Wound care products with antibacterial coatings

Abstract

The present disclosure generally relates to a wound care product (200; 300; 400) comprising a backing layer (201; 301; 401) and an adhesive layer (202; 302; 402) having a skin-facing surface (203; 403), at least a portion of the skin-facing surface (203; 403) of the adhesive layer (202; 302; 402) comprising an antimicrobial coating (204).

Description

[Technical Field]

[0001] This disclosure relates, in general terms, to a wound care product comprising a backing layer and an adhesive layer having a skin-facing surface, wherein at least a portion of the skin-facing surface of the adhesive layer has an antimicrobial coating. [Background technology]

[0002] Infection is a common problem in chronic and surgical wounds. Surgical sites or open wounds provide a favorable environment for bacteria to thrive and colonize. Bacterial infection within or surrounding the wound can disrupt the normal wound healing process, potentially leading to chronic, unhealed wounds.

[0003] In treating wounds, antimicrobial agents are often used to eliminate or reduce wound infection. Incorporating antimicrobial agents into bandages and wound dressings can promote healing and eliminate or reduce the risk of wound infection. Various types of antimicrobial dressings have been developed for this purpose.

[0004] In a surgical setting, so-called incision drapes are sometimes used to isolate the surgical site from non-sterile areas that could increase the risk of infection. Incision drapes are designed to be cut out during the surgical procedure.

[0005] In both surgical settings and wound treatment, it is necessary to prevent infections caused by contaminating microorganisms.

[0006] For many wound care products, rapid delivery of antimicrobial agents is desirable. This is because if antimicrobial agents are released slowly and gradually, bacteria present at the wound site or on the skin may adapt to generally low concentrations of the antimicrobial agent.

[0007] Wound care products, such as dressings and incision drapes, generally contain self-adhesive adhesives, also known as pressure-sensitive adhesives (PSAs). The purpose of these adhesives is to adhere to the wound and / or surrounding skin, thereby securing the dressing in the desired position. Various adhesives may be used to apply wound care products to the skin. Some of the most common are acrylic adhesives, silicone adhesives, and hot-melt adhesives. During the assembly of wound care products, the adhesive layer is generally covered with a release liner to protect the adhesive layer and the product from contamination before use. Products are generally sterilized before use in a surgical setting or before application to a patient's skin or wound.

[0008] To enable rapid release and, consequently, rapid effectiveness, an antimicrobial composition may be coated onto the skin-facing surface of the adhesive layer.

[0009] Based on Patent Documents 1 and 2, antimicrobial dressings containing a soluble silver salt coating on the adhesive surface are known. In these dressings, silver is released as positively charged ions when it comes into contact with a liquid. The release of silver has an antimicrobial effect and can reduce the bacterial concentration at the wound site, while its effect on fungi, such as Candida albicans, and the prevention and elimination of bacterial biofilms are limited.

[0010] Chlorhexidine is another antimicrobial compound commonly used as a wound cleanser before surgical procedures. Chlorhexidine is also used in oral applications such as mouthwashes and is applied to medical devices, such as dental implants and catheters. Chlorhexidine is considered environmentally sound and safe. The most commonly used chlorhexidine salts are chlorhexidine gluconate and chlorhexidine acetate.

[0011] When applying an antibacterial coating to the adhesive layer of a wound care product, the coating may affect the adhesive properties of the adhesive layer or "StickyIt is important not to compromise the "tackiness" of the material.

[0012] Furthermore, it is important that the antimicrobial coating remains on the adhesive surface of the wound care product when the product is to be applied to the patient's skin or wound. One problem associated with wound care products containing antimicrobial coatings is that once the release liner is removed from the wound care product, the antimicrobial composition is removed along with the release liner, thereby being removed from the adhesive layer. As a result, the antimicrobial effect of the dressing is eliminated or at least significantly reduced.

[0013] Therefore, the aforementioned difficulties concerning antimicrobial wound care products need to be overcome. More specifically, there is a need to provide wound care products that provide rapid delivery of antimicrobial compounds, and in which the effect remains within the wound care product even after the product has been disassembled, i.e., after the peeling liner has been removed. [Prior art documents] [Patent Documents]

[0014] [Patent Document 1] European Patent Application Publication No. 3191039 [Patent Document 2] European Patent No. 3191144 [Patent Document 3] European Patent Application Publication No. 3023083 (European Patent Application No. 14194054.4) [Overview of the project] [Problems that the invention aims to solve]

[0015] In light of the problems described above, the purpose of this disclosure is to provide an improvement relating to an antimicrobial wound care product, specifically a product including a soluble antimicrobial coating, wherein such a coating remains on the adhesive layer after the release liner has been removed from the product. [Means for solving the problem]

[0016] According to a first aspect, there is provided a wound care product comprising a backing layer and an adhesive layer having a skin-facing surface, at least a part of the skin-facing surface of the adhesive layer comprising an antibacterial coating, the coating being soluble in an aqueous medium and the coating comprising chlorhexidine phosphate.

Advantages of the Invention

[0017] The antibacterial coating is soluble in an aqueous medium. Thus, upon contact with wound exudate or moist skin, the antibacterial coating dissolves and allows for a rapid initial release of chlorhexidine phosphate, eradicating bacteria present in the wound or surgical site, or in the skin surrounding the wound or incision. This prevents the growth of infectious microorganisms on the surface of the adhesive layer. This avoids colonization in the wound site and in the wound care product.

[0018] The present disclosure is based on the recognition that an antibacterial coating comprising chlorhexidine phosphate can be readily deposited onto the adhesive layer of a wound care product, for example by spray coating, without impairing the adhesive properties of the adhesive layer. More importantly, the antibacterial coating of the present disclosure has the ability to remain on the skin-facing surface of the adhesive layer even after removal of the release liner.

[0019] Although numerous antibacterial compounds are provided as coatings on the adhesive skin contact layer of wound care products and may have antibacterial activity against various bacteria, many coatings have the problem that the antibacterial coating migrates from the adhesive surface to the release liner. As a result, the antibacterial effect is lost inside the dressing.

[0020] Chlorhexidine is a safe and powerful antibacterial agent. The inventors tested various types of chlorhexidine salts, and the conclusion obtained in that process was that chlorhexidine phosphate (CHP) had both the ability to remain on the adhesive layer after removal of the release liner and the ability to dissolve easily when further contacted with wound exudate. The surprising discovery that a soluble coating containing chlorhexidine phosphate remains on the adhesive layer, that is, inside the wound care product, makes the product of the present disclosure a commercially attractive solution for preventing infections from occurring in wounds and surgical sites.

[0021] The inventors also compared the antibacterial activity of chlorhexidine phosphate (CHP) with other antibacterial agents known to those skilled in the art. The conclusion obtained in that process was that CHP was surprisingly effective against both Gram-negative bacteria and Gram-positive bacteria, as well as Candida albicans. Furthermore, CHP is effective against bacterial biofilms.

[0022] In an embodiment, at least 60%, preferably at least 80%, of the antibacterial coating is formed so as to be dissolved within 3 hours after being exposed to an aqueous medium.

[0023] Therefore, a rapid antibacterial effect can be established at the wound site, and the antibacterial coating is completely dissolved when contacted with wound exudate.

[0024] In some embodiments, the wound care product includes a release liner, and the release liner is removably attached to the skin-facing surface of the adhesive layer.

