Dressing comprising patterned release liner

Abstract

The present invention relates generally to medical dressings (100) comprising a top layer (101), an adhesive skin-contacting layer (102), and a release liner (103) separably affixed to at least a portion of the adhesive skin-contacting layer (102); the release liner (103) has a first side (104) facing the adhesive skin contact layer (102) and an opposite second side (105). The first side (104) of the release liner (103) comprises a plurality of protrusions (106) spaced apart from each other by non-protruding regions (107), where the protrusions (106) are separably attached to the adhesive skin contact layer (102), and where the non-protruding regions (107) are not attached to the adhesive skin contact layer (102). The invention also relates to a method for producing a medical dressing (100).

Description

Technical Field

[0001] The present invention generally relates to a medical dressing comprising a top layer, an adhesive skin contact layer, and a release liner detachably attached to at least a portion of the adhesive skin contact layer. The release liner has a first side facing the adhesive skin contact layer and an opposing second side. The first side of the release liner comprises a plurality of protrusions spaced apart from each other by non-protrusion areas. The present invention also relates to a method for making a medical dressing comprising a patterned release liner. Background Art

[0002] Adhesive medical dressings are frequently used in wound care, both to treat wounds and scars and to prevent wounds from occurring in the first place.

[0003] There are various types of dressings on the market. Some dressings, often referred to as "film dressings", typically include a backing layer (top layer) and an adhesive skin contact layer. In addition, so-called "bordered dressings" are also often used, and these dressings include an absorbent pad arranged between a backing layer and an adhesive skin contact layer. In bordered dressings, the backing layer and the adhesive skin contact layer may be configured to extend beyond the contours of the absorbent pad.

[0004] The purpose of the adhesive skin contact layer is to adhere to the wearer's skin or wound and secure the dressing in the desired position. When an adhesive skin contact layer is used in a dressing, whether the dressing is a film-type or a bordered dressing, it is desirable that the adhesive skin contact layer should be thin and flexible so as to conform to the contours of the skin.

[0005] While the thinness and stickiness of (at least) the border portions of film dressings and bordered dressings are desirable, these attributes often make the dressings difficult to handle and apply to patients. The dressings are not self-supporting and may wrinkle and adhere to themselves during application. The wrinkles that form can create thin channels through which fluid can leak. As a result, the dressing can become ineffective and must eventually be discarded.

[0006] The adhesive surface of a medical dressing is usually covered and protected by a release liner that is configured to be removed before use. However, once the release liner is partially or completely removed, the adhesive layer may still wrinkle and adhere to itself. In addition, the edges of the adhesive skin contact layer (and the dressing) are prone to curling.

[0007] Adhesive medical dressings are usually applied after surgery and should be sterile initially for medical application. Aseptic application of dressings is key to avoiding the risk of wound infection. Users (e.g., clinicians) must often apply dressings under strict aseptic conditions, especially when using dressings in surgical environments. It is important not to touch the surface of the dressing to avoid bacterial contamination.

[0008] Various attempts have been made to facilitate the handling and application of thin adhesive dressings. For example, US2009 / 0105670 discloses a composite structure comprising a cover, a reinforcement and a releasable liner. The reinforcement and the releasable liner comprising three transverse positioning portions provide rigidity to the composite structure and prevent the dressing from adhering to itself and wrinkling during application. The reinforcement is releasably secured to the upper surface of the cover.

[0009] EP3373874B1 discloses a dressing with edges, comprising a release liner releasably attached to an adhesive skin contact layer. The release liner comprises at least two removable parts separated by a dividing line, the dividing line being arranged at a distance of less than 15 mm from the edge of the wound pad. The arrangement of the dividing line close to the edge of the wound pad allows the dressing to be arranged at the end of the incision and facilitates the process of applying the dressing to the patient's skin.

[0010] Although the above documents provide solutions to the problem of dealing with film dressings or bordered dressings having thin border portions, there is still room for improvement in this area.

[0011] In particular, there is a need to improve and simplify the handling and application of thin adhesive dressings by caregivers in order to avoid or at least significantly reduce the formation of wrinkles during application to a patient's skin while also preventing bacterial contamination. Summary of the invention

[0012] In view of the above problems, it is an object of the present invention to provide improvements in the field of adhesive medical dressings and to provide wrinkle-free and sterile handling and application of such dressings to the caregiver.

[0013] According to a first aspect of the present invention, a medical dressing is provided, comprising a top layer, an adhesive skin contact layer, and a release liner detachably attached to at least a portion of the adhesive skin contact layer; the release liner having a first side facing the adhesive skin contact layer and an opposing second side, wherein the first side of the release liner comprises a plurality of protrusions spaced apart from each other by non-protrusion areas, wherein the protrusions are detachably attached to the adhesive skin contact layer, and wherein the non-protrusion areas are not attached to the adhesive skin contact layer.

[0014] The present invention is based on the recognition that a patterned release liner as described above significantly improves and facilitates the handling of the dressing before and during application of the dressing to the patient's skin. More specifically, the dressing of the present invention significantly reduces the formation of wrinkles when the release liner is separated from the adhesive skin contact layer and when the dressing is applied to the patient's skin.

[0015] The protrusions form a contact surface with the adhesive skin contact layer, but the non-protrusion areas remain non-adherent to the adhesive skin contact layer. For conventional dressings, the release liner is usually flat and adheres completely to the surface of the adhesive dressing. When removing such a release liner from the adhesive surface, a relatively large removal force is required, which almost immediately results in the formation of wrinkles.

[0016] As described above, adhesive medical dressings are typically thin and fragile and are very difficult to handle because they are prone to forming wrinkles. Different from conventional plasters or band-aids (where the release liner is completely removed before dressing application), medical dressings used in care facilities and / or hospital settings are applied in a different manner. Usually, while the release liner is removed gradually or step by step, the dressing is applied to the patient's skin or wound. The application and handling of the dressing are carried out by caregivers.

