the first package layer from the second package layer. More particularly, the first package layer can be peeled away from the second package layer by breaking the seal between the first and second package layers. The wound care dressing and in particular at least most of the contact layer, which can comprise an adhesive, remains attached to the first package layer. The wound care dressing can then be applied by placing the adhesive side of the wound care dressing over the wound. The application of the wound care dressing can then be completed by removing the first package layer from the wound care dressing, leaving the wound care dressing in place over the wound. The first package layer and the second package layer, with an associated release structure, that was separated from the first package layer and the wound care dressing can then be discarded. 
         [0007]    In accordance with still other embodiments of the present disclosure, a wound care dressing can be formed using a method that includes forming or placing a backing layer on a first package layer, and covering or substantially covering the dressing with a layer of adhesive or other contact material. The method also includes forming a release structure on a second package layer. The two package layers can then be interconnected to one another about a periphery of the package layers to form a sealed volume containing the backing layer, the adhesive or contact material, and the release structure. 
         [0008]    Additional features and advantages of embodiments of the present disclosure will become more readily apparent from the following description, particularly when taken together with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  depicts a wound care assembly with release structure peaks in accordance with embodiments of the present disclosure in plan view; 
           [0010]      FIG. 2  depicts the wound care assembly of  FIG. 1  in a cross-sectional view taken along section line A-A; 
           [0011]      FIG. 3  depicts a wound care dressing in accordance with embodiments of the present disclosure in cross-section, after separation of the first and second package layers; 
           [0012]      FIG. 4  depicts a wound care dressing in accordance with embodiments of the present disclosure in cross-section, applied to the skin of a patient; 
           [0013]      FIG. 5  depicts a cross section of a wound care assembly with a uniform release structure; 
           [0014]      FIG. 6  depicts a wound care assembly in accordance with embodiments of the present disclosure in cross-section, after separation of the first and second package substrates; 
           [0015]      FIG. 7  depicts a wound care dressing in accordance with embodiments of the present disclosure in cross-section, applied to the skin of a patient; 
           [0016]      FIG. 8  is a flowchart depicting aspects of a process for applying a wound care dressing in accordance with embodiments of the present disclosure; and 
           [0017]      FIG. 9  is a flowchart depicting aspects of a process for forming a wound care dressing in accordance with embodiments of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]      FIG. 1  depicts a wound care dressing assembly  104  in accordance with embodiments of the present disclosure in plan view. The wound care dressing assembly  104  includes first or top package layer  108 . As shown in  FIG. 1  for purposes of clarity, the first package layer  108  can be transparent, translucent, opaque, non-transparent, or the like. A seal  112  is formed about a perimeter of the assembly  104 , creating a sealed volume  116  between the first package layer  108  and a second or bottom package layer  120 . A wound care dressing  124  can be formed on and/or interconnected to a surface of the first package layer  108  that faces a surface of the second package layer  120 , such that the wound care dressing  124  is located within the sealed volume  116 . The wound care dressing  124  may be any shape or size. A side of the wound care dressing  124  facing the second package layer  120  can be in contact with a release or support structure  128  formed on and/or interconnected to the surface of the second package layer  120 . The release structure  128  can also be located within the sealed volume  116 . As will be described in greater detail elsewhere herein, the release structure  128  can comprise a structure that extends from a surface of the second package layer  120 , to provide a reduced surface area in contact with the wound care dressing  124  and/or an adhesive associated with the wound care dressing  124 . 
