Local dressing and method of making same

The subject of the invention is a dressing and a method of producing a dressing. This type of dressing, when placed in a container with the active substance, is used especially for the administration through the skin of drugs or other substances.

Dressings that are in contact with the patient's skin by sticking them to the user's skin are known, while the active ingredients slowly pass through the skin and are absorbed for a long time by the patient's body, depending on the needs of the body.

From EP-A-0013606, an adhesive dressing is known comprising a laminated bottom tape with a cavity in which a polymer insert containing a medicament is placed. The recess is surrounded by an adhesive tape and sealed with a laminated cover tape. The top tape is provided with a surface layer of non-stick material, so it can be easily separated from the bottom tape to expose the diffusion polymer insert and adhesive.

EP-A-0013606 discloses a pressure sensitive adhesive dressing used for administering a medicament, comprising a laminated backing tape having a microporous material ring attached to a support sheet being a polyethylene / metal foil / polyester laminate. The ring of microporous material has a surface layer in the form of an adhesive and has a central depression containing the drug. The top band is made of the same laminated material as the support sheet. The top tape covers the cavity and is connected to a non-stick layer on the top surface of the tape on the skin adhesive side and by means of a welded sealing ring located between the laminated materials of the bottom and top tape, outside the outer periphery of the microporous material ring.

From EP-B-0181333 it is known to connect a layer preventing the adhesion with the bottom tape of the dressing by means of an outer, welded sealing ring. In this case, there is a problem that the drug in the cavity may at least partially escape, for example by diffusion, into the surrounding adhesive and / or other layers, especially if the drug is in liquid or volatile form, and in particular when the drug it is in the recess alone or is absorbed by the insert. Because the dressings are preferably intended for the administration of an exact dose of the drug, getting a certain amount of drug out of the cavity can be a serious problem for the patient.

Australian Patent No. 75975/91 discloses a dressing comprising a bottom sheet on which a resilient layer is placed, partially covering it. The trouser sheet has the form of a single disk-shaped layer, while during production, individual layers of individual dressings are arranged one after the other, on a continuous strip of elastic material, in predetermined places. This is a procedure that creates a new problem. Because the bottom sheet is made of very thin material (about 10-50 gm), the edges of the disk often bend upwards, which often causes the weld to be uneven. Even if the disk-shaped layer is placed on the elastic layer in a manner

176 982 proper, there is a risk of damage to the seal between the disc-shaped layer and the elastic structure, and as a result, when the dressing is leaking out of the medicine.

A dressing according to the invention comprising a top sheet and a bottom sheet, the bottom sheet having an elastic layer, and a disc-shaped layer is located on a part of the elastic layer surface, while an adhesive layer is placed on the opposite side of the elastic layer, the elastic layer and the adhesive layer they have a cut-out surrounding the cavity, and in the cavity there is an insert with the active substance, while the top sheet has an anti-stick liner and a bowl, shaped to match the shape of the insert with the active substance, the top sheet being in contact with the elastic layer of the bottom sheet on the side containing the adhesive layer, characterized in that the bottom sheet has at least one strip, protruding outwards, beyond the peripheral edge of the disk-shaped layer, towards the peripheral edges of the elastic layer, wherein the bottom sheet and the top sheet are joined together by a weld seam which is located inside the recess of the bottom sheet.

Preferably, the bottom sheet comprises four strips located along the periphery of the disc-shaped layer, which are arranged relative to each other at an angle of approximately equal to 90 °, and in particular when the strips and the disc-shaped layer are formed of an elongated continuous web of the same material.

It is advantageous if the top sheet has a top layer in which a protrusion is formed surrounding the bowl, the protuberance being adapted to cover the cavity with the insert and the elastic layer surrounding it underneath and forms the area for the weld seam located around the insert with the active substance.

The method of manufacturing a dressing according to the invention, in which a first elongated, continuous, web of impermeable material is provided and a bowl surrounded by protuberances is extruded thereon, then an elongated, continuous, second, elastic material web is applied to the first web of impermeable material, on which the adhesive layer is located with an anti-stick insert placed on it, wherein the second elastic material web is in contact with the first impermeable material web on the side of the adhesive layer and the non-stick liner, and then the cutouts of the elastic layer and, respectively, the non-stick liner and the protuberance of the first web of material are superimposed and a cavity is formed, and then provided elongated, continuous, third of impermeable ribbon, material and put on it inserts for the active substance of a porous material, characterized in that the third web of material is cut off parts from which a disk-shaped layer with at least one strip protruding outwards from its peripheral edge is cut off and formed from them a continuous sheet of trousers, and then after putting on the inserts with the active substance, it is placed on the elastic layer, wherein the inserts and cavities are covered with a resilient layer within the protuberances, and then the formed dressing sheet is cut into individual pieces.