[0017] The medical dressing of the present invention creates a reduced attachment between the release liner and the adhesive skin contact layer. The delamination force, i.e., the force required to remove the release liner, is significantly reduced. The reduced delamination force prevents the formation of wrinkles when peeling off the release liner and applying the dressing to the patient's skin. The release liner still has sufficient adhesiveness and adheres to the adhesive skin contact layer to prevent contaminants from entering the dressing.

[0018] The non-protrusion areas form a gap between the release liner and the adhesive skin contact layer.

[0019] This enables the non-protrusion areas to remain non-attached to the adhesive skin contact layer during transportation and storage. The adhesive skin contact layer does not follow the contour of the patterned release liner and is prevented from "sinking" into the gap, which is the case for adhesives commonly used in medical dressings. After assembling the medical dressing, the dressing (including the release liner) is subjected to sterilization, which can be considered a relatively harsh treatment. During the sterilization process, the layers of the dressing are pressed together. Such squeezing and closer contact between the layers also occur during transportation and storage. However, providing a gap between the adhesive skin contact layer and the release liner prevents the release liner from adhering completely to the adhesive skin contact layer.

[0020] In an exemplary embodiment, the first side of the release liner is separably attached to 10% to 80%, preferably 15% to 70%, and most preferably 20% to 50% of the surface area of the adhesive skin contact layer.

[0021] Therefore, the release liner serves a dual function of protecting the adhesive skin contact layer and facilitating the removal of the release liner, thereby preventing the formation of wrinkles during release liner removal.

[0022] In an exemplary embodiment, each of the plurality of protrusions has a substantially flat top surface; the top surface forms a contact surface for separably attaching the release liner to the adhesive skin contact layer.

[0023] This is beneficial in ensuring that, for example, during sterilization, shipping or storage of the medical dressing, the adhesive skin contact layer does not "sink" into the "valley" defined by the non-raised areas. Soft adhesives, such as silicone-based adhesives, have a tendency to follow the contours of the underlying surface. This is a desirable property when the dressing is to be applied to the patient's skin, but is undesirable for the purpose of preventing wrinkles during removal of the release liner.

[0024] The flat top surfaces of the protrusions ensure that the gap defined between the adhesive skin contact layer and the release liner is maintained and that a significant portion of the release liner is not attached to the adhesive skin contact layer. Rather than sinking into the valleys defined by the non-protrusion areas (which would be the result if, for example, a curved protrusion profile was used), the adhesive skin contact layer lies flat on top of the plurality of protrusions.

[0025] Furthermore, if the top surface of the protrusions is angled or sharp, the protrusions can create indentations and impressions in the adhesive skin contact layer, which is undesirable when the dressing is attached to the skin. Such impressions can reduce adhesion to the patient's skin and can impair the ability of the adhesive skin contact layer to conform to the skin.

[0026] In an exemplary embodiment, each of the plurality of protrusions has a top surface and a sidewall extending between the top surface and a non-protrusion area, wherein an angle α between the top surface and the sidewall is 60 to 120 degrees, preferably 75 to 105 degrees, and most preferably 85 to 95 degrees.

[0027] An angle within the above range further prevents the adhesive skin contact layer from sinking into the gap defined between the release liner and the adhesive skin contact layer. Thus, the adhesive skin contact layer remains substantially flat and is prevented from following the contours of the protrusions. This further ensures that the adhesive skin contact layer remains unattached to the release liner in non-protrusion areas.

[0028] In an exemplary embodiment, the height of each of the protrusions may be 0.3 mm to 2.0 mm, preferably 0.5 mm to 1.5 mm.

[0029] These dimensions are advantageous for achieving the proper balance of protecting the dressing from contamination, preventing marking in the adhesive skin contact layer, and ensuring that the non-raised areas do not adhere to the adhesive skin contact layer.

[0030] In an exemplary embodiment, the surface area of ​​the top surface of each of the protrusions may be 0.8 mm 2 Up to 3.0mm 2 , preferably 1.0mm 2 Up to 2.0mm 2 .

[0031] A surface area within the above range improves releasable adhesion to the adhesive skin contact layer. If the surface area is too large, the first side of the release liner may be too firmly attached to the adhesive skin contact layer. As a result, the delamination force may increase (causing wrinkles when removing the release liner). If the surface area is too small, the soft adhesive skin contact layer may be more inclined to sink into the valley or gap defined by the non-protruding area of ​​the first side of the release liner.

[0032] In an exemplary embodiment, the adhesive skin contact layer may include a silicone-based adhesive coating.

[0033] The silicone-based adhesive coating is soft and gentle on the skin and can be removed without causing trauma.

[0034] However, the softness of the silicone-based adhesive may make the adhesive skin contact layer more inclined to conform to the contours of the underlying surface structure. As described above, this is beneficial for accommodating the patient's skin or wound, especially curved or contoured skin surfaces. However, it is not desirable for the adhesive skin contact layer to conform to the peaks and valleys defined by the raised and non-raised areas, respectively, on the first side of the adhesive skin contact layer.

[0035] In an exemplary embodiment, the adhesive skin contact layer may include a polymer film provided with a silicone-based adhesive coating.

[0036] The polymer film provides stability to the applied silicone-based adhesive coating and counteracts the tendency of the silicone adhesive to follow the contours of the protrusions. Thus, the polymer film prevents the silicone-based adhesive from sinking deeper into the valleys defined by the non-protruding portions of the first side of the release liner.

[0037] In an exemplary embodiment, the silicone-based adhesive coating has a thickness of 35 gsm to 300 gsm, preferably 45 gsm to 250 gsm.

[0038] If the thickness of the silicone-based adhesive coating is too thin, it may result in poor adhesion to the skin. Conversely, thicker silicone-based adhesive coatings have an increased tendency to follow the contours of the protrusions. In addition, thicker silicone-based coatings increase the risk of protrusions forming impressions in the silicone-based adhesive skin contact layer.

