HK1148765A - Micro-and/or nano-structured protective or process film - Google Patents

Description

Micro-and/or nano-structured protective or treatment film

Technical Field

The invention relates to a protective or treatment film made of a thermoplastic material for producing laminates for medical technology, and to a laminate comprising a transdermal system containing an adhesive and a protective or treatment film which is adhered to the adhesive of the transdermal system by a surface.

Background

In the manufacture of medical technology laminates, such as ready-to-use transdermal therapeutic systems, a wide variety of films are used. A film type, for example, used as a carrier film, is permanently affixed to an adhesive-containing layer of a transdermal system. Another type of film, for example, used as a protective and treatment film, should be removable from the adhesive-containing layer after its use without residues. Finally, the film is a visbreaking equipped film.

In systems which have been treated for skin, the protective and treatment films have hitherto been provided with a viscosity-reducing coating, for example a silicone coating or a fluoropolymer coating. In this case, a base film is coated with a second material which must be taken into account in the formulation of the transdermal system. One such coating requires a pretreatment of the film surface, for example by means of a corona pretreatment, whereby polar groups are produced on the base film surface, the material of the coating adhering strongly to the base film surface. In this very costly method, there is in particular the risk of inadequate adhesion of the coating to the base film as a result of inadequate pretreatment. Furthermore, during the coating process, fluctuations in the application of the coating may occur up to the point of the defect. This may locally result in high adhesion, thus interfering with the controlled process of laminate manufacture or losing the functionality of the transdermal system.

Disclosure of Invention

The object of the invention is therefore to effectively prevent the adhesive from adhering to the protective and treatment film.

This object is achieved by the features of the independent claims. To this end, the protective or treatment film comprises at least one surface which has a plurality of recesses and/or a plurality of non-recessed areas. The spacing between two adjacent recessed portions and/or the spacing between two adjacent non-recessed regions is less than five times the thickness of the film. Furthermore, the depth of the recessed portion is at least 1.2 nm and at most 95% of the film thickness.

Drawings

Further details of the invention emerge from the dependent claims and the following description of the exemplary embodiments.

FIG. 1: a laminate product comprising a transdermal system and a protective film;

FIG. 2: details of a protective or handling film;

FIG. 3: details of an adhesive drop on a protective or handling film;

FIG. 4: protecting or treating the sharp-shaped structures of the film;

FIG. 5: micro-and nano-structured (Mikro-und nanostrukturrierte) protective or treatment films;

FIG. 6: variations of micro-and nano-structured protective or handling films;

FIG. 7: manufacturing a laminated product having a protective film;

FIG. 8: the manufacture of a laminate on a process film.

Detailed Description

Fig. 1 shows a laminate product 10 comprising a transdermal therapeutic system 21 and a protective film 31. One such laminate product 10 is, for example, a ready-to-use adhesive plaster which is removed from the package. The patient must remove the protective film 31 immediately prior to use so that the transdermal therapeutic system 21 can be secured to the skin with the adhesive-containing layer 22.

The transdermal therapeutic system 21 is, for example, a plaster 21 with an adhesive matrix containing biologically active substances. The biologically active substance 23 and the binding agent 24 are arranged, for example, in a common binding agent-containing layer 22 on a carrier film 27. The adhesive 24 may also be provided in a layer separate from the biologically active substance 23, for example, in a multi-layer transdermal system 21. In a top view of the skin treatment system 21, the carrier film 27 and the biologically active substance and the adhesive layer 22 have, for example, the same dimensions. In the embodiment of fig. 1, a protective film 31 is positioned beneath the bioactive material and adhesive layer 22, and is adhered to, for example, the bioactive material and adhesive layer 22. By adhering it is meant that the protective film 31 can be peeled off from the biologically active substance and the adhesive layer 22 without residue using little manual force. For example, the specific force consumption required for peeling is less than 5 newtons per 25 mm width of film. In contrast to adhesion, an adhesive bond produces a strong connection which is less residue-free and can be torn open only with a high force consumption, for example with a specific force greater than the force value.

The protective film 31 extends beyond the layer of biologically active substance and adhesive 22, for example at each edge 29. In embodiments in which the laminate 10 has multiple layers or separate biologically active substances 23 and adhesive 24, the protective film 31 is disposed on the adhesive-containing layer 22 remote from the carrier film 27. The laminate 10 may also be made without the bioactive material 23.

The adhesive 24 ensuring adherence to the skin of the patient when applying the transdermal therapeutic system 21 is, for example, pressure sensitive. The adhesive 24 essentially comprises, for example, a matrix-forming adhesive paste. For this purpose, for example polyacrylates, silicones, polyisobutenes, raw rubber, synthetic homopolymers like raw rubber, copolymers and block copolymers, butyl rubber, styrene/isoprene copolymers, polyurethanes, ethylene copolymers, polysiloxanes or styrene/butadiene copolymers may be used individually and/or in combination. However, the adhesive 24 may also comprise other substances, such as physiologically effective substances, colorants, plasticizers, tackifiers, penetration enhancers, etc. The surface tension of the adhesive 24 is, for example, between 30 and 50 milli-newtons per meter relative to its vapour phase.