[0025] The purpose of the release liner is to protect the dressing and the adhesive layer from contamination. The release liner is applied after the product is manufactured and removed before applying the dressing onto the skin surface.

[0026] The wound care product may be a dressing, such as a wound covering, or a surgical drape, preferably a laparotomy drape.

[0027] Dressings are generally applied to open wounds or scars that require treatment. Incision drapes are applied and cut during surgical procedures. In both types of products, prevention of infectious microorganisms at the wound or skin site is desirable.

[0028] In embodiments where the wound care product is an incision drape, the adhesive layer may contain a polyacrylate adhesive.

[0029] However, the adhesive layer of the drape may also contain other types of adhesives, such as silicone-based adhesives.

[0030] In embodiments where the wound care product is a dressing, the adhesive layer includes a silicone-based adhesive.

[0031] Such adhesives are gentle on the skin and allow the dressing to be removed and reapplied without harming the skin.

[0032] In this embodiment, the antibacterial coating is a discontinuous coating on the skin-facing surface of the adhesive layer.

[0033] Therefore, the antimicrobial coating does not completely cover the surface of the skin-facing side of the adhesive layer. This is beneficial in avoiding impairing the adhesion to the skin provided by the adhesive layer. Such a discontinuous coating may be provided, for example, by spray application.

[0034] The discontinuous coating allows for a good balance between sufficient release of chlorhexidine phosphate and maintenance of the adhesive properties of the adhesive layer.

[0035] In this embodiment, the concentration of chlorhexidine phosphate in the antimicrobial coating is 5 to 1000 μg / cm², for example 10 to 500 μg / cm², for example 20 to 200 μg / cm².

[0036] Therefore, when the coating comes into contact with wound fluid or skin moisture and dissolves, it allows for the sufficient release of the antimicrobial agent, namely chlorhexidine phosphate. Furthermore, such a range allows for a good balance between the sufficient release of chlorhexidine phosphate and the maintenance of the adhesive properties of the adhesive layer.

[0037] The dressings of this disclosure may be absorbent or non-absorbent.

[0038] In non-absorbent embodiments of the dressing, the dressing comprises a backing layer and an adhesive skin-contact layer. Such dressings may be useful in a variety of applications. For example, patients with epidermolysis bullosa, a disease (or group of diseases) characterized by mechanical fragility of the skin and mucous membranes, may be treated by applying a silicone-based adhesive dressing. Infection prevention is a key element of treatment.

[0039] In another embodiment, the wound care product is an absorbent dressing. In such an embodiment, the dressing further includes an absorbent pad positioned between the backing layer and the adhesive layer.

[0040] Many wounds, particularly infected wounds, can exude large amounts of fluid, so it is generally necessary to use dressings that include absorbent pads. Absorbent pads may contain any absorbent material, such as absorbent fibers, gels, or foams. Preferably, absorbent pads contain hydrophilic foam, such as hydrophilic polyurethane foam. Absorbent pads may contain one or more pad-forming layers.

[0041] The dressings of this disclosure may be used in all wound care settings where antimicrobial effects are desired. For example, the dressings may be used in negative pressure wound therapy (NPWT) applications. In these cases, the dressing is connected to a negative pressure source, such as a pump, which applies negative pressure, such as a vacuum, through the dressing. When used in negative pressure wound therapy, the dressing may be absorbent or non-absorbent. In the latter case, the dressing may act as a secondary dressing and is generally used in conjunction with a wound filler, such as gauze or foam initially applied to an open cavity wound.

[0042] To enhance the antibacterial effect of the dressing, the absorbent pad may contain at least one secondary antibacterial compound.

[0043] Providing a secondary antimicrobial compound within the pad generally results in a slower, more gradual release of the antimicrobial agent compared to the faster release provided by a soluble antimicrobial coating. For various applications, it may be desirable to configure the product so that rapid elimination of bacteria is achieved by the coating, and a slower release is achieved by the antimicrobial agent present within the absorbent pad.

[0044] In one embodiment, the adhesive layer contains at least one third antimicrobial compound. In other words, the adhesive layer of a dressing or incision drape may contain an antimicrobial compound. Providing the antimicrobial agent within the adhesive layer is associated with slower release and is advantageously combined with the rapid release provided by a soluble antimicrobial coating. Additional excipients may be required within the adhesive layer to facilitate the release of the third antimicrobial compound from the adhesive layer.

[0045] The second antimicrobial compound and the third antimicrobial compound may be the same or different. The at least one of the second and third antimicrobial compounds may be chlorhexidine phosphate.

[0046] In another embodiment, a method for manufacturing a wound care product, a) A wound care product comprising a backing layer and an adhesive layer having a skin-facing surface, wherein the wound care product optionally includes an absorbent pad placed between the backing layer and the adhesive layer. b) Prepare an aqueous solution of chlorhexidine phosphate by dissolving chlorhexidine in phosphoric acid and water. c) Applying the aqueous solution to at least a portion of the skin-facing surface of the adhesive layer, d) Drying the aqueous solution on the skin-facing surface of the adhesive layer. A method for manufacturing wound care products, including the following, is provided.

[0047] The method disclosed herein enables a simple but efficient method for manufacturing antimicrobial wound care products.

[0048] The aqueous solution is provided by dissolving chlorhexidine in phosphoric acid and water. Thus, a solution of dissolved chlorhexidine phosphate is obtained.

[0049] During the drying process, the aqueous phase of the coating is removed. However, upon contact with skin moisture or wound fluid, the dried coating dissolves, and chlorhexidine phosphate can be released into the wound and the surrounding skin.

[0050] In this embodiment, the pH of the aqueous solution of chlorhexidine phosphate is 4 to 6.

[0051] Infectious bacteria generally thrive at higher pH values, for example, around 7.5–8.5. Therefore, a low pH in the coating solution creates an environment unsuitable for the growth and colonization of infectious bacteria, and can also make the bacteria more susceptible to the antimicrobial effect provided by chlorhexidine phosphate.

[0052] The aqueous solution may be applied to at least a portion of the skin-facing surface of the adhesive layer by any means known to those skilled in the art.

[0053] Preferably, the aqueous solution may be applied by spray coating to at least a portion of the skin-facing surface of the adhesive layer.

[0054] Spray application is a simple coating method with several advantages. For example, the ability to spray the solution onto the bonding surface allows for more controlled adhesion of the coating. Adhesion can be concentrated within a specific dressing area, and the size of droplets on the skin-facing surface can be controlled.

[0055] Furthermore, the solution can be applied in a manner that does not adversely affect the adhesive properties of the adhesive layer.

[0056] In one embodiment, the method is e) A release liner is attached to the skin-facing surface of the adhesive layer. Further steps are included.

[0057] The release liner is formed to be removable from the adhesive layer (and coating) and to be removed before the dressing is applied to the patient's skin or wound.

[0058] Further features and advantages of this disclosure will become apparent upon study of the attached claims and the description below. It will be apparent to those skilled in the art that various different features of this disclosure can be combined to produce embodiments other than those described below, without departing from the scope of this disclosure.

