Wound care products having antimicrobial 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] The present disclosure generally relates to a wound care product including a backing layer and an adhesive layer having a skin-facing surface, at least a portion of the skin-facing surface of the adhesive layer having an antimicrobial coating. [Background technology]

[0002] Infection is a common problem in chronic and surgical wounds. The surgical site or open wound is a favorable environment for bacteria to adapt and colonize. Bacterial infection within the wound or in the skin surrounding the wound can disrupt the normal wound healing process, resulting in a chronic, non-healing wound.

[0003] In the treatment of wounds, antimicrobial agents are often used to eliminate or reduce infection of the wound. Incorporation of antimicrobial agents into bandages and wound coverings can promote healing and eliminate or reduce the risk of infection of the wound. To this end, various types of antimicrobial dressings have been developed.

[0004] In surgical environments, so-called incision drapes are sometimes utilized to isolate the surgical site from non-sterile fields that may increase the risk of infection at the surgical site. The incision drapes are configured to be cut through during the surgical procedure.

[0005] In both the surgical environment and in wound care, infections caused by contaminating microorganisms need to be prevented.

[0006] For many wound care products, rapid delivery of antimicrobial agents is desirable because a slow, gradual release of the antimicrobial agent may cause bacteria present at the wound site or on the skin to adapt to the generally low antimicrobial concentrations.

[0007] Wound care products, such as dressings and incise drapes, typically contain a self-adhesive adhesive, also known as a pressure-sensitive adhesive (PSA). The purpose is to adhere to the wound and / or the skin surrounding the wound, thus securing the dressing in the desired position. A variety of adhesives may be used to affix the wound care product onto the skin. Some of the most common are acrylic adhesives, silicone adhesives, and hot melt adhesives. During assembly of the wound care product, the adhesive layer is typically covered by a release liner to protect the adhesive layer and the product from contamination prior to use. The product is typically sterilized before use in a surgical environment or before application to the patient's skin or wound.

[0008] An antimicrobial composition may be coated on the skin-facing surface of the adhesive layer to allow for rapid release and therefore rapid effectiveness.

[0009] Antibacterial dressings are known that contain a soluble silver salt coating on the adhesive surface, based on Patent Documents 1 and 2. In these dressings, silver is released as positively charged ions when in contact with liquid. While the release of silver has an antibacterial effect and can reduce the bacterial concentration at the wound site, its effect on fungi, such as Candida albicans, and the prevention and elimination of bacterial biofilms are limited.

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

[0011] When applying an antimicrobial coating to the adhesive layer of a wound care product, the coating is considered to have the adhesive properties or " It is important not to lose the "tackiness."

[0012] Furthermore, it is important that the antimicrobial coating remain 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 that include an antimicrobial coating is that once the release liner is removed from the wound care product, the antimicrobial composition is removed with the release liner and thereby removed from the adhesive layer. As a result, the antimicrobial effectiveness of the dressing is eliminated or at least significantly reduced.

[0013] Thus, there is a need to overcome the above-mentioned difficulties with antimicrobial wound care products, and more particularly, to provide a wound care product that provides rapid delivery of antimicrobial compounds, the benefits of which remain within the wound care product even after the product has degraded, i.e., after the release 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) Summary of the Invention [Problem to be solved by the invention]

[0015] In light of the above-mentioned problems, it is an object of the present disclosure to provide an improvement relating to antimicrobial wound care products, and in particular to providing products that include a soluble antimicrobial coating, where such coating remains on the adhesive layer after the release liner is 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 portion of the skin-facing surface of the adhesive layer comprises an antimicrobial coating, the coating being soluble in an aqueous medium, and the coating comprising chlorhexidine phosphate. Effect of the Invention

[0017] The antimicrobial coating is soluble in aqueous media. Therefore, when in contact with wound exudate or wet skin, the antimicrobial coating dissolves and allows for the rapid initial release of chlorhexidine phosphate, which can eradicate bacteria present in the wound or surgical site, or on the skin surrounding the wound or incision. This prevents the growth of infectious microorganisms on the surface of the adhesive layer. This avoids colonization of the wound site and wound care product.

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

[0019] Although numerous antimicrobial compounds are provided as coatings on the adhesive skin contact layer of wound care products and may have antimicrobial activity against a variety of bacteria, many coatings suffer from migration of the antimicrobial coating from the adhesive surface to the release liner, resulting in the antimicrobial efficacy being lost within the dressing.

[0020] Chlorhexidine is a safe and powerful antibacterial agent. The inventors have tested various types of chlorhexidine salts and have concluded that chlorhexidine phosphate (CHP) has both the ability to remain on the adhesive layer after the release liner is removed, and also the ability to dissolve easily when contacted with wound exudate. The surprising discovery that a soluble coating containing chlorhexidine phosphate remains on the adhesive layer, i.e., within the wound care product, makes the product of the present disclosure a commercially attractive solution for preventing infection 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, and concluded that CHP is surprisingly effective against both gram-negative and gram-positive bacteria, as well as Candida albicans. Furthermore, CHP is effective against bacterial biofilms.

