Dressing comprising coating beneficial to skin and / or wounds

Abstract

The present invention relates to a medical dressing (100) comprising a top layer (101), an adhesive skin-contacting layer (102) and a release liner (103) separably attached to at least a portion of the adhesive skin-contacting layer (102); the adhesive skin contact layer (102) has a first side (102a) facing the top layer and a second side (102b) facing the release liner (103), where the second side (102b) of the adhesive skin contact layer (102) is provided with a coating (104) comprising a skin and / or wound benefit agent configured to be released from the adhesive skin contact layer (102) during use, wherein the release liner (103) has a first side (103a) facing the second side (102b) of the adhesive skin contact layer (102) and an opposite second side (103b), and wherein the first side (103a) of the release liner (103) comprises a plurality of protrusions (105). The invention also relates to a method for producing a medical dressing.

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 adhesive skin contact layer having a first side facing the top layer and a second side facing the release liner, wherein the second side of the adhesive skin contact layer is provided with a coating comprising a skin and / or wound beneficial agent, the skin and / or wound beneficial agent being configured to be released from the adhesive skin contact layer during use. The present invention also relates to a method for making a medical dressing. Background Art

[0002] Adhesive medical dressings are often 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, commonly referred to as "film dressings", typically include a backing layer (top layer) and an adhesive skin contact layer. Absorbent dressings typically include an absorbent pad arranged between the backing layer and the adhesive skin contact layer. In so-called "bordered dressings", the backing layer and the adhesive skin contact layer are 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.

[0005] In the treatment or prevention of wounds, various skin and / or wound benefit agents may be used and incorporated into dressings.

[0006] For example, in chronic wounds and surgical wounds, infection is a common problem. The surgical site or open wound is a suitable environment for bacteria to adapt and multiply. Bacterial infection in the wound or periwound skin can disrupt the normal wound healing process and lead to chronic, non-healing wounds.

[0007] In order to prevent wound infection, antimicrobial agents are generally used to eliminate or reduce wound infection. Incorporating antimicrobial agents into medical dressings can promote healing and eliminate or reduce the risk of wound infection.

[0008] To prevent wounds from occurring in advance, various types of skin benefit agents can be used.

[0009] Skin and / or wound benefit agents may be incorporated into a layer in a medical dressing, such as a wound pad. Alternatively, such agents may be applied as a coating on an adhesive layer of a medical dressing; that is, a layer arranged to contact the skin or wound during use.

[0010] In many cases, rapid delivery of skin and / or wound benefit agents is desired. In this regard, providing a coating on an adhesive layer may be a desired mode of incorporating such agents into a medical dressing.

[0011] During assembly of the medical dressing, the adhesive layer is usually covered by a release liner to protect the adhesive layer and the dressing from contamination before use. Prior to use, the medical dressing is sterile.

[0012] When applying a coating comprising a skin and / or wound benefit agent to the adhesive layer of a medical dressing, it is important that the coating does not impair the adhesive properties or "tack" of the adhesive layer.

[0013] Furthermore, it is important that the coating including the skin and / or wound benefit agent remain on the adhesive surface of the medical dressing when the dressing is applied to the skin or wound of a patient.

[0014] One problem associated with medical dressings that include a coating on an adhesive surface is that the coating is transferred from the adhesive surface to the release liner. Thus, when the release liner is removed from the dressing, the skin and / or wound benefit agent present in such a coating is removed with the release liner and thereby removed from the adhesive layer. As a result, the beneficial effect on the skin and / or wound is lost or at least significantly reduced.

[0015] Therefore, there is a need for a medical dressing that includes a skin and / or wound beneficial coating on an adhesive surface to overcome the above challenges. More specifically, there is a need to provide a medical dressing that provides rapid delivery of skin and / or wound beneficial agents, wherein the effect remains in the medical dressing even after the dressing is disassembled (i.e., even after the release liner is removed). Summary of the invention

[0016] In view of the above problems, an object of the present invention is to provide improvements to medical dressings comprising skin and / or wound beneficial agents and to ensure that the effects of such skin and / or wound beneficial agents are maintained in the dressings when the dressings are applied to the skin or wounds of a patient.

[0017] According to a first aspect, 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 adhesive skin contact layer having a first side facing the top layer and a second side facing the release liner, wherein the second side of the adhesive skin contact layer is provided with a coating comprising a skin and / or wound beneficial agent, which is configured to be released from the adhesive skin contact layer during use, wherein the release liner has a first side facing the second side of the adhesive skin contact layer and an opposite second side, wherein the first side of the release liner comprises a plurality of protrusions.

[0018] The present invention is based on the recognition that a release liner comprising a plurality of protrusions on the skin-facing (second) side of the adhesive skin contact layer significantly improves the ability of the coating to remain on the surface of the adhesive skin contact layer even after removal of the release liner.

[0019] For conventional dressings, the release liner is usually flat and completely attached to the adhesive dressing surface. When such a release liner is to be removed from the adhesive surface, a large removal force is usually required, and the skin and / or wound-friendly coating has an enhanced tendency to migrate toward the release liner during the removal process.

[0020] The medical dressing of the present invention produces reduced adhesion between the release liner and the adhesive skin contact layer and largely prevents the transfer of the coating beneficial to the skin and / or wound to the release liner. The release liner still has sufficient adhesiveness and adheres to the adhesive skin contact layer to prevent contaminants from entering the dressing.