[0059] Various aspects of this disclosure, including specific features and advantages, will be readily apparent from the detailed description below and the accompanying drawings. [Brief explanation of the drawing]

[0060] [Figure 1] Figure 1 is a conceptual diagram illustrating the problems associated with conventional dressing techniques. [Figure 2] Figure 2 is an exploded view showing a dressing based on an exemplary embodiment of the present disclosure. [Figure 3] Figure 3 is a schematic perspective view of a dressing based on an exemplary embodiment of the present disclosure, wherein the dressing comprises a plurality of pad-forming layers. [Figure 4a] Figure 4a is a schematic diagram showing an incision drape based on an exemplary embodiment of the present disclosure. [Figure 4b] Figure 4b is a cross-sectional view showing the incision drape shown in Figure 4a. [Figure 5] Figure 5 is a schematic diagram illustrating the steps of a method based on an exemplary embodiment of the present disclosure. [Figure 6a] Figure 6a is an optical microscope image showing the skin-facing surface of a wound contact layer containing an antimicrobial chlorhexidine phosphate (CHP) coating, both after sterilization and after removal of the peeling liner. [Figure 6b] Figure 6b is an optical microscope image showing the delamination liner removed from the wound contact layer in Figure 6a. [Figure 6c] Figure 6c is an optical microscope image showing the skin-facing surface of a wound contact layer containing an antimicrobial chlorhexidine gluconate (CHG) coating, both after sterilization and after removal of the exfoliating liner. [Figure 6d] Figure 6d is an optical microscope image showing the delamination liner removed from the wound contact layer in Figure 6c. [Figure 7] Figure 7 is an optical microscope image showing the skin-facing surface of an incision drape containing an antimicrobial chlorhexidine phosphate (CHP) coating, both after sterilization and after removal of the peeling liner. [Figure 8a] Figure 8a shows the antibacterial effect against Pseudomonas aeruginosa (PaO1)) by a sample containing polyurethane foam and a wound contact layer, with and without an antibacterial coating containing chlorhexidine phosphate, and with and without silver in the polyurethane foam. [Figure 8b]Figure 8b shows the antibacterial effect against Staphylococcus aureus (S. aureus (ATCC6538)) by a sample containing polyurethane foam and a wound contact layer, with and without an antibacterial coating containing chlorhexidine phosphate, and with and without silver in the polyurethane foam. [Modes for carrying out the invention]

[0061] The present disclosure will be described more fully below with reference to the accompanying drawings. The drawings show currently preferred embodiments of the present disclosure. However, the present disclosure may be embodied in a number of different forms and should not be construed as being limited to the embodiments shown herein. Rather, these embodiments are provided for the sake of perfection and completeness and will fully convey the scope of the present disclosure to those skilled in the art.

[0062] The problem underlying this disclosure is schematically illustrated in Figure 1. Figure 1 shows a prior art dressing 100, which includes an adhesive skin contact layer 101 and a release liner 102. The release liner shown in Figure 1 includes three release portions 102a-c and is attached to the adhesive skin contact layer 101 of the dressing. The adhesive skin contact layer 101 initially includes an antimicrobial coating on the skin-facing surface. When the first release liner portion 102a is removed, the coating is removed from the adhesive skin contact layer 101 (indicated by the arrow in Figure 1) and migrates to the surface of the release liner portion (see 103). As a result, the antimicrobial effect of the dressing is lost.

[0063] Figure 2 conceptually illustrates a wound care product based on an exemplary embodiment. The wound care product is a dressing 200 comprising a backing layer 201 and an adhesive layer 202 having a skin-facing surface 203, wherein at least a portion of the skin-facing surface 203 of the adhesive layer 202 comprises an antimicrobial coating 204, the antimicrobial coating 204 is soluble in an aqueous medium, and the coating 204 contains chlorhexidine phosphate.

[0064] The adhesive layer has a surface (not shown) opposite to the backing layer 201. Chlorhexidine has the following chemical structure, i.e. [ka] It has.

[0065] The phosphate counterion has the following chemical structure, i.e. [ka] It has.

[0066] In the embodiment shown in Figure 2, the dressing 200 further includes an absorbent pad 205 positioned between the backing layer 201 and the adhesive layer 202. Thus, the dressing 200 is absorbent. The adhesive layer 202 may, for example, be covered on the absorbent pad 205, or the adhesive layer may be bonded or laminated to the absorbent pad 205.

[0067] The adhesive layer includes a soluble coating 204 containing chlorhexidine phosphate on the skin-facing surface 203.

[0068] Preferably, at least 60%, preferably at least 80%, of the skin-facing surface of the adhesive layer includes an antimicrobial coating.

[0069] The antimicrobial coating 204 dissolves when exposed to wound exudate, releasing chlorhexidine phosphate to the wound site. This allows for a rapid antimicrobial effect.

[0070] As used herein, the term “soluble in aqueous media” means that the coating dissolves upon contact with an aqueous medium. The aqueous solution may be water. Therefore, the antimicrobial coating dissolves rapidly upon contact with wound exudate or skin moisture. Even small amounts of skin moisture or wound exudate will cause the antimicrobial coating to dissolve. The coating is initially applied to the surface of the adhesive layer as an aqueous solution and then dried. Upon contact with wound exudate or an aqueous medium, the dried coating dissolves and is released from the adhesive layer.

[0071] In this embodiment, at least 60%, preferably at least 80%, of the antimicrobial coating (204) is formed to dissolve within 3 hours of exposure to an aqueous medium.

[0072] In this embodiment, at least 90%, for example 100%, of the antimicrobial coating (204) is formed to dissolve within 3 hours of exposure to an aqueous medium.

[0073] Therefore, the antimicrobial coating of this disclosure enables the rapid release of active antimicrobial agents (CHPs) and a rapid antimicrobial effect.

[0074] The antimicrobial coatings of this disclosure contain dissolved chlorhexidine phosphate salt. In other words, when the coating is applied, typically in the form of an aqueous solution, there are virtually no undissolved CHP particles. This is to allow for rapid dissolution (and rapid effect) upon contact with wound exudate.

[0075] The inventors have found that chlorhexidine phosphate is not only efficient in killing Gram-positive and Gram-negative bacteria, but also efficient against Candida albicans (see Example 1). Therefore, the wound care product of this disclosure is a promising and commercially viable antimicrobial product that can be used against several microbial species. The wound care product also satisfies the more stringent (governmental) requirements that antimicrobial wound care products must meet at the time of commercialization.

[0076] Furthermore, compared to other commercially available chlorhexidine salts (and other antimicrobial agents), the inventors have found that coatings containing chlorhexidine phosphate have the ability to remain on the skin-facing surface 203 of the adhesive layer 202 of the dressing even after the release liner has been removed from the dressing. Therefore, the antimicrobial effect remains within the dressing when the release liner is removed.

[0077] The release liner in Figure 2 includes two release liner portions 206a and 206b. The first release liner portion 206a is positioned above the second release liner portion 206b. The second release liner portion 206b is folded back, and the first release liner portion 206a overlaps with the folded edge of the second release liner portion 206b and extends beyond this folded edge. Thus, a first tab and a second tab are formed, and the release liner can be easily removed by a caregiver or patient grasping these tabs.

[0078] While we do not wish to be bound by theory, for example, the lower hygroscopicity of chlorhexidine phosphate compared to chlorhexidine gluconate is thought to be a factor in the significantly lower amount of chlorhexidine phosphate transferred from the adhesive layer to the release liner.

[0079] The absorbent pad 205 is not limited to a specific material, and any absorbent material may be used. Preferably, the absorbent pad 205 includes foam, such as polyurethane foam.

[0080] Dressings containing polyurethane foam pads can absorb large amounts of wound exudate. Infected wounds exude a large amount of fluid, and dressings must be able to properly manage this fluid.

[0081] Polyurethane foam may be produced from a composition containing, for example, a prepolymer based on hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), or methylenediphenyl diisocyanate (MDI).

