EP3206757A1

EP3206757A1 - Method for application of a cosmetic composition containing at least one active substance to skin and a means for carrying out this method for application of the cosmetic composition

Info

Publication number: EP3206757A1
Application number: EP15797579.8A
Authority: EP
Inventors: Ladislav Mares; Jana Svobodova; Fatma YALCINKAYA
Original assignee: Nafigate Corp AS
Current assignee: NAFIGATE COSMETICS, A.S.
Priority date: 2014-09-30
Filing date: 2015-09-30
Publication date: 2017-08-23
Also published as: CZ2014674A3; WO2016050227A1

Abstract

The invention relates to a method for application of a cosmetic composition in the form of a (hydro)gel or a cream containing at least one active substance, in which this cosmetic composition (3) is applied on the skin (1) at the site (2) of desired action, whereupon it is at least partially overlaid by a barrier layer (4), which contains polymeric nanofibers made of or containing as one of its components at least one biocompatible polymer and/or its copolymer and/or at least one biopolymer and/or its derivative, and/or prior to being applied on the skin (1), the cosmetic composition (3) is applied on the surface of such a barrier layer (4), which is subsequently put with its surface with applied cosmetic composition (3) on the skin (1), by which means the cosmetic composition (3) and the site (2) of desired action of its active substance/substances are closed against external influences, but remain accessible to atmospheric oxygen. The invention also relates to a means for the application of the cosmetic composition (3) containing at least one active substance, the means containing the cosmetic composition (3) applied on a barrier layer (4), which contains polymeric nanofibers made of or containing as one of its components at least one biocompatible polymer and/or its copolymer and/or at least one biopolymer and/or its derivative.

Description

Method for application of a cosmetic composition containing at least one active substance to skin and a means for carrying out this method for application of the cosmetic composition

Technical field

The invention relates to a method for the application of a cosmetic composition containing at least one active substance on the skin.

The invention also relates to a means for carrying out this method of the application of the cosmetic composition.

Background art

Nowadays, numerous cosmetic compositions containing one or more active substances are used, especially those containing active substances from the group consisting of substances with hydration effects, such as polysaccharides, hyaluronic acid, salts of hyaluronic acid, chitosan and its derivatives, derivatives of glucuronic acid (e.g. pectin, sodium-calcium salt, sodium salt or another salt of microdispersed oxidised cellulose (=copoIymer of polyanhydroglucose and 1 ,4-B-D-polyanhydroglucuronic acid)), polypeptides and their hydrolysates (e.g. collagen, elastin, gelatin), synthetic polymers (e.g. polyglycols, polyesters), and/or from the group consisting of substances with a keratolytic effect, such as salicylic acid, lactic acid, glycolic acid, mandelic acid, azelaic acid or ellagic acid, and also vitamins, amino acids, antioxidants, coenzymes, substances with a soothing effect (e.g. plant extracts, such as aloe vera or chamomile, panthenol, etc.), substances based on the principle of mechanical pore cleansing (e.g. zeolite, kaolin, titanium dioxide, zinc oxide, etc.) and/or from the group consisting of active substances which are found in natural oils and essential oils (e.g. argan oil, almond oil, macadamia oil, tea tree oil, etc.), etc., including substances exhibiting antimicrobial properties or other known active substances stimulating skin regeneration. The aim of using these compositions is especially skin rehydration, which contributes to at least partial reducing or eliminating wrinkles and/or to accelerating/improving the healing process of wounds/scars or other undesirable skin defects. These cosmetic compositions are applied on the skin surface at the site of desired action, e.g. in the form of a (hydro)gel or a cream (ointment), or they are applied by injection as a filler.

The disadvantage of their application in the form of a (hydro)gel or a cream is the fact that neither the applied cosmetic composition, nor the site of the desired action are protected in any way form the external environment and its influences. Consequently, biological and/or mechanical impurities may cling to the applied cosmetic composition, and at the same time water may freely evaporate from it, which may change its properties. Due to the nature of some active substances, e.g. high-molecular hydrogels of hyaluronic acid, which are currently used in cosmetic compositions most widely, it is also highly likely that when using this method for application, the skin pores will not open as required and hyaluronic acid will not penetrate into the deeper layers of the skin, and so the resulting aesthetic effect will be only limited to the skin surface and will be short-term.

Moreover, the cosmetic composition applied freely on the skin is exposed to the risk of accidental removal, whereby a certain aesthetic disadvantage, especially in case of prolonged application, is also its visibility.

Furthermore, applying a cosmetic composition by injection is for the user rather unpleasant and requires specialist supervision.

The goal of the invention is to eliminate the drawbacks of the current methods for the application of cosmetic compositions by proposing a method for the application of cosmetic compositions on the skin in the form of a (hydro)gel or a cream (ointment), whereby this method would protect the site of aplication as well as the applied composition from external influences.

In addition, the aim of the invention is also to provide a means for the application of the cosmetic composition by the method according to the invention.

Principle of the invention

The goal of the invention is achieved by a method for the application of a cosmetic composition in the form of a (hydro)gel or a cream containing at least one active substance, in which the cosmetic composition is applied on the skin at the site of desired action, whereupon it is at least partially overlaid by a barrier layer, which contains polymeric nanofibers made of or containing as one of its components at least one biocompatible polymer and/or its copolymer and/or at least one biopolymer and/or its derivative, and/or before being applied on the skin, the cosmetic composition is applied on the surface of the barrier layer, which is then put on the skin by its surface with applied cosmetic composition, by which means the cosmetic composition and the site of desired action of the active substance/substances close against external influences, but remain accessible to atmospheric oxygen.

Preferably, the barrier layer contains at least one active substance which is identical with the active substance of the cosmetic composition and/or at least one active substance which strengthens and/or enhances and/or complements the effect of the active substance/substances of the cosmetic composition, and/or at least one antimicrobial substance.

