JPH11315018A - Composite film for surface treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composite film for surface treatment, having excellent water retention power, storable for a sufficient time, sufficient mechanical strengths, especially suitable for skin treatment, comprising a retention layer holding an active aqueous phase and having a specific constitution. SOLUTION: This composite film is obtained by successively bonding (A) a closed layer, (B) a retention layer having an active aqueous phase sealed in the inside and (C) a removable protective layer. The layer B is constituted of a matrix comprising a silicone polymer having dispersed an inclusion composed of the active aqueous phase gelatinized by a gelatinizing agent in the interior. Moreover, the matrix has adhesiveness to a treatment surface and the amount of the gelatinized active aqueous phase is 10-50 wt.% based on the total weight of the layer B. The average dimension of the inclusion of the gelatinized active aqueous phase is 0.05-3 mm and is equal to the thickness of the layer B in its largest size. Further a web for mechanically reinforcing the layer B is embedded inside the face of the layer B at the opposite side of the layer C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a composite film for the local treatment of a surface, in particular of the skin, and to a process for the production of said film. It is well known to apply a film to the skin, which allows a pharmaceutical or cosmetic treatment, especially in the form of an aqueous solution or an aqueous solution, to soak into the skin due to its skin permeation effect.

In particular, European Patent Application EP-A-0,285,
It has been proposed in 563 for this purpose to use a composite film comprising several successive layers in the following order. The first so-called closing layer generally consists of a sheet of material which is impermeable to the treatment and prevents its evaporation and facilitates a skin permeation effect. The second layer, the so-called holding layer, consists of the treatment product. This layer is generally in contact with the skin. The support layer is coated with an adhesive layer that is permeable to the treatment so that the composite film can be easily applied to the skin. Finally, these composite films are often protected during storage by a removable surface film. This surface film can be removed by peeling it off when used,
Also, it is arranged on the side opposite to the side where the closing layer is located.

[0003] In these composite films, it has been proposed to use, as the holding layer, a layer of silicone containing fine droplets of an aqueous phase, particularly an aqueous phase, in a dispersed state. When the composite film is applied to the skin, the water collects in the retaining layer due to the closing layer. Transfer of water and other active substances present in the aqueous phase through the skin is thus facilitated. However, water evaporates quickly from such a retaining layer and after a few hours practically disappears. Therefore, these films cannot be held and stored. It has previously been proposed to significantly reduce the evaporation of water by introducing into the silicone layer an aqueous phase and at least one gelling agent for this aqueous phase (see EP-A-0,117, 278). But in the case of such a film,
When the retention layer is filled with a gelled aqueous phase dispersed in a polymer matrix, it has always been necessary to use an adhesive layer to ensure that the film adheres to the skin for treatment using the skin permeation effect. Was. In fact, as soon as the amount of gelled aqueous phase exceeds about 10% by weight in the retaining layer, the partial nature of the polymerization of the silicone matrix is self-adhesive and sufficient to prevent crushing during use. It becomes practically impossible to produce a silicone polymer matrix having mechanical strength. In this case, if an adhesive layer is used as the holding layer, the effect of permeating the skin is reduced even if the adhesive is permeable to water, and an additional step is required in the manufacturing method. Increase.

The present inventor has provided a composite film which can eliminate the above-mentioned disadvantages. In this film, the silicone polymer matrix contains up to 50% by weight of the gelled aqueous phase, based on the total weight of the retaining layer. The matrix only partially polymerizes to give it self-adhesion. The mechanical strength of the matrix is ensured by the web provided in the matrix and forming the reinforcement of the holding layer. The mesh holes in this web are sufficient to not interfere with the flow of the aqueous phase in which the treatment is to be performed, but also form a barrier between the treatment surface and the contained gel to allow for automatic adhesion of the matrix to the treatment surface Is restrained enough to cause The dimensions of the web-retaining layer and the gel content are determined so that the composite film of the present invention can simultaneously have good treatment effects, easy handling, and automatic adhesion.

Accordingly, the present invention comprises a closure layer, a retention layer which encapsulates an active aqueous phase therein and is associated with the closure layer, and a removable protective layer which is associated with the retention layer. A composite film for local treatment of the surface, wherein the retaining layer is constituted by a matrix of a silicone polymer having an inclusion of an active aqueous phase gelled by at least one gelling agent disposed therein.
(a) the silicone polymer matrix is adherent to the surface to be treated, (b) the gelled active aqueous phase is 10 to 50% by weight of the total weight of the retaining layer, and (c) The average size of the gelled active aqueous phase inclusions is 0.05 to 3 mm, the average size being at most equal to the thickness of the retaining layer, and (d) the opposite side of the closure layer. A composite film, wherein a web for mechanically reinforcing the holding layer is embedded inside the surface of the holding layer.

