FR3072032A1 - ADHESIVE PLASTER - Google Patents

Abstract

Dressing (1) adhesive coated on one of its faces by a peelable outer layer (2) comprising a plastic film (3), impervious to steam, of 20 .mu.m to 200 .mu.m thick and having on its inner face an adhesive layer (4 ), continuous or discontinuous.

Description

Technical area

The present invention relates to a dressing comprising a peelable outer layer for carrying out a method of sterilizing such a dressing.

Prior art

Treatment of wounds or surgical openings on the surface of the skin usually includes the use of cover layers. These isolate the wound from potential environmental aggressions while allowing the conditions necessary for good healing to be maintained. Traditionally, this function was performed by dry or wet compresses held at the wound level by non-adhesive strips. The adhesive cover has the advantage of allowing rapid installation. However, the adhesion must be large enough to fulfill its function while allowing withdrawal which does not reopen the wound, while being as painless as possible.

In recent years, new types of dressings using a layer of silicone as an adhesive layer have been put on the market. Adhesive silicone has the advantage of being non-allergenic and of exhibiting suitable adhesion. Silicone also has the advantage of allowing certain gases and water vapor to pass, a characteristic which can moreover be significantly increased in the case of discontinuous coating.

In order to avoid adhering to its packaging, the surface of the layer of adhesive silicone intended to be in contact with the skin is usually covered by a protective film.

ZODIA1-FR-1_TEXTE depose_so / ag to be removed before use. These protective films are mostly plastic films impermeable to water vapor.

The layer of the dressing in contact with the external environment consists of a film allowing certain gases and water vapor to pass. This latter property ensures the evacuation of excessive moisture from the wound and allows the peri-lesional skin to breathe.

By way of example, the applicant has developed an adhesive cover, marketed under the name of Novespire®HB successively comprising a highly breathable polyurethane film, a knitted fabric coated with an adhesive silicone gel and a protective plastic film .

In some cases, the dressings must be sterilized by steam or hot, in an autoclave.

Steam sterilization is problematic because during this operation, the water vapor will pass through the breathable film of the dressing and be trapped between the waterproof protective film and the adhesive silicone layer. However, silicone is hydrophobic, this humidity therefore reduces the adhesive capacity of the silicone layer when the dressing is applied to the skin (see FIG. 3).

Note that the same phenomenon occurs in the case of hot sterilization of a dressing containing wet layers, in a sealed bag because the humidity of the dressing will turn into water vapor during hot sterilization.

There is therefore a need for a silicone adhesive dressing, sterilizable in the vapor phase or comprising a source of moisture in its structure and sterilizable under heat, comprising in its structure an external breathable film.

Summary of the invention

The present invention proposes to solve the

ZODIA1-FR-1_TEXTE depose_so / ag problem posed by the prior art by providing in particular a dressing comprising a waterproof peelable outer layer. Thus, the present invention relates to an adhesive dressing covered on one of its faces by a peelable external layer comprising a plastic film, impermeable to vapor, from 20 μm to 200 μm in thickness and said peelable external layer having on its internal face an adhesive layer, continuous or discontinuous.

In the context of the present invention, the term "external" means that said peelable layer is covered only on one of its faces (called internal face), the other face being accessible from the outside. In other words, the “external” face is the face opposite to the face of the dressing intended to be in contact with the skin.

The outer layer will have to be peeled so that the dressing regains its initial properties of flexibility and breathability.

The peelable outer layer will be able to facilitate the handling of the dressing by improving its rigidity. In fact, very breathable and conformable dressings are generally very thin and difficult to handle. This often makes dressing very difficult and often impossible to reposition.

The rigidity of the peelable outer layer can easily be adapted as required. The control of the thickness and of the material of the plastic film included in this peelable film makes it possible to obtain more or less rigid films.

Advantageously, the stiffness of said plastic film, as measured according to standard ASTM D 747-99 (eg with Stiffness Tester equipment from the Taber brand equipped with jaws of extreme sensitivity), is greater than 40, even more preferably greater than 60 and quite preferably greater than 80 units of stiffness.

