WO2020004428A1

WO2020004428A1 - Cosmetic process using microneedle sheet

Info

Publication number: WO2020004428A1
Application number: PCT/JP2019/025265
Authority: WO
Inventors: Gaurav Agarwal; Shu Liu; Yuanyuan Sun
Original assignee: L'oreal
Priority date: 2018-06-29
Filing date: 2019-06-19
Publication date: 2020-01-02
Also published as: JP2020002084A

Abstract

The present invention relates to a cosmetic process for a keratin substance such as the skin or the lips, comprising the steps of: applying onto the keratin substance at least one composition in the form of an oil/water (O/W) emulsion; and applying onto the keratin substance, to which the composition has been applied, a microneedle sheet comprising a substrate sheet and a plurality of microneedles on the substrate sheet, wherein the microneedles comprise at least one water-soluble or water-dispersible polymer. According to the present invention, microneedles can penetrate into a keratin substance without being pushed away from the keratin substance, and can rapidly dissolve or disintegrate.

Description

DESCRIPTION

COSMETIC PROCESS USING MICRONEEDLE SHEET TECHNICAL FIELD

The present invention relates to a microneedle sheet comprising a plurality of microneedles which can be used for cosmetic treatments of a keratin substance such as the skin and the lips. BACKGROUND ART

The stratum comeum (SC) constitutes the main barrier to exogenous substances including small molecular weight materials. In general, exogenous substances permeating the skin must diffuse through the highly organized intercellular lipid bilayers of the stratum comeum. This intercellular microroute, which is lipophilic, is the primary pathway for exogenous substances to pass through the SC barrier by passive diffusion along a concentration gradient between a delivery vehicle and the SC. It is difficult for some exogenous substances to penetrate into the skin. In order to provide exogenous substances deeper into the skin, it is possible to perform injections using a conventional needle. However, such injections cause pain, and need to be performed by a professional such as a doctor. Thus, injections using a conventional needle are not common for cosmetic purposes. The concept of using a micro-structured device with a plurality of microneedles to breach the stratum comeum (SC) barrier was first proposed in the l970s. The production of solid microneedle arrays has been described in the art, for example in WO 2008/139786, WO 2009/040548, WO 2015/147040 and WO 2016/076442. Microneedles have an advantage of potentially penetrating the SC without pain caused by the use of conventional needles for injections, and can be self-administered.

DISCLOSURE OF INVENTION

In general, microneedles are arrayed on a substrate sheet to form a microneedle sheet. A microneedle sheet is applied on a keratin substance such as the skin for some time so that the microneedles can be dissolved or disintegrated in the keratin substance by the moisture or water inside the keratin substance.

However, in some cases, it is not preferable for microneedles to remain in a keratin substance for a long period of time because this may lengthen the time required for cosmetic treatments provided by the microneedles.

In addition, in some cases, it is difficult for microneedles to remain inserted in a keratin substance due to back pressure from the keratin substance. The back pressure may push the microneedles away from the keratin substance, and therefore, at least a part of the

microneedles, in particular around the base or root of the microneedles, will not be present in the keratin substance. The part of the microneedles which is not present in the keratin substance cannot dissolve or disintegrate in the keratin substance. An object of the present invention is to provide a cosmetic process using a microneedle sheet with microneedles on a substrate sheet wherein the microneedles can penetrate into a keratin substance such as the skin or the lips, without being pushed away from the keratin substance, and can rapidly dissolve or disintegrate.

The above objective can be achieved by a cosmetic process for a keratin substance such as the skin or the lips, comprising the steps of:

applying onto the keratin substance at least one composition in the form of an oil/water (O/W) emulsion; and

applying onto the keratin substance, to which the composition has been applied, a

microneedle sheet comprising a substrate sheet and a plurality of microneedles on the substrate sheet, wherein the microneedles comprise at least one water-soluble or water- dispersible polymer.

The microneedle may have a height of from 50 to 1000 microns, preferably from 100 to 750 microns, and more preferably from 150 to 500 microns.

The microneedle may be in the shape of a cone.

The base of the cone of the microneedle may have a diameter of from 50 to 350 microns, preferably from 100 to 300 microns, and more preferably from 150 to 250 microns.

The ratio of (the height of the cone)/(the diameter of the base of the cone) of the microneedle may be 1 or more, preferably 1.5 or more, and more preferably 2.0 or more.