[0021] In an exemplary embodiment, the coating may be a discontinuous coating.

[0022] A discontinuous coating is beneficial in ensuring that the adhesive skin contact layer retains its adhesive properties and that the adhesive properties of the adhesive layer are maintained despite the presence of the coating.

[0023] In an exemplary embodiment, the coating is soluble in an aqueous medium.

[0024] Thus, upon contact with wound exudate or moist skin, the coating dissolves and enables rapid initial release of the skin and / or wound benefit agent.

[0025] In an exemplary embodiment, the skin and / or wound benefit agent is an antimicrobial agent, preferably an antimicrobial salt.

[0026] Antimicrobial agents, such as antimicrobial salts, are beneficial in preventing wound infection. When the antimicrobial agent is released from the adhesive skin contact layer, bacteria present at the wound or the skin around the wound can be eradicated. The growth of infectious microorganisms at the surface of the adhesive skin contact layer is thereby prevented, which avoids colonization at the wound site and within the wound medical dressing.

[0027] In an exemplary embodiment, the concentration of the skin and / or wound benefit agent in the coating may be 1 μg / cm 2 Up to 1000 μg / cm 2 , preferably 5 μg / cm 2 Up to 500 μg / cm 2 , more preferably 10 μg / cm 2 Up to 200 μg / cm 2 .

[0028] Thus, the coating dissolves when in contact with wound fluid or skin moisture, thereby enabling adequate release of the skin and / or wound beneficial agent. In addition, this range provides a good balance between adequate release of the beneficial agent and maintaining the adhesive properties of the adhesive skin contact layer.

[0029] In an exemplary embodiment, the plurality of protrusions are spaced apart from one another by non-protrusion areas, wherein the non-protrusion areas form gaps between the first side of the release liner and the second side of the adhesive skin contact layer.

[0030] Thus, the projections are detachably attached to the adhesive skin contact layer and the non-projection areas are not attached to the adhesive skin contact layer.

[0031] The gap defined between the second side of the adhesive skin contact layer and the first side of the release liner reduces the contact area between the release liner and the adhesive skin contact layer. By reducing the adhesion between these layers, the inventors have found that the skin and / or wound benefit agent has a significantly enhanced retention ability; i.e., remains coated on the adhesive skin contact layer, rather than migrating to the release liner (and thereby being removed from the dressing). Therefore, the beneficial effects on the wound and / or skin are maintained in the dressing.

[0032] In an exemplary embodiment, the first side of the release liner is releasably attached to 5% to 75%, preferably 10% to 70%, and most preferably 10% to 50% of the surface area of ​​the second side of the adhesive skin contact layer.

[0033] Thus, the release liner performs the dual function of protecting the adhesive skin contact layer while preventing the skin and / or wound beneficial coating from migrating toward the release liner.

[0034] In an exemplary embodiment, the height of each protrusion may be 0.1 mm to 2.0 mm, preferably 0.2 mm to 1.5 mm, and most preferably 0.3 mm to 1.2 mm.

[0035] If the protrusions are too high, they may create indentations and impressions in the adhesive skin contact layer, which is undesirable when the dressing is attached to the skin. Such impressions may reduce adhesion to the patient's skin and may impair the ability of the adhesive skin contact layer to conform to the skin.

[0036] Conversely, if the height is too low, the gap defined by the non-protruding area of ​​the first side of the release liner will decrease, and the adhesion of the first side of the release liner to the adhesive skin contact layer will increase.

[0037] Furthermore, the protrusion height within the above range is suitable for ensuring that the release liner prevents contaminants from entering the dressing.

[0038] In an exemplary embodiment, a medical dressing may include an absorbent pad disposed between the top layer and the adhesive skin contact layer, and wherein the plurality of protrusions are disposed in an area on the first side of the release liner underlying the absorbent pad.

[0039] Absorbent pads are used to manage large amounts of wound fluid exuded from wounds. Since many wounds, particularly infected wounds, may exude large amounts of exudate, it is often necessary to use a dressing comprising an absorbent pad. The absorbent pad may comprise any absorbent material, such as absorbent fibers, gels, foams, etc. The absorbent pad may comprise one or more pad-forming layers.

[0040] In the case where the dressing comprises an absorbent pad, the beneficial effect on the skin and / or wound is suitably arranged in the region of the adhesive skin contact layer located below the absorbent pad. In this regard, a plurality of protrusions are preferably arranged to cover this region, which is typically the central portion of the dressing.

[0041] In an exemplary embodiment, the adhesive skin contact layer comprises a silicone-based adhesive coating.

[0042] The silicone-based adhesive coating is soft and gentle on the skin and can be removed without causing trauma.

[0043] However, the softness of the silicone-based adhesive can make the adhesive skin contact layer more inclined to conform to the contours of the underlying surface structure. This property is beneficial for accommodating the patient's skin or wound, especially curved or contoured skin surfaces. However, it is undesirable if the adhesive skin contact layer conforms "too much" to the peaks and valleys defined by the protrusions on the first side of the adhesive skin contact layer, because this may result in too strong adhesion between the release liner and the adhesive skin contact layer. This may result in undesirable migration, i.e., the coating is transferred to the adhesive skin contact layer.

