EP4267064A1

EP4267064A1 - Improved plaster

Info

Publication number: EP4267064A1
Application number: EP21840153.7A
Authority: EP
Inventors: Andreas Jetter
Original assignee: Apaloo GmbH
Current assignee: Apaloo GmbH
Priority date: 2020-12-22
Filing date: 2021-12-22
Publication date: 2023-11-01
Also published as: CN116669673A; DE102020134781B4; WO2022137177A1; AU2021405412A1; KR20230121116A; DE102020134781A1; US20240050380A1

Abstract

The method for producing a plaster comprises the following steps: (1) providing a substrate material; (2) coating an underside of the substrate material with a suitable non-UV-curing acrylate adhesive, which is used here in the form of a solution of a polyacrylate in an organic solvent or solvent mixture, wherein the solvent or solvent mixture is used in an amount of 25 to 70 wt.%; (3) fabricating the plaster; (4) producing a grid structure on the plaster such that this comprises a plurality of crossing strips. According to the invention, the adhesive is applied at a temperature of 90°C to 120°C over a time of 5 s to 60 s, and the plaster is activated, before and/or after the adhesive is applied, by repeated irradiation of the underside using ultraviolet light.

Description

Improved Patch

introduction

The invention relates to the field of medical technology. More specifically, the invention relates to a method of making an improved patch, and a patch made by that method.

State of the art and disadvantages

Adhesive bandages, also known as band-aids, band-aids or simply plasters, are well known in the art. They are used to cover small wounds. They protect them, for example to reduce the risk of contamination from impurities penetrating the wound and/or to prevent blood or wound fluid from escaping.

Such a patch comprises a backing material that is typically rectangular, round, or oval. This is at least partially provided with an adhesive layer on the underside facing the wound. This has the task of releasably attaching the plaster to the skin surrounding the wound. In the case of a heat patch, for example, the entire underside can also be self-adhesive. In the central area of the underside there is often a wound dressing that does not stick because it comes into contact with the actual wound.

Plasters are also known which accelerate the healing of the covered wound by providing active ingredients in their wound dressing. These are gradually released and absorbed by the tissue through the wound.

Active ingredients are also known which can be used to prevent the itching that occurs with insect bites. Accordingly, plasters are known whose wound dressing contains an active ingredient that prevents or reduces itching.

A disadvantage of such patches is that their structure is more complex due to the multi-layer structure, and that the active ingredients are subject to a certain aging process and/or only to a certain, narrow extent Temperature range are storable. A further disadvantage is the fact that plasters of this type typically have to be packaged in a sterile manner in order to prevent infection through a contaminated plaster.

Object of the invention and solution

The invention is therefore based on the object of providing a method for producing a plaster and a plaster produced using this method, which avoids the disadvantages of the prior art.

Accordingly, the plaster should have a simple structure, and the effectiveness against the itching caused by insect bites should be largely independent of the storage conditions and the storage time.

The object is achieved by a method for producing a plaster according to claim 1 and a plaster according to independent claim 15 . Advantageous embodiments can be found in the dependent subclaims, the following description and the figures.

description

First, the method of manufacturing the improved patch according to the present invention will be described. A description of the patch produced using the method according to the invention then follows.

The invention relates to a method for producing a patch for reducing itching and/or swelling caused by insect bites. Such symptoms are particularly common side effects of such stings; although they are not normally dangerous, they are unpleasant and often require a relatively long time to subside. During its existence, the itching leads to corresponding scratching reactions in the affected person, which further delays the healing of the swelling.

The procedure includes the following steps : 1) Provision of an organic carrier material that can be coated with adhesive, preferably a carrier material comprising artificial silk, polyurethane or polyester. The backing material ensures the physical integrity of the patch. It preferably has a thickness in the range of 0.1 to 1.0 mm, preferably it has a thickness of 0.25 mm. It is particularly preferably elastic, with a modulus of elasticity (E modulus) which is preferably between 0.05 and 5 gigapascals and preferably between 0.5 and 2.0 gigapascals at a temperature of about 20° C. to 40° C. and most preferably at a temperature of about 22°C. 1.6 gigapascals.

2) Coating of an underside of the carrier material with a non-UV-hardening acrylate adhesive suitable for connecting the same to human skin, which is used as a solution of a polyacrylate in an organic solvent or solvent mixture, the solvent or solvent mixture being present in an amount of 25 to 70% by weight %, preferably 30 to 60% by weight, based on the total weight of the acrylate adhesive.