[0082] The adhesive layer is sometimes called the "wound contact layer" or "skin contact layer." Preferably, the adhesive layer of the dressing contains a silicone-based adhesive. Such adhesives are gentle on the skin and allow for removal of the dressing without damaging the skin. The adhesive layer has a skin-facing surface and an opposite surface. The opposite surface faces the backing layer of the dressing. The opposite surface may be positioned in contact with the backing layer or, if present, with an absorbent pad.

[0083] The peel liner 206 may be formed from one or more peel liner portions. In Figure 2, the peel liner includes two peel liner portions 206a and 206b.

[0084] In the context of dressings, the release liner may include a material selected from polyurethane, polyester, polypropylene, and silicone-coated paper. For example, the release liner may be a polyethylene film with a thickness of 30 to 300 μm, for example, 50 to 150 μm.

[0085] The antimicrobial coating may be provided as a discontinuous or continuous coating on at least a portion of the skin-facing surface 203 of the adhesive layer 202.

[0086] Depending on the mode of coating adhesion, the coating may be discontinuous, that is, it may not completely cover the skin-facing surface of the adhesive layer, or it may be continuous.

[0087] A continuous coating may be provided by dipping or immersing the adhesive layer in an aqueous solution containing chlorhexidine phosphate.

[0088] To avoid impairing the adhesion to the skin provided by the adhesive layer 202, a discontinuous coating 204 is generally preferred.

[0089] The concentration of chlorhexidine phosphate in the antimicrobial coating 204 may be 5 to 1000 μg / cm², for example 10 to 500 μg / cm², or for example 20 to 200 μg / cm². In this embodiment, the concentration of chlorhexidine phosphate in the antimicrobial coating 204 is 50 to 200 μg / cm², for example 10 to 130 μg / cm², or for example 20 to 100 μg / cm².

[0090] This ensures that chlorhexidine phosphate is released in an amount sufficient to provide an antibacterial effect at the wound site.

[0091] Figure 3 shows a so-called "border dressing." The dressing 300 may include a backing layer 301, an adhesive layer 302, and an absorbent pad 303 positioned between the backing layer 301 and the adhesive layer 302. The backing layer 301 and the adhesive layer 302 are formed to extend beyond the contour of the absorbent pad 303 in order to form a boundary portion 304.

[0092] The absorbent pad may be formed from a single layer or multiple pad-forming layers. The absorbent pad is not limited to a specific material, but may generally include an absorbent foam or gel. This may include a superabsorbent material, such as a superabsorbent polymer (SAP) or a superabsorbent fiber (SAF).

[0093] In an exemplary embodiment, the absorbent pad comprises two or more layers having different properties, which are bonded together.

[0094] As shown in Figure 3, the absorbent pad 303 may include a first absorbent layer 305, a liquid distribution layer 306, and a second absorbent layer 307. Generally, the liquid distribution layer 306 is located between the first absorbent layer 305 and the second absorbent layer 307, and the first absorbent layer 305 is the bottom layer of the absorbent pad.

[0095] The first absorbent layer 305 may contain foam. Suitable foam materials for use within the first absorbent layer 305 include, but are not limited to, polyurethane foam.

[0096] The second absorbent layer 307 may be a superabsorbent layer. Therefore, the second absorbent layer may contain a superabsorbent polymer (SAP) or a superabsorbent fiber (SAF).

[0097] The liquid distribution layer 306 may contain any material capable of efficiently distributing the exudate. For example, the liquid distribution layer 306 may contain a nonwoven fabric material. The nonwoven fabric provides a well-balanced rigidity to the layer and, as such, to the dressing. The nonwoven fabric can efficiently distribute and spread the liquid absorbed by the absorbent layer 305, allowing the liquid to evaporate over a large surface area through the backing layer 301. For example, the nonwoven fabric may contain viscose, polyester, or a mixture thereof.

[0098] The layers can be joined together, for example, by adhesive or bonding using pressure and heat.

[0099] The absorbent pad may include additional layers, such as a liquid transport layer, and various combinations of laminated foam layers and nonwoven fabric layers.

[0100] Referring to Figure 3, layer 305 may contain absorbent foam, layer 306 may be a liquid trapping layer, and layer 307 may be a superabsorbent layer.

[0101] Such a layered pad structure prevents bodily fluids from accumulating close to the skin, improving the fluid management of the dressing. Most wounds contain some exudate, but the level of exudate varies. In chronic wounds, exudate production is extremely high due to persistent inflammation. Dressings with the above structure are suitable for managing large amounts of exudate and are also suitable for preventing maceration of the skin surrounding the wound. Thus, dressings are particularly suitable for infection prevention.

[0102] The adhesive layer 302 may be a laminate comprising at least one polymer film and an adhesive silicone layer, wherein the adhesive silicone layer is arranged to be in contact with the skin or wound.

[0103] The polymer film simplifies the manufacturing process and provides stability and integrity to the adhesive layer 302.

[0104] The polymer film is preferably a breathable film and may contain, for example, polyethylene, polyamide, or polyester polyurethane. Preferably, the polymer film contains polyurethane. The thickness of the polyurethane film may be 15 to 100 μm, for example 20 to 80 μm, preferably 20 to 60 μm.

[0105] Examples of silicone gels suitable for use in the adhesive silicone layer of adhesive layer 302 and / or within adhesive layer 202 as described in relation to Figure 2 include two-component RTV systems, e.g., Liveo MG-7-9960 (DuPont), and SilGel 612 (Wacker Chemie AG) as described herein, as well as NuSil silicone elastomers. In embodiments of the present invention, the adhesive may include a soft silicone gel with a softness (penetration) of, for example, 8 to 22 mm, or e.g., 12 to 17 mm, as measured by methods based on ASTM D 937 and DIN 51580. Methods are described in Patent Document 3. The thickness of the adhesive layer is generally at least 20 μm. The thickness of the adhesive layer may be 30 to 200 μm.

[0106] As shown in Figure 3, the adhesive layer 302 may include multiple apertures 308. The apertures 308 extend through the adhesive skin contact layer 302. The apertures 308 allow for rapid absorption into the pad 303 without compromising the tight fit with the skin provided by the adhesive layer 302. The adhesive skin contact layer 302 includes multiple apertures 308 in the region located beneath the absorbent pad 303, but there are no apertures in the region forming the boundary portion 304. The absence of apertures in the boundary portion of the dressing is beneficial for improving adhesion at the boundary portion 304 of the dressing, and thereby improving the retention capacity of the dressing.

[0107] The apertures 308 may have different shapes and densities along various regions of the adhesive skin contact layer 302, and may be arranged in regular or irregular patterns.

[0108] A soluble antimicrobial coating containing chlorhexidine phosphate is generally provided on the non-aperture portion of the skin-facing side of the adhesive layer (not shown). Preferably, the antimicrobial coating is provided within at least the area of ​​the adhesive layer located beneath the absorbent pad 303.

[0109] In the various embodiments described above, the backing layer may be a thin vapor-permeable film, sheet, or membrane. Suitable materials for the backing layer include, but are not limited to, polyurethane, polyethylene, or polyamide films, silicone films, polyester nonwoven fabrics, and laminates of polyester nonwoven fabrics and polyurethane films. Preferably, the backing layer is a polyurethane film with a thickness of 5 to 40 μm, for example, 15 to 25 μm.