[0039] In an exemplary embodiment, the dressing may further include an absorbent pad disposed between the top layer and the adhesive skin contact layer, wherein the top layer and the adhesive skin contact layer are configured to extend beyond a contour of the absorbent pad to define a border portion along the contour of the absorbent pad.

[0040] Thus, the medical dressing may be a bordered dressing. The absorbent pad is used to handle large amounts of wound fluid exuded by the wound. For a bordered dressing, the border portion is particularly prone to wrinkling and once the release liner is removed, the border portion tends to wrinkle and adhere to itself. Therefore, it is beneficial to arrange the release liner so that the plurality of protrusions cover the adhesive skin contact layer in at least the border portion of the dressing. The absorbent pad may provide a degree of rigidity to the overall dressing structure and, in this regard, facilitate the process of removing the release liner and applying the dressing by the caregiver.

[0041] The plurality of protrusions on the first side of the release liner may be provided by any technique known in the art.

[0042] In an exemplary embodiment, the plurality of protrusions may be formed by embossing.

[0043] Embossing is a simple and reliable technique that is able to provide distinct three-dimensional protrusions in a release liner, wherein the protrusions remain in place during, for example, storage and transport of the dressing.

[0044] According to another aspect, there is provided a method for manufacturing a medical dressing, comprising:

[0045] a) providing a dressing comprising a top layer and an adhesive skin contact layer,

[0046] b) providing a release liner having a first side and an opposing second side, wherein at least a portion of the first side of the release liner comprises a plurality of protrusions spaced apart from one another by non-protrusion areas;

[0047] c) applying a release liner to the adhesive skin contact layer such that the plurality of projections are releasably attached to the adhesive skin contact layer and are not attached to the adhesive skin contact layer in non-projection areas.

[0048] In an exemplary embodiment, the protrusions on the first side of the release liner are formed as an in-line step in the method.

[0049] This has several advantages from a process and storage perspective. If the protrusions are provided in the release liner as a separate process step prior to the process of manufacturing the dressing, the protruded release liner will require more space during storage, for example on a storage roll. In contrast, if the plurality of protrusions are formed as an in-line step, the release liner can be stored in a flat state on a storage roll.

[0050] In an exemplary embodiment, the plurality of protrusions on the first side of the release liner may be formed by embossing.

[0051] As mentioned above, embossing is a simple technique for forming three-dimensional features, such as protrusions in a layer. In addition, embossing is suitable for embodiments in which the protrusions are formed as an in-line step of the method.

[0052] Further features and advantages of the present invention will become apparent when studying the attached claims and the following description.Those skilled in the art realize that different features of the present invention can be combined to produce embodiments other than those described in the following, without departing from the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Various aspects of the present invention, including specific features and advantages, will be readily understood from the following detailed description and accompanying drawings, in which:

[0054] Figure 1a A medical dressing according to an exemplary embodiment of the present invention is shown as seen from the bottom side when a caregiver is about to peel off the release liner.

[0055] Figure 1b yes Figure 1a Magnified view of a portion of the dressing.

[0056] Figure 1c yes Figure 1a Cross-sectional view of a portion of a medical dressing showing the release liner being peeled away from the adhesive skin contact layer.

[0057] Figure 2 A medical dressing according to an exemplary embodiment of the present invention is shown.

[0058] Figure 3a and Figure 3b The application process of the medical dressing according to the present invention by a nursing staff is shown.

[0059] Figure 4a Scanning electron microscope (SEM) images of release liners having a pattern of pyramidal protrusions used in Dressing B and Dressing E in Example 1 are shown.

[0060] Figure 4b Shown is a SEM image of the adhesive skin contact layer of Dressing B (Example 1) after peeling off the release liner.

[0061] Figure 4c A SEM image of a cross section of Dressing B in Example 1 is shown.

[0062] Figure 4d A SEM image of a cross section of Dressing C, ie, the dressing according to a preferred embodiment of the present invention in Example 1 is shown. DETAILED DESCRIPTION

[0063] The present invention will be described more fully below with reference to the accompanying drawings, in which currently preferred embodiments of the present invention are shown. However, the present invention may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness and to fully convey the scope of the present invention to the skilled person. The same reference numerals refer to the same elements throughout.

[0064] Figure 1a A medical dressing according to an exemplary embodiment of the present invention is shown wherein the release liner is to be peeled off by a caregiver. Figure 1b yes Figure 1a A magnified view of the dressing in Figure 1c Shows Figure 1a Partial cross-sectional view of a medical dressing.

[0065] Medical dressing 100 includes top layer 101, adhesive skin contact layer 102, and release liner 103 detachably attached to at least a portion of adhesive skin contact layer 102. Release liner 103 has a first side 104 facing adhesive skin contact layer 102 and an opposing second side 105, wherein first side 104 of release liner 103 includes a plurality of protrusions 106 spaced apart from each other by non-protrusion areas 107, wherein protrusions 106 are detachably attached to adhesive skin contact layer 102, and wherein non-protrusion areas 107 are not adhered to adhesive skin contact layer 102.

[0066] As used herein, the term "top layer" refers to the uppermost layer of a medical dressing; that is, the layer that faces away from the patient's skin during use. The top layer may also be referred to as a backing layer.

[0067] An adhesive skin contact layer is a layer that is arranged to come into contact with the patient's skin. A skin contact layer may also be referred to as a wound contact layer.

[0068] The top layer and the adhesive skin contact layer are generally coextensive. The surface area of ​​the top layer is the same as the surface area of ​​the adhesive skin contact layer.

[0069] The release liner is arranged to cover the entire surface area of ​​the adhesive skin contact layer.

[0070] The release liner may include one or more removable portions. Figure 1a (and Figure 3a to Figure 3b ), the release liner includes two removable parts (103a and 103b), but the present invention is by no means limited to this structure. Figure 2 The dressing shown includes a release liner 103 having a removable portion.