The solvent or solvent mixture is particularly preferably used in an amount of 40 to 55% by weight, based on the total weight of the acrylate adhesive.

The organic solvent or solvent mixture contained in the adhesive preferably contains at least one solvent from the group consisting of ethyl acetate, 2-propanol, heptane, toluene and 2,4-pentanedione. According to another preferred embodiment, the solvent is selected from the group consisting of isopropanol, heptane and ethyl acrylate. A solvent mixture is preferably used which consists of at least 90% by weight of ethyl acetate, 2-propanol and/or heptane. If toluene and/or 2,4-pentanedione are used, their proportion in a solvent mixture is preferably not more than 10% by weight, the proportion of 2,4-pentanedione preferably being 0.3 to 5% by weight. Most preferred is a solvent mixture comprising isopropanol, heptane and ethyl acetate. Even more preferred is a solvent mixture comprising isopropanol, heptane, ethyl acetate, toluene and 2,4-pentanedione. It is preferred that the solvent mixture contains 30 to 35% by weight isopropanol, 30 to 35% by weight heptane, 30 to 35% by weight ethyl acetate, 3 to 9.5% by weight toluene and 0.5 to 2% by weight 2,4-pentanedione.

The acrylic polymer used according to the invention is preferably an acrylic copolymer, ie it is preferably made up of at least two different monomer units. Since it is used in solution, it is not a hot melt adhesive. There is no further restriction other than that the acrylic polymer is chosen so that it is completely soluble in the organic solvent or mixture of solvents. It has thus been shown that numerous acrylic polymers can be used according to the invention. The effect of the invention thus seems to be based on the interaction of all the features listed in the independent claim.

The underside is the side that comes into contact with the skin during use. The purpose of the adhesive is to permanently but detachably connect the patch to the skin. In this context, "permanent" means a period of at least several hours up to several days. The adhesive can preferably be harmless with regard to prolonged contact with the skin. Advantageously, it should move away together with the carrier material without leaving any residue and without excessive tensile forces The underside of the carrier material is preferably completely coated with the adhesive.

3) Making up the patch to a size suitable to cover an area from which the itch originates. "Suitable" in this context means that the size of the patch exceeds the typical size of a swelling caused by an insect bite by at least 0.5 cm, preferably 1-2 cm. Accordingly, the size of the patch is at least 2x2 to 10x10 cm. The geometry can, for example, be rectangular, round or oval. "Confectioning" means reducing or separating the plaster, which typically comes from a larger sheet or a wider or at least longer roll, to the desired external dimensions. This can be done, for example, by means of punching, mechanical cutting or laser cutting.

4) Production of a lattice structure on the patch, so that it comprises a plurality of intersecting strips ("structuring") revealed that material is missing between said strips. Accordingly, the recesses are introduced into the surface of the carrier material (subtractive method), so that said lattice structure is formed. This is characterized by regularly repeating recesses. It is clear that the excess material when making the recesses must also be removed from there and disposed of. The structuring can also take place, for example, by means of stamping, mechanical cutting or laser cutting.

Alternatively, the lattice structure can also be formed in that the strips are placed next to and on top of one another in a suitable manner, with them being correspondingly spaced apart from one another (additive method).

The lattice structure may also be formed by deploying a plurality of randomly crossing strips, which may be linear or tortuous, and connecting them together at the crossing points; recesses are also formed in such a structure.

The lattice structure leads to a reduction in the (global) modulus of elasticity of the patch, since the amount of material available in the corresponding direction is reduced, reduced by the width of the recesses in the direction of tension.

According to the invention, the adhesive is applied to the carrier material at a temperature of 45° C. to 155° C. for a time of 5 s to 60 s. Under these conditions, the solvent present in the adhesive is almost completely, preferably completely, evaporated. Preferably the temperature is 90°C to 120°C, and more preferably 105°C. The application time is preferably 10 s to 30 s, and particularly preferably 20 s. Tests have surprisingly shown that a patch in which the adhesive has been applied with the above parameters has particularly good properties in terms of effectiveness against itching and/or swelling, since the mechanical properties of the patch are influenced in a particularly advantageous manner.

According to the invention, the patch is also activated by repeated exposure of the underside to ultraviolet light.

The irradiation preferably takes place at a wavelength of 100 to 380 nm. The cumulative irradiation time is preferably 0.01 to 2 s, and is particularly preferably carried out by means of several, in particular 3 to 5, consecutive short light pulses. The time between the pulses should preferably be measured in such a way that the temperature of the irradiated surface falls back to room temperature (21 °C + 5 °C).