[0044] In an exemplary embodiment, the adhesive skin contact layer may include a polymer film provided with a silicone-based adhesive coating.

[0045] The polymer film imparts 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. The inventors have discovered that this feature is important for preventing migration of skin and wound benefit agents applied as a coating to the release liner.

[0046] In an exemplary embodiment, the silicone-based adhesive coating has a thickness of 35 gsm to 300 gsm, preferably 45 gsm to 250 gsm.

[0047] 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 adhesive coatings increase the risk of protrusions forming impressions in the silicone-based adhesive skin contact layer.

[0048] In an exemplary embodiment, each of the plurality of protrusions has a substantially flat top surface; the top surface forms a contact surface for releasably attaching the release liner to the adhesive skin contact layer.

[0049] This is particularly advantageous in embodiments using thicker silicone-based adhesive coatings, as thicker silicone-based adhesive coatings have an increased tendency to "sink" into the gap defined by the non-protrusion area of ​​the first side of the release liner, a behavior that is counteracted by the protrusions having a substantially flat top surface.

[0050] According to another aspect, there is provided a method for manufacturing a medical dressing, comprising:

[0051] a) providing a dressing comprising a top layer and an adhesive skin contact layer having a first side facing the top layer and an opposing second side;

[0052] b) applying a coating onto the second side of the adhesive skin contact layer, wherein the coating comprises a skin and / or wound benefit agent configured to be released from the adhesive skin contact layer during use;

[0053] c) 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 includes a plurality of protrusions; and

[0054] d) applying a release liner to the adhesive skin contact layer such that the plurality of protrusions are releasably attached to the second side of the adhesive skin contact layer.

[0055] In an exemplary embodiment, step b) of applying the coating is performed by spraying.

[0056] This coating technique is beneficial because it allows flexibility depending on the dressing to be used and the type of wound to be treated. It is also a simple means of applying the coating. Selected areas of the adhesive skin contact layer can be coated and the size of the droplets on the surface can be controlled to avoid interfering with the adhesive properties of the adhesive skin contact layer.

[0057] In an exemplary embodiment, the protrusions are formed as an in-line step in the method, preferably by embossing.

[0058] Providing the protrusions in-line 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 when stored 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.

[0059] Furthermore, embossing is a simple technique to form three-dimensional features such as protrusions in a layer and is suitable where the protrusions are formed as an in-line step in the process.

[0060] 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

[0061] 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:

[0062] Figure 1 Problems associated with prior art dressings are conceptually illustrated.

[0063] Figure 2 An exploded view of a medical dressing according to an exemplary embodiment of the present invention is shown, seen from bottom to top.

[0064] Figure 3 An exploded view of a medical dressing according to an exemplary embodiment of the present invention is shown, seen from top to bottom, wherein the dressing further comprises an absorbent pad.

[0065] Figure 4a A medical dressing according to an exemplary embodiment of the present invention is shown as seen from the bottom side when a caregiver peels off the release liner.

[0066] Figure 4b yes Figure 4a Magnified view of a portion of the dressing.

[0067] Figure 4c yes Figure 4a A cross-sectional view of a portion of a medical dressing in , showing the release liner being peeled away from the adhesive skin contact layer.

[0068] Figure 5 Scanning electron microscope (SEM) images of the release liners having pyramid-shaped protrusion patterns used in Examples 1 and 2 are shown. DETAILED DESCRIPTION

[0069] 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.

[0070] Figure 1 The following problem of the present disclosure is schematically illustrated in FIG. Figure 1 A dressing 100' according to the prior art is shown comprising an adhesive skin contact layer 102' and a release liner 103'. Figure 1 The release liner shown in FIG. 1 comprises three removable portions and is attached to an adhesive skin contact layer 102' of the dressing. The adhesive skin contact layer 102' initially comprises a coating on the skin-facing surface that comprises a skin and / or wound benefit agent. When the first release liner portion is removed, the coating comprising the benefit agent is removed from the adhesive skin contact layer 102' (by Figure 1 ) and transferred to the surface of the removed release liner portion (see 104'). Therefore, the beneficial effects of the dressing on the skin and / or wound are eliminated.

[0071] Figure 2 A medical dressing according to an exemplary embodiment of the present invention is shown. The medical dressing 100 comprises 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 adhesive skin contact layer 102 has a first side 102a facing the top layer and a second side 102b facing the release liner 103, wherein the second side 102b of the adhesive skin contact layer 102 is provided with a coating 104 comprising a skin and / or wound benefit agent, which is configured to be released from the adhesive skin contact layer 102 during use, wherein the release liner 103 has a first side 103a facing the second side 102b of the adhesive skin contact layer 102 and an opposite second side 103b, wherein the first side 103a of the release liner comprises a plurality of protrusions 105.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] The release liner is arranged to cover the entire surface area of ​​the adhesive skin contact layer.

[0076] The release liner may include one or more removable portions. Figure 2 and Figure 3 In the case of Figure 4a In the release liner, there are two removable parts.

[0077] If the first release liner includes more than one removable portion, the first release liner may be divided by a dividing line, wherein the first removable portion and the second removable portion of the release liner overlap along the dividing line. The overlapping removable portions ensure that the adhesive skin contact layer is completely covered and no gaps are formed, thereby preventing contaminants from entering the dressing. Figure 4a As shown, the overlapping removable parts can form a gripping member so that the applicator (e.g., caregiver 111) can grip the gripping member to remove and separate the removable parts. For example, the edge of the second removable part can be folded over itself, and the edge of the first removable part can be configured to overlap with the folded edge.