Preferably, circular or oval stripes protruding outwardly of the peripheral edges of the disk-shaped layer are formed.

It is advantageous if the continuous bottom sheet is formed by cutting off unnecessary fragments of the third web of impermeable, elastic material from which the disc-shaped layer with strips is formed, with adjacent disc-shaped layers joined together by means of strips.

It is advantageous if four strips are formed for each disc-shaped layer, which are arranged relative to each other at an angle of 90 ° along the perimeter of the disc-shaped layer.

It is advantageous if, before placing the insert on the bottom sheet, the active substance is introduced into it.

It is advantageous if, after placing the insert on the bottom sheet, it is welded to a disc-shaped layer, after which the active substance is introduced into the insert.

It is advantageous when the active substance is introduced into the insert in the form of a medicine.

The dressing according to the invention is easily filled with the active substance and closed securely, without the possibility of leakage of the drug, the proposed method of its production ensures mass production, while ensuring an appropriate degree of hygiene and safety. In addition, the dressing is convenient to use and provides effective treatment, while preventing the release of substances that could contaminate clothing and cause the patient discomfort.

The object of the invention is illustrated in the embodiment in the drawing, in which Fig. 1 shows the dressing in cross section taken along the line II in Fig. 3, Fig. 2 - the dressing in a top view, from the top sheet side, Fig. 3 - the dressing in a view from below, from the bottom sheet side, fig. 4 - a scheme for producing a dressing by the method according to the invention.

As shown in Fig. 1, the dressing has a multi-layer structure, and includes a bottom sheet 1 and a top sheet 2.

The top sheet 2 shown in Fig. 2 is made of an impermeable material, for example a laminate, such as a metal foil, on which one side a polymer layer is placed. Preferably, the top sheet 2 is made of a metal foil, which is thicker and stiffer than the material of the bottom sheet 1. The top sheet 2 provides support for the dressing to prevent its deformation and leakage of the active substance during storage and handling.

The bottom sheet 1 shown in Fig. 3 comprises a disc-shaped layer 3 of impermeable material, for example a laminate, in the form of a metal foil, coated on opposite walls with polymer layers. One wall of the laminate or one of the polymer layers is centrally attached to the layer 4 of elastic material in the form of synthetic foam. The resilient foam is covered with an adhesive layer 5 that adheres to the user's skin.

As shown in Fig. 3, to prevent upward bending, the edges of the disk-shaped layer 3 placed on the elastic layer 4 are equipped with reinforcing strips 20. Preferably, four strips 2θ protrude outwards from the peripheral edge of the disk-shaped layer 3, towards the circumferential edges of the elastic layer 4 and are arranged along the periphery of the disk-shaped layer 3 and arranged relative to each other at an angle of 90 °. The strips 20 are made of the same material as the disk-shaped layer 3 and are attached to the elastic layer 4. The size of the strips 20 depends on the distance between the circumferential edge of the disk-shaped layer 3 and the circumferential edges of the elastic layer 4. Tests have shown that bending when the strips 20 are located centrally along the sides of the elastic layer 4, as seen in figure 2. The strips 20 have a specific lateral dimension, e.g. a certain width, this lateral dimension must be small enough so that it does not significantly deteriorate the elastic properties of the elastic layer 4. In a preferred embodiment, the width of the strips 20 is about 5 to 20%, preferably about 10% with the total length of the elastic layer sides 4.

The disk-shaped layer 3 is centrally attached to the elastic layer 4. The elastic layer 4 has a centrally located circular notch 7. The entire surface of the elastic layer 4 is covered with an adhesive layer 5, and the centrally located notch 7 is out of reach of the adhesive layer 5.

Inside the recess 7 there is a recess 8, and inside the recess 8 there is a disk-shaped insert 9 made of porous material. The thickness of the insert 9 is slightly larger than the thickness of the elastic layer 4. The insert 9 is located centrally in the recess 8 and has a diameter smaller than the diameter of the notch 7 so that an annular space 10 is formed between them. The insert 9 is attached to the disc-shaped layer 3 in any way, for example by welding.

The top layer 2 comprises a disk 12 of an impermeable material, such as a metal foil, coated on both sides with polymer layers. One side of the disk 12 is attached to the non-stick liner sheet 13, the disk 12 preferably being attached to the non-stick liner 13 through a circular seal. The non-stick liner 13 has a central cutout 15 of the same size as the cutout 7 of the elastic layer 4.