Irradiation with UV-A light (wavelength 380 nm to 315 nm) is preferably carried out first, and then with UV-B light (wavelength 315 nm to 280 nm) and/or UV-C light (wavelength 280 nm to 100 nm) .

The irradiation takes place before or after the step of applying the adhesive. In the case of irradiation before coating, the underside of the carrier material is advantageously prepared for the application of the adhesive, which in turn has a positive effect on the mechanical properties of the patch.

If irradiation takes place after coating with adhesive, the adhesive itself, and in particular its side intended for contact with the skin, is also changed in an advantageous manner, which also has a positive effect on the mechanical properties of the plaster, and in particular the "composite system" made of plaster and skin .

Irradiation before and after the application of the adhesive is also possible in order to combine the advantages mentioned with one another.

The irradiation also has an effect on the stress pattern in the irradiated material. Irradiation with different wavelengths results in different penetration depths, which leads to different mechanical stress patterns at these depths.

As explained, it is preferred to combine the features “temperature” and “irradiation” described above with one another. In this way, the mechanical properties of the plaster, as well as the "composite system" of plaster and skin, are improved in an optimal way. The result is an increased effectiveness of the plaster against itching and/or swelling when it has been stuck on the affected area . There is no need to add a known agent for reducing itching and/or swelling. It has been shown that a patch produced using such a method is also suitable without such an agent for reducing itching and/or swelling caused by insect bites. In a preferred embodiment of the method, neither drugs nor active ingredients are therefore added during production of the patch. It has been shown that the positive effect of the patch is due in particular to the above measures. The patch according to the invention therefore preferably also contains neither medicaments nor active ingredients.

The invention thus avoids the disadvantages known from the prior art. The construction of the patch according to the invention is very simple due to its possible and particularly preferred single-layer structure, which simplifies production and reduces costs. Medicinal agents can be completely dispensed with. This means that the patch can be stored for up to 5 years before use. At the same time, it is significantly less sensitive to particularly high or low storage temperatures. At the same time, the manufacturing method according to the invention improves the mechanical properties of the plaster and thus also its effectiveness against itching and/or swelling.

Various embodiments of the invention are described in more detail below.

It should be noted that the assembly step can be carried out before, after and during the step of producing the lattice structure. Assembling with a previous or subsequent production of the lattice structure (subtractive or additive structuring) causes the stresses induced by the processing to be shifted to the center of the pavement or towards the edge of the pavement. If the packaging and structuring are done at the same time, the tensions across the entire pavement are more balanced. The state of tension of the patch can also affect its attachment to the skin.

The assembly step particularly preferably takes place before or after, ie not at the same time as, the structuring step, while the carrier material is coated with acrylate adhesive at any time Underside is arranged on a protective film. The associated mechanical processing is therefore two-stage in terms of time. The protective film, which can be designed as peel-off paper, ensures that it is possible in a simple manner to first structure (i.e. to produce the recesses) and only then to assemble (i.e. to separate the patches from one another). ) , or the other way around .

A heat treatment of the product at a temperature between 30° C. and 90° C., preferably of approx. 60 °, and for a period of 2 to 120 seconds, preferably from 5 to 30 seconds, and particularly preferably from about. 10 seconds . This treatment relaxes the areas (edges) already treated by cutting or punching. In contrast, such a treatment does not take place again after the further step that follows, so that the stresses introduced by this further step continue to remain in the areas treated within the scope of this step. In this way, the patch has different internal stresses in its edge area (outer edges) than in its inner area (area of the recesses). Since the carrier material is arranged on said protective film and remains in place until it is used, this ensures that the state of tension that has been created is maintained over the long term, since the carrier material does not move or z. B. Wrinkles in order to compensate for the difference in tension between the interior and the edge. Since the plaster is normally applied to the skin immediately after it has been detached from the protective film, there is essentially no reduction in internal tension in this short period of time; rather, these are transferred to the user's skin where they contribute to the desired effect of reducing itching.