[0022] In an embodiment, the antimicrobial coating is configured such that at least 60%, preferably at least 80%, is dissolved within 3 hours of exposure to an aqueous medium.

[0023] Thus, a rapid antimicrobial effect can be established at the wound site and the antimicrobial coating is completely dissolved upon contact with wound exudate.

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

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

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

[0027] Dressings are typically applied to open wounds or scars in need of healing. Incise drapes are designed to be applied and cut through during a surgical procedure. With both types of products, prevention of infectious organisms at the wound or skin site is desirable.

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

[0029] However, it is contemplated that the adhesive layer of the drape may include other types of adhesives, such as silicone-based adhesives.

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

[0031] Such adhesives are skin friendly, allowing the dressing to be removed and reapplied without harming the skin.

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

[0033] Thus, the antimicrobial coating does not completely cover the surface of the skin-facing side of the adhesive layer, which is beneficial in order to avoid compromising 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 maintaining the adhesive properties of the adhesive layer.

[0035] In an embodiment, the concentration of the chlorhexidine phosphate in the antimicrobial coating is from 5 to 1000 μg / cm 2 , such as from 10 to 500 μg / cm 2 , for example from 20 to 200 μg / cm 2 .

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

[0037] Dressings of the present disclosure may be absorbent or non-absorbent.

[0038] In embodiments where the dressing is non-absorbent, the dressing comprises a backing layer and an adhesive skin contact layer. Such dressings can 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, can be treated by applying a silicone-based adhesive dressing. Prevention of infection is an important component of treatment.

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

[0040] Many wounds, particularly infected wounds, can exude large amounts of exudate, and so it is generally necessary to utilize a dressing that includes an absorbent pad. The absorbent pad may include any absorbent material, such as absorbent fibers, gels, foams, etc. Preferably, the absorbent pad includes a hydrophilic foam, such as a hydrophilic polyurethane foam. The absorbent pad may include one or more pad-forming layers.

[0041] The dressings of the present disclosure may be utilized in all wound care settings where an antimicrobial effect is desired. The dressings may be utilized, for example, in negative pressure wound therapy (NPWT) applications. In these cases, the dressings are connected to a negative pressure source, e.g., a pump, which applies a negative pressure, e.g., a vacuum, through the dressing. The dressings, when used in negative pressure wound therapy, may be absorbent or non-absorbent. In the latter case, the dressings may act as a secondary dressing and are typically used in conjunction with a wound filler, e.g., gauze or foam, that is first applied to an open cavity wound.

[0042] To enhance the antimicrobial effectiveness of the dressing, the absorbent pad may contain at least one second antimicrobial compound.

[0043] Providing a second antimicrobial compound within the pad is generally associated with a slower, more gradual release of the antimicrobial agent compared to the more rapid release provided by a soluble antimicrobial coating. For various applications, it may be desirable to configure the product such that rapid destruction of bacteria is achieved by the coating and a slower release is achieved by the antimicrobial agent present within the absorbent pad.

[0044] In an embodiment, the adhesive layer comprises at least one third antimicrobial compound. In other words, the adhesive layer of the dressing or incise drape may comprise an antimicrobial compound. Providing an antimicrobial agent within the adhesive layer is associated with a slower release rate and is advantageously combined with the rapid release provided by the 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 and third antimicrobial compounds may be the same or different. The at least one second and third antimicrobial compound may be chlorhexidine phosphate.

[0046] According to another aspect, there is provided a method of producing a wound care product comprising the steps of: a) providing a wound care product comprising a backing layer and an adhesive layer having a skin-facing surface, said wound care product optionally comprising an absorbent pad disposed between said backing layer and said adhesive layer; b) preparing an aqueous solution of chlorhexidine phosphate by dissolving chlorhexidine in phosphoric acid and water; c) depositing the aqueous solution onto 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 producing a wound care product is provided, comprising:

[0047] The methods of the present disclosure allow for a simple, yet efficient method for producing antimicrobial wound care products.

[0048] The aqueous solution is prepared by dissolving chlorhexidine in phosphoric acid and water, thus obtaining a dissolved solution of chlorhexidine phosphate.

[0049] During the drying process, the aqueous phase of the coating is removed. However, upon contact with skin moisture or wound fluids, the dried coating can dissolve and release chlorhexidine phosphate into the wound and onto the skin surrounding the wound.

[0050] In an embodiment, the aqueous solution of chlorhexidine phosphate has a pH of 4-6.

[0051] Infectious bacteria generally grow at higher pH values, such as about 7.5 to 8.5, and therefore the low pH of the coating solution may provide an inhospitable environment for the infectious bacteria to grow and colonize, and may also render the bacteria more susceptible to the antimicrobial effects provided by chlorhexidine phosphate.