[0078] No matter how many removable portions the release liner comprises, the release liner is arranged to cover the entire adhesive skin contact layer.

[0079] The dressings 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 the first place).

[0080] As used herein, the term "skin and / or wound beneficial agent" refers to any agent having a beneficial effect on the skin and / or wound. Skin and / or wound beneficial agents can prevent wound formation in advance, improve the wound healing process, or treat existing wounds.

[0081] For example, the skin and / or wound benefit agent can be an antimicrobial agent, a pH buffering agent, an immunomodulator, an anti-inflammatory agent, a vitamin, a growth factor, an agent that affects angiogenesis, cell migration, and the like.

[0082] The coating 104 may be a discontinuous coating.

[0083] As used herein, the term "discontinuous coating" means that the coating does not completely cover the skin-facing surface of the adhesive skin-contact layer.

[0084] Discontinuous coatings are generally preferred to avoid compromising the adhesion to the skin provided by the adhesive skin contact layer.

[0085] The coating 104 is soluble in an aqueous medium.

[0086] As used herein, the term "soluble in aqueous media" means that the coating dissolves when in contact with an aqueous medium. The aqueous solution can be water. Thus, the coating dissolves rapidly when in contact with wound exudate or skin moisture. Even small amounts of skin moisture or wound exudate can cause dissolution of the coating. The coating comprising the skin and / or wound beneficial agent can initially be applied to the surface of the adhesive skin contact layer in the form of an aqueous solution and subsequently dried. Upon contact with wound exudate or an aqueous medium, the dried coating will dissolve and the skin and / or wound beneficial agent will be released from the adhesive skin contact layer.

[0087] Thus, upon contact with wound exudate or moist skin, the coating dissolves and enables rapid initial release of the skin and / or wound benefit agent.

[0088] For example, at least 60%, such as at least 80%, such as at least 100%, of the coating 104 can be configured to dissolve within 3 hours of exposure to an aqueous medium.

[0089] To prevent or reduce wound infection, the skin and / or wound benefit agent may be an antimicrobial agent, preferably an antimicrobial salt.

[0090] The antimicrobial agent may be any agent that has the ability to prevent or slow the growth of bacteria or to kill bacteria present at the wound site.

[0091] Examples of antimicrobial salts include silver salts, PHMB salts, chlorhexidine salts, and the like.

[0092] In an exemplary embodiment, the antimicrobial salt is a chlorhexidine salt.

[0093] The present invention may be particularly useful with chlorhexidine salts, such as chlorhexidine gluconate, which have an enhanced tendency to migrate from the adhesive surface to the release liner.

[0094] The concentration of the skin and / or wound benefit agent in the coating 104 may be 1 μg / cm 2 Up to 1000 μg / cm 2 , for example 5 μg / cm 2 Up to 500 μg / cm 2 , for example 10 μg / cm 2 Up to 200 μg / cm 2 .

[0095] This ensures that the skin and / or wound benefit agent is released in an amount sufficient to produce a wound healing or wound benefit effect at the wound site.

[0096] The concentration may vary depending on the skin and / or wound benefit agent being used. For some benefit agents, low concentrations are sufficient, while other benefit agents may require higher concentrations.

[0097] For example, if the skin and / or wound benefit agent is an antimicrobial agent, the concentration in the coating may be 30 μg / cm 2 Up to 200 μg / cm 2 within the range.

[0098] like Figure 3 As best shown in FIG. 1 , a plurality of protrusions 105 are spaced apart from one another by non-protrusion areas 106. The non-protrusion areas form gaps between the first side 103a of the release liner 103 and the second side 102b of the adhesive skin contact layer 102.

[0099] The protrusions 105 are detachably attached to the second side 102b of the adhesive skin contact layer 102, and wherein the non-protrusion areas 106 are not adhered to the second side 102b of the adhesive skin contact layer.

[0100] In addition to the advantages associated with reducing migration of the skin and / or wound beneficial coating from the adhesive surface to the release liner, the inventors have found that providing protrusions on the second side of the release liner significantly facilitates the handling and application process of the dressing by the caregiver.

[0101] Adhesive medical dressings are often thin and fragile, and are very difficult to handle because they wrinkle easily. Unlike conventional plasters or band-aids, where the release liner is completely removed before the dressing is applied, medical dressings used in care facilities and / or hospital settings are applied in a different manner. The dressing is usually applied to the patient's skin or wound while the release liner is removed in a gradual or stepwise manner. The application and handling of the dressing is performed by the caregiver.

[0102] The medical dressing of the present invention produces reduced adhesion between the release liner and the adhesive skin contact layer. The delamination force (i.e., the force required to remove the release liner) is thus significantly reduced. The reduced delamination force prevents wrinkles from occurring when the release liner is peeled off and the dressing is applied to the patient's skin.

[0103] like Figure 2 and Figures 4a to 4c As shown, the second side 103b of the release liner 103 may include a depression 112. The depression 112 of the second side 103b of the release liner 103 overlaps the protrusion 105 on the first side 103a of the release liner 103. The depression 112 on the second side 103b 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 a protrusion 105 on the first side 103a of the release liner and forming a corresponding depression 112 on the second side 103b of the release liner. However, the present disclosure is not limited to embossed protrusions. In an exemplary embodiment, the second side 103b of the release liner is flat.