[0071] If the first release liner comprises more than one removable portion, the first release liner may be separated by a dividing line, wherein the first removable portion 103a and the second removable portion 103b of the release liner overlap along the dividing line. The overlapping configuration is important to ensure that the adhesive skin contact layer is completely covered and no gaps are formed, thereby preventing contaminants from entering the dressing. The overlapping removable portions may form a gripping member that an applicator, such as a caregiver 112, may grip to remove and separate the removable portions. For example, as Figure 1a As shown, the edge of the second removable portion 103b can be folded upon itself, and the edge of the first removable portion 103a can be configured to overlap the folded edge.

[0072] Regardless of how many removable portions the release liner comprises, the release liner is arranged to cover the entire adhesive skin contact layer.

[0073] The dressing of the present invention can be used on all types of wounds, incisions, and even intact skin (if the purpose of the dressing is to prevent the occurrence of a wound in advance). The dressing is advantageously used on larger wounds or scars and can be of relatively large size.

[0074] Larger sized dressings are generally more complicated to apply as they have an increased tendency to self-stick and to wrinkle easily, particularly at the edges of the dressing.The dressings of the present invention are also advantageously used with dressings comprising large and "fragile" border portions.

[0075] However, it should be noted that the present invention also has several advantages for smaller sized dressings. For example, smaller sized bordered dressings may suffer from the same problems of wrinkling and "curling" when the release liner is removed.

[0076] Conventional release liners are generally flat; that is, they are completely adhered to the adhesive skin contact layer before use. When such release liners are removed from the adhesive skin contact layer before and during application to the patient's skin, the force required to remove the release liner is high. As a result, removal of the release liner may cause significant wrinkle formation.

[0077] The handling of thin adhesive dressings places demands on the applicator, who is usually a caregiver (sometimes more than one caregiver). Figure 3a and Figure 3b As shown, the dressing is anchored to the patient's skin while the release liner is removed. Figure 3a value Figure 3bIn the present invention, the release liner includes two removable parts (103a and 103b). The first removable part 103b is first removed from the adhesive skin contact layer portion, and the exposed adhesive surface is positioned on the patient's wound or incision (usually at the edge of the incision or wound). While pressing the dressing lightly onto the skin, the caregiver 112 can gradually remove the first removable part 103 with one hand, and simultaneously fix the adhesive skin contact layer (and the dressing) to the skin in a smooth and wrinkle-free manner with the other hand. Since the gradual removal of the release liner requires significantly reduced force to remove and separate from the adhesive surface, it is very convenient for the caregiver to apply the dressing to the patient's skin. A more controlled, sterile and wrinkle-free application method is achieved.

[0078] like Figure 1b and Figure 1c As best shown in FIG. 1 , the plurality of non-raised areas 107 define a gap 108 between the first side 104 of the release liner 103 and the adhesive skin contact layer 102 .

[0079] The distinct gap between the first side 104 of the release liner 103 and the adhesive skin contact layer 102 ensures that the non-raised areas 107 remain non-adherent to the adhesive skin contact layer 102 .

[0080] exist Figure 1a to Figure 1c In the embodiment, the second side 105 of the release liner 103 includes a recess (in Figure 1a and Figure 1b The depression 113 on the second side 105 of the release liner 103 coincides with the protrusion 106 on the first side 104 of the release liner 103. The depression 113 on the second side 105 can be formed when the release liner is embossed. For example, the release liner can be subjected to an embossing tool on the second side of the release liner, thereby forming the protrusion 106 on the first side 104 of the release liner and forming a corresponding depression 113 on the second side 105 of the release liner. However, the present disclosure is not limited to embossed protrusions. In an exemplary embodiment, the second side 105 of the release liner is flat.

[0081] The first side 104 of the release liner 103 may be releasably attached to 10% to 80%, preferably 15% to 70%, and most preferably 20% to 50% of the surface area of ​​the adhesive skin contact layer.

[0082] Thus, problems associated with too firm an attachment of the adhesive skin contact layer are overcome and detachment of the release liner and subsequent application of the dressing to the skin is very convenient for the caregiver.

[0083] like Figure 1b and Figure 1cAs shown, each of the plurality of protrusions has a flat top surface 109 ; the top surface 109 forms a contact surface for releasably attaching the release liner 103 to the adhesive skin contact layer 102 .

[0084] This is considered beneficial for a variety of reasons. Firstly, because marks in the adhesive skin contact layer caused by too sharp or too angled protrusion top surfaces are avoided. Furthermore, the flat top surface ensures that the adhesive skin contact layer lies flat on top of the plurality of protrusions, without sinking into the valleys defined by the non-protrusion areas. This is particularly advantageous in that the adhesive skin contact layer is not easily lost in the adhesive skin contact layer. Figure 4d This can be clearly seen in the SEM image of FIG, which also shows a clear and distinct gap 108 defined by the non-protruding area of ​​the first side of the release liner. In contrast, Figure 4c The SEM picture of shows how the adhesive skin contact layer clearly conforms to the patterned protrusions of the release liner (see Example 1 below) and leaves no gaps between the release liner and the adhesive skin contact layer.

[0085] like Figure 1c As best shown in the figure, each of the plurality of protrusions 106 has a top surface 109 and a side wall 110, wherein the side wall extends between the top surface 109 and the non-protrusion area 107, wherein an angle α between the top surface 109 and the side wall 110 is 60 to 120 degrees, preferably 75 to 105 degrees, and most preferably 85 to 95 degrees.

[0086] If the angle α is too large, which may be the case, for example, with a patterned release liner having a "wavy" pattern, the adhesive skin contact layer has a tendency to follow the contours of the wavy pattern. In this regard, the delamination forces between the adhesive skin contact layer and the release liner may actually increase (see Example 1).

[0087] The height h1 of each of the protrusions 106 may be 0.3 mm to 2.0 mm, and preferably 0.5 mm to 1.5 mm.

[0088] The height hi is the maximum longitudinal extension of the protrusion and is measured between the top surface 109 of the protrusion and the non-protrusion area 107 .