[0110] To enhance the antibacterial effect, additional layers or components of the dressing may contain antibacterial compounds. For example, in this embodiment, the absorbent pad 303 contains at least one second antibacterial compound. Alternatively, at least one of the pad-forming layers of the absorbent pad 303 contains at least one second antibacterial compound.

[0111] Alternatively, or in addition to this, the adhesive layer 302 contains at least one third antimicrobial compound.

[0112] At least one of the second antimicrobial compounds and the third antimicrobial compound may be the same or different.

[0113] Any antimicrobial compound suitable for incorporation into the pad or adhesive layer may be used. In embodiments, the second and / or third antimicrobial compound may be selected from the group including silver salts, chlorhexidine salts, polyhexamethylene biguanide, benzethonium chloride, and polydiallyldimethylammonium chloride.

[0114] In one embodiment, the second and / or third antimicrobial compound is a silver salt, such as a sulfate.

[0115] In this embodiment, the second and / or third antimicrobial compound is chlorhexidine phosphate.

[0116] In this embodiment, at least one second antimicrobial compound is incorporated into the absorbent pad or pad-forming layer. For example, at least one second antimicrobial compound may be incorporated into the foam layer of the absorbent pad shown in Figure 3, or into the foam pad shown in Figure 2. At least one second antimicrobial compound may be chemically bonded to the structure or inner surface of the foam, for example, to the pores. The second antimicrobial compound may be bonded, for example, to the charged inner surface of the foam.

[0117] It is also conceivable that the second antimicrobial compound could be incorporated into the foam by adding it to the prepolymer before the foaming process. In this way, the antimicrobial compound would be incorporated into the foam and bonded within the cell walls of the foam.

[0118] Alternatively, at least one second antimicrobial compound may optionally be provided as a coating on a layer of absorbent pad before bonding or laminating with one or more pad-forming layers or other pad layers.

[0119] Alternatively, the foam may be impregnated with at least one second antimicrobial compound. In this way, the second antimicrobial compound can be coated onto the surface of the foam. This deposition method can also provide a coating of the second antimicrobial compound on the internal pore surface of the foam.

[0120] In this embodiment, at least one third antimicrobial compound is incorporated into the adhesive skin contact layer. In this example, the third antimicrobial compound is added to an uncured silicone gel adhesive mixture, which is then cured. Additional excipients configured to facilitate the release of at least one third antimicrobial compound may be added.

[0121] The concentrations of the second and / or third antimicrobial compounds are generally higher than the concentrations of chlorhexidine phosphate in the antimicrobial coating. The second and / or third antimicrobial compounds may have a slower release profile and, consequently, provide a longer-lasting antimicrobial effect.

[0122] Figures 4a and 4b conceptually illustrate a wound care product based on an exemplary embodiment. In Figure 4, the wound care product is an incision drape 400, and area 406 schematically indicates where the drape is to be cut out during the surgical procedure.

[0123] As used herein, “incisional drape” refers to a surgical drape used during a surgical procedure, which is designed to be cut out. Sometimes also called a “surgical incisional drape,” an incisional drape is attached to the patient’s skin to isolate the surgical site from non-sterile areas that could increase the risk of infection at the surgical site.

[0124] As shown in Figure 4b, the incision drape 400 comprises a backing layer 401 and an adhesive layer 402 having a skin-facing surface 403, wherein at least a portion of the skin-facing surface 403 of the adhesive layer 402 comprises an antimicrobial coating (not shown), the antimicrobial coating is soluble in an aqueous medium, and the antimicrobial coating contains chlorhexidine phosphate.

[0125] The antimicrobial coating is advantageous because, when used on the incision drape during surgical procedures, it prevents and combats the infection of the incision site by contaminating microorganisms.

[0126] The term "backing layer" as used in the context of surgical drapes, for example, incisional drapes as used herein, means the top layer of the wound care product, i.e., the layer separated from the patient's skin. The backing layer of the drape may include, for example, polyurethane, polyester, and / or polypropylene.

[0127] The adhesive layer 402 may contain any suitable adhesive and is by no means limited to a particular type of adhesive. Generally, the adhesive used is a silicone-based adhesive or a polyacrylate-based adhesive. Preferably, in the case of an incision drape, the adhesive layer 402 contains a polyacrylate-based adhesive.

[0128] The materials of the backing layer 401 and the adhesive layer 402 are configured to facilitate cutting out each of the layers of the drape.

[0129] As shown in Figure 4, the incision drape includes a release liner 404 formed to be removed before the drape is applied. The release liner 404 is removably attached to the adhesive layer. In Figure 4, the release liner 404 has the same cross-sectional area as the backing layer 401. The release liner 404 may also have a larger cross-sectional area to facilitate removal from the drape before use.

[0130] As shown in Figure 4a, the excess of the adhesive layer 402 can form handle portions 405a-b, and by grasping these handle portions, the caregiver can remove the release liner 404 from the adhesive layer 402. Surgical drapes are generally relatively large in size and often require the assistance of two caregivers for the procedure. One caregiver grasps the first handle portion 405a of the drape, while the other caregiver grasps the second handle portion 405b, and the release liner is gradually removed from the adhesive layer, thereby exposing the adhesive surface. The incision drape is then applied to the patient and subsequently smoothed to prevent wrinkle formation. The handle portions 405a-b may be formed from any material. For example, polymer films, such as polyethylene, may be used. The release liner 404 is not adhered to the handle portions 405a-b. This is to facilitate the removal of the release liner 404 from the adhesive layer 402.

[0131] The release liner 404 is not limited to a specific material, and any material known to those skilled in the art may be used. In embodiments, the release liner includes silicone-coated paper or a polyester liner.

[0132] Antimicrobial coatings prevent contaminating microorganisms from migrating into the incision or wound site. Although the skin is generally cleaned before application to prevent contamination, pores may still contain bacteria, and these bacteria can migrate to the incision site. Therefore, antimicrobial coatings prevent surgical site contamination.

[0133] Referring to Figure 5, a second aspect of this disclosure is schematically shown, which relates to a method for manufacturing wound care products.

[0134] This delicious, a) A wound care product is provided comprising a backing layer and an adhesive layer having a skin-facing surface, wherein the wound care product optionally includes an absorbent pad disposed between the backing layer and the adhesive layer (step 501), b) Prepare an aqueous solution of chlorhexidine phosphate by dissolving chlorhexidine in phosphoric acid and water (step 502), c) Apply the aqueous solution to at least a portion of the skin-facing surface of the adhesive layer (step 503), d) Dry the aqueous solution on the skin-facing surface of the adhesive layer (step 504) This includes the following.

[0135] Wound care products may be provided by means known to those skilled in the art. The assembly of the backing layer, the adhesive layer, and the absorbent pad, if present, is not limited to any particular method and any means (e.g., bonding, lamination, etc.) may be used.

[0136] An aqueous solution of chlorhexidine phosphate is provided by dissolving chlorhexidine in phosphoric acid and water. The aqueous solution is mixed and optionally stirred to ensure complete dissolution of the salt.

[0137] The step of applying an aqueous solution to at least a portion of the skin-facing surface of the adhesive layer may be achieved using any coating technique.

[0138] Preferably, the aqueous solution is applied by spray coating onto at least a portion of the skin-facing surface of the adhesive layer.

[0139] This covering technique is beneficial because it allows for flexibility depending on the dressing or support 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 layer may be covered, and the size of droplets on the surface may be controlled to avoid interfering with the adhesive properties of the adhesive skin-contact layer.