The water-soluble or water-dispersible polymer may be selected from hyaluronic acids, monosaccharides, disaccharides, oligosaccharides, polysaccharides, dextrins, dextrans, polyethylene glycols, polyvinyl alcohols, poly(methyvinylether/maleic anhydride), polyvinylpyrrolidone, poly(methyl/vinyl ether/maleic acid) (PMVE/MA) and esters thereof, poly(methyl/vinyl ether/maleic anhydride) (PMVE/MAH), and mixtures thereof.

The water-soluble or water-dispersible polymer may have a molecular weight of from 10,000 to 200,000 Dalton, preferably from 30,000 to 150,000 Dalton, and more preferably from 50,000 to 100,000 Dalton.

The amount of water in the composition to be used for the present invention may be from 50% to 95% by weight, preferably from 55% to 90% by weight, and more preferably from 60% to 85% by weight, relative to the total weight of the composition.

The composition may comprise at least one polyol.

The amount of the polyol in the composition to be used for the present invention may be from 1% to 20% by weight, preferably from 3% to 15% by weight, and more preferably from 5 to 10% by weight, relative to the total weight of the composition.

It is preferable that the microneedle sheet be applied onto the keratin substance without a step of drying the composition on the keratin substance.

At least one of the microneedles may comprise at least one cosmetic active ingredient. The present invention also relates to a kit comprising:

a microneedle sheet comprising a substrate sheet and a plurality of microneedles on the substrate sheet, wherein the microneedles comprise at least one water-soluble or water- dispersible polymer;

and

a composition in the form of an O/W emulsion.

The present invention also relates to a process for accelerating the dissolution of microneedles of a microneedle sheet comprising a substrate sheet and the microneedles on the substrate sheet, wherein the microneedles comprise at least one water-soluble or water-dispersible polymer, comprising the step of:

contacting the microneedles with a composition in the form of an O/W emulsion before the use of the microneedle sheet.

The present invention also relates to a use of a composition in the form of an O/W emulsion, in order to accelerate the dissolution of microneedles of a microneedle sheet comprising a substrate sheet and the microneedles on the substrate sheet, wherein the microneedles comprise at least one water-soluble or water-dispersible polymer, before the use of the microneedle sheet.

BEST MODE FOR CARRYING OUT THE INVENTION

After diligent research, the inventors have discovered that it is possible to provide a cosmetic process using a microneedle sheet with microneedles on a substrate sheet wherein the microneedles can penetrate into a keratin substance such as the skin or the lips, without being pushed away from the keratin substance, and can rapidly dissolve or disintegrate.

Thus, one aspect of the present invention is a cosmetic process for a keratin substance such as the skin or the lips, comprising the steps of:

applying onto the keratin substance at least one composition in the form of an O/W emulsion; and

According to the present invention, microneedles can penetrate into a keratin substance without being pushed away from the keratin substance, and can rapidly dissolve or disintegrate.

Therefore, the cosmetic process according to the present invention can be performed in a relatively short period of time.

Also, according to the present invention, microneedles can be maintained in a state where they are inserted in a keratin substance, and therefore, the microneedles can dissolve or disintegrate as much as possible in the keratin substance. Thus, the present invention can perform cosmetic treatments effectively.

Since microneedles do not cause any pain, the cosmetic process according to the present invention can provide cosmetic treatments without pain. The present invention is convenient for cosmetic or non-therapeutic treatments.

Hereafter, the cosmetic process, kit, and the like according to the present invention will be described in a detailed manner.

[Cosmetic Process]

The cosmetic process according to the present invention for a keratin substance such as the skin or the lips, comprises the steps of:

It is preferable that the microneedle sheet be applied onto the keratin substance without a step of drying the composition on the keratin substance. In other words, it is preferable that the microneedle sheet be applied onto the keratin substance before the composition is dried or while the keratin substance is wet.

The cosmetic process according to the present invention may be intended for cosmetic treatments of a keratin substance such as the skin or the lips, preferably the skin, and more preferably the skin of the face.

The cosmetic process according to the present invention may be used to improve the aesthetic appearance of a keratin substance, for example, by reducing the appearance of wrinkles or by providing the keratin substance with any cosmetic active ingredient, if present, in the microneedles.

A reduction in the amount of matrix, such as epidermis, in the skin tends to lead to a decrease in skin thickness and deterioration of skin elasticity, causing the formation of wrinkles. The microneedles can increase the amount of matrix in the skin to cause an increase of skin elasticity which results in the reduction of wrinkles on the skin.

If the microneedle, in particular the distal end portion, is swellable, it can swell in the skin to further increase the volume of the microneedle along with its absorption of, for example, water in the skin. Such volume expansion beneath the skin surface of a wrinkle site can effectively push the wrinkles from inside the skin and makes the wrinkles become shallower and wider. Thus, the wrinkles can be reduced or made less noticeable.