[0104] The first side 103a of the release liner 103 may be releasably attached to 5% to 75%, preferably 10% to 70%, and most preferably 10% to 50% of the surface area of ​​the second side 102b of the adhesive skin contact layer 102 .

[0105] Therefore, the release liner 103 plays a dual function of protecting the adhesive skin contact layer from contamination and reducing the migration of skin and / or wound benefit agents to the release liner. In addition, it is easy to remove the release liner and apply it to the patient's skin, and prevent the formation of wrinkles.

[0106] The adhesion between the first side of the release liner and the second side of the release liner can vary depending on the type of adhesive skin contact layer used, the thickness of the adhesive skin contact layer, etc.

[0107] The height of each of the protrusions 105 may be 0.1 mm to 2.0 mm, preferably 0.2 mm to 1.5 mm, and most preferably 0.3 mm to 1.2 mm.

[0108] The height h1 of a protrusion is Figure 4c Shown in.

[0109] The height refers to the maximum longitudinal extension of the protrusion. The height is measured from the top surface of the protrusion to the bottom portion of the protrusion. Thus, the height h1 can be measured from the top surface 109 of the protrusion to the non-protrusion area 106.

[0110] These dimensions are suitable for achieving well-defined gaps between the protrusions (see Figure 4b to Figure 4c 107 in). If the height of the protrusion is too high, the risk of forming marks in the adhesive skin contact layer increases. On the contrary, 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.

[0111] like Figure 3 As best shown in FIG. 1 , the medical dressing 100 may include an absorbent pad 108 disposed between the top layer 101 and the adhesive skin contact layer 102 .

[0112] Figure 3 The dressing in is a so-called "bordered dressing." The top layer 101 and the adhesive skin contact layer 102 are configured to extend beyond the contour of the absorbent pad 108 to form a border portion.

[0113] exist Figure 3 In FIG. 1 , a boundary portion of the adhesive skin contact layer 102 is indicated as 114 .

[0114] The absorbent pad 108 can be formed by a single layer or multiple pad-forming layers. The absorbent pad is not limited to a specific material but generally includes absorbent foam or gel. Alternatively or additionally, the absorbent pad can include superabsorbent materials such as superabsorbent polymers (SAP) or superabsorbent fibers (SAF).

[0115] In an exemplary embodiment, the absorbent pad includes two or more layers having different properties.

[0116] As Figure 3 shown, the absorbent pad 108 can include a first absorbent layer 108a, a liquid distribution layer 108b, and a second absorbent layer 108c. The liquid distribution layer 108b can be disposed between the first absorbent layer 108a and the second absorbent layer 108c.

[0117] The first absorbent layer 108a can include foam. Suitable foam materials for the first absorbent layer 108a include but are not limited to polyurethane foam.

[0118] The second absorbent layer 108c can be a superabsorbent layer. Thus, the second absorbent layer can include superabsorbent polymer (SAP) or superabsorbent fiber (SAF).

[0119] The liquid distribution layer 108b can include any material having the ability to distribute exudate in an effective manner. For example, the liquid distribution layer 108b can include a nonwoven material. The nonwoven material imparts a proper balance of rigidity to the layer and the dressing. It can also effectively distribute and disperse the liquid absorbed by the absorbent layer 108a such that the liquid can evaporate on a large surface through the top layer 101. For example, the nonwoven material can include viscose fibers, polyester, or blends thereof.

[0120] These layers can be joined by adhesion, lamination (e.g., by using pressure and heat).

[0121] The absorbent pad can include additional layers such as a liquid transfer layer, various combinations of stacked foam and nonwoven layers.

[0122] Referring Figure 3 , layer 108a can include absorbent foam, layer 108b can be a liquid collection layer, and layer 108c can be a superabsorbent layer.

[0123] The multi-layer pad prevents the accumulation of body fluids near the skin and improves the liquid handling of the dressing. Most wounds will contain some exudate, but the level of exudate can vary. In chronic wounds, very large amounts of exudate may be produced due to persistent inflammation. Dressings having the above structure are suitable for handling large amounts of exudate and preventing the skin around the wound from maceration. Thus, the dressing is particularly suitable for preventing infection.

[0124] As Figure 3As shown, the absorbent pad 108 can include a plurality of cuts 115 extending at least partially through the absorbent pad 108. The cuts 115 can have a variety of shapes to make the pad more flexible and enhance the flexibility of the overall dressing.

[0125] Figure 3 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.

[0126] If the absorbent pad 108 comprises several pad-forming layers, the cut 115 may extend through at least one of these layers.

[0127] Preferably, the plurality of protrusions 105 are arranged in a region below the absorbent pad 108 on the first side 103 a of the release liner 103 .

[0128] Since the absorbent pad 108 covers the wound site and is arranged to treat fluid exuded by the wound, optimal wound healing effects are generally achieved if the coating and protrusions are arranged in the area beneath the absorbent pad 108 .

[0129] To facilitate handling of the dressing and application to the skin, a plurality of protrusions may be arranged in the area beneath the border portion of the dressing.

[0130] The plurality of protrusions 105 may be arranged in a pattern extending across the first side 103a of the release liner 103. The plurality of protrusions 105 may be arranged in a pattern extending across the entire first side 103a of the release liner 103, such as Figure 3 shown.