When the top sheet 2 is applied to the bottom sheet 1, the insert 13 is applied to the coated layer 5, the elastic layer 4, and the two bottom sheets 1 and the top 2 are

176 982 connected together by an adhesive layer 5 and a weld between the disk-shaped layer 3 and the disk 12.

The central circular portion 16 of the disk 12 has a circular relief 17 surrounding the bowl 18 for the active substance insert 9. The shape of the protuberances 17 is selected so that it fits inside the cutout borders 15 in the anti-stick liner 13 and the elastic layer 4 when the bottom sheet 1 and the top sheet 2 are joined together. In this position, the protuberance 17 protrudes through the two cutouts 15, 7 and connects with a disc-shaped layer 3. The protuberance 17 is welded to the disc-shaped layer 3.

The active substance intended for administration through the skin using the dressing according to the invention is absorbed by the insert 9. The insert 9 is made of a porous material, preferably cellulose.

Examples of active substances that can be applied dermally using the topical dressing according to the invention are anesthetics, analgesics, steroids, nicotine, antibiotics.

The active substance is completely sealed between the disk-shaped layer 3 of the bottom sheet 1 and the disk 12 of the cover sheet 2 so that it cannot get into adjacent layers.

In use, the top sheet 2 is torn off, separating it from the adhesive layer 5 in the area of ​​the non-stick liner 13, and the protuberance 17 pulls away from the disk-shaped layer 3, tearing the existing seal between them. The dressing is then applied to the wearer's skin, and the adhesive layer 5 holds the dressing in place and the pad 9 contacts the skin.

As shown in Fig. 4, the impermeable laminate of the facing sheet 2 provides in the form of a first elongated web 21 wound on the first roll 22. At the driving station 23, a protuberance 17 is formed on the first web 21 and a bowl 18 is formed at the same time.

The elastic layer 4 with the adhesive layer 5 and the non-stick liner 13 are provided on a second continuous elongated web 41 wound on the second roll 42, and the cut-outs 7 are made in the cut-out stand 43. The cut-outs 7 define the depressions 8 in the elastic layer 4. After the cut-outs 7 , the second elongated web 41 is placed on the laminate of the cover sheet 2 in the form of the first web 21 and is preferably attached by welding.

Trouser sheet 1 is made on a parallel production line. The impervious laminate of the back sheet is provided in the form of a continuous web 51 disposed on the third roll 52.

The inserts 9 are then delivered from magazines 91 and placed on a third continuous web 51, after which they are sealed with welding at the welding station 92. The active substance is then introduced into the inserts 9 at the filling station 93. Preferably, the active substance is introduced into the inserts 9 after they have been placed and welded to the bottom sheet, but it is also possible to introduce the active substance before the placing and welding step.

After filling the inserts 9, the third web 51 of material is directed to the cutting station 53. At the cutting station 53, laminate fragments that are not part of the disc-shaped layer 3 and strips 20 are cut off, while the third web 51 is still elongated and the strips 20 that are connected to adjacent discs 3 are connected to each other. This avoids bending the edges of the rollers 3 and greatly facilitates handling and production.

In the next step, the continuous elongated sheet comprising the disc-shaped layer 3 with the strips 20 and the attached inserts 9 is turned downwards and placed on the elastic layer 4, as shown in Fig. 4. The inserts 9 are placed inside the bowl 18, surrounded by a protrusion 17. Then, the elastic layer 4, bottom sheet 2, disc-shaped layer 3 are joined in the region of protuberances 17, preferably by welding at welding station 55. Circular welds 6 are made around the recess 8, the protuberances 17, the bowl 18 with the insert 9 and the notches 7.

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Then a continuous sheet of ready-made dressings is cut into individual dressings at the clipping station.

Advantageously, other materials may be used to make individual dressing elements. Also, their shape and size may be different, in particular the cutouts 7 and the disc-shaped layer 3 of the back sheet 1 may have a different shape than, for example, round, oval, square or rectangular. The strips 20 can be made in various ways around the circumference of the disc-shaped layer 3 of the back sheet 1 and can have different shapes. However, the trouser sheet 1 must have elastic properties and must provide an impermeable support for the active substance.

The top sheet and the bottom sheet 1 may be made of the same or different materials, preferably a metal foil / polymer laminate, but any other material having similar characteristics may be used. The polymer contained in the laminate can be polyethylene, polypropylene, polyester, ionomer.

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