[0089] These dimensions are suitable for achieving well-defined gaps between the protrusions and ensuring that the adhesive skin contact layer does not conform to or adhere to the release liner in the gaps (non-protrusion areas). If the height of the protrusions is too high, the risk of forming marks in the adhesive skin contact layer increases. Conversely, if the height is too low, the adhesive skin contact layer may adhere to the entire first side of the release liner, which is undesirable.

[0090] The width w1 of the protrusion may be in the range of 0.8 mm to 3.0 mm, for example 1.0 mm to 2.0 mm.

[0091] The width w1 is the maximum lateral extension of a protrusion 106 .

[0092] The surface area of ​​the top surface 109 of each protrusion 106 may be 0.8 mm 2 Up to 3.0mm 2 , preferably 1.0 mm 2 Up to 2.0mm 2 .

[0093] The surface area within the above range improves the releasable attachment to the adhesive skin contact layer. If the surface area is too large, the first side of the release liner may become too firmly adhered to the adhesive skin contact layer. As a result, the delamination force may be increased (causing wrinkles when the release liner is removed). If the surface area is too small, the adhesive skin contact layer may be more inclined to sink into the valley or gap defined by the non-protruding area of ​​the first side of the release liner.

[0094] The top surface 109 of each protrusion is not limited to a specific shape, but any conceivable shape, such as circular, oval, square, rectangular, etc.; and typically, the top surface is circular.

[0095] The plurality of protrusions 106 may be arranged in a pattern extending across the entire surface facing the adhesive skin contact layer 102 .

[0096] At least 50% of the first side 104 of the release liner 103 may include the pattern of protrusions.

[0097] If the dressing is a bordered dressing and includes a centrally disposed absorbent pad, the plurality of protrusions 106 may be arranged in a pattern extending across the surface of the adhesive skin contact layer 102 facing the border portion.

[0098] The plurality of protrusions are generally arranged in a regular pattern across the first side of the release liner.

[0099] The distance between one protrusion and an adjacent protrusion may be 1.0 mm to 8.0 mm, for example 1.0 mm to 3.0 mm. The distance between adjacent protrusions depends on the size of the protrusions, the size of the dressing, etc. The distance between one protrusion and an adjacent protrusion may correspond to the diameter or maximum width of the protrusion.

[0100] The adhesive skin contact layer 102 may include a silicone based adhesive coating.

[0101] Such adhesives are skin friendly and allow for removal of the dressing without causing damage to the skin. The softness of silicone-based adhesives can be associated with some challenges, as soft silicone-based adhesives have an enhanced tendency to conform to the underlying surface. In the context of the present disclosure, this is avoided by the unattached area of ​​the first side of the release liner that defines a distinct gap.

[0102] The silicone-based adhesive coating may have a thickness of 35 gsm to 300 gsm, for example 45 gsm to 250 gsm.

[0103] Thus, a proper balance between skin adhesion, preventing markings in the silicone-based adhesive, and preventing the silicone-based adhesive from following the contours of the protrusions is achieved.

[0104] The adhesive skin contact layer 102 may comprise a polymer film (not shown) provided with a silicone based adhesive coating.

[0105] The polymer film creates stability to the applied silicone-based adhesive coating and prevents the silicone-based adhesive from following the contours of the protrusions.

[0106] The polymer film is preferably a breathable film and may comprise, for example, polyethylene, polyamide or polyurethane. Preferably, the polymer film comprises polyurethane. The thickness of the polymer film may be 15 μm to 100 μm, for example 20 μm to 80 μm, preferably 20 μm to 50 μm.

[0107] The silicone-based adhesive coating of the tacky skin contact layer is arranged to contact the wearer's skin.

[0108] like Figure 2 As best shown in , the medical dressing 100 may further include an absorbent pad 111 disposed between the top layer 101 and the adhesive skin contact layer 102 , wherein the top layer 101 and the adhesive skin contact layer 102 are configured to extend beyond the contour of the absorbent pad 111 to define a boundary portion along the contour of the absorbent pad 111 .

[0109] like Figure 2 As shown, the adhesive skin contact layer may include a central portion 102a and an edge portion 102b surrounding the central portion 102a. The surface area of ​​the central portion 102a generally corresponds to the surface area of ​​the absorbent pad 111. The edge portion 102b extends beyond the contour of the absorbent pad 111 and forms a border portion of the dressing together with the top layer 101.

[0110] The adhesive skin contact layer 102 may include a plurality of perforations 114 at least in the area below the absorbent pad 111. Figure 2 In the embodiment, the adhesive skin contact layer has no perforations in the edge portion 102b, ie, in the area forming the border portion.

[0111] Providing perforations in the adhesive skin contact layer improves fluid management within the dressing, and this also applies to the dressing shown in Figure 1-c.

[0112] In the case of side dressing, e.g. Figure 2As shown, the perforations 114 are used to improve the absorption of wound exudate into the dressing and are therefore arranged in the area where the absorption occurs. The area of ​​the adhesive skin contact layer that forms the border portion of the dressing may be free of perforations. In this way, the adhesion to the skin is enhanced and the staying power of the medical dressing is thereby prolonged. However, this structure also makes the border portion more fragile, more prone to wrinkling, and more difficult to handle and apply to the skin.

[0113] If the adhesive skin contact layer 102 comprises a polymer film and a silicone based adhesive coating, the perforations 114 extend through both layers.

[0114] The absorbent pad 111 may include foam or gel. It may also include superabsorbent material, such as superabsorbent polymer (SAP) or superabsorbent fiber (SAF).

[0115] For example, the absorbent pad 111 may include two or more layers having different properties.

[0116] The absorbent pad 111 may include a first absorbent layer and a liquid collection layer. The absorbent pad may further include a second absorbent layer. The first absorbent layer may be a super absorbent layer, and the second absorbent layer may include absorbent foam. Typically, the super absorbent layer is disposed between the liquid collection layer and the second absorbent layer. Suitable foam materials for the second absorbent layer include, but are not limited to, polyurethane foam.