Particularly preferably, the abovementioned activation is carried out by means of ultraviolet light by applying a first pulse with a length of 5 s±1 s, followed by a first pause of 10 s±2 s, and a second pulse with a length of 5 s±1 s , followed by a second pause of 10 s ± 2 s, and a third pulse with a length of 2.5 s ± 0.5 s, onto which the adhesive layer already applied is delivered. The dose radiated onto the adhesive is preferably between 0.1 mJ/cm 2 and 1000 mJ/cm ^A 2 . It is particularly preferably between 20 mJ/cm 2 and 200 mJ/cm ^A 2 . It is preferably 85 mJ/cm ^A 2 ± 15%. As a result of the repeated heating and cooling of the adhesive that accompanies this sequence, a particularly advantageous connection is achieved between it and the carrier material and (later) between the adhesive and the skin. In addition, a particularly advantageous result of the activation mentioned above is achieved.

The total irradiated dose should be between 0.1 mJ/cm 2 and 1000 mJ/cm ^A 2 . It is preferably between 5 and 500 mJ/cm 2 . It is particularly preferably between 20 mJ/cm 2 and 200 mJ/cm 2 . It is preferably 85 mJ/cm 2 ±15%.

According to one embodiment, the lattice structure preferably consists of three vertical strips and preferably four horizontal strips. Each strip is approx. 3mm wide. The gaps between the strips have a width of 3 mm x 3 mm. This results in a total width of 21 mm and a length of 27 mm.

Other preferred embodiments have dimensions of 36 mm x 28 mm with a strip width of 4 mm, and also 4 x 3 strips, or 52 mm x 44 mm with 6 x 5 strips.

According to a further embodiment, the vertical stripes and the horizontal stripes are at an angle of 90° to one another. This means that a rectangular pattern results. The tool producing the recesses is placed accordingly (e.g. punching tool) or adjusted (e.g. cutting laser) so that the desired angles result. The recesses are then rectangular, such as square in particular. The advantage of this embodiment lies in a modulus of elasticity that is identical in the two main directions of pull. (The main directions of pull are two directions of pull lying in the plane of the paving and perpendicular to each other). This is advantageous in cases in which the plaster is to be applied to a skin area that stretches approximately equally in all directions, since the position of the plaster then plays no significant role.

According to an alternative embodiment, the vertical stripes and the horizontal stripes are at an angle of 7°, 30°, 42°, 45°, 60°, or 75° to one another. This results in recesses, which one have diamond shape. Depending on the angle, these diamonds are more or less flat. The advantage of this embodiment lies in a modulus of elasticity that is different in the two main directions of pull. In cases where the patch is to be applied to areas of skin with different levels of stretching, this embodiment can be used to achieve a mechanical reaction of different strength depending on the position on the skin.

According to a further embodiment, the lattice structure consists of three or more groups of strips each running parallel to one another. Each group encloses an angle to the remaining groups, so no group runs parallel to another group. The recesses then have - with 3 groups - a triangular shape, with 5 groups a pentagonal shape, etc. In the present case, 3 groups are particularly preferred. The advantage of this embodiment lies in the provision of 3 directions with a larger and 3 further directions with a lower modulus of elasticity, which can be desirable in certain applications.

According to a preferred embodiment, each strip ends in a free section on both sides. "Both sides" means that the beginning and end of the strip has a free section. The free sections result in a non-linear edge of the patch. For example, while the envelope of the patch is rectangular, the actual contour is defined by the free sections. Alternatively, this structure can be created by placing the outermost recesses in such a way that their outer edge coincides with the outer edge of the envelope of the patch, or by these recesses even being made to cover the outer edge .The advantage of such a design lies in the further improved interaction of the patch bonded to the skin .

The edges of each free section are preferably at an angle of 90° to one another. Experiments have shown that edges shaped in this way achieve particularly good work results. The corners of the sections lead to a concentration of stresses when the patch is stuck on the skin, which further improves the effectiveness.

In an alternative embodiment, the ends of each free section are tapered at an angle of 10° to 170°. This means that the sections form "arrows" pointing away from the center of the patch. The tips of these darts also cause stress concentration when the patch is adhered to the skin, further enhancing effectiveness.

According to another embodiment, the ends of each free portion are rounded. In some cases, the concentration of stresses described above can be disadvantageous, which can be avoided by rounded ends.

According to a further embodiment of the invention, the adhesive is applied under a pressure of 1 bar to 10 bar, preferably 2 bar to 6 bar, particularly preferably 3.057 bar to 5.095 bar, and most preferably 4.076 bar ± 0.05 bar. This means that the liquid or pasty adhesive emerging from a dispensing device such as a nozzle does so with the aforesaid pressure. Alternatively, the pressure can also be provided by application in an atmosphere under said pressure. Applying the adhesive under said pressure leads to improved adhesion between it and the carrier material, which in turn has an advantageous effect on the mechanical properties of the patch.