The protective film 31 is in this embodiment made of a thermoplastic material, such as polyester, polyethylene, polypropylene or the like. The membrane 31 is for example made aromatic, watertight and/or oxygen tight. The thickness of which is for example one tenth of a millimeter. At least for example the non-polar surface 32 of the protective film 31 is free of silicone or fluoropolymer coating.

The thermoplastic material has, for example, a surface tension in the case of smooth surfaces which is equal to the surface tension of the adhesive 24 used or deviates therefrom by, for example, a maximum of 20%. A smooth surface of the adhesive 24 and the film material thus has a strong tendency to adhere to each other.

In fig. 1 the surface 32 of the protective film 31 directed towards the system 21 undergoing skin treatment has recesses 33 and areas 34 without recesses. Fig. 2 shows an example of one such structure. The structure shown here as a fragment has cylindrical recesses 33 which are surrounded by grid-shaped, non-recessed regions 34. The depth of the recessed portion 33 is, for example, 100 nm. It may be between 1.2 nanometers and 95% of the film thickness. The diameter of the recess 33 shown here is for example 50 nm. It may for example be at most five times the film thickness.

The grid struts 35 of the regions 34 which are not recessed here have a thickness of, for example, a maximum of 50 nm, so that in the present exemplary embodiment two mutually adjacent recesses 33 have a spacing of 50 nm. The spacing may also be up to five times the film thickness. The end surface 36 is, for example, a flat surface.

In the present embodiment, a large number of recessed portions 33 and regions 34 that are not recessed are uniformly provided. But the structure may be provided unevenly and the depth of each recess 33 may be different. The bottom surface 37 can be designed to be planar, concave, convex, etc.

In a construction with a large number of non-recessed regions 34, these regions can be configured, for example, as posts with a square, circular, rectangular, triangular, etc. cross section. The end face 36 can then be of planar or convex design. The non-recessed regions 34 may be configured as cones or pyramids, mushrooms, etc.

The formation of the surface 32 results in an effective surface which is in contact with the adhesive-containing layer 22 and whose properties differ from those of the base material. Thus, a correspondingly configured surface 32 exhibits a significantly lower surface energy, for example with respect to a coated adhesive bead, than a smooth, uncoated base material. It is thus possible to form, for example, an adhesive bond between the adhesive 24 and the protective film 31 only to a slight extent. Thus effectively preventing adhesion of the protective film 31 to the adhesive-containing layer 22 or the transdermal therapeutic system 21.

The surface 38 of the protective film 31 on the side remote from the transdermal therapeutic system 21 may be smooth or textured.

The manufacture of the laminate product 10 with a transdermal therapeutic system 21 is for example carried out in a multistage, closely coupled process, see fig. 7. Thus, for example, the adhesive-containing substance, which may also be biologically active substance-containing, is first applied as a layer 22 directly onto the protective film 31 unwound from a reel 2 at an application station 1. The protective film 31 serves at this time as a transport film and is transported through the manufacturing apparatus. After drying, the moisture content of the solvent-containing substance is reduced, which is achieved, for example, by means of a drying station 9, or in the case of hot-melt adhesives, after the adhesive mass has cooled, the exposed surface of the adhesive matrix is covered over with further layers and/or carrier films 27. This results in a single-layer or multi-layer laminate intermediate product containing biologically active substances and biologically inactive substances.

Alternatively, a layer of a substance containing a binder can also be applied to the carrier film 27. In this case, the carrier film 27 is a transport film, by means of which the intermediate product is transported through the production device. After the adhesive-containing layer 22 has dried and cooled, it is then covered over its entire surface with further layers and/or a protective film 31. In this case, the protective film 31 is placed on the last adhesive-containing layer 22 in such a way that the structured surface 32 is directed towards the adhesive-containing layer 22.

The individual laminated products 10 are punched out of the thus obtained intermediate product of the laminated product by means of a single-stage or multi-stage punching device 9, for example as laminated product sections 10. By cutting and removing the projecting edges by means of a corresponding contour of the adhesive plaster 21, for example, a complete projection of the protective film 31 of the biologically active substance and the adhesive layer 22 is achieved. The thus prepared separate lengths 10 of laminated product are now fed to a packaging station and are for example packaged in a packaging unit.