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

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

[0054] Spray application is a simple coating method that is associated with a variety of advantages. For example, the ability to spray the solution onto the adhesive surface allows for more controlled deposition of the coating. The deposition can be localized within specific dressing areas and the size of the droplets on the skin-facing surface can be controlled.

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

[0056] In an embodiment, the method comprises: e) applying a release liner to the skin-facing surface of the adhesive layer. The method further comprises the steps of:

[0057] The release liner is configured to be releasably attached to the adhesive layer (and coating) and is configured to be removed prior to application of the dressing onto the patient's skin or wound.

[0058] Further features and advantages of the present disclosure will become apparent upon studying the appended claims and the following description. It will be apparent to one skilled in the art that different features of the present disclosure may be combined to create embodiments other than those described below without departing from the scope of the present disclosure.

[0059] Various aspects of the present disclosure, including specific features and advantages thereof, will be readily understood from the following detailed description and the accompanying drawings. [Brief description of the drawings]

[0060] [Figure 1] FIG. 1 is a schematic diagram illustrating the problems associated with prior art dressings. [Diagram 2] FIG. 2 is an exploded view of a dressing according to an exemplary embodiment of the present disclosure. [Diagram 3] FIG. 3 is a schematic perspective view of a dressing according to an exemplary embodiment of the present disclosure, the dressing including multiple padding layers. [Figure 4a] FIG. 4a is a schematic diagram illustrating an incise drape according to an exemplary embodiment of the present disclosure. [Figure 4b] FIG. 4b is a cross-sectional view of the incise drape of FIG. 4a. [Diagram 5] FIG. 5 is a schematic diagram illustrating the steps of a method according to an exemplary embodiment of the present disclosure. [Figure 6a] FIG. 6a is an optical microscope image showing the skin-facing surface of the wound contact layer containing an antimicrobial chlorhexidine phosphate (CHP) coating after sterilization and removal of the release liner. [Figure 6b] FIG. 6b is an optical microscope image showing the release liner removed from the wound contact layer of FIG. 6a. [Figure 6c] FIG. 6c is an optical microscope image showing the skin-facing surface of the wound contact layer containing an antimicrobial chlorhexidine gluconate (CHG) coating after sterilization and removal of the release liner. [Figure 6d] FIG. 6d is an optical microscope image showing the release liner removed from the wound contact layer of FIG. 6c. [Figure 7] FIG. 7 is a light microscope image showing the skin-facing surface of an incise drape containing an antimicrobial chlorhexidine phosphate (CHP) coating after sterilization and removal of the release liner. [Figure 8a] FIG. 8a shows the antibacterial efficacy against P. aeruginosa (PaO1) by samples comprising polyurethane foam and a wound contact layer, with and without an antibacterial coating comprising chlorhexidine phosphate, and with and without silver in the polyurethane foam. [Figure 8b]FIG. 8b shows the antimicrobial efficacy against S. aureus (ATCC 6538) by samples comprising polyurethane foam and a wound contact layer, with and without an antimicrobial coating comprising chlorhexidine phosphate, and with and without silver in the polyurethane foam. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0061] The present disclosure will now be more fully described with reference to the accompanying drawings, in which presently preferred embodiments of the disclosure are illustrated. However, the present disclosure may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided for thoroughness and completeness, and will fully convey the scope of the present disclosure to those skilled in the art.

[0062] The problem underlying the present disclosure is illustrated diagrammatically 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 releasable 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 arrows in Figure 1) and transferred to the surface of the release liner portion (see 103). As a result, the antimicrobial effect of the dressing is lost.

[0063] A wound care product according to an exemplary embodiment is conceptually shown in Figure 2. The wound care product is a dressing 200 including a backing layer 201 and an adhesive layer 202 having a skin-facing surface 203, at least a portion of the skin-facing surface 203 of the adhesive layer 202 includes an antimicrobial coating 204, the antimicrobial coating 204 is soluble in an aqueous medium, and the coating 204 includes chlorhexidine phosphate.

[0064] The adhesive layer has an opposing surface (not shown) that faces the backing layer 201. Chlorhexidine has the following chemical structure: [ka] It has.

[0065] The phosphate counterion has the following chemical structure: [ka] It has.

[0066] 2, the dressing 200 further comprises an absorbent pad 205 disposed between the backing layer 201 and the adhesive layer 202. Thus, the dressing 200 is absorbent. The adhesive layer 202 may, for example, be coated onto the absorbent pad 205 or the adhesive layer may be glued or laminated to the absorbent pad 205.

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

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

[0069] The antimicrobial coating 204 dissolves when exposed to wound exudate and releases the chlorhexidine phosphate to the wound site, thereby achieving rapid antimicrobial efficacy.

[0070] The term "soluble in aqueous media" as used herein means that the coating dissolves upon contact with an aqueous medium. The aqueous solution may be water. Thus, the antimicrobial coating dissolves quickly 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 as an aqueous solution to the surface of the adhesive layer and subsequently dried. Upon contact with wound exudate or aqueous media, the dried coating will dissolve and be released from the adhesive layer.