[0131] Typically, at least 50% of the first side 103 a of the release liner 103 may include the pattern of protrusions 105 .

[0132] The adhesive skin contact layer 102 may include a silicone based adhesive coating.

[0133] 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 because soft silicone-based adhesives have an enhanced tendency to conform to the underlying surface, making the coating 104 applied to the silicone-based adhesive more prone to migrate to the release liner.

[0134] In the context of the present disclosure, such undesirable migration is avoided by the gaps defined by the protrusions on the first side of the release liner.

[0135] The silicone-based adhesive coating may have a thickness of 35 gsm to 300 gsm, for example 45 gsm to 250 gsm.

[0136] Thus, a suitable balance is achieved between skin adhesion, preventing marking in the silicone-based adhesive and preventing the silicone-based adhesive from following the contours of the protrusions.

[0137] The adhesive skin contact layer 102 may comprise a polymer film (not shown) provided with a silicone based adhesive coating.

[0138] 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. Thus, when the release liner is removed from the dressing, the polymer film ensures that the coating remains attached to the silicone-based adhesive coating.

[0139] 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.

[0140] The silicone-based adhesive coating of the tacky skin contact layer is arranged to contact the wearer's skin during use.

[0141] The protrusions on the first side of the release liner are not limited to a particular shape. However, in embodiments where thicker silicone-based adhesive coatings are used, it may be advantageous if the protrusions have a substantially flat top surface.

[0142] like Figures 4a to 4c As best shown in , the protrusion has a substantially flat top surface 109.

[0143] Each of the plurality of protrusions 105 may have a top surface 109 and a sidewall 110, wherein the sidewall 110 extends between the top surface 109 and the non-protrusion area 106. The top surface 109 forms a contact surface for detachably attaching to the second side 102b of the adhesive skin contact layer 102.

[0144] As mentioned above, if a thick silicone-based adhesive is used, for example, with a thickness above 200 μm, a flat protrusion top surface 109 is considered to be beneficial. First, because marks in the silicone-based adhesive coating caused by too sharp or too angled protrusion top surfaces are avoided. In addition, 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. In this regard, undesirable transfer of the coating 104 applied to the silicone-based adhesive of the adhesive skin contact layer 102 is significantly reduced.

[0145] like Figure 4cAs best shown in FIG. 1 , the angle α between the top surface 109 and the sidewall 110 may be 45 to 125 degrees, such as 60 to 120 degrees, such as 80 to 100 degrees.

[0146] 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, and a greater surface area of ​​the second side of the adhesive skin contact layer may be attached to the first side of the release liner.

[0147] The width w1 of the protrusion may be in the range of 0.7 mm to 3.0 mm.

[0148] The width w1 is the maximum lateral extension of a protrusion 105 .

[0149] The surface area of ​​the top surface 109 of each protrusion 105 may be 0.1 mm 2 Up to 2.5mm 2 , for example 2.0mm 2 Up to 2.0mm 2 , for example 0.3mm 2 Up to 1.6mm 2 .

[0150] A surface area within the above range improves removable attachment to the adhesive skin contact layer 102. If the surface area is too large, the first side of the release liner may become too firmly attached to the second side of the adhesive skin contact layer. As a result, the risk of coating transfer to the release liner may increase.

[0151] If a thicker silicone-based adhesive is used, the surface area of ​​the top surface 109 can be in a higher range (to prevent the adhesive from sinking into the gap defined by the non-protruding area). Conversely, if the silicone-based adhesive is thin (less than 200 μm thick, such as less than 150 μm), the surface area of ​​the top surface 109 can be in a lower range (to prevent coating transfer).

[0152] The top surface 109 of each protrusion is not limited to a specific shape, but may be any conceivable shape, such as a circle, an oval, a square, a rectangle, etc.

[0153] 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.

[0154] In an exemplary embodiment, the plurality of protrusions may be formed by embossing.

[0155] 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.

[0156] According to another aspect, there is provided a method for manufacturing a medical dressing 100, comprising:

[0157] a) providing a dressing 100 comprising a top layer 101 and an adhesive skin contact layer 102, the adhesive skin contact layer having a first side 102a facing the top layer and an opposing second side 102b;

[0158] b) applying a coating 104 onto the second side 102b of the adhesive skin contact layer 102, wherein the coating 104 comprises a skin and / or wound benefit agent configured to be released from the adhesive skin contact layer 102 during use;

[0159] c) providing a release liner 103 having a first side 103a and an opposite second side 103b, wherein at least a portion of the first side 103a of the release liner 103 comprises a plurality of protrusions 105;

[0160] d) applying the release liner 103 onto the adhesive skin contact layer 102 such that the plurality of protrusions 105 are detachably attached to the second side 102b of the adhesive skin contact layer 102 .

[0161] 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 skin contact layer and absorbent pad (if present) is not limited to a particular method, but may utilize any means (e.g., adhesive bonding, lamination, etc.).

[0162] The skin and / or wound benefit agent may be dissolved or dispersed in a solvent prior to applying the coating to the second side 102b of the adhesive skin contact layer 102. For example, the skin and / or wound benefit agent may be dissolved in an aqueous solution and the solution may be mixed and optionally stirred to ensure dissolution.