[0117] The superabsorbent layer may include a superabsorbent polymer (SAP). "Superabsorbent polymer" or "SAP" is a polymer that can absorb up to 300 times its own weight of aqueous fluid. Superabsorbent polymers are composed of water-swellable and water-insoluble polymers that can absorb a large amount of fluid when forming a hydrogel. The superabsorbent polymer used according to the present invention can be an inorganic or organic cross-linked hydrophilic polymer, such as polyvinyl alcohol, polyethylene oxide, cross-linked polyacrylate, etc. Typically, superabsorbent material (SAP) includes sodium acrylate. SAP materials can be in the form of particles, fibers, flakes, etc.

[0118] The liquid collection layer may comprise any material having the ability to distribute exudate in an effective manner. For example, the liquid collection layer may comprise a nonwoven material. As such, the nonwoven material imparts a properly balanced rigidity to the layer and the dressing. It may also effectively distribute and diffuse the liquid absorbed by the superabsorbent layer so that it can evaporate over a large surface through the top layer. For example, the nonwoven material may comprise viscose, polyester, or a blend thereof.

[0119] The layers may be joined by bonding, lamination (eg by using pressure and / or heat).

[0120] The absorbent pad 111 may include additional layers, such as liquid transfer layers, and various combinations of foam and nonwoven layers.

[0121] like Figure 2 As shown, the absorbent pad 111 can include a plurality of cuts 115 extending at least partially through the absorbent pad 111. The cuts 115 can have a variety of shapes to make the pad more flexible and enhance the flexibility of the overall dressing.

[0122] Figure 2 The cuts 115 shown in each of the drawings include three cuts extending from a common starting point. The angles between these cuts can be between 40° and 150°. Thus, the pad or pad layer is cut in the longitudinal (y) and transverse (x) directions of the pad, making the pad flexible in all directions.

[0123] If the absorbent pad 111 comprises several pad-forming layers, the cut 115 may extend through at least one of these layers.

[0124] The absorbent pad 111 may include one or more bioactive substances, such as compounds having antimicrobial or wound healing effects. Examples of such compounds include, but are not limited to, silver compounds, such as silver salts and metallic silver; biguanide salts, such as polyhexamethylene biguanide (PHMB) or any salt thereof, or polyhexamethylguanidine (PHMG) or any salt thereof), or chlorhexidine or any salt thereof; iodine; salicylic acid or any salt thereof; acetylsalicylic acid or any salt thereof; quaternary ammonium salts, such as benzethonium chloride; povidone iodine (bital iodine); lactoferrin; xylitol; antimicrobial peptides, such as human cationic antimicrobial protein 18 (hCAP18 or LL37); borneol; bismuth subgallate; antifungal drugs; and antibiotics, such as gentamicin and streptomycin.

[0125] The top layer 101 and adhesive skin contact layer 102 may be bonded to each other in those areas of the two layers that extend beyond the contours of the absorbent pad 111. The top layer may also be bonded to the absorbent pad 111, for example, by an adhesive such as a pressure sensitive adhesive (eg, polyacrylate).

[0126] The dressing of the present invention is not limited to a specific shape, but can be any shape that can be imagined, such as square, rectangular, oval, circular, etc.

[0127] The maximum longitudinal extension, eg length, of the dressing may be 3.0 cm to 50 cm, such as 6.0 cm to 45 cm, such as 7.0 cm to 40 cm.

[0128] The maximum lateral extension of the dressing, for example the width, may be from 3.0 cm to 30 cm, for example from 4.0 cm to 20 cm.

[0129] In order to achieve sufficient adhesive properties, the border portion may have a width of 10 mm to 50 mm, for example 20 mm to 30 mm, and extend along the contour of the absorbent pad 111 .

[0130] Smaller sized dressings may have smaller border portions than larger sized dressings. This allows the product to be easily handled and applied while still remaining sufficiently tacky when applied.

[0131] Forming the protrusions in the release liner is not limited to a particular technique. The protrusions 106 may be formed by any suitable technique known to those skilled in the art.

[0132] In an exemplary embodiment, and as Figure 1a-Figure 1c As shown, the protrusions 106 are embossed protrusions. Therefore, the plurality of protrusions 106 are formed by embossing.

[0133] According to another aspect, there is provided a method for manufacturing a medical dressing 100, comprising:

[0134] a) providing a dressing 100 comprising a top layer 101 and an adhesive skin contact layer 102,

[0135] b) providing a release liner 103 having a first side 104 and an opposing second side 105, wherein at least a portion of the first side 104 of the release liner 103 comprises a plurality of protrusions 106 spaced apart from each other by non-protrusion areas;

[0136] c) applying a release liner to the adhesive skin contact layer such that the plurality of projections are releasably attached to the adhesive skin contact layer and are not adhered to the adhesive skin contact layer in non-projection areas.

[0137] The dressing (step a) may be provided by means known to those skilled in the art. The dressing may also include an absorbent pad between the top layer and the adhesive skin contact layer. The assembly of the top layer, adhesive layer and absorbent pad (if present) is not limited to a particular method, but may be performed using any means (e.g. adhesive bonding, lamination, etc.).

[0138] Preferably, the plurality of protrusions 106 on the first side 104 of the release liner 103 are formed as an in-line step in the method.

[0139] The process is thus significantly simplified and is also advantageous from a storage point of view. This enables the release liner to be stored in a flat state, for example on a roll, requiring less space than if the release liner were provided with protrusions.

[0140] For example, the plurality of protrusions may be formed by embossing.

[0141] Embossing is a simple technique to form three-dimensional features, such as protrusions in a layer. Furthermore, embossing is a suitable technique in embodiments where the protrusions are formed as an in-line step in the process.