[0006] The presence of a gelling agent in the aqueous phase significantly slows the evaporation of water from the retention layer, and the composite film made with this retention layer can be stored for a sufficient period of time under normal conditions of use. In addition, more water can be introduced into the holding layer in the presence of the gelling agent. For example, 60% by weight of water can be introduced into the matrix of the retaining layer in the presence of polyvinyl alcohol, but without the gelling agent the water cannot exceed 30% by weight. This description is not intended to be limiting in any way, in which case the cells of the inclusion are torn while handling the film, or if the cells are opened due to being located at the edge of the retaining layer, the aqueous phase It is considered that the amount of the stored aqueous phase is increased because the inclusions do not flow out of the cell where the aqueous phase exists because the inclusions are gelled.
In this case, wear is reduced and drying which begins at the edge of the closure layer is prevented.

In the present application, the silicone polymer is C ₁ -C ₆
A linear organopolysiloxane in which Si atoms are substituted by a group selected from the group consisting of an alkyl group, an aryl group and an ar (C ₁ -C ₂ alkyl group. The terminal silicon atom is trisubstituted. Organopolysiloxanes are particularly useful in U.S. Pat. Nos. 2,541,137 and 2,723,9.
No. 66, No. 2,863,846, No. 2,890,
No. 188, No. 2,927,907, No. 3,000
No. 2,951 and 3,035,016.

In a preferred embodiment of the composite film according to the invention, the surface treated with this film is an area of the skin, and the active aqueous phase comprises at least one cosmetic or pharmaceutical or both.

The aqueous phase consists of water or a water / propylene glycol mixture. The aqueous phase may also be an aqueous solution of at least one cosmetic or pharmaceutical or both active substance. The aqueous phase also consists of an oil emulsion or dispersion containing a water-insoluble substance, such as a fat-soluble active substance. Among the water-soluble or liposoluble cosmetic or pharmaceutical active substances which can be introduced into the aqueous phase or both, these include, but are not limited to:

Cell oxidizing factors such as D-panthenol, spleen extract, guanosine, thymic peptide, oligo elements.
Hydroxyproline, yeast extract, placenta extract, growth factor, Asian centella (Centella asiatica), fetal extract or other biological extracts and other lipids in cerebroside, sufingoseril or ceramide (Ceramide) form An activator having such a regenerative, nutritional or curative or each of these properties.

[0011] Monomethylsilanol lactate, mannuronate, trimethylsilanol and alchemille (alc
hemille).

Film-forming agents and / or tensioning agents such as amniotic fluid, albumin serum and horse serum, or both.

Glycerin, urea, sodium lactate, mucopolysaccharide, amino acid, hyaluronic acid, filaglinol, chitin and chitosan derivatives, peptide, D
Wettable powders such as NA, collagen and elastin.

Vitamin C, B ₂ , H, panthenol, B
₆ , water-soluble vitamins such as PP, folic acid, magnesium 2-ascorbyl phosphate.

Fat-soluble vitamins or derivatives thereof such as vitamins A, E, F, vitamin A palmitate and retinol.

Anti-inflammatory agents such as glycyrrhetinic acid, α-bisabolol, allantoin, palmityl collagenic acid or acetylsalicylic acid.

Extracts of plants such as, for example, crisp, algae, birch, ruscaus or squid raft, two-split Ichigo, carrot, carp or aloe.

Bleaching agents such as hydroquinone or kojic acid.

Xanthate groups such as caffeine, α
-Tocopherol nicotinate, methyl nicotinate,
Menthol, camphor, asiatic acid,
Other specialty agents such as estine, cycloaliphatic acids or thioxolone.

The gelling agent is preferably a gelling agent which swells with water. Among the gelling agents which can be used according to the invention, starch, natural resins (guar gum, gum arabic, tragacanth gum), casein, plant colloids (caraginate, alginate, agar) and preferably natural substances such as gelatin, carboxymethylcellulose Such semi-synthetic cellulose derivatives, polyvinyl alcohol water-soluble vinyl polymers, such as the product marketed by Goodrich under the trade name Carbopol, the superabsorbent with a high swelling rate in water to be the crossover Synthetic polymers such as linked polyacrylates, such as the product marketed by NORSOLOR under the trade name AQUAKEEEP.