If the barrier properties of the barrier layer were insufficient, it is advantageous if this layer is after being overlaid or after the application of the cosmetic composition, or before the application of the cosmetic composition at least partially overlaid by an auxiliary layer, which contains polymeric nanofibers made of or containing as one of its components at least one biocompatible polymer and/or its copolymer and/or at least one biopolymer and/or its derivative.

Also the auxiliary layer may in case of need contain at least one active substance identical with that contained in the cosmetic composition and/or at least one active substance which strengthens and/or enhances and/or complements the effect of the active substance/substances of the cosmetic composition and/or at least one antimicrobial substance.

A suitable biocompatible polymer for the preparation of the barrier layer or, if necessary, the auxiliary layer, is particularly a biocompatible polymer selected from the group consisting of polycaprolactone (PCL), polylactic acid (PLA), copolymer of lactic acid and glycolic acid (PLGA), polyglutamic acid (PGA), polyvinyl alcohol (PVA), polyethylene oxide (PEO), their copolymers, derivatives or their mixtures. A suitable biocompatible polymer for the preparation of the barrier layer or, if necessary, the auxiliary layer, is especially biopolymer selected from the group consisting of polysaccharides (hyaluronic acid, chitosan, pectin, copolymers of glucuronic acid and its derivatives), alginates, peptides and their hydrolysates (collagen, elastin, silk fibroin, zein), cellulose, their copolymers, derivatives or their mixtures.

The barrier and/or the auxiliary layer may further contain nanofibers made of synthetic polymer and/or nanofibers containing synthetic polymer as one of its components which provides suitable mechanical properties to this layer. The suitable synthetic polymer is especially synthetic polymer selected from the group consisting of polyamide (PA), polyvinylidene (di)fluoride (PVDF), polyurethane (PUR), their copolymers and mixtures.

To reduce the visibility during the application, it is advantageous if the barrier layer and/or the auxiliary layer is overlaid by a cover layer of material in the form of a (hydro)gel or a cream, which contains a lipid (oil) component, which penetrates into the interfibrous spaces of the barrier layer and/or the auxiliary layer or into its nanofibres and increases its transparency. In another variant, the barrier layer and/or the auxiliary layer is overlaid by a cover layer containing a pigment. If necessary, also the cover layer in any of the embodiments may contain at least one active substance which is identical with the active substanceof the cosmetic composition and/or at least one active substance which strengthens and/or enhances and/or complements the effect of the active substance/substances of the cosmetic composition, and/or at least one antimicrobial substance. In a preferred embodiment, the cover layer is formed directly by the cosmetic composition.

At least one active substance which strengthens and/or enhances and/or complements the effect of the active substance/substances of the cosmetic composition, present in the barrier layer and/or in the auxiliary layer and/or in the cover layer, is preferably an active substance selected from the group consisting of antioxidants, vitamins, proteins, coenzymes, amino acids, peptides and their hydrolysates, synthetic polymers, salicylic acid, lactic acid, glycolic acid, mandelic acid, azelaic acid, ellagic acid, plant extracts, zeolites, kaolin, titanium dioxide, zinc oxide, natural oils, natural essential oils.

To enhance the effect, it is advantageous if the barrier layer and/or the auxiliary layer is moistened before the application, whereby during subsequent drying shrinkage occurs, causing contraction of the skin, which may contribute to the penetration of the active substance/substances of the cosmetic composition into the skin.

Furthermore, the aim of the invention is achieved by a means for the application of the cosmetic composition containing at least one active substance, in which the cosmetic composition is arranged on a barrier layer which contains polymeric nanofibers made of or containing as one of its components at least one biocompatible polymer and/or its copolymer and/or its derivative and/or at least one biopolymer and/or copolymer and/or its derivative.

If necessary, on the surface of the barrier layer, which is opposite to the surface with the applied cosmetic composition, is arranged an auxiliary layer made of or containing as one of its components at least one biocompatible polymer and/or its copolymer and/or its derivative and/or at least one biopolymer and/or its copolymer and/or its derivative, or the cover layer.

The barrier layer and/or the auxiliary layer and/or the cover layer preferably contains at least one active substance which is identical with the active substance of the cosmetic composition and/or at least one active substance which strengthens and/or enhances and/or complements the effect of active substance/substances of the cosmetic composition, and/or at least one antimicrobial substance.

For storage and handling purposes, this means is at least from one side overlaid by a protective layer based on a polymer in the form of a foam, a film, a foil, a woven and non-woven fabric or their combinations.

The aim of the invention is further achieved by a method for the application of a cosmetic composition containing hyaluronic acid on the skin with a wrinkle/wrinkles, whose principle consists in that after this cosmetic composition is applied on the skin, it is at least partially overlaid by a barrier layer which contains polymeric nanofibers made of or containing as one of its components at least one biocompatible polymer and/or its copolymer and/or at least one biopolymer and/or its derivative and/or at least one synthetic polymer and/or its derivate and/or its copolymer, and which is pressed to the skin, following the shape of its surface, and/or before being applied to the skin, the cosmetic composition is applied on the surface of the barrier layer, which is afterwards pressed to the skin with its surface covered with the applied cosmetic composition, following the shape of its surface. In this manner, the cosmetic composition and the site of desired action of its active substance/substances are closed against external influences, but remain accessible to atmospheric oxygen, whereby the barrier layer subsequently shrinks due to the contact with hyaluronic acid contained in the cosmetic composition, which pulls out the skin in the wrinkle area to the level of the surrounding skin. As a result, small and medium wrinkles are mechanically smoothed out and the depth and size of the larger ones is reduced, whereby this effect of the barrier layer is complemented and fixed by the penetration of hyaluronic acid and, simultaneously, by adding moisture from the cosmetic composition into the skin and the hypodermis.

If necessary, e.g., in the case of low skin hydration, after applying the barrier layer on the skin, on its outer surface another layer of the cosmetic composition containing hyaluronic acid is applied.

A suitable barrier layer for this application is a layer of nanofibers having a basis weight in the range from 3 to 15 g/m², preferably from 6 to 13 g/m².