         [0019]      FIG. 2  depicts a cross-section of the wound care dressing assembly  104  of  FIG. 1 , taken along section line A-A in  FIG. 1 . As seen in  FIG. 2 , the first package layer or substrate  108  generally extends across the entire width, and also the length, of the wound care dressing assembly  104 . The seal  112  connects a first or inner surface  204  of the first package layer  108  to a first or inner surface  208  of the second package layer or substrate  120 , such that a sealed volume  116  is defined between the first package layer  108 , the second package layer  120 , and the seal  112 . In some embodiments, a liner layer (not shown) may be placed on the first or inner surface  204 ,  208  of the first package layer  108  and/or the second package layer  120 . The liner layer may be a polymeric material, including but not limited to polyester, polyurethane, polypropylene or the like. The liner layer may cover all, or a portion of the first or inner surface  204 ,  208  of the first package layer  108  and/or the second package layer  120 . The second package layer  120  generally has a width, and also a length, that is the same or similar to that of the first package layer  108 . The wound care dressing  124  is connected to the first surface  204  of the first package layer  104 . The wound care dressing  124  can include or be associated with a backing layer  210  and a contact layer  212 . As an example, the backing layer  210  of the wound care dressing can comprise a side of the wound care dressing that is connected to the first surface  204  of the first package layer, while the contact layer  212  comprises some or all of a side of the wound care dressing  124  adjacent the first surface  208  of the second package layer  120 . In addition, the contact layer  212  and/or the backing layer  210  of the wound care dressing  124  can be in contact with the release structure  128 . Moreover, as shown in  FIG. 2 , the release structure  128  extends from the first surface  208  of the second package layer  120 , to provide a support for the wound care dressing  124 . In addition, the release structure  128  can present a reduced surface area to the surface of the wound care dressing  124  facing the release structure  129 . More particularly, embodiments of the present invention provide a release structure  128  with support elements  132  that create a reduced surface area as compared to a configuration in which the wound care dressing area and/or the adhesive  212  is entirely in contact with the first surface  208  of the second package layer  120 . As examples, but without limitation, the backing layer  210  may comprise a polyurethane material, and the contact layer  212  may comprise an adhesive, such as an acrylic adhesive. 
         [0020]    As shown in  FIGS. 1 and 2 , the release structure  128  can comprise individual support elements  132 . The individual support elements  132  can be projections that extend from the first surface  208  of the second package layer  120 . Moreover, the release structure  128  can include support elements  132  that are interconnected to one another. For instance, the release structure  128  can comprise a unitary structure. Alternatively, some or all of the support elements  132  can be separate from other support elements  132 . In accordance with further embodiments, the support elements  132  extend vertically from the first surface  208  of the second package layer, or from a portion of the release structure  128  interconnecting support elements  132 , for a distance that is greater than the thickness of the contact layer  212 . The support elements can be provided in various shapes, including but not limited to cones, cylinders, rectangles, squares, spheres, hemispheres, truncated cones, ridges, or triangles. In accordance with still other embodiments, the release structure  128  can comprise ridges, corrugations or other projections that create a three-dimensional surface to partially contact the contact layer  212 . 
         [0021]      FIG. 3  depicts a wound care dressing assembly  104  with the first package layer  108  separated from the second package layer  120 . In general, the wound care dressing  124  remains interconnected to the first package layer  104 . The release structure  128  remains interconnected to the second package layer  120 . As can be appreciated by one of skill in the art after consideration of the present disclosure, by separating the first package layer  104  from the second package layer  120 , for example by breaking the seal  112  formed about the peripheries of the first package layer  104  and the second package layer  120 , the sealed volume  116  no longer exists. Moreover, the contact layer  212 , comprising some or all of the surface of the wound care dressing  124  opposite the first package layer  108 , is exposed. 
         [0022]      FIG. 4  depicts the wound care dressing  124  in cross-section, attached to the skin  604  of a patient by the contact layer  212 . The first package layer  108  has been removed. 
         [0023]    The shape and size of the wound care dressing assembly  104  and/or the wound care dressing  124  may be any suitable shape or size, including a square, rectangle, circle, oval, triangle, strip or any suitable shape in any desired size. 
         [0024]      FIG. 5  depicts a cross-section of the wound care dressing assembly  504 . As seen in  FIG. 5 , the first package substrate  508  generally extends across the entire width, and also the length, of the wound care dressing assembly  504 . The seal  512  connects a first or inner surface  503  of the first package substrate  508  to a first or inner surface  511  of the second package substrate  520 , such that a sealed volume  516  is defined between the first package substrate  508 , the second package substrate  520 , and the seal  512 . In some embodiments, a liner layer (not shown) may be interconnected to the first or inner surface  503 ,  511  of the first package substrate  508  and/or the second package substrate  520 . The liner layer may be a polymeric material, including but not limited to polyester, polypropylene or the like. The liner layer may cover all, or a portion of the first or inner surface  503 ,  511  of the first package substrate  508  and/or the second package substrate  520 . The second package substrate  520  generally has a width, and also a length, that is the same or similar to that of the first package substrate  508 . The wound care dressing  524  is connected to the first surface  504  of the first package substrate  504 . The wound care dressing  524  can include or be associated with a backing layer  510  and a contact layer  513 . The contact layer  513  can comprise some or all of a side of the wound care dressing  524  adjacent the first surface  511  of the second package substrate  520 . The wound care dressing  524  may be any shape or size. In some instances, the contact layer  513  covers the entire surface of the backing layer  510 , or is slightly smaller than the backing layer  510 . In addition, the contact layer  513  and/or the backing layer  510  can be in contact with the release structure  528  as shown in  FIG. 5 . Moreover, as shown in  FIG. 5 , the release structure  528  extends from the first surface  511  of the second package substrate  520 , to provide a support for the wound care dressing  524 , for instance through the contact layer  513 , and has a reduced surface friction. The release structure  528  may be slightly larger, slightly smaller, or the same size as the wound care dressing  524  and/or the contact layer  513 . 