The silicone matrix contains dispersed aqueous phase inclusions. The size of this inclusion is controlled by adjusting the agitation used to mix the components during the manufacture of the retention layer.

The retention layer also contains a catalyst that crosslinks the silicone, as is well known. Further, the retaining layer contains dispersed hydrophilic particles of vegetable or mineral nature. These particles may be fibers or powders. The holding layer contains up to 50% by weight of hydrophilic particles, based on the weight of the silicone polymer. The advantage of introducing the hydrophilic particles into the matrix of the retaining layer is that in this case the outflow of the aqueous phase responsive to the treatment of the surface to which the film according to the invention is applied may be enhanced by capillary action.

According to the present invention, the retaining layer comprises a non-perishable web that mechanically reinforces this layer. The web comprises a sheet of perforated plastic material, perforated nonwoven or woven mesh. The nonwoven or mesh is made of natural or synthetic fibers. This is the case, for example, in French Patent 2,620,
No. 914, polyamide mesh.

The retaining layer can be made by mixing the active aqueous phase, which has been gelled by the stirring action, with a non-crosslinked silicone polymer. This retention layer can also be made by mixing the non-crosslinked silicone, the active aqueous phase and the gelling agent by a mixing action.
Mixing by stirring is carried out at 1-3 ° C. or at room temperature or at a temperature at which the gelling agent is in a liquid state to prevent the onset of cross-linking of the silicone polymer. The mixture adapted to form the retention layer includes a cross-linking catalyst. This mixture
25 to 150 ° C for a time period of 1 to 120 min
Heat to a temperature of The amount of cross-linking catalyst and the heating are selected to provide incomplete cross-linking of the silicone in the retention layer so as to take advantage of satisfactory auto-adhesion.

In addition to the retaining layer described above, the composite film according to the invention comprises a closing layer. The closure layer comprises a sheet of thermoplastic material with or without elastomer,
Particularly preferred are sheets made of polyvinyl chloride, a copolymer of ethylene and vinyl acetate, polyethylene, polyester or polyurethane. The sheet is embossed or forms micropores. A non-slip procedure may be used to increase the adhesion between the closure layer and the retaining layer. It is particularly advantageous to select the closure layer with a polyethylene sheet, which is possible by cross-linking the silicone polymer matrix sufficiently to be self-adhesive. This material has the advantage of using polyethylene due to its good water impermeability, and the composite film according to the invention during storage does not dry out of the holding layer if it is adequately protected on the side opposite the closing layer. Is shown.

According to a first embodiment, the removable protective body of the composite film according to the invention is a removable protective surface film covering the holding layer surface opposite the closing layer. According to another embodiment, the removable protective body to which the composite film according to the invention is attached is a container comprising an active aqueous phase. A subassembly consisting of a closure layer and a retaining layer allows a film to be obtained which can be immersed in the container and used for treatment. The retaining layer of this subassembly contains only inclusions consisting of a gelling agent without an active aqueous phase prior to introduction into the container.

If the retaining layer is protected by a removable or peelable protective surface film, it protects the retaining layer during storage of the product or during various handling operations. Remove this film when in use. The protective surface film may consist of a sheet of silicone-treated paper or a sheet of thermoplastic which has been rendered non-adhesive with, for example, varnish. According to a particularly preferred embodiment, the protective surface film is made of polyethylene as well as the closing layer. In such cases, the protective surface film has a greater thickness than the closure layer and is made more rigid so that it can be more easily separated when using the product. This separation is more easily achieved because the protective surface film is applied to the retaining layer on the side of the retaining layer where the web is located, and in this case the area of adhesion of the protective surface film to the self-adhesive silicone polymer matrix is reduced. Become. It has been found that particularly satisfactory results are obtained when the closure layer has a thickness of 0.01 to 0.1 mm and the protective surface film has a thickness of 0.05 to 0.3 mm. The thickness of the protective surface film is 1.5 to 3 times the thickness of the closing layer.

As is well known, the composite film of the present invention can be cut along a suitable contour corresponding to the surface area to be treated. The periphery of this contour may then be compressed to bring the closure layer and the protective surface film into substantial contact except for most of the retaining layer. As described above, where the closure layer has a smaller thickness than the protective surface film, providing more rigidity to the protective surface film results in preferential distortion of the closure layer due to compression. In this case, the product has a flatter mating surface, i.e. it lies approximately in the same plane as the surface of the retaining layer where the edge of the closing layer comes into contact with the skin.