In the supply situation, the protective film 31, for example having a length of a few hundred meters and a width of between, for example, 10mm and 7000mm, is wound, for example, on a roll 4. Starting from this reel 4, which reel 4 here has a width of, for example, between 500mm and 2500mm, the protective film 31 is guided, for example, via a support roller 5 and a gravity-loaded oscillating roller 6, to a pressure roller 7.

The surface 32 facing the adhesive layer 22 is prepared before the adhesive substance is applied to the protective or treatment film 31 or before the adhesive substance is covered with the protective or treatment film 31. This can already be achieved outside the adhesive coating device. A structure is applied over the entire surface 32 of the protective film 31, for example by means of injection molding, thermoplastic molding or rolling. It is also conceivable to apply the structure by means of substrate deposition.

The basic structure to be applied can be produced, for example, by means of a holographic recording method. This is for example achieved by techniques of two-ray interference on the basis of coherent optical systems or by conversion by electron beam systems. In this case, for example, a glass plate coated with a photosensitive lacquer is introduced into an interference pattern generated by a laser beam. By exposure, a pattern is formed on the lacquer, the pitch of which lies, for example, in the nanometer range. By means of a glass plate made electrically conductive by metallization, a replica of the structured surface can be produced by means of nickel deposition, for example by electroforming or by electroplating replication. These replicas can be made in the form of plates or thin nickel films. These shapes can then be transferred to the protective film by injection molding, thermoplastic molding or by rolling.

In the production of a laminated product section 10, for example, comprising a carrier film 27, a layer 22 containing biologically active substance and adhesive and a protective film 31, the separating force which is generated for peeling off the protective film 31 depends in particular on whether the coating of adhesive substance is formed directly on the structured protective film 31 or whether the structured protective film 31 is pressed onto it only after the adhesive substance has dried and cooled. If the adhesive substance is applied directly to the protective film, the liquid adhesive substance can penetrate into the structure of the surface 32 more deeply, depending on the viscosity, than would be the case, for example, if the protective film 31 were applied to a dry or cold, highly viscous adhesive layer. The force required to peel the protective film 31 from the adhesive 24 may be greater in the first case than in the second case.

Once the protective film 31 is in contact with the adhesive 24, the adhesive 24 is applied to the non-recessed areas 34 of the protective film 31, see the cross-sectional view in fig. 3. Due to the small contact area, which in the present exemplary embodiment corresponds to a part of the end face 36 of a region 34 which is not recessed, no adhesive 24 can be caught on the protective film 31 when the protective film 31 is peeled off from the biologically active substance and the adhesive layer 22. The skin-treated system 21 can be peeled from the protective film 31 without residue.

Fig. 3 shows, for example, a bead 51 of adhesive. This adhesive bead is exactly the same as an adhesive layer applied, for example, in a planar manner to the structured surface 32 of the protective film 31. After application to the surface 32 of the protective film 31, the adhesive bead 51 shrinks. For example, a contact angle 41 of 160 ° is formed between the adhesive drop 51 and the film 31. The adhesive drops 51 are only loosely applied to the protective film 31 or slightly adhere thereto.

Due to the described micro-and/or nano-architecture of the surface 32, the physical properties of the bond of e.g. the protective film 31 and the adhesive 24 are influenced. This results in a significantly reduced effective surface area relative to a full-scale adhesive application, and thus also in a reduction of the effective surface energy of the film surface 32 relative to the unstructured material. Only a weak adhesive bond is formed between the protective film 31 and the adhesive 24. Preventing the adhesion of the two materials.

Fig. 4 shows an adhesive bead 52 which extends over a plurality of non-recessed regions 34, which are formed here, for example, in the shape of an angular cone. It partially intrudes into each recess 33. Above the adhesive bead 52, an air cushion 59 has been formed in each recess 33, which prevents the adhesive bead 52 from penetrating further into the recess 33. The depth of the recess 33 above the adhesive bead 52 is greater than the effective distance of the chemical and physical adhesive forces between the materials. Finally, the effective distance of the force is, for example, between 0.2 nm and 1 nm. The depth of the recessed portion 33 is at least 1.2 nanometers.

On such an effective surface 42, which is composed of the air cushion 59 and the non-recessed regions 34, which is referred to as a combined surface, for example, the adhesive bead 52 only adheres with little adhesion. For example, it forms a contact angle of, for example, 160 ° in each recess 33 with the side 39 of each non-recessed region 34. Such surface texture properties are particularly desirable if the protective film 31 is coated directly with a liquid adhesive substance.

In fig. 5, a protective or handling film 31 having microstructures 47 and nanostructures 46 is shown, on which a plurality of adhesive drops 53-55 are placed. The microstructures 47 have, for example, a sinusoidal shape in the cross-section shown. The spacing of the peaks 49 (e.g. between one micron and five times the film thickness) is in this embodiment so large that the drops 53-55 of adhesive can follow their contours. A nanostructure 46 is created in the film 31 along the microstructure 47. The pitch of the individual recesses 33 of the nanostructures 46 is, for example, less than one micrometer. The spacing of the non-recessed regions 34 of the nanostructures 46 shown in the cross-sectional view of fig. 5 is also, for example, less than one micron. The nanostructures 46 are constructed, for example, as described in connection with fig. 1-3. The protective or treatment film 31 can also be provided with only one microstructure 47 or only one nanostructure 46.