         [0025]      FIG. 6  depicts a wound care dressing assembly  504  with the first package substrate  508  separated from the second package substrate  520 . In general, the wound care dressing  524  remains interconnected to the first package substrate  508 . The release structure  528  remains interconnected to the second package substrate  520 . As can be appreciated by one of skill in the art after consideration of the present disclosure, by separating the first package substrate  508  from the second package substrate  520 , for example by breaking the seal  512  formed about the peripheries of the first package substrate  508  and the second package substrate  520 , the sealed volume  516  no longer exists. Moreover, the contact layer  513  forming some or all of one surface of the wound care dressing  524  is exposed. 
         [0026]      FIG. 7  depicts the wound care dressing  524  in cross-section, attached to the skin  504  of a patient by the contact layer  513 . The first package substrate  508  has been removed. 
         [0027]      FIG. 8  depicts aspects of a process for applying a wound care dressing  124 ,  524  to the skin  604 ,  504  of a patient in accordance with embodiments of the present disclosure. Initially, at step  804 , a wound care dressing assembly  104 ,  504 , such as depicted in  FIGS. 1 and 2  and  FIGS. 5 and 6 , respectively, is obtained. At step  808 , the seal  112 ,  512  is broken, and the first package layer or substrate  108 ,  508  is separated from the second package layer or substrate  120 ,  520 . In accordance with embodiments of the present disclosure, the backing layer  210 ,  510 , and the contact layer  212 ,  513  comprising the wound care dressing  124 ,  524  remain with the first package layer or substrate  104 ,  508 . The backing layer  210 ,  510  and the associated contact layer  212 ,  513  are released from the second package layer or substrate  120 ,  520  and the release structure  128 ,  528  when the first package layer or substrate  108 ,  508  is disconnected from the second package layer  120 ,  520 . More particularly, the bond between the backing layer  210 ,  510  and the first package or substrate  108 ,  508  is greater than the bond between the contact layer  212 ,  513  and the release structure  128 ,  528  that is connected to the second package layer or substrate  120 ,  520 . In some embodiments, the reduced surface area of the release structure  128  in contact with the contact layer  212  is reduced compared to the surface area of the backing layer  210 ,  510  in contact with the contact layer  212 . In other embodiments, materials of the release layer  128 ,  528  are chosen such that the bond between the contact layer  212 ,  513  and the release layer  128 ,  528  is weak. The second package layer or substrate  120 ,  520  and the interconnected release structure  128 ,  528  can then be discarded (step  812 ). 
         [0028]    At step  816 , the contact layer  212 ,  513  is placed over a wound on the patient&#39;s skin  604 ,  504 . As can be appreciated by one of skill in the art after consideration of the present disclosure, the wound care dressing  124 ,  524  can be applied to the skin  604 ,  504  of a patient by handling the first package layer or substrate  104 ,  508 , and without requiring contact with the wound care dressing  124 ,  524  by a medical practitioner or other person applying the wound care dressing  124 ,  524 . At step  820 , the first package layer  104 ,  508  can be removed from the wound care dressing  124 ,  524 . As a result, the wound care dressing  124 ,  524  and the contact layer  212 ,  513  remain attached to the patient&#39;s skin  604 ,  504 . The first package layer  104 ,  508  can then be discarded (step  824 ). 