Furthermore, the shrinkage of the barrier layer can be increased by addition of a suitable salt in an amount from 0.05 to 5 % (w/w) of dry weight of polymeric nanofibres. Such salts include, for example, monovalent salts of Li⁺ (e.g. LiCI), Na⁺, K⁺, divalent salts of Mg²⁺, Ca²⁺, Zn²⁺, Cu²⁺, ammonium salts (NH4) ⁺ of organic and inorganic acids, etc., or a mixture of at least two of them.

Apart from addition of salt/salts, it is also possible to adjust the visual characteristics of the barrier layer of nanofibers, e.g. by addition of any tenside, or a mixture of at least two tensides, the tenside/tensides enhancing the transparency as well as wettability of the barrier layer. The amount of the tenside, or a mixture of tensides, is by one or two orders lower than the amount of the salt, i.e. it is in an interval of 0.0005 to 0.5 % of dry weight of the polymeric nanofibers.

Description of drawings

In the enclosed drawing, Fig. 1 schematically represents the principle of one variant of the method of the application of a cosmetic composition on the skin according to the invention, whereas Fig. 2 schematically represents the principle of the second variant of the application of a cosmetic composition on the skin according to the invention. Fig. 3 schematically represents the application of a cosmetic composition according to the invention in the variant aimed at smoothing wrinkles and Fig. 4 illustrates the principle of the application of this variant. Fig. 5a shows a photograph of the skin before the application of the cosmetic composition using the method according to the invention, Fig. 5b shows a photograph of this skin 24 hours after the application of the cosmetic composition by the method according to the invention and Fig. 5c shows a photograph of this skin 48 hours after the application of the cosmetic composition according to the invention. In Fig. 6a there is a digital image of the skin relief before the application of the cosmetic composition by the method according to the invention, Fig. 6b shows a digital image of the skin relief 24 hours after the application of the cosmetic composition by the method according to the invention and Fig. 6c shows a digital image of the skin relief 48 hours after the application of the cosmetic composition by the method according to the invention.

Specific description

The method for the application of a cosmetic composition containing at least one active substance, e.g. an active substance selected from the group of substances with hydratation effects, e.g. polysaccharides, such as hyaluronic acid, salts of hyaluronic acid, chitosan and its derivatives, derivatives of glucuronic acid (e.g. pectin, sodium-calcium salt, sodium salt or another salt of microdispersed oxidised cellulose (=copolymer of polyanhydroglucose and 1 ,4- β-D-polyanhydroglucuronic acid)), polypeptides and their hydrolysates (e.g. collagen, elastin, gelatin), synthetic polymers (e.g. polyglycols, polyesters), and/or selected from the group consisting of substances with a keratolytic effect, such as salicylic acid, lactic acid, glycolic acid, mandelic acid, azelaic acid or ellagic acid, and/or vitamins, amino acids, antioxidants, coenzymes, substances with a soothing effect (e.g. plant extracts, such as aloe vera or chamomile, panthenol, etc.), substances based on mechanical pore cleansing (e.g. zeolite, kaolin, titanium dioxide, zinc oxide, etc.), possibly an active substance which is found in natural oils and essential oils (e.g. argan oil, almond oil, macadamia oil, tea tree oil, etc.), and other known active substances, including substances exhibiting antimicrobial properties or other known active substances stimulating skin regeneration, etc., or another known cosmetically active substance, or a mixture of at least two of them, on the skin according to the invention consists in that to the skin 1 at the site 2 of desired action of the active substance/substances (e.g. in the area of a wrinkle, a scar, acne, or another skin defect or imperfection, or, as the case may be, in the area of low hydration of the skin , any known cosmetic composition 3 is applied in a usual manner in the form of a (hydro)gel or a cream (ointment) containing this/these active substance/substances, which is after that at least partially overlaid by a barrier layer 4. The barrier layer 4 is then in case of need at least partially overlaid by the cover layer 5 (see Fig. 1 and Fig. 2). Depending on the size and shape of the site 2 of desired action, or on the character of the active substance/substances, the cosmetic composition 3 is applied in the form of a continuous or discontinuous layer (e.g. pointwise).

The barrier layer 4 contains polymeric nanofibers, or it is formed by at least one layer of polymeric nanofibers. Due to the small interfibrous spaces (having a size in the order of tens to hundreds of nanometers) it prevents penetration of undesired biological impurities (e.g. microorganisms) and mechanical impurities (e.g. dust particles, etc.) from the external environment to the site 2 of desired action or to the cosmetic composition 3, by which means this site 2 with the applied cosmetic composition 3, including, as the case may be, also its surroundings, closes against external influences. At the same time, however, it does not prevents the access of atmospheric oxygen, which around the site 2 of desired action helps to create a suitable microclimate for the action of the active substance/substances of the cosmetic composition 3, and promotes the healing process (if the site 2 of desired action is, e.g., a cut or a wound, a scar or acne, etc.), and, optionally, it also keeps the skin 1 pores open. Suitable materials of the nanofibers of the barrier layer 4 include especially biocompatible polymers, such as polycaprolactone (PCL), polylactic acid (PLA), copolymer of lactic acid and glycolic acid (PLGA), polygfutamic acid (PGA), polyvinyl alcohol (PVA), polyethylene oxide (PEO) etc., their copolymers, derivatives or mixtures (whereby these at least two biocompatible polymers, or at least one biocompatible polymer and at least one copolymer/derivative, or two copoiymers/derivatives simultaneously included in the individual nanofibers, or constitute at least two types of nanofibers, each type being made of a different biocompatible (co)polymer), and particularly biopolymers, such as polysaccharides (e.g. hyaluronic acid, chitosan, pectin, copolymers of glucuronic acid and their derivatives, alginates, etc.), polypeptides and their hydrolysates (collagen, elastin, silk fibroin) zein, cellulose and other known biopolymers, including their derivatives or mixtures containing at least one biopolymer and/or at least one derivative (provided that these at least two biopolymers, or at least one biopolymer and at least one derivative, or two derivatives are simultaneously included in the individual nanofibers, or constitute at least two types of nanofibers, each type being made of a different biopolymer and/or derivative or mixture), at least one of which is biocompatible. In addition, it is also possible to use a mixture of at least one biopolymer and/or a biologically compatible polymer, or a mixture of at least one biopolymer and/or a biologically compatible polymer with at least one sanitary unobjectionable synthetic polymer, whereby the nanofibers or parts of the nanofibers made of the synthetic polymer/polymers provide the required mechanical properties to the resulting barrier layer 4, and the nanofibers or parts of the nanofibers from the biocompatible polymer/polymers reduce the danger of allergic reaction or other unwanted effects caused by the presence of a synthetic material. Examples of synthetic polymer which can be used include polyamide (PA), polyvinylidene (di)fluoride (PVDF) and polyurethanes (PUR), their copolymers and mixtures (containing at least two synthetic polymers or at least one synthetic polymer and at least one copolymer, or at least two copolymers). In a preferred embodiment, the barrier layer 4 is at least partially composed of a hydrophobic polymer (containing nanofibers made of a hydrophobic polymer or from mixtures of at least one hydrophobic polymer with at least one non-hydrophobic polymer), which prevents water from penetrating from the external environment to the site of 2 of desired action with the applied cosmetic composition 3, due to which this site 2 is closed against the external influences even more thoroughly, but it remains accessible to atmospheric oxygen from the external environment.