[0071] In an embodiment, 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.

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

[0073] Thus, the antimicrobial coating of the present disclosure allows for rapid release of the active antimicrobial agent (CHP) and rapid antimicrobial efficacy.

[0074] The antimicrobial coatings of the present disclosure contain dissolved chlorhexidine phosphate salts, in other words, when the coating is applied, typically in the form of an aqueous solution, there are substantially no undissolved CHP particles, allowing for rapid dissolution (and rapid effectiveness) 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 effective against Candida albicans (see Example 1). Thus, the wound care product of the present disclosure is a promising and commercially viable antimicrobial product that can be used against several microbial species. The wound care product also meets the more stringent (governmental) requirements that antimicrobial wound care products must meet upon commercialization.

[0076] Furthermore, the inventors have found that, in comparison to other commercially available chlorhexidine salts (and other antimicrobial agents), a coating including chlorhexidine phosphate has the ability to remain on the skin-facing surface 203 of the adhesive layer 202 of the dressing even when the release liner is removed from the dressing. Thus, the antimicrobial benefit remains within the dressing upon removal of the release liner.

[0077] The release liner of Figure 2 includes two release liner portions 206a and 206b. The first release liner portion 206a is disposed above the second release liner portion 206b. The second release liner portion 206b is folded over such that the first release liner portion 206a overlaps and extends beyond the folded edge of the second release liner portion 206b. Thus, a first tab and a second tab are formed that can be grasped by a caregiver or patient to facilitate removal of the release liner.

[0078] Without wishing to be bound by theory, it is believed that the lower hygroscopicity of chlorhexidine phosphate compared to, for example, chlorhexidine gluconate, is responsible for the significantly lower amount of chlorhexidine phosphate migrating from the adhesive layer to the release liner.

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

[0080] Dressings including polyurethane foam pads are capable of absorbing large amounts of wound exudate. Infected wounds exude large amounts of exudate, and the dressing must be able to adequately manage such exudate.

[0081] Polyurethane foams may be prepared, for example, from compositions including prepolymers based on hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI) or methylene diphenyl diisocyanate (MDI).

[0082] The adhesive layer may also be referred to as the "wound contact layer" or "skin contact layer." Preferably, the adhesive layer of the dressing comprises a silicone-based adhesive. Such an adhesive is gentle to the skin and allows removal of the dressing without incurring damage to the skin. The adhesive layer has a skin-facing surface and an opposing surface. The opposing surface faces the backing layer of the dressing. The opposing surface may be placed in contact with the backing layer or an absorbent pad, if present.

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

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

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

[0086] Depending on the application mode of the coating, the coating may be discontinuous, ie, not completely covering 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] A discontinuous coating 204 is generally preferred to avoid compromising the adhesion to the skin provided by adhesive layer 202 .

[0089] The concentration of chlorhexidine phosphate in the antimicrobial coating 204 may be 5-1000 μg / cm2, such as 10-500 μg / cm2, such as 20-200 μg / cm2. In an embodiment, the concentration of chlorhexidine phosphate in the antimicrobial coating 204 is 50-200 μg / cm2, such as 10-130 μg / cm2, such as 20-100 μg / cm2.

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

[0091] A so-called "border dressing" is shown in Figure 3. The dressing 300 may include a backing layer 301, an adhesive layer 302, and an absorbent pad 303 disposed 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 contours of the absorbent pad 303 to form a border 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 particular material, but may generally comprise an absorbent foam or gel. It may also comprise a superabsorbent material, such as superabsorbent polymers (SAP) or superabsorbent fibers (SAF).

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

[0094] 3, the absorbent pad 303 may include a first absorbent layer 305, a liquid distribution layer 306, and a second absorbent layer 307. Typically, the liquid distribution layer 306 is disposed 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 comprise a foam. Suitable foam materials for use in the first absorbent layer 305 include, but are not limited to, polyurethane foam.

[0096] The second absorbent layer 307 may be a superabsorbent layer. Thus, the second absorbent layer may comprise superabsorbent polymers (SAP) or superabsorbent fibers (SAF).

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

[0098] The layers can be joined by gluing, lamination, for example using pressure and heat.

[0099] The absorbent pad may contain additional layers such as liquid transport layers, various combinations of foam layers and nonwoven layers laminated together.

[0100] Referring to FIG. 3, layer 305 may comprise an absorbent foam, layer 306 may be a liquid acquisition layer, and layer 307 may be a superabsorbent layer.

[0101] Such a layered pad structure prevents fluids from accumulating adjacent to the skin, improving the fluid handling of the dressing. Most wounds contain some exudate, but the level of exudate varies widely. In chronic wounds, the amount of exudate produced is quite high due to persistent inflammation. A dressing having the above structure is suitable for handling large amounts of exudate and also for preventing maceration of the skin surrounding the wound. As such, the dressing is particularly suitable for preventing infection.