According to a further embodiment, the adhesive is applied with a surface pressure of 200 kilopascals to 600 kilopascals, and preferably of 300 kilopascals to 500 kilopascals, and particularly preferably of 400 kilopascals, each ± 1%. This corresponds to a value of 2.03 kg/cm 2 to 6.1 kg/cm 2, preferably 3.1 kg/cm 2 to 5.1 kg/cm 2, and particularly preferably 4.1 kg/cm 2. This surface pressure can be generated, for example, by means of a transfer plate after wetting the carrier material and maintained for at least 0.5 seconds, preferably at least 2 seconds, and particularly preferably 3-5 seconds. In this way, a good connection between the adhesive and the carrier material is achieved.

According to a further preferred embodiment, the solvent is selected from the group consisting of isopropanol, heptane and ethyl acrylate.

The invention also relates to a plaster for reducing itching and/or swelling caused by insect bites, the plaster is produced with a method according to the above description. The advantages resulting from the shaping and treatment during production are not repeated; instead, reference is made to the sections above.

The backing material of the plaster particularly preferably comprises artificial silk, cellulose acetate, polyurethane or polyester. These materials are particularly skin-friendly, can be easily structured and treated using the method according to the invention, and have strengths of 0.1 and 1.0 denominated. g . suitable modulus of elasticity. Another benefit of cellulose acetate is its low moisture absorbency; thus , in web form , this material tends to build up static electricity . While this effect is generally undesirable, it is preferred in the case of the present patch, since it attaches itself to the skin almost automatically. The effect is more pronounced with thinner and thus more pliable material thicknesses.

The proportion by weight of the backing material on the patch (without the protective layer) is preferably 50% to 70%, and the proportion by weight of the adhesive is 25% to 30%, more preferably 30% to 50%.

According to the invention, the adhesive is an acrylic adhesive (also: acrylate adhesive). Such an adhesive has proven to be particularly skin-friendly; moreover, it can be applied well at the temperatures and pressures provided according to the invention. Surprisingly, it has been shown that such an adhesive, although not UV-curing, has the above-mentioned advantages as a result of exposure to UV light and in connection with the method according to the invention.

The acrylic adhesive preferably comprises the substances isopropanol, heptane and ethyl acetate as a solvent for the polyacrylate.

An adhesive with these substances is particularly well suited to being connected to the carrier material by means of the method according to the invention. In addition, an adhesive comprising these components has turned out to be particularly skin-friendly and pleasant when it is removed again after the plaster has been used. character description

The invention is explained below by way of example with reference to figures.

while showing

FIG. 1 shows a schematic flow diagram relating to the method for producing an improved plaster;

FIG. 2 shows a schematic representation of an embodiment of a patch according to the invention;

FIG. 3 shows a schematic representation of a further embodiment of a patch according to the invention.

FIG. 1 shows a schematic flow chart relating to the method for producing an improved plaster. In a first step, the carrier material is provided. The adhesive is then applied to the underside of the carrier material, with the parameters specified in the figure with regard to temperature, time, pressure and surface pressure preferably being observed. Then follows the structuring (production of the lattice structure), as well as packaging (separation of the patches from the panel). As shown, the two last-mentioned steps can be carried out one after the other, but they can also be carried out simultaneously.

According to the invention, the underside is activated before and/or after the coating by means of UV radiation.

To avoid repetition, reference is made to the statements above.

FIG. 2 shows a schematic representation of an embodiment of a plaster 1 according to the invention. Accordingly, this patch 1 has a lattice structure consisting of four vertical strips 2 and three horizontal strips 3 . Between the strips 2, 3 there are recesses 4 (only two provided with a reference number). The cutouts 4 result in the modulus of elasticity of the plaster being reduced (compared to a conventional plaster without cutouts, not shown). In the exemplary embodiment shown, the vertical strips 2 and the horizontal strips 3 are at an angle 5 of 90° to one another. The recesses 4 are therefore rectangular, in this case square.

The in this Fig. The embodiment shown has strips 2, 3 which end in free sections 6 on both sides (only two provided with reference numbers). The edges of each free section 6 are at an angle of 90° to one another (no reference number).