In all variants of embodiment, the basis weight of the barrier layer 4 is 1 to 30 g/m², preferably 10 to 30 g/m², although, if necessary, or, e.g., in the case of the presence of at least one active substance, may be even higher.

The barrier layer 4 may be prepared by any of the known methods for producing a layer of polymeric nanofibers based on any chemical and/or physical principle, the most suitable of them being electrostatic spinning using a spinning electrode of an elongated shape - for example in the shape of a cylinder (see, e.g., EP 1673493) or a string (see, e.g., EP 2059630 or EP 2173930), or any method thereof modified according to WO 2014079400, since these methods currently ensure achieving the highest homogeneity of the layer of polymeric nanofibers being formed in all directions, and, moreover, these methods are the only ones that enable industrial-scale preparation of this layer.

If necessary, the barrier layer 4 may contain at least one active substance, which may be incorporated in the material of its nanofibers in the form of (nano)particles and/or may be arranged on the surface of the nanofibers and/or on the surface of the barrier layer 4 in the form of (nano)particles and/or impregnation and/or a film and/or it may be chemically covalently and/or non- covalently bound directly to the polymer of the nanofibers and/or in the case of polymeric active substances, at least some nanofibers of the barrier layer 4 may be made at least partially directly from it. A suitable active substance is, e.g., an active substance which strengthens and/or enhances and/or complements the effect of the active substance/substances of the cosmetic composition and/or acts in another positive manner on the site 2 of desired action - e.g. renews the natural biochemistry of the skin, cleans or disinfects the skin , causes opening of the sebaceous channels and expanding pores, soothes the skin 1, etc. These active substances include, e.g. antioxidants, vitamins, proteins, coenzymes, amino acids, polypeptides and their hydrolysates (e.g. collagen, elastin, gelatin), synthetic polymers (e.g. polyglycols, polyesters), and/or substances with a keratolytic effect, namely especially salicylic acid, lactic acid, glycolic acid, mandelic acid, azelaic acid, ellagic acid, and/or substances with a soothing effect (e.g. plant extracts, such as aloe vera or chamomile, panthenol, etc.) and/or substances based on mechanical pore cleansing (e.g. zeolite, kaolin, titanium dioxide, zinc oxide, etc.) and/or an active substance which is found in natural oils and essential oils (e.g. argan oil, almond oil, macadamia oil, tea tree oil, etc.) and other known active substances, including substances exhibiting antimicrobial properties or other known active substances promoting the regeneration of the skin, etc., and any other known active substance. Beside this/these active substance/substances or instead of it/them the barrier layer 4 may contain at least one active substance, which protects the site 2 of desired action of the cosmetic composition 3 e.g. from microorganisms from the external environment, etc. - e.g. an antimicrobial substance, including antibiotics, silver and/or its compounds and/or compounds of iodine, copper, etc.

If the barrier ability of the barrier layer 4 is insufficient, e.g. due to the presence of an active substance/substances (or, more specifically, due to the releasing of this substance/these substances from its structure) or for some other reason, it is advantageous if its outer surface is covered with an auxiliary layer 41_, which contains polymeric nanofibers or is composed of a layer of polymeric nanofibers (see Fig. 2). The auxiliary layer 41 may be the same as the barrier layer 4, or it can differ from it by a material and/or diameter of nanofibers and/or size of the interfibrous spaces and/or basis weight and/or thickness and/or content of the active substance/substances and/or type of the active substance/substances and/or by another parameter or aspect. In a preferred embodiment, the auxiliary layer 41 contains at least one active substance which protects the site 2 of desired action of the cosmetic composition 3 from penetration of microorganisms, whereby in that case the barrier layer 4 may only contain an active substance/substances which strengthens/strengthen and/or enhances/enhance and/or complements/complement the effect of the active substance/substances of the cosmetic composition and/or acts/act in another positive manner on the site 2 of desired action. In this alternative, it is also advantageous if the auxiliary layer 41 has larger interfibrous spaces than the barrier layer 4, and so the barrier layer 4 mechanically blocks possible biological impurities and the auxiliary layer 41 simultaneously acts on them by its active substance/substances, which liquidates/liquidate or at least weakens/weaken them. Beside this active substance/these active substances or instead of it/them, the auxiliary layer 4J_ may contain at least one antimicrobial substance. The application of the barrier layer 4 and, possibly, also the auxiliary layer 41 on the user^'s skin 1 with sufficient resistance is ensured by the adhesive properties of the cosmetic composition 3. Nevertheless, the barrier layer 4, or the auxiliary layer 41 if it overlaps the barrier layer 4, may be provided with an adhesive means arranged along at least a part of its circumference.