ZODIA1-FR-1_TEXTE depose_so / ag

The peelable outer layer is also advantageously repositionable if necessary.

In the case of a silicone dressing comprising a source of humidity and hot sterilized (eg a wet compress), or sterilized in the vapor phase, the vapor emitted during the hot sterilization of the adhesive dressing will not be able to interfere with the layer of adhesive silicone because it will be blocked by the external peelable waterproof layer

steam of water. In the frame of this invention, the term "Covered " hears mean that layer is placed from

so as to form a physical barrier with respect to the covered layer. Preferably, the term “covered” is intended to denote continuous contact between the layers mentioned.

In the context of the present invention, the term “permeable to water vapor” is intended to denote vapor breathability known by the acronym MVTR (for moisture vapor transmission rate) greater than 100 g / m ² / 24h measured according to standard NF EN 13 726-2. In contrast, the term "water vapor impermeable" is intended to designate a breathable vapor less than 10 g / m ² / 24h measured according to the same standard EN 13 726-2.

In the context of the present invention, the term "peelable" is intended to denote an adhesive film which can be peeled off from the surface to which it is directly associated without damaging it or leaving residues. Thus the adhesive strength of the "peelable" film, which can be measured by a T peel test according to standard ASTM D 1876, is less than the adhesive strength of the dressing on the skin, so that the shrinkage peelable film does not peel the dressing off the patient's skin. According to a preferred embodiment of the invention the adhesion strength of the peelable film is less than 70%, even more preferably

ZODIA1-FR-1_TEXTE depose_so / ag less than 50% and quite preferably less than 30% of the value of the strength of adhesion of the dressing to the skin. This property is provided by the adhesive layer of said peelable outer layer.

According to a preferred embodiment of the invention, the adhesive layer of the peelable outer layer consists of an adhesive silicone.

According to a preferred embodiment of the invention, the adhesive silicone layer constituting the adhesive layer of the peelable external film has a basis weight between 2 and 100 g / m ² . According to an even more preferred embodiment of the invention, said layer of adhesive silicone constituting the adhesive layer has a basis weight of between 15 g / m2 and

25g / m2.

According to a plastic film preferred embodiment of the invention, the peelable external film is made of a material chosen from polyethylene.

polyester,

When the polypropylene dressing or according to the invention is intended to be sterilized hot, the plastic film is preferably made of polyester and impermeable to steam.

Advantageously, said plastic film is made of polyester, which gives the final dressing a handling which it is not possible to obtain with other peelable films available on the market. Indeed, peelable films, dressings currently available, do not include adhesive layers but are obtained by co-extrusion of a peelable film (in PE) and a layer forming the dressing (in PU). Although the thickness of the coextruded peelable film can be adjusted, it does not allow an adequate rigidity to be obtained.

According to a preferred embodiment of the invention, the plastic film of the peelable external film has a thickness of between 40 μm and 60 μm.

According to a preferred embodiment of the invention, the plastic film of the peelable external film is treated with a zodiai-fr-i_texte depose_so / ag corona treatment or by coating with a bonding primer before being coated with the layer of adhesive silicone.

According to a preferred embodiment of the invention, the dressing according to the invention further comprises a layer of adhesive silicone intended to be in contact with the skin of the patient, different from the adhesive layer of the peelable film.

According to a preferred embodiment of the invention, the dressing according to the invention comprises a wet layer. In the context of the present invention, the term “wet layer” is intended to denote an absorbent foam, a woven or nonwoven fabric, a hydrogel, a superabsorbent or a mixture of these materials, comprising more than 10% by weight of liquid.

The present invention also relates to a method for hot sterilization of a dressing according to the invention.

Brief description of the drawings

The figure 1 present a view cutting a layer external peelable usable in the dressing according to 1'invent ion. The figure 2 present a view of cutting a bandage according to 1 ' invention. The figure 3 present a view of cutting a bandage

according to the prior art.

Description of the embodiments

The nonlimiting embodiment presented in FIGS. 1-2 comprises a peelable external layer 2 comprising a vapor-impermeable plastic film 3 and an adhesive layer 4.