FIG. 3 shows a schematic representation of another embodiment of a plaster 1 according to the invention. This differs from the one previously described in that the vertical strips 2 and the horizontal strips 3 are at an angle to one another which differs from 90°. In the present case, the angle 5 is approximately 68°. This results in different global moduli of elasticity for the two main directions of tension X, Y. In the main pulling direction Y, this is smaller than in the main pulling direction X. A load in the X-direction is primarily absorbed by the strips running in the X-direction, which continue to be loaded along their longitudinal axis. In the case of a load in the Y direction, however, the (tilted) vertical strips are no longer loaded in the direction of their longitudinal axis.

It also differs in that the recesses were not made in the carrier material, for example by punching or laser cutting, but are formed by superimposing individual strips that are spaced apart from one another.

This embodiment also has strips 2 , 3 which end in free sections 6 on both sides. However, the edges of each free section 6 here run at an angle of approx. 45°, which can lead to stress concentration at the tips after application of the patch 1 to the skin (not shown).

It should be noted that the variants described in FIGS. 2 and 3 are also possible in combinations other than those presented by the exemplary embodiments described, since they are not mutually dependent. reference character list

1 plaster

2 vertical stripes

3 horizontal stripe 4 recess

5 angles

6 free section

X Main pulling direction Y Main pulling direction

Claims

patent claims

1 . Method for producing a patch ( 1 ) for reducing itching and/or swelling caused by insect bites, comprising the following steps:

providing an organic carrier material that can be coated with adhesive, preferably a carrier material comprising artificial silk, cellulose acetate, polyurethane or polyester;

- Coating an underside of the carrier material with a non-UV-hardening acrylate adhesive suitable for connecting the same to human skin, which is used as a solution of a polyacrylate in an organic solvent or solvent mixture, the solvent or solvent mixture in an amount of 25 to 70 wt. -%, based on the total weight of the acrylate adhesive, is used;

- Manufacture of the patch ( 1 ) to a size suitable for covering an area from which the itching and the swelling originate;

- producing a lattice structure with recesses on the plaster (1) so that it comprises a plurality of intersecting strips (2, 3); whereby

- the adhesive is applied at a temperature of 45 °C to 155 °C for a time of 5 s to 60 s, and

- Before and/or after the application of the adhesive, the patch (1) is activated by repeated irradiation of the underside with ultraviolet light.

2 . Method according to claim 1 , wherein the assembly step takes place before or after the structuring step , while the carrier material is at all times arranged with its underside coated with acrylate adhesive on a protective film .

3 . The method according to claim 1 or 2, wherein the activation by means of ultraviolet light comprises a first pulse with a length of 5 s ± 1 s, followed by a first pause of 10 s ± 2 s, and a second

Pulse with a length of 5 s ± 1 s, followed by a second pause of 10 s ± 2 s, and a third pulse with a length of 2.5 s ± 0.5 s, comprising the method according to any one of claims 1 to 3 , the energy radiated onto the adhesive being 85 mJ/cm 2 ± 15%. Method according to one of Claims 1 to 4, in which the lattice structure consists of vertical strips (2) and horizontal strips (3). Method according to claim 5, wherein the vertical stripes (2) and the horizontal stripes (3) are at an angle (5) of 90° to one another. Method according to Claim 5, in which the vertical stripes (2) and the horizontal stripes (3) are at an angle (5) of 7°, 30°, 42°, 45°, 60° or 75° to one another. Method according to one of Claims 1 to 4, in which the lattice structure consists of three or more groups of strips (2; 3) each running parallel to one another, and in which each group includes an angle (5) to the remaining groups. Method according to one of the preceding claims, in which each strip (2, 3) ends in a free section (6) on both sides. A method according to claim 9, wherein the edges of each free portion (6) are at an angle (5) of 90° to each other. A method according to claim 9, wherein the ends of each free portion (6) are tapered at an angle of 10° to 170°. A method according to claim 9, wherein the ends of each free portion (6) are rounded. Method according to one of Claims 1 to 12, characterized in that the adhesive is applied under a pressure of 3.057 bar to 5.095 bar, or is applied under a surface pressure of 3.1 kg/cm 2 to 5.1 kg/cm 2 . Process according to any one of Claims 1 to 13, characterized in that the solvent is selected from the group consisting of isopropanol, heptane and ethyl acrylate. A patch (1) for reducing itching and/or swelling caused by insect bites, the patch (1) being made by a method according to any one of claims 1 to 14. Plaster (1) according to claim 15, wherein the backing material comprises rayon, cellulose acetate, polyurethane or polyester. A patch (1) according to claim 15 or 16, wherein the acrylic adhesive comprises isopropanol, heptane and ethyl acetate.

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