The barrier layer 4 and/or the auxiliary layer 41 may contain beside polymeric nanofibers also other components, e.g. microfibers or another/other linear and/or planar formation/formations (e.g. a substrate, preferably permeable, on which the nanofibers of this layer 4, 41 were deposited during their preparation), which provides/provide the required mechanical properties to this layer 4, 41 and/or facilitates/facilitate handling it/them, etc.

To make the barrier layer 4 and, possibly, also the auxiliary layer 41 invisible after the application, it is advantageous if a cover layer 5 in the form of a (hydro)gel or a cream is applied on the external surface of the barrier layer 4, or the auxiliary layer 41, whereby the composition of the (hydro)gel or cream makes the barrier layer 4 and, possibly, also the auxiliary layer 41 transparent or more transparent, which is either based on the principle of filling the interfibrous spaces and a corresponding change in the index of light refraction on the surface of the layer/layers 4, 41_^ and/or its/their material, or one of the components penetrates directly into the structure of the nanofibers of the barrier layer 4 and/or the auxiliary layer 41, changing their colour into transparent or more transparent - either temporarily or permanently. In the case of temporary transparency the cover layer 5 must be applied repeatedly depending on the requirements of transparency duration. As a signal for its repeated application it is possible to use lightening (or whitening) of the barrier layer 4 or the auxiliary layer 41, which occurs as a result of reduced content of water in it. In a preferred embodiment, the cover layer 5 contains a proportion of a lipid (oil) component and water, which is determined by the material and/or parameters of the barrier layer 4 and/or the auxiliary layer 41 , whereby its lipid (oil) component penetrates into the interfibrous spaces of the barrier layer 4_and/or the auxiliary layer 4J. and/or into their nanofibers.

In another alternative of embodiment, the cover layer 5 is composed of a layer made of a nontransparent materia! and masking the barrier layer 4 and, possibly, the auxiliary layer 41, is based on the principle of make-up, whereby this layer is overlaid and possibly its interfibrous spaces are also at least partially filled by a material (e.g. in the form of emulsion) containing a pigment or other components, which are capable of masking the barrier layer 4 and, possibly, also the auxiliary layer 41 according to the type and colour of the user^'s skin.

The cover layer 5, regardless its particular embodiment, may contain at least one active substance/substances identical with the active substance of the cosmetic composition 3, or it can be even formed directly by this cosmetic composition (preferably, e.g., by hyaluronic acid and/or its salt/salts), or it can contain at least one active substance which strengthens and/or enhances and/or complements the effect of the active substance/substances of the cosmetic composition 3 and/or acts in another positive manner on the site 2 of desired action, whereby the barrier layer 4 and, possibly, also the auxiliary layer 41 due to its/their structure and interfibrous spaces enables/enable the penetration of this active substance/these active substances to the site 2 of desired action. Beside this active substance/these active substances or instead of it/them the cover layer 5 may contain at least one antimicrobial substance, which protects the site 2 of desired action of the active substance/substances of the cosmetic composition 3, for example from microorganisms from the external environment.

After the absorption of the active substances of the cosmetic composition 3 and/or after a predetermined period the entire structure, or, in other words, all the applied layers are simply removed from the skin i by peeling off. The entire procedure is repeated as needed.

Preferably, the barrier layer 4 and/or the auxiliary layer 41 is applied on the applied cosmetic composition 3 moistened (or possibly during the application it is sufficiently moistened by moisture content in the cosmetic composition 3), whereby during subsequent drying it shrinks and causes slight contraction of the skin at the site 2 of desired action, which is desirable when using some active substances, and this/these active substance/substances therefore penetrate into the structure of the skin 1 more easily and more deeply.

The barrier layer 4, possibly in combination with the auxiliary layer 41_, is preferably stored and applied arranged on a suitable carrier, based, e.g., on polymer, particularly polyolefins or polyesters or polyurethanes, or their combination in the form of a foam, a film, a foil, a woven or non-woven textile and their combinations. After the application of the barrier layer 4 or the auxiliary layer 41 , this carrier is either removed or, in case of need, remains on it, whereby it may create or help to create a cover layer 5. in another variant of the application of the cosmetic composition 3 on the skin 1 according to the invention, the cosmetic composition 3 is applied on the surface of the cover layer 4, and is applied together with it, when the cover layer 4 is applied on the skin Λ with its surface with the applied cosmetic composition 3.

A suitable active substance of the cosmetic composition 3 is especially hyaluronic acid. It is a biocompatible linear polysaccharide polymer, naturally occurring in high concentrations in intercellular matrix and in the form of a sodium salt, or, more specifically, hyaluronan or sodium hyaluronate, is part of connective, epithelial and neural tissues. Since it has the ability to bind an enormous quantity of water and prevent collagen deposition at the site of injured tissue, it enables the so-called scarless healing and a very good hydration of the skin Λ . For this reason, it is advantageous to use hyaluronic acid and/or its salt/salts as an active substance of the cosmetic composition 3 (or as the case may be, to use it as the cosmetic composition 3 itself) and/or as an active substance of the barrier layer 4 and/or the auxiliary layer 41 and/or the cover layer 5. A means for the application of the cosmetic composition 3 according to the invention contains a barrier layer 4 containing or composed of nanofibers made of biocompatible polymer and/or biopolymer (possibly with the addition of synthetic polymer or synthetic polymer nanofibers), on one surface of which is applied the cosmetic composition containing at least one active substance. On its opposite surface it is possible to apply the auxiliary layer 41 containing or composed of nanofibers of biocompatible polymer and/or biopolymer (possibly with the addition of synthetic polymer or synthetic polymer nanofibers), or the cover layer 5, or the cover layer 5 covers the surface of auxiliary layer 41. The barrier layer 4 and/or the auxiliary layer 41 and/or the cover layer 5 may contain at least one active substance which strengthens and/or enhances and/or complements the effect of the active substance/substances of the cosmetic composition 3 and/or acts in another positive manner on the na site 2 of desired action - e.g. renews the natural biochemistry of the skin, cleans or disinfects the skin 1, causes opening the sebaceous channels, expanding pores, soothes the skin i, etc. Such an active substance is particularly salicylic acid, lactic acid, glycolic acid, mandelic acid, azelaic acid, ellagic acid, vitamins, amino acids, antioxidants, coenzymes, substances with a soothing effect (e.g. plant extracts, such as aloe vera or chamomile, panthenol etc.) and/or a substance based on mechanical pore cleansing (e.g. zeolites, kaolin, titanium dioxide, zinc oxide, etc.) and/or an active substance which is found in natural oils and essential oils (e.g. argan oil, almond oil, macadamia oil, tea tree oil, etc.) and/or any other known active substance, or a mixture at least two of them. In addition to the active substance/substances or instead of it/them, the barrier layer 4 and/or the auxilliary layer 41 and/or the cover layer 5 may contain at least one active substance which protects the site 2 of desired action of the cosmetic composition 3, for example, from microorganisms from the external environment, etc. - e.g. an antimicrobial substance, including antibiotics, silver and/or its compounds and/or compounds of iodine, copper, etc.