[0140] Drying is carried out by means well known to those skilled in the art. For example, heating the coating can accelerate the evaporation of liquid from the coating.

[0141] The pH of the aqueous solution of chlorhexidine phosphate may be between 4 and 6.

[0142] This area creates an environment unfavorable for infectious microorganisms to grow and form colonies.

[0143] The molar ratio of chlorhexidine to phosphate in the aqueous solution may be 1:1 to 1:3, preferably 1:2.

[0144] Therefore, the salt dissolves completely in the aqueous solution with very few undissolved particles. If the ratio is too low, the solubility decreases. Conversely, if the ratio is too high, the solution to be deposited may not contain enough of the active substance.

[0145] The method is, e) A release liner is attached to the skin-facing surface of the adhesive layer. The process may further include step (step 505). [Examples]

[0146] Example 1: Antimicrobial effect of CHP Test organisms: Pseudomonas aeruginosa ATCC 9027 (bacteria), Staphylococcus aureus ATCC 6538 (bacteria), Candida albicans ATCC 10231 (fungus), Pseudomonas aeruginosa ATCC PAO1 (bacteria, Example 1b) Test duration: 24 hours for bacteria, and 48 hours for fungi. Starting inoculum: Bacteria 1 x 10^6 CFU / ml, fungi 4 x 10^6 CFU / ml.

[0147] Example 1a: Minimum concentration required to eliminate microorganisms in the solution A simulated wound fluid (SWF) consisting of equal proportions of fetal bovine serum (FBS) and peptone water (PW), corresponding to the protein and electrolyte concentrations of wound exudate (Emiko Aiba-Kojima, MD et al. Wound Rep Reg (2007) 15 511-520; Trengove, N et al Wound Rep Reg (1996) 4 1067-1927), was used as the test medium to compare the efficacy of silver sulfate, chlorhexidine phosphate, and chlorhexidine gluconate in solution. The objective was to define the minimum concentration of antimicrobial agents required to kill specific microorganisms. Test microorganisms were suspended in SWF, and antimicrobial substances were added at different concentrations before secondary incubation in well microtiter plates. Positive and negative controls were used to demonstrate sufficient microbial growth and medium sterility throughout the incubation period.

[0148] The results showed that more than 190 times the amount of silver compared to chlorhexidine phosphate was required to kill Candida albicans. Chlorhexidine phosphate (CHP) was the most efficient antimicrobial agent compared to both silver sulfate and chlorhexidine gluconate (CHG) (see Table 1 below). [Table 1]

[0149] Example 1b: Decrease in biofilm count after contact with CHP solution To evaluate the efficacy of chlorhexidine phosphate (CHP) against biofilms cultured on a collagen matrix, the study was conducted in solution using SWF as the test medium.

[0150] The objective was to determine whether the concentration of CHP, which can be spray-applied onto the surface of a silicone contact layer, affects the biofilm. The test microorganism was Pseudomonas aeruginosa PAO1, suspended in SWF solution and placed on the collagen matrix in the wells of a 24-well plate. Biofilm formation was induced by incubating the well-plate at 37°C and 95% relative humidity for 24 hours. After incubation and biofilm formation, the antimicrobial agent CHP was added to the top of the biofilm at three different concentrations and then incubated for a further 24 hours at 37°C and 95% relative humidity. Positive and negative controls were used to demonstrate sufficient biofilm growth and medium sterility over the incubation period. Viable cell counts were determined by culturing on PetriFilms.

[0151] The results shown in Table 2 below demonstrate that concentrations of CHP solution at 37 μM, 75 μM, and 150 μM, which can be achieved by spraying onto a silicone contact layer, reduced the amount of biofilm, and showed a logarithmic reduction higher than the FDA requirement of reduction 4. Therefore, chlorhexidine phosphate (CHP) is an efficient antimicrobial agent against bacterial biofilms, particularly compared to silver sulfate, which has low efficacy against biofilms. [Table 2]

[0152] Sample 1C: Antimicrobial effect of CHP sprayed onto a silicone surface 75 μg / cm³ 2 The effectiveness of the prototype coated with silver sulfate was measured at 45 μg / cm³. 2 and 75 μg / cm³ 2 To compare with a prototype coated with chlorhexidine phosphate, the test was performed on a coated and sterile wound adhesion layer. By punching out the prototype, 7 cm 2 These were formed into discs and placed in wells in contact with 2 mL of SWF containing a solution of suspended microorganisms (the same microorganisms used in Example 1a).

[0153] The wound contact layer used in the test consisted of a polyurethane film coated with a 200gsm silicone adhesive.

[0154] Silver sulfate coating and CHP coating were applied to the silicone surface by spray application (Sono-Tek ultrasonic nozzle (120kHz)).

[0155] Using positive and negative controls, we demonstrated sufficient microbial growth and culture medium sterility throughout the incubation period. Microbial growth was evaluated on a silicone layer, i.e., on the skin-facing surface, and in a suspension state in liquid.

[0156] 45 μg / cm³ 2 and 75 μg / cm³ 2 A chlorhexidine phosphate prototype sprayed at this concentration demonstrated complete elimination of all microorganisms both on the silicone surface and in solution. Silver sulfate did not even achieve a log-4 reduction in inoculum against Staphylococcus aureus, so this was not further evaluated against other microorganisms.

[0157] Example 2: Transfer of antibacterial agent to the release liner To compare the migration of antimicrobial agents to the release liner, tests were conducted on a covered and sterile wound adhesion layer.

[0158] The wound contact layer used in the test consisted of a polyurethane film coated with a 200gsm silicone adhesive.

[0159] Prototypes coated with an antimicrobial solution of chlorhexidine phosphate (0.56 wt%) were compared with prototypes sprayed with an antimicrobial solution of chlorhexidine gluconate (0.56 wt%). The spraying was performed using the same parameters and equipment as described in Example 1. After spraying, the samples were sent to the sterilization facility in the production area, subjecting them to the typical sterilization cycle required for antimicrobial products.

[0160] After sterilization, the sterile samples were observed using an optical microscope (Olympus Zoom high-performance stereomicroscope SZH). The results showed that only a small amount of chlorhexidine phosphate (CHP) was observed to transfer from the silicone surface of the wound contact layer to the delamination liner (see Figures 6a-6b). However, in the case of wound contact layers coated with chlorhexidine gluconate (CHG), most of the CHG coating migrated to the delamination liner. Some areas on the skin-facing side showed almost complete migration, leaving most of the silicone area stripped of the antimicrobial CHG (Figures 6c-6d).

[0161] To better understand the migration of the antimicrobial agent, a 7cm section was punched out of a sterile sample. 2 A disc was formed. Three silicone coating films (wound contact layers) and a release liner were separated and placed in wells in contact with 2 ml of aqueous solution for a time deemed sufficient to allow for adequate dissolution of the antimicrobial particles of CHP and CHG. After calibration of the equipment for the solution, the concentrations of CHP and CHG in different wells were evaluated by liquid chromatography-mass spectrometry to quantify the amount of antimicrobial agent present on the silicone and the amount transferred to the release liner.

[0162] The results showed that after sterilization, over 66% of the CHP sprayed onto the wound contact layer remained on the silicone surface and was therefore available for antimicrobial activity. Less than 36% of the sprayed CHG remained on the silicone, and the majority of the CHG (over 64%) migrated to the delamination liner. Consequently, the antimicrobial effect was significantly lost once the delamination liner was removed.