In this case, a comfortable feeling at the time of fitting and an improvement of the external smoldering of the processing area are obtained, and the generation of the skin penetration effect is promoted.

When applied to the human body, the composite film according to the present invention is well known in the form of a mask applied to the face, a semi-annular shape applied to the chest, or applied to a specific area of the human body. It can be cut into a disc shape or any other shape required for this.

According to a preferred embodiment, the silicone polymer containing inclusions, cross-linking catalyst and optionally other additives is
Keep stirring continuously at a temperature of 50 to 60 ° C. in the hopper. The mixture is delivered by a pump or cock, for example, in front of a doctor blade through which a removable protective surface film and web exiting the roll pass underneath. Similarly, the closing sheet coming out of the roll should be at the top prior to calendaring. The thickness of the retaining layer preformed by the upstream doctor blade is controlled by passing under the calender.
The composite film obtained in this case is passed through a hot air tunnel for adjusting the temperature and the passing speed of the composite film so that an appropriate polymerization time can be obtained.

In order to obtain the product constituting the composite film of the present invention, for example, a first treatment for arranging the web of the holding layer on the protective surface film is used. A mixture of a silicone polymer with a gelled aqueous phase inclusion is coated on the assembly. The sheet constituting the closing layer applies to the layer thus formed. The composite film is cut such that its edges have a contour corresponding to the surface area to be treated.
The perimeter of the cut film is compressed to extrude most of the mixture that makes up the retaining layer in the compression zone. The product is heated to cause partial cross-linking of the silicone polymer of the retaining layer.

However, according to another method, the gelling agent comprising the superabsorbent crosslinked polyacrylate in the non-hydrated state is introduced and dispersed in the silicone polymer of the holding layer. This mixture is coated on the sheet constituting the closing layer. A web of composite film is applied. Partial cross-linking of the silicone polymer of the retaining layer occurs, and the film thus obtained is immersed in the active aqueous phase contained within the container. This container constitutes a protective body for the composite film.

EXAMPLE 40 g of an aqueous solution containing 10% by weight of D-panthenol are added to 2 g of polyacrylate powder (commercially available under the trade name AQUA-KEEP10SHNP from the company Noah Solar). Slow mixing is performed by a stirrer with perforated blades. 100 g of organopolysiloxane (commercially available from Dow Corning under the trade name Silastic MDX4-4210 medical grade) is then added. Silastak MDX4-4210 commercially available from Dow Corning
6 g of medical grade hardener are added with stirring at 1000 rpm and the stirring action is continued for 10 min.

The product homogenized in this way is spread on a 0.2 mm thick polyethylene sheet into 0.5 mm thick layers. The surface of this protective surface film has been pretreated with silicone oil to reduce its adhesion. Prior to coating, a web consisting of a polyamide network of about 20 mesh / cm ² with an average mesh size of 0.4 mm and a thickness of 0.1 mm is applied to the protective surface film.

A 0.04 mm thick polyethylene film (not slid) is applied to the upper side of the coating. This combination is 3 mi inside the vent
Heat to 90 ° C. for n days.

After cooling, a composite film is obtained which comprises a closing layer and a holding layer comprising a matrix of a partially polymerized silicone polymer. The whole is provided with a protective surface film that, when removed, allows the silicone polymer matrix to adhere to the skin. This protective surface film can be easily removed. After use, the film can be easily separated from the skin to which it has been applied. These two results are:
This is based on the reinforcement formed by the web of the holding layer. This is obtained even when the degree of polymerization of the silicone polymer matrix is low.

The composite film is cut into single pieces of the desired dimensions and applied to the affected area of the skin, for example to the dermatitis or to the burn with a slight pressing force. This composite film should be applied in the evening. The drug is released during the night and the spent matrix is removed in the morning.

Claims (1)

[Claims] 1. A method according to claim 1, further comprising a closing layer, a retaining layer enclosing the active aqueous phase therein and associated with said closing layer, and a removable protective layer associated with said retaining layer. A composite film for topical treatment of a surface, wherein the layer is constituted by a matrix of a silicone polymer with an inclusion of an active aqueous phase gelled by at least one gelling agent disposed therein. The silicone polymer matrix is adhesive to the surface to be treated, (b) the gelled active aqueous phase is 10 to 50% by weight of the total weight of the retention layer, and (c) the gelled The average size of the active aqueous phase inclusions is 0.05 to 3 mm, and this average size is at most equal to the thickness of the retaining layer, and (d) the retaining layer on the side opposite to the closing layer. Inside this face Composite film comprising at crowded embedded web to mechanically reinforce the layer, the.