In each variant of embodiment of the means it is advantageous if the means is at least on one side covered with a protective layer based on polymer, particularly polyolefin or polyester or polyurethane, or their combinations, in the form of a foam, a film, a foil, a woven or non-woven textile and their combinations, which protects it from mechanical damage and/or contamination, and also facilitates handling it.

The above-described materials and methods for the application of the cosmetic composition are intended especially for long-term cosmetic application, e.g. all day long or even longer, during which the main factor of desired action is the cosmetic composition 3, or, more specifically, the active substance/substances contained in it. In addition, however, to achieve a desired effect, it is possible, especially for the cosmetic treatment of wrinkles 8, to use a combination of hyaluronic acid and the mechanical contraction of the barrier layer 4, which occurs when it is in contact just with hyaluronic acid. Given that in this case the barrier layer 4 is applied only for a very limited period of minutes or a maximum of tens of minutes, it is not necessary for its nanofibers to be made of biocompatible polymer. In particular, a suitable polymer is, for example, polyvinylidene fluoride (PVDF) or polyurethane (PUR). However, in other variants of embodiment, the barrier layer 4 may be formed by or contain nanofibers made of any of the above-mentioned biocompatible polymers (and/or their derivatives and/or copolymers) and/or biopolymers (and/or their derivatives), which when in contact with hyaluronic acid shrinks (which in principle applies to each of the above-mentioned materials), or this type of synthetic polymer/such synthetic polymers. An example of suitable synthetic polymers are, for example, polyamides, proteins and polypeptides (e.g. gelatin, collagen, albumin, keratin, casein, silk protein, etc.), including glycoproteins, lipoproteins and enzymes; polysaccharides (e.g. chitin, chitosan, carrageenans, alginates, pectins, guar gum, starch, xanthan, polygalacturonic acid, hyaluronic acid, cellulose, cyclodextrins, dextrans), including their derivatives; polystyrenes; poly(alkyl methacrylates); polyalkylimides; polyanhydride esters; polycaprolacone; polyacrylic acid; polycarbonates; polyvinyl acetate; polyvinyl carbazole; polyvinyl chloride; polyvinyl pyrrolidone; polyvinyl butyral; polyiactic acid; polyglycolic acid; polylactic-co-glycolic acid; polybutylene terephthalate; polyaniline; poly (2-hydroxyethyl methacrylate); polyether imides; polyethylene glycol, polyethylene oxide; polyvinyl alcohol; polyhydroxyalkanoates; etc., including derivatives, copolymers and salts of any of them. A suitable material of the barrier layer 4 is - among others - e.g. a layer of polyurethane nanofibers, which at a basis weight below 6 g/m² has shrinkage approximately 30 % and tensile strength approximately 2 N, while at a basis weight from 6 to 12 g/m² the shrinkage achieved is approximately 25 % and tensile strength is more than 5 N - see the following table. In the case of polyvinylidene fluoride, the mechanical properties with similar basis weights are very similar. If needed, so as to achieve the required mechanical properties of the barrier layer 4± it is possible to combine polyurethane and polyvinylidene fluoride, or any of them with another biocompatible polymer which has been mentioned above (and/or its derivative and/or copolymer) and/or biopolymer (and/or its derivative) and/or synthetic polymer.

nanofibers of size 50 x 25 mm was used, the distance between clamping points of this sample was 30 mm, the speed of stretching the sample was 20 mm/min, the load of the sample was 100 N.

The shrinkage of the barrier layer 4 of nanofibers may be increased by addition of a suitable salt in an amount ranging from 0.05 to 5 % (w/w) of dry weight of polymeric nanofibers. Such salts include, for example, monovalent salts of Li⁺ (e.g. LiCl), Na⁺, K⁺, divalent salts of Mg²⁺, Ca ⁺, Zn²⁺, Cu²⁺, ammonium salts (NH4) ⁺ of organic and inorganic acids, etc., or a mixture of at least two of them. For example, in a layer of polyurethane nanofibers the content of LiCl below 1 % w/w increases shrinkage by up to 29 %. Salt/salts is/are added to a solution of polymer, being entrained into individual fibers during spinning. Moreover, it is also possible to adjust the visual characteristics of the barrier layer 4 of nanofibres, namely by addition of any tenside, or a mixture of tensides (beside addition of salt/salts), which increases the transparency as well as wettability of the barrier layer 4. The amount of the tenside, or the mixture of tensides, is by one or up to two orders lower than the amount of salt/salts, that is in the interval 0.0005 - 0.5 % (w/w) of dry weight of polymeric nanofibers.

The cosmetic composition 3 is applied either directly on the skin Λ (usually of the face and neck), whereupon it is at least partially overlaid by the barrier layer 4, and/or before being applied to the skin 1 , the cosmetic composition 3 is applied to one surface of the barrier layer 4, which is subsequently put with this surface on the skin 1. During both processes the barrier layer 4 is pressed to the skin so that it will follow the shape of the surface as perfectly as possible, including the individual wrinkles 8. In this phase, hyaluronic acid ensures sufficient adhesion between the skin i and the barrier layer 4. If necessary, another cosmetic composition 3 or another layer of the same cosmetic composition is afterwards applied to the free space of the barrier layer 4.