This peelable outer layer 2 has a rigidity making it possible to easily handle the dressing 1. It waterproofs the dressing and prevents the penetration of water vapor during the step of hot sterilization of the dressing 1 according to the invention.

ZODIA1-FR-1_TEXTE DEPOSE_SO / AG

The vapor-impermeable plastic films 3 which can be used in the context of the present invention are chosen so as to be able to withstand the sterilization temperatures. Preferably, these films are made of polyester, but it is also possible to use films of polypropylene or polyethylene, in particular in the case where the peelable film only serves to stiffen the dressing.

The adhesive layer 4 can be continuous, that is to say cover the entire surface of the plastic film 3 or discontinuous, that is to say cover only certain areas of the same face with the plastic film 3. Advantageously, the adhesive layer 4 consists of an adhesive silicone. This adhesive layer must be specially formulated to obtain the appropriate level of adhesion, for example by mixing and / or diluting formulas well known to those skilled in the art and commercially available. Mention may in particular be made of the ranges Silbione® (Bluestar), Silpuran® (Wacker), Silopren® (Momentive) and Soft Skin Adhesive® (Dow corning). In fact, the adhesive strength of this adhesive layer must not be too strong so as not to peel off the dressing from the patient's skin when it is removed, or be too weak not to fall off during sterilization or storage of the dressing and thus no longer fulfill its sealing function.

The grammage of the adhesive layer 4 is between 2 and 100 g / m ² and more particularly between 15 and 25 g / m ² .

The association between the plastic film 3 and the adhesive layer 4 can be carried out by any process known to those skilled in the art. Among these, mention may especially be made of coating. In order to improve the adhesion of the adhesive layer 4 to the plastic film 3, the plastic film 3 can in particular be treated beforehand by a corona treatment and / or with a bonding primer (eg a silicone compatible with the silicone layer adhesive 4),

ZODIA1-FR-1_TEXTE depose_so / ag prior to the removal of the adhesive layer 4.

The peelable outer layer 2 advantageously covers a breathable film 5. The latter is advantageously flexible in order to allow optimal conformability of the dressing. This type of breathable film is advantageously waterproof, permeable to water vapor (MVTR breathability> 100 g / m ² / 24h). Those skilled in the art know how to choose the most suitable materials and thicknesses according to the intended use. PU is a preferred material, but other materials can also be used such as PE.

For the sake of clarity, it is specified the assembly consisting of the peelable external layer 2 and the breathable film 5 is not obtained by co-extrusion. The peelable outer layer 2 is associated with the breathable film 5 after the production of said peelable outer layer 2.

The breathable film 5 is advantageously covered on one of its surfaces by a continuous or discontinuous layer of adhesive silicone 6.

The latter preferably covers the entire surface of the breathable film 5 in a discontinuous - continuous - manner.

It is also possible to envisage embodiments where a part of the surface of the breathable film 5 is not covered by the layer of adhesive silicone 6. The grammage of the adhesive silicone layer 6 is between 50 and 500 g / m ² and more particularly between 150 and 250 g / m ² . On the face opposite to the face in contact with the breathable film 5, the adhesive silicone layer 6 can be partially covered by a wet layer 7. This wet layer 7 is more particularly intended to be in direct contact with the wound. It can in particular be a hydrophilic foam, a woven or nonwoven fabric, a hydrogel, a superabsorbent or a mixture of these materials.

The solution included in said wet layer 7 can comprise a pharmaceutical preparation. Among these

ZODIA1-FR-1_TEXTE DEPOSE_SO / AG, we can notably mention antiseptics, agents promoting wound healing.

The surface of the adhesive silicone layer 6 not covered by the wet layer 7 is covered in whole or in part, and preferably entirely, by a protective film 8 impermeable to water vapor. The latter makes it possible to prevent the adhesive surface from sticking to the sachet, or accumulating contaminants (dust, fibers, etc.) before the use of the protective waterproof dressing 1 can be part of the wet layer, the invention is intended to be according to the invention. The film also cover all or When the dressing according to hot sterilized, the protective film 8 is preferably made of polyester.