         [0029]    With reference now to  FIG. 9 , a flowchart depicting aspects of a process for forming a wound care dressing assembly  104 ,  504  in accordance with embodiments of the present disclosure is illustrated. Initially, at step  904 , a first sheet of material is provided. The first sheet of material will be used to form the first package layer or substrate. In accordance with embodiments of the present disclosure, the first package layer or substrate can include, but is not limited to, a polymeric film, such as polyethylene, polyester, polyurethane, or polypropylene, paper, coated paper, or the like. At step  908 , a second sheet of material is provided. The second sheet of material will be used to form the second package layer or substrate  120 ,  520 . The second package layer or substrate  120 ,  520  can be formed from the same or different material or materials used to form the first package layer  104 ,  508 . At step  912 , the release structure  128 ,  528  is interconnected to and/or formed on the first surface  208 ,  511  of the second package layer or substrate  120 ,  520 . In accordance with embodiments of the present disclosure, the release structure  128 ,  528  is a release material such as, for example only, silicone, fluorine, or polymeric fluorine material. The release structure  128 ,  528  extends from the first surface  208 ,  511  of the second package layer or substrate  120 ,  520 . The release structure  128 ,  528  can be formed using various methods, including printing processes. In some embodiments, a plurality of support elements  132  comprising the release structure  128  are formed on the first surface  208  of the second package layer  120 . In other embodiments, the release structure  528  is a continuous part, and may have a substantially uniform thickness across a portion of the second package substrate  520 . 
         [0030]    At step  916 , the backing layer  210 ,  510  of the wound care dressing  124 ,  524  is formed on the first surface  204 ,  503  of the first package layer or substrate  108 ,  508 . The backing layer  210 ,  510  can include, but is not limited to, a polymeric material, such as a polyurethane film. Moreover, the backing layer  210 ,  510  can be cast onto the first surface  204 ,  503  of the first package layer or substrate  208 ,  508 . At step  920 , a contact layer  212 ,  513  is applied to the backing layer  210 ,  510  of the wound care dressing  124 ,  524 . In some embodiments, the contact layer  212 ,  513  may comprise an adhesive, a polyurethane material, a hydrocolloid material, nicotine, antimicrobial, antibacterial, silver, antibiotic, pharmaceutical, including but not limited to birth control, combinations thereof or the like. The backing layer  210 ,  510  and/or the contact layer  212  can incorporate or hold an absorbent foam, hydrogel, or other material. In accordance with further embodiments, a release coating can be applied to portions of the first package layer or substrate  108 ,  508  that are not occupied by the wound dressing  124 ,  524  and/or the contact material  212 ,  513 , and/or to the surface of the second package layer or substrate  120 ,  520 . At step  924 , a seal  112  is applied to the first surface  204 ,  503  of the first package layer or substrate  108 ,  508 , and/or the first surface  208 ,  511  of the second package layer or substrate  120 ,  520 , about the perimeter of the first surface  204 ,  503  and/or  208 ,  511  of the first and/or second package layers or substrate  104 ,  508  and  120 ,  580 , respectively. The first package layer or substrate  104 ,  508  is then joined to the second package layer or substrate  120 ,  520  by the seal  112 ,  512 , to form the sealed volume  116 ,  516  containing the wound care dressing  124 ,  524 , including the backing layer  210 ,  510  and the contact layer  212 ,  513 , and the release structure  128 ,  528  (step  928 ). The seal  112 ,  512  can comprise an applied material, such as an acrylic, a pressure sensitive adhesive, an adhesive, a co-adhesive, glue, or a weld between the first package layer or substrate  108 ,  508  and second package layer or substrate  120 ,  520 . The process for forming a wound care dressing assembly  104 ,  504  is then complete. 
         [0031]    One advantage of the present invention is the ability to put multiple zones of materials, such as adhesives, in the wound care assembly. The zones may comprise different materials, adhesives or/and different adhesive levels. This ability is advantageous because different adhesive strengths are advantageous at different locations within the wound care assembly. Near the edge of the wound care assembly, for example at the seals, a high adhesive strength material is advantageous so the perimeter is sufficiently sealed. Near the interior of the wound care assembly, a lower strength adhesive or contact material is advantageous so that the wound care dressing may be removed from the wound care assembly prior to application to the patient and/or from the patient after use so as to decrease pain when the wound care dressing is removed from the patient, while having sufficient strength to keep the wound dressing in contact with the patient during use. The present invention allows multiple zones of adhesive to be applied without additional processing, such as exposing a portion of the wound care assembly to ultraviolet (UV) light or other process, to change the properties of the adhesive for the exposed portion (for example to decrease the adhesive strength in some areas of the wound care assembly). 
         [0032]    Furthermore, different types of materials may be applied throughout the wound care assembly. Thus, by way of example, one zone of the wound care assembly may have an adhesive surface for drug delivery, i.e. the contact layer, and another zone exterior to the contact layer that does not have a drug delivery adhesive, i.e. the seal. The seal and the contact layer may have different characteristics or performance features. In another example, the contact layer and/or the dressing may have a high absorption capability for wound fluid, while the seal material of the assembly has a low absorption capability. 