Fig. 3 shows a cross sectional view of of the skin lacking molecules of hyaluronic acid 6 and with collapsed bonds between the cells 7, causing creation of wrinkles 8, with the applied layer of the cosmetic composition 3 and the barrier layer 4.

During this process, the barrier layer 4 not only closes the space of the application of the cosmetic composition 3 against the external environment, but at the same time it helps to smooth out small and medium wrinkles 8, and to reduce the depth and size of the large ones 8, when it shrinks in contact with hyaluronic acid, thus pulling out the skin in the area of the wrinkle 8 to the level of the surrounding skin i - see Fig. 4. Synchronic penetration of hyaluronic acid into the skin Λ and hypodermis, where hyaluronic acid fills up the free spaces between the cells 7 and binds water molecules from the cosmetic composition 3, thereby hydrating and rejuvenating the skin , not only appropriately complements the mechanical action of the barrier layer 4, but also fixes the achieved results of smoothing out the small and medium wrinkles 8 and reducing the large ones, whereby there is a synergy of these two factors. Fig. 4 schematically represents the action of the barrier layer 4 during its shrinking, when the surface of the skin 1_ is pulled out, and hyaluronic acid 6 and water is supplemented into its structure.

A suitable barrier layer 4 for this application is a layer of nanofibers made of any of the above-mentioned biocompatible polymers (and their derivatives and/or copolymers) and/or biopolymers (and their derivatives) and/or polyvinylidene fluoride and/or polyurethane having a basis weight from 3 to 15 g/m², preferably from 6 to 13 g/m². As is apparent from the above, the larger the basis weight of the barrier layer 4, the larger the force which it is able to develop during its shrinking and thus also the effect achieved. Therefore, by changing this parameter the barrier layer 4 can be adapted to specific application.

Should the need arise, also in this case the barrier layer 4 or the layer of the cosmetic composition 3, which covers the barrier layer 4, can be overlaid by the auxiliary layer 41 or the cover layer 5, as described above.

Figures 5a to 5c are photographs of a part of the skin before application and 24 and 48 hours after the application of the cosmetic composition 3 containing 1 % low molecular hyaluronic acid and 1 % high molecular of hyaluronic acid, when using the barrier layer 4 composed of a layer of polyurethane nanofibers with a basis weight of 1 g/m². In Fig. 6a to 6c there are digital images of the skin relief of this part of the skin I before application and 24 and 48 hours after the application of the cosmetic composition by the method according to the invention. From these photographs removal of small and medium wrinkles 8 is apparent, as well as a substantial reduction of the depth and size of the larger wrinkles 24 hours (Fig. 5b, 6b) or 48 hours (Fig. 5c, 6c) after the application of the cosmetic composition 3.

Claims

PATENT CLAIMS

1. A method for application of a cosmetic composition in the form of a (hydro)gel or a cream containing at least one active substance, in which the cosmetic composition (3) is applied on the skin (1) at the site (2) of desired action, characterized in that after being applied on the skin (1), the cosmetic composition (3) is at least partially overlaid by a barrier layer (4) which contains polymeric nanofibers made of or containing as one of its components at least one biocompatible polymer and/or its copolymer and/or at least one biopolymer and/or its derivative, and/or before being applied to the skin (1) the cosmetic composition (3) is applied on the surface of the barrier layer (4), which with its surface with applied cosmetic composition (3) is subsequently applied on the skin (1), by which means the cosmetic composition (3) and the site (2) of desired action of its active substance/substances is closed against external influences, but remain accessible to atmospheric oxygen.

2. The method according to Claim 1 , characterized in that the barrier layer (4) contains at least one active substance which is identical with the active substance of the cosmetic composition (3) and/or at (east one active substance which strengthens and/or enhances and/or complements the effect of the active substance/substances of the cosmetic composition (3), and/or at least one antimicrobial substance.

3. The method according to any of the preceding Claims, characterized in that the barrier layer (4), after being overlaid or after the application of the cosmetic composition (3), or before being overlaid or before the application of the cosmetic composition (3) is at least partially overlaid by an auxiliary layer (41) which contains polymeric nanofibers made of or containing as one of its components at least one biocompatible polymer and/or its copolymer and/or at least one biopolymer and/or its derivative.

4. The method according to Claim 3, characterized in that the auxiliary layer (41) contains at least one active substance which is identical with the active substance of the cosmetic composition (3) and/or at least one active substance which strengthens and/or enhances and/or complements the effect of the active substance/substances of the cosmetic composition (3) and/or at least one antimicrobial substance.

5. The method according to Claim 1 , 2 or 4, characterized in that the biocompatible polymer is selected from the group consisting of polycaprolactone (PCL), polylactic acid (PLA), copolymer of lactic acid and glycolic acid (PLGA), polyglutamic acid (PGA), polyvinyl alcohol (PVA), polyethylene oxide (PEO), their copolymers, derivatives or their mixtures.

6. The method according to Claim 1 , 2 or 4, characterized in that the biopolymer is selected from the group consisting of polysaccharides (hyaluronic acid, chitosan, pectin, copolymers of glucuronic acid and its derivatives), alginates, proteins and their hydrolysates (collagen, elastin, silk fibroin, zein), cellulose, their copolymers, derivatives or their mixtures.

7. The method according to Claim 1 , 2 or 4, characterized in that the barrier layer (4) and/or the auxiliary layer (5) contain nanofibers made of synthetic polymer and/or containing synthetic polymer as one of its components.

8. The method according to Claim 7, characterized in that the synthetic polymer is selected from the group consisting of polyamide (PA), polyvinylidene

(di)fluoride (PVDF), polyurethanes (PUR), copolymers and their mixtures.

9. The method according to any of the preceding Claims, characterized in that the barrier layer (4) and/or the auxiliary layer (41) is overlaid by a cover layer (5) of material in the form of a (hydro)gel or a cream, which contains a lipid (oil) component which penetrates into the interfibrous spaces of the barrier layer (4) and/or the auxiliary layer (41) or into their nanofibers and increases their transparency.