[0102] The adhesive layer 302 may be a laminate including at least one polymeric film and an adhesive silicone layer, the adhesive silicone layer being placed 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 comprise, for example, polyethylene, polyamide, or polyester polyurethane. Preferably, the polymeric film comprises polyurethane. The polyurethane film may have a thickness of 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 the adhesive layer 302 and / or in the adhesive layer 202 described in connection with FIG. 2 include two-component RTV systems such as Liveo MG-7-9960 (DuPont) and SilGel 612 (Wacker Chemie AG) as described herein, as well as NuSil silicone elastomers. In an embodiment of the invention, the adhesive may comprise a soft silicone gel having a softness (penetration) of, for example, 8 to 22 mm, for example 12 to 17 mm, as measured by a method based on ASTM D 937 and DIN 51580. The method is described in US Pat. No. 5,999,336. 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 FIG. 3, the adhesive layer 302 may include a plurality of 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 a plurality of apertures 308 in the area underlying the absorbent pad 303, but is free of apertures in the area forming the interface 304. The absence of apertures in the interface of the dressing is beneficial for improving adhesion at the interface 304 of the dressing, and thus improving the stay ability 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 comprising chlorhexidine phosphate is typically provided on the non-apertured portion of the skin-facing surface of the adhesive layer (not shown). Preferably, the antimicrobial coating is provided in at least the area of ​​the adhesive layer underlying the absorbent pad 303.

[0109] In the various embodiments described above, the backing layer may be a vapor-permeable thin film, sheet or membrane. Examples of suitable materials for the backing 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. Preferably, the backing layer is a polyurethane film having a thickness of 5 to 40 μm, for example 15 to 25 μm.

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

[0111] Alternatively, or in addition, adhesive layer 302 includes at least one third antimicrobial compound.

[0112] The at least one second antimicrobial compound 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 an embodiment, the second and / or third antimicrobial compound may be selected from the group including silver salts, chlorhexidine salts, polyhexamethylene biguanide, benzethonium chloride, polydiallyldimethylammonium chloride, and the like.

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

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

[0116] In an 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 of FIG. 3 or into the foam pad shown in FIG. 2. At least one second antimicrobial compound may be chemically bonded to the structure or inner surface of the foam, such as the pores. The second antimicrobial compound may be bonded, for example, to the charged inner surface of the foam.

[0117] It is contemplated that a second antimicrobial compound may be incorporated into the foam by adding the second antimicrobial compound to the prepolymer prior to the foaming process step, such that the antimicrobial compound becomes incorporated into the foam and bound within the foam cell walls.

[0118] Alternatively, at least one second antimicrobial compound is optionally provided as a coating on a layer of the absorbent pad prior to bonding or lamination with one or more pad-forming layers or other pad layers.

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

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

[0121] The concentration of the second and / or third antimicrobial compound is generally greater than the concentration of chlorhexidine phosphate in the antimicrobial coating. The second and / or third antimicrobial compound may have a slower release profile, thus providing a longer lasting antimicrobial effect.

[0122] A wound care product according to an exemplary embodiment is conceptually shown in Figures 4a and 4b. The wound care product is an incise drape 400 in Figure 4, and area 406 shows generally where the drape is intended to be cut during a surgical procedure.

[0123] As used herein, "incise drape" means a surgical drape used during a surgical procedure that is configured to be cut out. An incise drape, sometimes called a "surgical incise drape," is placed against the patient's skin and isolates the surgical site from non-sterile areas that may increase the risk of infection at the surgical site.

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

[0125] Antimicrobial coatings are advantageously used on incise drapes during surgical procedures to prevent and combat contaminating microorganisms from infecting the incision site.

[0126] The term "backing layer" as used herein in the context of a surgical drape, such as an incise drape, refers to the top layer of the wound care product, i.e., the layer away from the patient's skin. The backing layer of the drape may comprise, for example, polyurethane, polyester, and / or polypropylene.

[0127] The adhesive layer 402 may comprise any suitable adhesive and is in no way limited to a particular type of adhesive. Typically, the adhesives used are silicone-based adhesives or polyacrylate-based adhesives. Preferably, in the case of an incise drape, the adhesive layer 402 comprises a polyacrylate-based adhesive.

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

[0129] As shown in Figure 4, the incise drape includes a release liner 404 configured to be removed prior to application of the drape. 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. It is contemplated that the release liner 404 could have a larger cross-sectional area to facilitate removal from the drape prior to use.