[0163] The step of applying a coating on the second side of the adhesive skin contact layer may be accomplished by any coating technique.

[0164] Preferably, the step of applying the coating to the second side of the adhesive skin contact layer is performed by spraying.

[0165] This coating technique is beneficial because it is simple and produces a discontinuous coating on the adhesive surface. Selected areas of the adhesive layer can be coated and the size of the droplets on the surface can be controlled to avoid interfering with the adhesive properties of the adhesive skin contact layer.

[0166] The applied coating is generally subsequently dried.

[0167] Drying is carried out by means well known to the skilled person. For example, the coating may be heated to enhance evaporation of the liquid from the coating.

[0168] Preferably, the plurality of protrusions 105 on the first side 103a of the release liner 103 are formed as an in-line step in the method.

[0169] The process is thus significantly simplified and is also advantageous from a storage point of view. This allows the release liner to be stored in a flat state, for example on a roll, requiring much less space than if the release liner were provided with protrusions.

[0170] Suitably, the plurality of protrusions may be formed by embossing.

[0171] 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.

[0172] For example, the release liner can be subjected to an embossing tool on the second side of the release liner, which forms protrusions 105 on the first side 103a of the release liner and corresponding depressions 112 on the second side 103b of the release liner. The embossing tool can be arranged in a production line and can provide the embossed protrusions before the release liner is applied to the adhesive skin contact layer 102.

[0173] The present invention is not limited to forming the protrusions by embossing.

[0174] In alternative embodiments, the protrusions may be formed by molding or casting.

[0175] 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 108 or any other layer of the dressing.

[0176] The adhesive skin contact layer preferably comprises a silicone based adhesive.

[0177] Examples of suitable silicone 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. The softness is measured by a method based on ASTM D 937 and DIN51580, 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.

[0178] Preferably, the adhesive skin contact layer comprises a plurality of perforations (in Figure 2 and Figure 3 113).

[0179] If the adhesive skin contact layer comprises a polymer film and a silicone based adhesive coating, the perforations extend through both layers.

[0180] 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).

[0181] Example

[0182] Example 1: Evaluation of Chlorhexidine Gluconate (CHG) Migration to Release Liner

[0183] Testing was performed to evaluate the migration of chlorhexidine gluconate (CHG) from the adhesive skin contact layer to the release liner.

[0184] The dressing samples evaluated contained: a 20 μm polyurethane film as the top layer; an adhesive skin contact layer comprising a polymer film (20 μm polyurethane film) coated with a silicone adhesive of varying thickness (see below); and a 100 μm polyethylene film as the release liner. The dressings tested differed in the thickness of the adhesive coating and the nature of the release liner, respectively.

[0185] Sample A: 50 gsm thick silicone adhesive coating, flat release liner.

[0186] Sample B: 50 gsm thick silicone adhesive coating, embossed with a pyramid-shaped protrusion pattern on the release liner (see Figure 5 ).

[0187] Sample C: 200 gsm thick silicone adhesive coating, flat release liner.

[0188] Sample D: 200gsm thick silicone adhesive coating, embossed as Figure 4a to Figure 4b Release liner with the protrusion pattern shown.

[0189] The height of the protrusions of sample B was about 0.4 mm, while the height of the protrusions of sample D was about 1.0 mm. The protrusions of sample D had a substantially flat top surface (with a thickness of about 1.5 mm). 2 The protrusion of sample B has 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.

[0190] An aqueous solution of CHG (0.56 g / L) was prepared and then sprayed substantially uniformly onto the silicone adhesive layer to achieve a concentration of approximately 55 mg / cm 2 (40mg / cm 2 -70 mg / cm 2 The samples were dried and then three different variations of release liners (see above) were applied to the silicone surface.

[0191] The samples were sent to the manufacturing site for sterilization to undergo the typical sterilization cycle required for wound dressings (EtO sterilization).

[0192] After sterilization and storage at room temperature for approximately 8 weeks, CHG migration was evaluated.

[0193] To evaluate CHG migration, sterilized samples were first punched into 3.14 cm 2 The release liner and adhesive skin contact layer were separated and placed in individual wells and contacted with 1 mL of aqueous solution over a period of 24 hours to allow complete dissolution of the CHG particles. After calibrating the device for the solution of interest, the concentration of CHG in the different wells was assessed by liquid chromatography-mass spectrometry to quantify the amount of CHG present on the silicone surface and the amount that migrated to the release liner.

[0194] In each sample category A to D, three dressing samples were tested.

[0195] The results are shown in Table 1 below.

[0196]

[0197] Table 1: CHG migration to release liner

[0198] As shown in Table 1, when the raised release liner was used, the migration of CHG to the release liner was significantly reduced (Sample B and Sample D). These results were surprising given the increased tendency of CHG to migrate to the release liner.

[0199] Example 2: Evaluation of PHMB Migration to Release Liner

[0200] Additional testing was performed to evaluate the migration of polyhexamethylene biguanide (PHMB) from the release liner to the adhesive skin contact layer.

[0201] The test setup was similar to the setup explained in Example 1.

[0202] The dressing samples evaluated contained: a 20 μm polyurethane film as the top layer; an adhesive skin contact layer comprising a polymer film (20 μm polyurethane film) coated with 60 gsm of silicone adhesive; and a 100 μm polyethylene film as the release liner.