[0163] Example 3: Presence of CHP on the incision drape observed by optical microscopy To confirm the potential migration of the antimicrobial agent to the delamination liner, tests were also conducted on an incision drape spray-coated with CHP (Moelnlycke Health Care 921014-00 BNS Incise Drape). One prototype was used for the test, and the adhesive surface of the incision drape (including the polyacrylate adhesive) was sprayed with a CHP solution (0.56 wt%) using the same spray equipment as described in Examples 1-2 above. After drying, the sample was observed by optical microscopy (Olympus Zoom High Performance Stereoscopic Microscope SZH). The results showed that a high concentration of CHP was present on the surface of the incision drape when the delamination liner was removed (see Figure 7).

[0164] Example 4: Dissolution rate of antimicrobial coating To evaluate the dissolution rate of the antimicrobial coating, i.e., the release rate of the antimicrobial compound, tests were conducted on a coated and sterilized wound adhesion layer. Comparisons were made between a prototype spray-coated with an antimicrobial solution of chlorhexidine phosphate (0.56 wt%) and a prototype spray-coated with an antimicrobial solution of chlorhexidine acetate (0.68 wt%). Spray coating was performed using the same parameters and equipment as described in Examples 1 and 2 above. After spraying, the samples were sent to the sterilization facility in the production area, subjecting them to the general sterilization cycle required for antimicrobial products.

[0165] After sterilization, the prototype is punched out to 7cm2 A disc was formed. Three silicone coating films (wound contact layers) and a release liner were separated and placed in a well in contact with 2 ml of aqueous solution for 3 hours, then removed and placed in a new well for 24 hours to evaluate immediate (>3 hours) and short-term (>24 hours) dissolution.

[0166] After calibrating the equipment for the solution, the concentration of CHP and CHAc in different wells was evaluated by liquid chromatography-mass spectrometry to quantify the amount of antimicrobial coating that could be dissolved immediately or in the short term.

[0167] CHP exhibited immediate dissolution, i.e., immediate release from the silicone surface. 100% of CHP dissolved after 3 hours, compared to only 28% of CHA after 3 hours, and less than 40% after 24 hours. [Table 3]

[0168] These tests demonstrated that CHP has a higher dissolution rate compared to CHAc, which has a lower dissolution rate, thus enabling rapid release and rapid antimicrobial effects.

[0169] Example 5: Abrasion test / Adhesion test Tests were conducted to evaluate the effect of chlorhexidine phosphate (CHP) on the tackiness of samples sprayed with it. Tack, or tackiness, is a material property that allows a material to adhere to a surface immediately upon contact. Tackiness was evaluated using the tack rolling ball test (ASTM D 3121-06). In this test, the displacement of a metal ball on a silicone surface is measured.

[0170] The tack-rolling ball test was performed on sterile wound contact layers (as described above) sprayed with chlorhexidine phosphate at concentrations of 15, 45, and 75 μg / cm2, respectively.

[0171] As shown in Table 4 below, no significant effect on adhesion was observed even at higher concentrations of chlorhexidine phosphate (CHP). An uncoated, sterile wound contact layer was used as a control. [Table 4]

[0172] Example 6: Migration of CHP from peel liner Additional tests were conducted to further evaluate the transfer of chlorhexidine phosphate from the wound contact layer to the delamination liner.

[0173] The wound contact layer used in the test consisted of a polyurethane film coated with a 50gsm silicone adhesive.

[0174] The test was carried out as described in Example 2, with some deviations, namely the application of the CHP coating to the 50 gsm silicone adhesive by spray application (using an air atomizing nozzle from Sprayin System Co.), followed by an in-line drying step under a hood. Furthermore, the sample size of each test specimen was 3.1 cm², and the test was performed on four specimens. The wound contact layer and its delamination liner were separated and placed in a well with 1 ml of water for 24 hours.

[0175] As shown in Example 2, the amount of antimicrobial agent (CHP) present on the wound contact layer, i.e., on the silicone adhesive, and the amount of CHP transferred to the delamination liner were quantified using liquid chromatography-mass spectrometry (LCMS).

[0176] As shown in Table 5 below, virtually all of the CHP remains on the wound contact layer after sterilization. When the surface concentration of CHP on the wound contact layer is 28 - 92 μg / cm2, little or no CHP has migrated to the release liner.

Table 5

[0177] Example 7: Antibacterial Effect of Samples Containing CHP Coating and Silver - Containing Polyurethane Foam Respectively 10 6 CFU / mL suspensions of Pseudomonas aeruginosa (PaO1) and Staphylococcus aureus (ATCC6838) were prepared in heat - inactivated SWF and inoculated into the well plate in a volume of 145 μL. Triplicate replicates of each sample having a size of 2.5 cm2 were applied onto each inoculum material with the wound contact layer facing the inoculum material and incubated at 35 °C for 24 hours.

[0178] Each of the test samples included a polyurethane foam and a wound contact layer containing a polyurethane film with a silicone adhesive layer. The wound contact layer was adhered to the polyurethane foam. In some of the samples, the polyurethane foam was made to contain silver in an amount of about 1.2 mg / cm2 (Samples A and B below). The CHP coating was deposited onto the wound contact layer, i.e., the silicone adhesive layer, by spray - coating at a concentration of approximately 45 μg / cm 2 The spray - coating was carried out using the same parameters and the same equipment as described for Example 6 above.

[0179] The growth of microorganisms was evaluated in the whole sample, i.e., the wound contact layer and the silver - containing foam.

[0180] Sample A included a silver - containing polyurethane foam with an adhesive skin contact layer containing a CHP coating.

[0181] Sample B contained a silver-containing polyurethane foam with an adhesive skin-contact layer that did not have an antimicrobial coating.

[0182] Sample C contained a polyurethane foam without any antimicrobial agents, and had an adhesive skin-contact layer that did not contain an antimicrobial coating.

[0183] As shown in Figure 8a, complete elimination of Pseudomonas aeruginosa was observed in the sample (Sample A) containing silver in the polyurethane foam and CHP coated on the wound contact layer. Therefore, a combined effect of having silver in the foam and CHP in the coating was observed. Under these test conditions, the bacterial concentration for the sample (Sample B) containing silver in the polyurethane foam but without CHP on the wound contact layer remained at the inoculum level. Therefore, the presence of silver in the foam inhibited the growth of Pseudomonas aeruginosa, but did not reduce the bacterial count as much as in Sample A. The control sample (Sample C) without an antimicrobial agent reached a bacterial count of approximately Log 8. This is a 2 Log increase from the starting inoculum.

[0184] Similar combined effects were observed against Staphylococcus aureus (S. aureus) (see Figure 8b).

[0185] The terms, definitions, and embodiments of all aspects of this disclosure may apply to other aspects of this disclosure with necessary modifications.

[0186] While this disclosure has been described with reference to certain exemplary embodiments, numerous different variations, modifications, and similar forms will become apparent to those skilled in the art.