[0130] As shown in FIG. 4a, the margins of the adhesive layer 402 can form handle portions 405a-b, and the caregiver can grasp these handle portions to remove the release liner 404 from the adhesive layer 402. Surgical drapes generally have a relatively large size and often require the assistance of two caregivers for the procedure. One caregiver can grasp the first handle portion 405a of the drape while the other caregiver can grasp the second handle portion 405b, and gradually remove the release liner from the adhesive layer, thereby exposing the adhesive surface. The incise drape is then applied to the patient, followed by smoothing to prevent wrinkles from forming. The handle portions 405a-b can be formed from any material. For example, a polymer film, such as polyethylene, can be utilized. The release liner 404 is not bonded 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 particular material and any material known to one of ordinary skill in the art may be utilized, in an embodiment, the release liner comprises a silicone coated paper or a polyester liner.

[0132] Antimicrobial coatings prevent the migration of contaminating microorganisms into an incision or wound site. Prior to application, the skin is typically cleansed to prevent contamination, but pores may still contain bacteria, which can migrate to the incision site. Thus, antimicrobial coatings prevent surgical site contamination.

[0133] Referring to FIG. 5, a second aspect of the present disclosure is shown generally and is directed to a method of manufacturing a wound care product.

[0134] This method is a) providing a wound care product comprising a backing layer and an adhesive layer having a skin-facing surface, the wound care product optionally including an absorbent pad disposed between the backing layer and the adhesive layer (step 501); b) preparing an aqueous solution of chlorhexidine phosphate by dissolving chlorhexidine in phosphoric acid and water (step 502); c) depositing the aqueous solution onto at least a portion of the skin-facing surface of the adhesive layer (step 503); d) Allowing the aqueous solution to dry on the skin-facing surface of the adhesive layer (step 504). This includes:

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

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

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

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

[0139] This coating technique is beneficial because it allows flexibility depending on the dressing or support to be used and on the type of wound to be treated. It is also a simple means to apply the coating. Selected areas of the adhesive layer may be coated and the size of the droplets on the surface may be controlled to avoid interfering with the adhesive properties of the adhesive skin contact layer.

[0140] Drying is accomplished by means well known to those skilled in the art, for example, the coating can be heated to promote evaporation of the liquid from the coating.

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

[0142] This range creates an unfavorable environment for infectious microorganisms to grow and colonize.

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

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

[0145] The method is: e) applying a release liner to the skin-facing surface of the adhesive layer. The method may further include a step (step 505). EXAMPLES

[0146] Example 1: Antibacterial effect of CHP Test organisms: P. aeruginosa ATCC 9027 (bacteria), S. aureus ATCC 6538 (bacteria), C. albicans ATCC 10231 (fungi), P. aeruginosa ATCC PAO1 (bacteria, Example 1b) Test time: 24 hours for bacteria and 48 hours for fungi Starting inoculum: 1x10^6 CFU / ml for bacteria and 4x10^6 CFU / ml for fungi.

[0147] Example 1a: Minimum concentration required to eliminate microorganisms in solution Tests were performed in solution to compare the efficacy of silver sulfate, chlorhexidine phosphate, and chlorhexidine gluconate using SWF (a simulated wound fluid mixed in equal proportions with fetal bovine serum (FBS) and peptone water (PW)) to represent 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)) as the test medium. The aim was to define the minimum concentration of antimicrobial required to kill a particular microorganism. Test microorganisms were suspended in SWF to which different concentrations of antimicrobial substances were added before subculturing in well microtiter plates. Positive and negative controls were used to demonstrate sufficient microbial growth over the incubation period and medium sterility.

[0148] The results showed that up to 190 times more silver was required to kill Candida albicans than chlorhexidine phosphate, and 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: Reduction in biofilm counts upon contact with CHP solutions Tests were performed in solution to evaluate the effectiveness of chlorhexidine phosphate (CHP) against biofilms cultured on collagen matrices, using SWF as the test medium.

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

[0151] The results, shown in Table 2 below, show that CHP solutions at concentrations of 37 μM, 75 μM, and 150 μM, concentrations that can be achieved by spraying onto the silicone contact layer, reduced the amount of biofilm, and showed a log reduction greater than the FDA requirement of a reduction of 4. Thus, chlorhexidine phosphate (CHP) is an efficient antimicrobial agent against bacterial biofilms, especially compared to, for example, silver sulfate, which is less effective against biofilms. [Table 2]

[0152] Sample 1C: Antibacterial effect of CHP sprayed onto silicone surface 75μg / cm 2 The efficacy of the prototype coated with silver sulfate at 45 μg / cm 2 and 75 μg / cm 2 Tests were performed on coated and sterilized wound adhesives for comparison with a prototype coated with 100% chlorhexidine phosphate. 2 disks were formed and placed in the wells in contact with 2 mL of SWF containing a solution of the microorganism in suspension (the same microorganism as used in Example 1a).

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

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

[0155] Positive and negative controls were used to demonstrate sufficient microbial growth over the incubation period and medium sterility. Microbial growth was assessed on the silicone layer, i.e., on the skin-facing side, and in suspension in liquid.