The air cushion 59 in each recess 33 prevents the adhesive drops 53 from adhering too strongly to the protective or treatment film 31 and prevents the adhesive drops 53 from adhering to the protective or treatment film 31.

Fig. 6 shows a protective or treatment film 31 with a microstructure 47 and a nanostructure 46, wherein the microstructure 47 has a shorter wavelength than in the illustration of fig. 5. The drops of adhesive 56 do not follow the contour of the microstructures 47 but are merely placed on their highest points 49. A protective film 31 having such a laminated structure has particularly good anti-tackiness properties. The stacked nanostructures 46 prevent sticking of the drop 56 if one adhesive drop 56 follows the contour of the microstructure 47, again for example due to temperature or pressure effects. By stacking the microstructures and nanostructures, a protective or handling film 31 can be produced, for example, having hierarchical anti-adhesive properties. The separating force required for peeling the protective or treatment film 31 from the adhesive layer 22 can be adjusted specifically by the configuration selected accordingly according to the application.

Fig. 8 shows a release film 31 having the characteristics and geometric surface structure of the above-described protective film 31 as a handling film 31 in use. The treatment film 31 is, for example, a continuously fed, circumferential film 31, to which the adhesive substance is applied as a viscous solution at a coating device 1. In a subsequent drying station 8 of the laminated product 10, the moisture content is reduced to a desired value. The adhesive-containing layer 22 prepared in this way is then pushed, for example, downward from the treatment film 31 and, for example, onto a carrier film 27. On the side facing away from the carrier film 27, for example, a further cover film 28 is provided. The cover film 28 may have the same surface structure as the treatment film 31 on the side facing the adhesive-containing layer 22.

Upon drying and removal of the adhesive-containing layer 22, no residues of adhesive 24 remain on the handling film 31, so that new, for example biologically active substances and adhesive layers 22 are not adversely affected in the next cycle of the film 31.

The geometry of the surface 32 of the handling film 31 may conform to the shape described in connection with fig. 2-6. Such a treatment film 31 can also be used, for example, for the temporary storage of a laminate 10 or a part of a laminate 10 for a short time. The manufacture of the surface 32 of the anti-tack treated film 31 facing the adhesive containing layer 22 is effected, for example, as described in connection with the first embodiment.

Combinations of the described embodiments are also conceivable.

List of reference numerals

1 bioactive substance and adhesive supply, coating station

2 winding drum

4 reel

5 support roller

6 oscillating roller

7 pressure roller

8 drying station

9 punching device

10 laminated product, laminated product segment

21 transdermal therapeutic system, adhesive plaster

22 comprises an adhesive layer, a biologically active substance and an adhesive layer

23 bioactive substances

24 adhesive

27 carrier film

28 cover film

29 edge

31 detackifying, protecting, or treating films

3231 inner surface

33 recessed part

34 area without recess

35 grid pole

36 end face

37 bottom surface

38 outer surface

39 side surface

41 contact Angle

42 effective surface

46 nanometer structure

47 micron structure

4947 highest point

51-56 adhesive drops

59 air cushion

Claims (4)

1. Protective or treatment film (31) made of a thermoplastic material for producing a laminate product (10) for medical technology, characterized in that,

-the protective or treatment film comprises at least one surface (32) having a plurality of recessed portions (33) and/or a plurality of non-recessed areas (34),

-the spacing of two adjacent recessed portions (33) and/or the spacing of two adjacent non-recessed areas (34) is less than five times the film thickness, and

-the depth of the recess (33) is at least 1.2 nm and at most 95% of the film thickness.

2. Protective or treatment film (31) according to claim 1, characterised in that the configuration featuring the recesses (33) is made on the entire surface (32).

3. Medical-technical laminate (10) comprising a transdermal system (21) comprising an adhesive and a protective or treatment film (31) which is adhered to the adhesive (24) of the transdermal system (21) with a surface (32), characterized in that,

-said protective or treatment film (31) is made of a thermoplastic material,

-the surface (32) has a plurality of recessed portions (33) and/or a plurality of non-recessed areas (34),

-the spacing of two adjacent recessed portions (33) and/or the spacing of two adjacent non-recessed areas (34) is less than five times the film thickness, and

-the depth of the recess (33) is at least 1.2 nm and at most 95% of the film thickness.

4. A laminated product (10) according to claim 3, wherein said adhesive (24) is pressure sensitive.