Example

In order to show the effectiveness of the adhesive bandage according to the invention, it has been verified that following hot steam sterilization, the peelable outer layer 2 is still stuck to the rest of the bandage 1 and that there is no of water between the layer of adhesive silicone gel 6 and protective film 8.

In our example, the peelable film 2 was produced with a PET support (polyester).

This has been validated using laboratory tests. An adhesive dressing as described in Figure 2 was subjected to steam sterilization for 90 min at 120 ° C.

The most significant results are presented in the 3 tables below:

Table 1

Standard Product before sterilization Product after sterilization T-coat breathable film 5 / peelable film 2 (N / 25mm) ASTM D 1876 0.10 0.12

ZODIA1-FR-1_TEXTE depose_so / ag

It can be observed that the steam sterilization has no influence on the adhesive power of the peelable external layer 2 on the breathable film 5. Thus the steam sterilization 5 does not modify the ease of removal of the peelable film 2, nor does it weaken its grip on the breathable film 5.

ZODIA1-FR-1_TEXTE depose_so / ag

Table 2

standards Product before sterilization (after removal of peelable films 2 and protective film 8) Product after sterilization with peelable film (after removal of peelable films 2 and protective film 8) MVTR (g / m ² / 24h) NF EN 13 726-2 10,000 10,000 slip breathable film 5 ISO 8295 0.28 0.27

The starting product (layers 5 and 6) retains its initial breathability and slipperiness properties well after sterilization carried out in the presence of the peelable outer layer 2. After removal, the peelable layer 2 therefore leaves no residue on the film. Breathable PU 5, and does not change its initial surface condition.

Table 3

standards Product as is Product after sterilization, without peelable film 2 Product after sterilization, with peelable film 2 Adhesive power of the adhesive layer 6, after removal of the protective film 8, on PolyCarbonate (N / 25mm) FINAT repository 0.8 0.6 0.8

It can be observed that when sterilization is carried out without protecting the breathable film 5 of the dressing 1, the adhesive silicone 6 loses part of its adhesive power (0.6 instead of 0.8 N / 25 mm, ie a loss of 25%). As previously explained, without a peelable film 2, the silicone which is hydrophobic loses its adhesion on contact with the water droplets resulting from sterilization and transferred through the breathable film 5. This loss of adhesive power is significant. However, when sterilization is carried out with the peelable outer layer 2, the adhesive power of the adhesive silicone layer 6 is retained.

ZODIA1-FR-1_TEXTE depose_so / ag

Thus, there is an external peelable dressing 1 initials.

demonstrated in this example that the layer makes it possible to sterilize by hot silicone vapor while retaining its properties

ZODIA1-FR-1_TEXTE depose_so / ag

Claims (8)

1. adhesive dressing (1) covered on one of its faces by a peelable external layer (2) comprising a plastic film (3), vapor impermeable, from 20 pm to 200 pm thick and said peelable external layer (2) having on its internal face an adhesive layer (4), continuous or discontinuous. 2. Adhesive dressing (1) according to the preceding claim characterized in that the adhesive layer (4) of the peelable outer layer (2) consists of an adhesive silicone. 3. adhesive dressing (1) according to one of claims 1 to 2 characterized in that the adhesive silicone layer constituting the adhesive layer (4) of the peelable film (2) has a grammage between 2 and 100 g / m ² . 4. adhesive dressing (1) according to one of claims 1 to 3 characterized in that the plastic film (3) is in a material selected from polyester, polypropylene or polyethylene. 5. Dressing (1) adhesive according to one of claims 1 to 4 characterized in that the plastic film (3) has a thickness between 40pm and 60pm. 6. adhesive dressing (1) according to one of claims 1 to 5 characterized in that the plastic film (3) is treated by a corona treatment or by coating with a bonding primer, prior to the deposition of the layer adhesive 4. 7. adhesive dressing (1) according to one of claims 1 to 6 characterized in that it further comprises a layer zodiai-fr-i_texte depose_so / ag of adhesive silicone (6). 8. Adhesive dressing (1) according to one of claims 1 to 7 characterized in that it further comprises a layer 5 wet.