10. The method according any of Claims 1 to 9, characterized in that the barrier layer (4) and/or the auxiliary layer (41) is overlaid by the cover layer (5) containing a pigment.

11. The method according to Claim 9 or 10, characterized in that the cover layer (5) contains at least one active substance which is identical with the active substance of the cosmetic composition (3) and/or at least one active substance which strengthens and/or enhances and/or complements the effect of the active substance/substances of the cosmetic composition (3) and/or at least one antimicrobial substance.

12. The method according to any of Claims 9 to 11 , characterized in that the cover layer (5) is formed by the cosmetic composition (3).

13. The method according to any of Claims 2, 4 or 1 1 , characterized in that at least one active substance which strengthens and/or enhances and/or complements the effect of the active substance/substances of the cosmetic composition (3) is selected from the group consisting of antioxidants, vitamins, proteins, coenzymes, amino acids, polypeptides and their hydrolysates, synthetic polymers, salicylic acid, lactic acid, glycolic acid, mandelic acid, azelaic acid, ellagic acid, plant extracts, zeolites, kaolin, titanium dioxide, zinc oxide, natural oils, natural essential oils.

14. The method according to any of Claims 2, 4 or 1 1 , characterized in that the barrier layer (4) and/or the auxiliary layer (51) is moistened before the application.

15. A means for the application of a cosmetic composition (3) containing at least one active substance, characterized in that the cosmetic composition (3) is applied on a barrier layer (4), which contains polymeric nanofibers made of or containing as one of its components at least one biocompatible polymer and/or its copolymer and/or its derivative and/or at least one biopolymer and/or its copolymer and/or its derivative.

16. The means according to Claim 15, characterized in that on the opposite surface of the barrier layer (4) than the cosmetic composition (3) is arranged an auxiliary layer (41) made of or containing as one of its components at least one biocompatible polymer and/or its copolymer and/or its derivative and/or at least one biopolymer and/or its copolymer and/or its derivative.

17. The means according to Claim 15 or 16, characterized in that a cover layer (5) is arranged on the opposite surface of the barrier layer (4) than the cosmetic composition (3) or on the surface of the auxiliary layer (41).

18. The means according to any of Claims 15 to 17, characterized in that the barrier layer (4) and/or the auxiliary layer (41) and/or the cover layer (5) contains at least one active substance which is identical with the active substance of the cosmetic composition (3) and/or at least one active substance which strengthens and/or enhances and/or complements the effect of the active substance/substances of the cosmetic composition (3), and/or at least one antimicrobial substance.

19. The means according to any of Claims 15 to 18, characterized in that it is overlaid at least from one side by a protective layer based on polymer in the form of a foam, a film, a foil, a woven or non-woven fabric or their combinations.

20. The means according to any of Claims 15 to 18, characterized in that the barrier layer contains in its nanofibers a salt selected from the group consisting of monovalent salts of Li⁺, Na⁺, K⁺, divalent salts of g²⁺, Ca²⁺, Zn²⁺, Cu²⁺, ammonium salts (NH4) ⁺ of organic and inorganic acids or a mixture of at least two of them, in an amount ranging from 0.05 to 5 % (w/w) of dry weight of the nanofibers.

21. The means according to Claim 20, characterized in that the barrier layer contains in its nanofibers at least one tenside or a mixture of at least two tensides in an amount ranging from 0.0005 to 0.5 % (w/w) of dry weight of the nanofibers.

22. A method for the application of a cosmetic composition (3) containing hyaluronic acid on the skin (1) with a wrinkle/wrinkles (8), characterized in that after being applied on the skin (1), the cosmetic composition (3) is at least partially overlaid by a barrier layer (4), which contains polymeric nanofibers made of or containing as one of its components at least one biocompatible polymer and/or its copolymer and/or at least one biopolymer and/or its derivative and/or at least one synthetic polymer and/or its derivative and/or its copolymer, whereby the barrier layer is pressed to the skin (1) and follows the shape of the surface, including the wrinkles (8), and/or before being applied on the skin (1) the cosmetic composition (3) is applied on the surface of such a barrier layer (4), which is then pressed to the skin (1) with its surface with the applied cosmetic composition (3), following the shape of its surface, including the wrinkles (8), by which means the cosmetic composition (3) and the s^'rte of desired action of its active substance/substances is closed against external influences, but remain accessible to atmospheric oxygen, whereby subsequently the barrier layer (4), due to the contact with hyaluronic acid contained in the cosmetic composition (3), begins to shrink, and thanks to adhesion to the skin (1) pulls out the skin (1) in the area of the wrinkle (8), causing the skin surface to even out to the level of the surrounding skin (1), as a result of which it mechanically smoothes out small and medium wrinkles (8) and reduces the depth and size of the larger ones.

23. The method according to Claim 22, characterized in that after applying barrier layer (4) to the skin (1), on its outer surface is applied a layer of the cosmetic composition (3) containing hyaluronic acid.

24. The method according to Claim 22, characterized in that the barrier layer (4) is formed by a layer of nanofibers having a basis weight of 3 to 15 g/m².

25. The method according to Claim 24, characterized in that the barrier layer (4) is formed by a layer of nanofibers having a basis weight of 6 to 13 g/m².

26. The method according to any of Claims 22 to 25, characterized in that the barrier layer (4) contains in its nanofibers a salt from the group consisting of monovalent salts of Li⁺, Na⁺, K⁺, divalent salts of Mg²⁺, Ca²⁺, Zn²⁺, Cu²⁺, ammonium salts (NH4) ⁺ of organic and inorganic acids, etc., or a mixture of at least two of them, in an amount of 0.05 to 5 % (w/w) of dry weight of the nanofibers.

27. The means according to Claim 26, characterized in that the barrier layer (4) contains in its nanofibers at least one tenside or a mixture of at least two tensides in an amount of 0.0005 to 0.5 (w/w) of dry weight of the nanofibers.