[0156] 45μg / cm 2 and 75 μg / cm 2 The chlorhexidine phosphate prototype sprayed at a concentration of 100 mg / mL demonstrated complete elimination of all microorganisms both on the silicone surface and in solution. Silver sulfate did not achieve even a log 4 reduction from the inoculum size against Staphylococcus aureus, so this was not evaluated further against other microorganisms.

[0157] Example 2: Migration of antimicrobial agents to release liners To compare the migration of antimicrobial agents to release liners, tests were performed on coated and sterilized wound adhesives.

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

[0159] A comparison was made between prototypes coated with an antimicrobial solution of chlorhexidine phosphate (0.56% by weight) and sprayed with an antimicrobial solution of chlorhexidine gluconate (0.56% by weight). The spraying was carried out using the same parameters and with the same equipment as described in Example 1. After spraying, the samples were sent to a production site for sterilization where they were subjected to the typical sterilization cycle required for antimicrobial products.

[0160] After sterilization, the sterilized samples were observed by optical microscopy (Olympus Zoom high performance stereo microscope SZH). The results showed that only a small amount of chlorhexidine phosphate (CHP) was observed migrating from the silicone surface of the wound contact layer to the release liner (see Figures 6a-6b). However, in the case of the wound contact layer coated with chlorhexidine gluconate (CHG), the majority of the CHG coating migrated to the release liner. Some areas of the skin-facing surface showed near complete migration, leaving most of the silicone area stripped of antimicrobial CHG (Figures 6c-6d).

[0161] To better understand antimicrobial migration, sterile samples were punched out to a 7 cm 2 Three pieces of the silicone-coated film (wound contact layer) and the release liner were separated and placed in the wells in contact with 2 ml of an aqueous solution for a time estimated to allow sufficient dissolution of the CHP and CHG antimicrobial particles. After calibration of the equipment to the solution, the concentrations of CHP and CHG in the different wells were assessed by liquid chromatography-mass spectrometry to quantify the amount of antimicrobial present on the silicone and the amount that had transferred to the release liner.

[0162] The results showed that after sterilization, over 66% of the CHP sprayed onto the wound contact layer was present on the silicone surface and thus available for antimicrobial activity. Less than 36% of the sprayed CHG was left on the silicone, and the majority of the CHG (over 64%) was transferred to the release liner. Thus, when the release liner was removed, there was a significant loss of antimicrobial efficacy.

[0163] Example 3: Presence of CHP on incise drapes observed by light microscopy Testing was also performed on an incise drape (921014-00 BNS Incise Drape from Moelnlycke Health Care) spray-coated with CHP to confirm potential migration of the antimicrobial agent to the release liner. One prototype was used for testing, and utilizing the same spray equipment described in Examples 1-2 above, the adhesive side of the incise drape (containing the polyacrylate adhesive) was sprayed with a solution of CHP (0.56 wt%). After drying, the samples were observed by optical microscopy (Olympus Zoom high performance stereo microscope SZH). The results showed that a high concentration of CHP was present on the incise drape surface when the release liner was removed (see Figure 7).

[0164] Example 4: Dissolution Rate of Antimicrobial Coatings Tests were performed on coated and sterilized wound adhesives to evaluate the dissolution rate of the antimicrobial coating, i.e. the release rate of the antimicrobial compounds. Comparisons were made between prototypes sprayed with an antimicrobial solution of chlorhexidine phosphate (0.56% by weight) and prototypes sprayed with an antimicrobial solution of chlorhexidine acetate (0.68% by weight). The spray application was performed using the same parameters and with the same equipment as described for Examples 1 and 2 above. After spraying, samples were sent to a production site for sterilization, where they were subjected to the typical sterilization cycle required for antimicrobial products.

[0165] After sterilization, the prototype was punched out to produce a 7 cm2 Three pieces of the silicone coated film (wound contact layer) and release liner were separated and placed into wells in contact with 2 ml of aqueous solution for 3 hours, then removed and placed into new wells for 24 hours to assess immediate (>3 hours) and short-term (>24 hours) dissolution.

[0166] After calibration of the equipment to the solutions, the concentrations of CHP and CHAc in the different wells were assessed by liquid chromatography-mass spectrometry to quantify the amount of antimicrobial coating that was immediately or short-term dissolvable.

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

[0168] These studies demonstrated that CHP has a high dissolution rate, as compared to, for example, CHAc, which has a lower dissolution rate, thus allowing for rapid release and rapid antimicrobial effect.

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

[0170] The Tack Rolling Ball test was performed on sterile wound contact layers (as described above) that had been sprayed with chlorhexidine phosphate at 15, 45 and 75 μg / cm2, respectively.

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

[0172] Example 6: Migration of CHP from a release liner Additional studies were performed to further evaluate the migration of chlorhexidine phosphate from the wound contact layer to the release liner.

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

[0174] The test was carried out as described in Example 2 with some deviations, namely, that the CHP coating was applied to a 50 gsm silicone adhesive by spray application (Air Atomizing nozzle from Sprayin System Co.) followed by an in-line drying step under a hood. Additionally, the sample size of each specimen was 3.1 cm2 and the test was carried out on 4 specimens. The wound contact layer and its release liner were separated and placed in a well with 1 ml of water for 24 hours.