[0203] The dressings tested differed in the properties of their release liners.

[0204] Sample E: Flat release liner.

[0205] Sample F: Release liner with pyramid-shaped protrusion pattern (see Figure 5 ).

[0206] An aqueous solution of PHMB (7 g / L, i.e. 0.7%) was prepared and then diluted to about 50 mg / cm 2 The target concentration was sprayed substantially evenly onto the silicone adhesive layer. The sample was dried in an oven (about 2 minutes, 90°C).

[0207] After drying, two release liner variations (see above) were attached to the sprayed silicone adhesive layer.

[0208] The samples were sent to the manufacturing site for sterilization to undergo the typical sterilization cycle required for wound dressings (EtO sterilization).

[0209] After sterilization and storage at room temperature for approximately 8 weeks, the migration of PHMB was evaluated.

[0210] To understand the migration of PHMB, sterilized samples were punched into 3.8 cm 2 The three adhesive skin contact layers and release liners of two dressing variations (E and F) were separated and placed in separate wells and contacted with 5 ml of aqueous solution for a period of time (24 hours) to allow the PHMB to completely dissolve. The concentration of PHMB in each well was analyzed by UV-visible spectroscopy. The amount found on the surface of each material of samples E and F at 24 hours is shown in Table 2 below.

[0211]

[0212] Table 2: Migration of PHMB to release liner

[0213] As shown in Table 2, when a raised release liner is used, PHMB migration to the release liner is significantly reduced (Sample F). PHMB does not migrate as readily as CHG, but even for this material, the reduction in migration to the release liner is a significant improvement.

[0214] The terms, definitions and embodiments of all aspects of the invention apply mutatis mutandis to the other aspects of the invention.

[0215] 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.

[0216] 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 adhesive skin contact layer (102) having a first side (102a) facing the top layer and a second side (102b) facing the release liner (103), wherein the second side (102b) of the adhesive skin contact layer (102) is provided with a coating (104) comprising a skin and / or wound beneficial agent, the skin and / or wound beneficial agent being configured to be released from the adhesive skin contact layer (102) during use, wherein the release liner (103) has a first side (103a) facing the second side (102b) of the adhesive skin contact layer (102) and an opposite second side (103b), wherein the first side (103a) of the release liner (103) comprises a plurality of protrusions (105).

2. The medical dressing (100) according to claim 1, in, The coating (104) is a discontinuous coating.

3. The medical dressing (100) according to claim 1 or claim 2, in, The coating (104) is soluble in an aqueous medium.

4. The medical dressing (100) according to claim 1 or claim 2, in, The skin and / or wound benefit agent is an antimicrobial agent, preferably an antimicrobial salt.

5. The medical dressing (100) according to any one of the preceding claims, in, The concentration of the skin and / or wound benefit agent in the coating is 1 μg / cm 2 Up to 1000 μg / cm 2 , preferably 5 μg / cm 2 Up to 500 μg / cm 2 , more preferably 10 μg / cm 2 Up to 200 μg / cm 2 .

6. The medical dressing (100) according to any one of the preceding claims, in, The plurality of protrusions (105) are spaced apart from one another by non-protrusion areas (106), wherein the non-protrusion areas (106) form gaps (107) between the first side (103a) of the release liner (103) and the second side (102b) of the adhesive skin contact layer (102).

7. The medical dressing (100) according to claim 1, in, The first side (103a) of the release liner (103) is detachably attached to 5% to 75%, preferably 10% to 70%, most preferably 10% to 50% of the surface area of ​​the second side (102b) of the adhesive skin contact layer (102).

8. The medical dressing (100) according to any one of the preceding claims, in, The height of each of the protrusions (105) is 0.1 mm to 2.0 mm, preferably 0.2 mm to 1.5 mm, and most preferably 0.3 mm to 1.2 mm.

9. The medical dressing (100) according to any one of the preceding claims, in, The medical dressing (100) comprises an absorbent pad (108) arranged between the top layer (101) and the adhesive skin contact layer (102), and wherein the plurality of protrusions (105) are arranged in an area of ​​the first side (103a) of the release liner (103) below the absorbent pad (108).

10. 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.

11. 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.

12. The medical dressing (100) according to claim 10 or claim 11, in, The thickness of the silicone-based adhesive coating is 35 gsm to 300 gsm, preferably 45 gsm to 250 gsm.

13. The medical dressing (100) according to any one of the preceding claims, in, Each of the plurality of protrusions 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).

14. 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), the adhesive skin contact layer (102) having a first side (102a) facing the top layer (101) and an opposing second side (102b); b) applying a coating (104) onto the second side (102b) of the adhesive skin contact layer (102), wherein the coating (104) comprises a skin and / or wound benefit agent configured to be released from the adhesive skin contact layer (102) during use; c) providing a release liner (103) having a first side (103a) and an opposing second side (103b), wherein at least a portion of the first side (103a) of the release liner (103) comprises a plurality of protrusions (105); and d) applying the release liner (103) to the adhesive skin contact layer (102) such that the plurality of protrusions (105) become detachably attached to the second side (102b) of the adhesive skin contact layer (102).

15. The method according to claim 14, in, Said step b) of applying the coating (104) is performed by spraying.

16. A process according to claim 14 or claim 15, in, The plurality of protrusions (105) are formed as an in-line step in the method, preferably by embossing.

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