[0187] Modifications to the disclosed embodiments can be understood and achieved by those skilled in the art in carrying out the disclosure by studying the drawings, disclosures, and appended claims. Furthermore, in the claims, “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude the plural form. The inventions disclosed herein include the following embodiments: [1] A wound care product (200;300;400) comprising a backing layer (201;301;401) and an adhesive layer (202;302;402) having a skin-facing surface (203;403), wherein at least a portion of the skin-facing surface (203;403) of the adhesive layer (202;302;402) comprises an antimicrobial coating (204), characterized in that the antimicrobial coating (204) is soluble in an aqueous medium and the antimicrobial coating (204) contains chlorhexidine phosphate. [2] The wound care product according to [1], wherein at least 60%, preferably at least 80%, of the antimicrobial coating (204) is configured to dissolve within 3 hours of exposure to an aqueous medium. [3] The wound care product (200;300;400) according to [1] or [2] above, wherein the wound care product includes a release liner (206;404), the release liner (206;404) is removably attached to the skin-facing surface (203;403) of the adhesive layer (202;302;402). [4] The wound care product (200;300;400) according to any one of [1] to [3] above, wherein the wound care product (200;300;400) is a dressing (200;300) or a surgical drape, preferably an incision drape (400). [5] The wound care product (200; 300; 400) according to [4] above, wherein the wound care product is an incision drape (400) and the adhesive layer (402) contains a polyacrylate adhesive. [6] The wound care product (200;300;400) according to any one of [1] to [4] above, wherein the wound care product (200;300;400) is a dressing (200;300) and the adhesive layer (202;302) contains a silicone adhesive. [7] The wound care product (200;300;400) according to any one of [1] to [6] above, wherein the antimicrobial coating (204) is a discontinuous coating on the skin-facing surface (203;403) of the adhesive layer (202;302;402). [8] The concentration of chlorhexidine phosphate in the antimicrobial coating (204) is 5 to 1000 μg / cm³ 2 For example, 10-500 μg / cm³ 2 For example, 20-200 μg / cm³ 2 The wound care product (200;300;400) described in any one of the above [1] to [7]. [9] A wound care product (200;300;400) according to any one of [1] to [4] or [6] to [8], wherein the wound care product is a dressing (200;300), and the dressing (200;300) further comprises an absorbent pad (205;303) disposed between the backing layer (201;301;401) and the adhesive layer (202;302;402).

[10] The wound care product (200;300;400) according to [9] above, wherein the absorbent pad (205;303) comprises at least a second antimicrobial compound.

[11] The wound care product (200;300;400) according to any one of [1] to

[10] above, wherein the adhesive layer (202;302;402) comprises at least a third antimicrobial compound.

[12] A method for manufacturing wound care products (200;300;400), a) A wound care product (200;300;400) is provided, comprising a backing layer (201;301;401) and an adhesive layer (202;302;402) having a skin-facing surface (203;403), wherein the wound care product (200;300;400) optionally includes an absorbent pad (205;303) placed between the backing layer (201;301;401) and the adhesive layer (202;302;402). b) Prepare an aqueous solution of chlorhexidine phosphate by dissolving chlorhexidine in phosphoric acid and water. c) Applying the aqueous solution to at least a portion of the skin-facing surface (203;403) of the adhesive layer (202;302;402), d) Dry the aqueous solution on the skin-facing surface of the adhesive layer (202;302;402). A method for manufacturing wound care products (200; 300; 400) including [a specific substance].

[13] The method according to

[12] , wherein the pH of the aqueous solution of chlorhexidine phosphate is 4 to 6.

[14] The method according to either

[12] or

[13] , wherein the molar ratio of chlorhexidine to phosphate in the aqueous solution is 1:1 to 1:3, preferably 1:2.

[15] The method according to any one of

[12] to

[14] above, wherein the aqueous solution is applied by spray application to at least a portion of the skin-facing surface (203;403) of the adhesive layer (202;302;402).

[16] The method described above, e) Apply a release liner (206;404) to the skin-facing surface (203;403) of the adhesive layer (202;302;402). A method according to any one of the above

[12] to

[15] , further including the steps.

Claims

1. A wound care product (200;300;400) comprising a backing layer (201;301;401) and an adhesive layer (202;302;402) having a skin-facing surface (203;403), wherein at least a portion of the skin-facing surface (203;403) of the adhesive layer (202;302;402) includes an antimicrobial coating (204), The antibacterial coating (204) is soluble in an aqueous medium, and The antimicrobial coating (204) contains chlorhexidine phosphate, Here, chlorhexidine has the following chemical structure: 【Chemistry 1】 It has the following chemical structure, and its phosphate counterion has the following chemical structure: 【Chemistry 2】 A wound care product (200; 300; 400) characterized by having [a certain feature].

2. The wound care product according to claim 1, wherein at least 60% of the antimicrobial coating (204) is configured to dissolve within 3 hours of exposure to an aqueous medium.

3. The wound care product (200;300;400) according to claim 1, wherein the wound care product includes a release liner (206;404), the release liner (206;404) being removably attached to the skin-facing surface (203;403) of the adhesive layer (202;302;402).

4. The wound care product (200; 300; 400) according to claim 1, wherein the wound care product (200; 300; 400) is a dressing (200; 300) or a surgical drape.

5. The wound care product (200; 300; 400) according to claim 4, wherein the wound care product is an incision drape (400) and the adhesive layer (402) comprises a polyacrylate adhesive.

6. The wound care product (200;300;400) according to claim 1, wherein the wound care product (200;300;400) is a dressing (200;300), and the adhesive layer (202;302) comprises a silicone adhesive.

7. The wound care product (200;300;400) according to claim 1, wherein the antibacterial coating (204) is a discontinuous coating on the skin-facing surface (203;403) of the adhesive layer (202;302;402).

8. The wound care product (200; 300; 400) according to claim 1, wherein the concentration of chlorhexidine phosphate in the antimicrobial coating (204) is 5 to 1000 μg / cm².

9. The wound care product (200;300;400) according to claim 1, wherein the wound care product is a dressing (200;300), and the dressing (200;300) further comprises an absorbent pad (205;303) disposed between the backing layer (201;301;401) and the adhesive layer (202;302;402).

10. The wound care product (200; 300; 400) according to claim 9, wherein the absorbent pad (205; 303) comprises at least a second antimicrobial compound.

11. The wound care product (200;300;400) according to claim 10, wherein the adhesive layer (202;302;402) comprises at least a third antimicrobial compound.

12. A method for manufacturing a wound care product (200; 300; 400) according to any one of claims 1 to 11, a) A wound care product (200;300;400) is provided, comprising a backing layer (201;301;401) and an adhesive layer (202;302;402) having a skin-facing surface (203;403), wherein the wound care product (200;300;400) optionally includes an absorbent pad (205;303) placed between the backing layer (201;301;401) and the adhesive layer (202;302;402). b) Prepare an aqueous solution of chlorhexidine phosphate by dissolving chlorhexidine in phosphoric acid and water. c) Applying the aqueous solution to at least a portion of the skin-facing surface (203; 403) of the adhesive layer (202; 302; 402), d) Drying the aqueous solution on the skin-facing surface of the adhesive layer (202; 302; 402). A method for manufacturing wound care products (200; 300; 400) including [the specified element].

13. The method according to claim 12, wherein the pH of the aqueous solution of chlorhexidine phosphate is 4 to 6.

14. The method according to claim 12, wherein the molar ratio of chlorhexidine to phosphate in the aqueous solution is 1:1 to 1:

3.

15. The method according to claim 12, wherein the aqueous solution is applied by spray application to at least a portion of the skin-facing surface (203; 403) of the adhesive layer (202; 302; 402).

16. The method described above is e) Applying a release liner (206; 404) to the skin-facing surface (203; 403) of the adhesive layer (202; 302; 402). The method according to claim 12, further comprising the step.

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