         [0033]    In some embodiments, the present invention is made with the use of a three-dimensional printer. An advantage of this manufacturing method is that the layers may be built on the substrate such that adhesive layers are not required between each layer to hold the each layer in place. Thus, for example, no adhesive is required between the first package substrate and the wound care dressing. 
         [0034]    Another advantage of the present invention is that the first package layer with or without the liner, from the wound dressing with minimal force, in many cases less than about 1 N/linear inch. In some embodiments, the force to remove the wound dressing from the first package layer or substrate is less than about 10 N. In some embodiments, the force to remove the wound dressing from the first package layer was less than about 10 N, 9 N, 8 N, 7 N, 6 N, 5 N, 4 N, 3 N or about 1 N. 
       Examples 
       [0035]    A test was performed to determine the force required to remove a wound dressing from a test panel. The wound dressing was removed at an approximately 90° angle to a standard steel panel. Test specimens were cut to approximately 25 mm in width and 100 mm in length or the length of the product. The specimens were conditioned at room temperature for approximately 8 hours. The panel was cleaned prior to testing and allowed to dry for at least 10 minutes. At one end of the specimen, approximately 20-30 mm of the adhesive which will be affixed to the clamp were separated. The remainder of the specimen is removed from its liner and placed above the test panel. The entire specimen is allowed to fall gently onto the panel. Then a weighted roller is placed on the specimen and rolled once in each direction over the specimen. Care was taken to minimize air bubbles between the sample and the test specimen and not to apply additional force on the roller during the passes over the specimen. Approximately 15 mm of the specimen is attached to the tensile tester and the specimen is pulled from the panel at an angle of approximately 90°. 
         [0036]    Table summarizes the results of the peel test. The values, in Newtons, were taken over time as the dressing was removed in a linear motion. The peak force occurred as the initial point that the dressing lifted from the package layer or substrate. 
         [0000]                                                                                                                            Test/Force                1   2   3   4   5   6   7   8   9                            0   −0.21   −0.33   0   −0.26   −2.54   −6.3   −2.97   −2.02           −1.24   −0.37   −0.52   −0.26   −0.33   −9.25   −6.61   −3.57   −3.95           −0.54   −0.35   −0.49   0.08   −0.36   −9.38   −1.27   −0.17   −1.68           −6.4   −0.92   −0.95   −4.82   −0.73   −0.38   −1.18   −0.1   −1.6           −6.44   −0.93   −0.89   −3.69   −0.5   −0.38   −0.71   −0.2   −1.14           −1.37   −6.39   −4.26   −0.26   −2.32   −0.42   −0.82   −0.23   −1.14           −0.99   −4.78   −2.72   −0.35   −2.09   −0.42   −0.54   −0.14   −0.98           −0.37   −0.41   −0.77   −0.43   −4.68   −0.43   −0.54   −0.17   −1.1           −0.38   −0.44   −0.76   −0.42   −3.74   −0.47   −0.54   −0.22   −0.82           −0.33   −0.46   −0.78   −0.32   −0.28   −0.43   −0.52   −0.22   −0.76           −0.31   −0.47   −0.79   −0.34   −0.29   −0.43   −0.45   −0.28   −0.57           −0.29   −0.56   −0.79   −0.13   −0.37   −0.43   −0.55   −0.27   −0.54           −0.33   −0.61   −0.78   −0.13   −0.38   −0.42   −0.07   −0.29   −0.7           −0.26   −0.63   −0.75   −0.02   −0.47   −0.45   −0.2   −0.27   −0.65           −0.32   −0.61   −0.82   −0.1   −0.42   −0.46   −0.01   −0.26   −0.55       Peak   6.44   6.39   4.26   4.82   4.68   9.38   6.61   3.57   3.95                    
The peak force to remove the dressing from the first package layer or substrate was about 9.38 N.
 
         [0037]    Although processes described herein have been presented with a particular ordering of steps, different sequences and/or collections of steps are possible. 
         [0038]    The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and the skill or knowledge of the relevant art, are within the scope of the present invention. The embodiment described hereinabove is further intended to explain the best mode known for practicing the invention and to enable others skilled in the art to utilize the invention in such, or other, embodiments and with various modifications required by the particular applications or uses of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.