[0142] For example, the release liner may be subjected to an embossing tool on the second side of the release liner, which forms protrusions 106 on the first side 104 of the release liner and corresponding depressions 113 on the second side 105 of the release liner. The embossing tool may be arranged in a production line and may provide the embossed protrusions before the release liner is applied to the adhesive skin contact layer 102.

[0143] The present invention is not limited to forming the protrusions by embossing.

[0144] In alternative embodiments, the protrusions may be formed by molding or casting.

[0145] In various embodiments described above, the top layer can be a vapor permeable film, sheet or membrane. Examples of suitable materials for the top layer include, but are not limited to, polyurethane, polyethylene or polyamide films, silicone films, polyester-based nonwoven materials, and laminates of polyester-based nonwoven materials and polyurethane films. Suitably, the top layer is a polyurethane film. The thickness of the top layer can be 5 μm to 40 μm, for example 15 μm to 25 μm. A thin layer of adhesive such as a polyacrylate adhesive can be applied to the top layer 101 to adhere the top layer 101 to the adhesive skin contact layer 102 or, if present, to the absorbent pad 111 or any other layer of the dressing.

[0146] The adhesive skin contact layer preferably comprises a silicone based adhesive.

[0147] Examples of suitable silicone-based adhesives include two-component RTV systems, such as Q72218 (DowCorning) and SilGel 612 (Wacker Chemie AG) mentioned herein, and NuSil silicone elastomers. In embodiments of the present invention, the adhesive may include a soft silicone gel having a softness (permeability) of 8 mm to 22 mm, such as 12 mm to 17 mm, measured according to the method of ASTM D 937 and DIN 51580, which is described in European Patent Application No 14194054.4. The thickness of the silicone-based adhesive coating is typically at least 20 μm. The thickness of the silicone-based adhesive coating may be 40 μm to 300 μm.

[0148] Preferably, the adhesive skin contact layer comprises a plurality of perforations.

[0149] If the adhesive skin contact layer comprises a polymer film and a silicone based adhesive coating, the perforations extend through both layers.

[0150] The adhesive skin contact layer is arranged to receive body fluids, such as wound exudate, from the wound, while the function of the absorbent pad is to absorb wound exudate and transport it away from the wound by evaporating it from the top of the dressing (ie through the top layer 101).

[0151] The terms, definitions and embodiments of all aspects of the invention apply mutatis mutandis to the other aspects of the invention.

[0152] Even though the invention has been described above with reference to specific exemplifying embodiments thereof, many different alternatives, modifications and the like will be apparent for those skilled in the art.

[0153] By studying the drawings, the disclosure and the appended claims, those skilled in the art can understand and implement variations of the disclosed embodiments when practicing the present invention. In addition, in the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality of.

[0154] Example 1: Adhesion between release liner and adhesive skin contact layer

[0155] Testing was performed to evaluate the adhesion between the release liner and the adhesive skin contact layer of various samples. Adhesion may also be referred to as delamination force; that is, the force required to remove the release liner from the adhesive skin contact layer.

[0156] The evaluated dressing samples each comprised: a 20 μm polyurethane film as top layer; an absorbent pad having a thickness of approximately 3 mm; an adhesive skin contact layer comprising a polymer film (20 μm polyurethane film) coated with a silicone-based adhesive of varying thickness (see below); and a 100 μm polyethylene film as a release liner. The evaluated dressing samples were bordered dressings; that is, the top layer and the adhesive skin contact layer were arranged to extend beyond the contours of the absorbent pad. The tested dressings differed in the thickness of the silicone-based adhesive coating and the nature of the release liner, respectively.

[0157] Sample A: 50gsm thick silicone adhesive coating, flat release liner

[0158] Sample B: 50 gsm thick silicone adhesive coating, release liner embossed with a pyramid-shaped protrusion pattern (see Figure 4A)

[0159] Sample C: 50gsm thick silicone adhesive coating, embossed as Figure 1b to Figure 1c and Figure 2 Release liner with raised pattern shown

[0160] Sample D: 200gsm thick silicone adhesive coating, flat release liner

[0161] Sample E: 200 gsm thick silicone adhesive coating, release liner embossed with a pyramid-shaped protrusion pattern (see Figure 4A)

[0162] Sample F: 200gsm thick silicone adhesive coating, embossed as Figure 1b to Figure 1c and Figure 2 Release liner with the protrusion pattern shown.

[0163] The silicone adhesive coatings of Samples A to F have the same composition but different viscosities (Samples A to C have higher viscosities than Samples D to F).

[0164] The height of the protrusions of Samples B and E was about 0.4 mm, while the height of the protrusions of Samples C and F was about 1.0 mm. The protrusions of Samples C and F had a substantially flat top surface (with a thickness of about 1.5 mm). 2 The protrusions of samples B and E have a surface area of ​​about 0.3 mm and the angle between the top surface and the side wall is about 90 degrees. 2 and the angle between the top surface and the side wall is about 45 degrees.

[0165] The samples were sent to the manufacturing site for sterilization to undergo the typical sterilization cycle required for wound dressings (EtO sterilization).

[0166] The adhesion at the border portion and the pad portion of the dressing was evaluated separately.

[0167] Each dressing sample was punched out into a size of 25 x 200 mm using a punching tool.

[0168] A vertical tensile tester with a flat grip was used, with a calibration speed of 2500 mm / min and a head stroke of 250 mm (crosshead speed: 2500 mm / min, gauge length: 50 mm).

[0169] At the short side of each dressing sample, the release liner was separated from the adhesive skin contact layer and the sample and release liner were attached together at the lower grip of the tensile tester.

[0170] The average force was recorded over a measuring length of 250 mm. The average force was calculated between 20 mm and 220 mm of the dressing sample; i.e. excluding the first 20 mm and the last 30 mm of the sample. Therefore, the average force was calculated over a total length of 200 mm.

[0171] In each sample category A to F, five dressing samples were tested.

[0172] The results are shown in Table 1 below.