[0175] As shown in Example 2, liquid chromatography-mass spectrometry (LCMS) was used to quantify the amount of antimicrobial agent (CHP) present on the wound contact layer, i.e., on the silicone adhesive, as well as the amount of CHP transferred to the release liner.

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

[0177] Example 7: Antibacterial Efficacy of Samples Containing CHP Coating and Silver-Containing Polyurethane Foam 10 each 6 CFU / mL suspensions of P. aeruginosa (PaO1) and S. aureus (ATCC6838) were prepared in heat-inactivated SWF and inoculated into well plates in a volume of 145 μL. Triplicates of each sample with a size of 2.5 cm2 were placed on top of each inoculum with the wound contact layer facing the inoculum and incubated at 35° C. for 24 hours.

[0178] Each of the test samples included a polyurethane foam and a wound contact layer comprising 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 loaded with silver in an amount of approximately 1.2 mg / cm2 (samples A and B below). Approximately 45 μg / cm2 2 The CHP coating was applied to the wound contact layer, i.e., the silicone adhesive layer, by spray application at a concentration of: Spray application was carried out using the same parameters and with the same equipment as described for Example 6 above.

[0179] Microbial growth was assessed throughout the sample, ie, in the wound contact layer and in the silver-containing foam.

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

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

[0182] Sample C included polyurethane foam without any antimicrobial agent with an adhesive skin contact layer that did not include an antimicrobial coating.

[0183] As shown in FIG. 8a, a complete elimination of P. aeruginosa was observed for the sample containing silver in the polyurethane foam and CHP coated on the wound contact layer (Sample A). Thus, a combined effect of having silver in the foam and CHP in the coating was observed. Using these test conditions, the bacterial concentration remained at the inoculum for the sample containing silver in the polyurethane foam and no CHP on the wound contact layer (Sample B). Thus, the presence of silver in the foam inhibited the growth of P. aeruginosa, but did not reduce the bacterial count as in Sample A. The control sample without antimicrobial (Sample C) reached a bacterial count of about Log8, which is a 2-Log increase from the starting inoculum.

[0184] A similar combined effect was observed against S. aureus (see Figure 8b).

[0185] The terms, definitions, and embodiments of all aspects of this disclosure apply mutatis mutandis to other aspects of this disclosure.

[0186] Although this disclosure has been described with reference to specific exemplary embodiments thereof, many different alterations, modifications and the like will become apparent to those skilled in the art.

[0187] Variations of the disclosed embodiments can be understood and effected by those skilled in the art in practicing the disclosure, from a study of the drawings, the disclosure, and the appended claims. Moreover, in the claims, "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plural form.

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 said skin-facing surface (203; 403) of said adhesive layer (202; 302; 402) comprises an antimicrobial coating (204), characterized in that said antimicrobial coating (204) is soluble in an aqueous medium and that said antimicrobial coating (204) comprises chlorhexidine phosphate.

2. 10. The wound care product of claim 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. 3. The wound care product (200; 300; 400) of claim 1 or 2, wherein the wound care product comprises 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. 2. The wound care product (200; 300; 400) of claim 1, wherein the wound care product (200; 300; 400) is a dressing (200; 300) or a surgical drape, preferably an incise drape (400).

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

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

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

8. 2. A wound care product (200; 300; 400) according to claim 1, wherein the concentration of chlorhexidine phosphate in the antimicrobial coating (204) is between 5 and 1000 μg / cm2, such as between 10 and 500 μg / cm2, for example between 20 and 200 μg / cm2.

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

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

11. 11. The wound care product (200; 300; 400) of claim 1, 9 or 10, wherein said adhesive layer (202; 302; 402) comprises at least a third antimicrobial compound.

12. A method for producing a wound care product (200; 300; 400), comprising the steps of: a) providing 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), said wound care product (200; 300; 400) optionally comprising an absorbent pad (205; 303) disposed between said backing layer (201; 301; 401) and said adhesive layer (202; 302; 402); b) preparing an aqueous solution of chlorhexidine phosphate by dissolving chlorhexidine in phosphoric acid and water; c) depositing said aqueous solution onto at least a portion of said skin-facing surface (203; 403) of said adhesive layer (202; 302; 402); d) drying said aqueous solution on said skin-facing surface of said adhesive layer (202; 302; 402).

20. A method for producing a wound care product (200; 300; 400) comprising:

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

14. 14. The method according to any one of claims 12 or 13, wherein the molar ratio of chlorhexidine:phosphate in the aqueous solution is from 1:1 to 1:3, preferably 1:

2.

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

16. The method further comprising: e) applying a release liner (206; 404) to the skin-facing surface (203; 403) of the adhesive layer (202; 302; 402); The method of claim 12 further comprising the steps of:

Images