[0173] sample Average delamination force (N) - boundary part Average delamination force (N) - pad part Sample A 2.47 1.63 Sample B 2.09 1.31 Sample C 0.72 0.45 Sample D 1.17 0.75 Sample E 1.36 0.67 Sample F 0.39 0.22

[0174] Table 1: Adhesion between release liner and adhesive skin contact layer

[0175] As shown in Table 1, for samples A to C including 50 gsm silicone adhesive coating, the delamination force was reduced when the embossed release liner was used. The delamination force of sample C was significantly reduced. Compared with the delamination force of sample A, the delamination force of sample C was reduced by at least 70% (both at the boundary portion and at the pad portion).

[0176] The same results can be seen when comparing Sample D to Sample F which has a thicker silicone adhesive coating.

[0177] The delamination force of sample E (comprising an embossed release liner) is actually greater than the delamination force of sample D (comprising a flat release liner). This can be explained by the thicker silicone adhesive layer having an enhanced tendency to follow the contours of the pyramidal protrusions.

[0178] Figure 4b A scanning electron microscope (SEM) image of the skin-facing side (also referred to as the second side) of the adhesive skin contact layer of Sample B is shown. Figure 4b As shown, an impression from the sharper protrusion is formed.

[0179] For Sample C, no marks were formed in the adhesive skin contact layer.

[0180] Figure 4c and Figure 4d Cross-sectional SEM images of sample B and sample C are shown, respectively.

[0181] like Figure 4d As shown, the adhesive skin contact layer 102 lies flat on the top surface of the protrusions and does not sink into the gap 108 defined between the release liner and the adhesive skin contact liner.

[0182] In contrast, the adhesive skin contact layer 102 of Sample B conformed to the protrusions of the release liner.

[0183] The terms, definitions and embodiments of all aspects of the invention apply mutatis mutandis to the other aspects of the invention.

[0184] Even though the invention has been described above with reference to specific exemplifying embodiments thereof, many different alternatives, modifications and the like will be apparent for those skilled in the art.

[0185] By studying the drawings, the disclosure and the appended claims, those skilled in the art can understand and implement variations of the disclosed embodiments when practicing the present invention. In addition, in the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality of.

Claims

1. A medical dressing (100), comprising a top layer (101), an adhesive skin contact layer (102), and a release liner (103) detachably attached to at least a portion of the adhesive skin contact layer (102); the release liner (103) having a first side (104) facing the adhesive skin contact layer (102) and an opposite second side (105), wherein the first side (104) of the release liner (103) comprises a plurality of protrusions (106) spaced apart from each other by non-protrusion areas (107), wherein the protrusions (106) are detachably attached to the adhesive skin contact layer (102), and wherein the non-protrusion areas (107) are not attached to the adhesive skin contact layer (102).

2. The medical dressing (100) according to claim 1, in, The non-raised area (107) forms a gap (108) between the release liner (103) and the adhesive skin contact layer (102).

3. The medical dressing (100) according to claim 1, in, The first side of the release liner is detachably attached to 10% to 80%, preferably 15% to 70%, most preferably 20% to 50% of the surface area of ​​the adhesive skin contact layer (102).

4. The medical dressing (100) according to any one of the preceding claims, in, Each of the plurality of protrusions (106) has a substantially flat top surface (109); the top surface (109) forms a contact surface for releasably attaching the release liner (103) to the adhesive skin contact layer (102).

5. The medical dressing (100) according to any one of the preceding claims, in, Each of the plurality of protrusions (106) has a top surface (109) and a side wall (110), wherein the side wall (110) extends between the top surface (109) and the non-protrusion area (107), wherein an angle α between the top surface (109) and the side wall (110) is 60 to 120 degrees, preferably 75 to 105 degrees, and most preferably 85 to 95 degrees.

6. The medical dressing (100) according to any one of the preceding claims, in, The height of each of the protrusions (106) is 0.3 mm to 2.0 mm, preferably 0.5 mm to 1.5 mm.

7. The medical dressing (100) according to any one of the preceding claims, in, The surface area of ​​the top surface (109) of each of the protrusions (106) is 0.8 mm 2 Up to 3.0mm 2 , preferably 1.0mm 2 Up to 2.0mm 2 .

8. The medical dressing (100) according to any one of the preceding claims, in, The adhesive skin contact layer (102) comprises a silicone based adhesive coating.

9. The medical dressing (100) according to any one of the preceding claims, in, The adhesive skin contact layer (102) comprises a polymer film provided with a silicone based adhesive coating.

10. The medical dressing (100) according to claim 8 or 9, in, The silicone-based adhesive coating has a thickness of 35 gsm to 300 gsm, preferably 45 gsm to 250 gsm.

11. The medical dressing (100) according to any one of the preceding claims, in, The dressing (100) further comprises an absorbent pad (111) arranged between the top layer (101) and the adhesive skin contact layer (102), wherein the top layer (101) and the adhesive skin contact layer (102) are configured to extend beyond the contour of the absorbent pad (111) to define a border portion along the contour of the absorbent pad (111).

12. The medical dressing (100) according to any one of the preceding claims, in, The plurality of protrusions (106) are formed by embossing.

13. A method for manufacturing a medical dressing (100), include: a) providing a dressing (100) comprising a top layer (101) and an adhesive skin contact layer (102), b) providing a release liner (103) having a first side (104) and an opposing second side (105), wherein at least a portion of the first side (104) of the release liner (103) comprises a plurality of protrusions (106) spaced apart from one another by non-protrusion areas; c) applying the release liner (103) to the adhesive skin contact layer (102) such that the plurality of protrusions (106) become detachably attached to the adhesive skin contact layer (102) and are not attached to the adhesive skin contact layer (102) in the non-protrusion areas (107).

14. The method according to claim 13, in, The protrusions (106) on the first side (104) of the release liner (103) are formed as an in-line step in the method.

15. The method according to claim 13 or 14, in, The plurality of protrusions on the first side (104) of the release liner (103) are formed by embossing.

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