Thus, it is preferable that the cosmetic process according to the present invention comprise the step of pressing onto the keratin substance the microneedle sheet to securely insert the microneedles of the microneedle sheet into the keratin substance such as the skin.

In a particular embodiment, the cosmetic process according to the present invention can be used to apply semi-permanent or permanent cosmetic treatments to a keratin substance such as the skin. Hereafter, the microneedle sheet and the porous sheet used for the cosmetic process according to the present invention will be explained in a detailed manner.

{Microneedle Sheet}

The microneedle sheet to be used for the process according to the present invention comprises a substrate sheet and a plurality of microneedles on a substrate sheet, wherein the

microneedles comprise at least one water-soluble or water-dispersible polymer. The microneedle sheet to be used for the present invention may be a cosmetic device, preferably a cosmetic device for a keratin substance, and more preferably a cosmetic device for the skin, in particular the skin of the face, as well as the lips.

(Microneedles)

The microneedle sheet to be used for the present invention comprises a plurality of microneedles.

The microneedles are present on the surface of a substrate sheet. The microneedles may be present on 50% or more, preferably 70% or more, and more preferably 90% or more of the surface of the substrate sheet.

It is preferable that the microneedles be present on one of the surfaces of a substrate sheet. It is preferable that the microneedles of the microneedle sheet to be used for the present invention be designed to penetrate or enter into the stratum comeum of the skin, in particular the skin of the face, as well as the lips.

A microneedle can be any suitable size and shape to puncture the stratum comeum. It may be preferable that the microneedles be designed to pierce and cross the stratum comeum. The microneedles may be capable of creating openings in the stratum comeum.

If necessary, the height of the microneedles may be altered so as to allow penetration into the epidermis and/or dermis of the skin, preferably into the upper dermis, and more preferably into the lower dermis.

The shape of the microneedles is not limited as long as the shape is a“needle”. It will be apparent to those skilled in the art that the microneedles for the present invention can take any reasonable shape, including, but not limited to, cones, rods and/or pillars. As such, the microneedles may have the same diameter at the tip as at the base or may taper in diameter in the direction from the base to the tip.

For example, the shape of the microneedle may be in the form of a triangular pyramid, a square pyramid or a pentagonal pyramid. Alternatively, the microneedle may be in the form of a cylinder preferably with a tip which may be formed by diagonally cutting the cylinder. The cross section of the microneedle may take any geometric form including, circular, triangular, square, rectangular, polyhedral, regular or irregular forms, and the like. In an embodiment, a group of microneedles may take the form of hollow microcapillaries. Thus, reference is made to "microneedles" as a type of microprotrusion or microprojection which is being employed. It will be understood by persons skilled in the art that in many cases the same inventive principles apply to the use of other microprotrusions or

microprojections to penetrate the skin. Other microprotrusions or microprojections may include, for example, microblades as described in U.S. Patent No. 6,219,574 and Canadian Patent Application No. 2,226,718, and edged microneedles as described in U.S. Patent No. 6,652,478.

The height or length of the microneedle of the microneedle sheet to be used for the present invention may be from 50 to 1000 microns, preferably from 100 to 750 microns, and more preferably from 150 to 500 microns.

According to one embodiment of the present invention, the microneedle is in the form of a cone.

The cone may comprise a distal end such as a tip and a base. The shape of the base may be a circle or oval.

The height or length of the cone of the microneedle of the microneedle sheet to be used for the present invention may be from 50 to 1000 microns, preferably from 100 to 750 microns, and more preferably from 150 to 500 microns.

The base of the cone of the microneedle of the microneedle sheet to be used for the present invention may have a diameter or width of from 50 to 350 microns, preferably from 100 to 300 microns, and more preferably from 150 to 250 microns. If the base of the cone of the microneedle of the microneedle sheet to be used for the present invention is in the shape of an oval or ellipse, the length of the major axis or width of the oval may be from 50 to 350 microns, preferably from 100 to 300 microns, and more preferably from 150 to 250 microns.

The microneedle may have an aspect ratio (length/width at base) of at least about 3: 1, at least about 2: 1 , or at least about 1 : 1. The ratio of (the height of the cone)/(the diameter of the base of the cone) of the microneedle may be 1 or more, preferably 1.5 or more, and more preferably 2.0 or more.

Preferably, the microneedles do not fracture by force when a pressure of insertion of less than 50.0 N/cm², for example less than 20.0 N/cm², such as less than 10 N/cm² is exerted on the microneedles along their length.

It is also preferable that the microneedle sheet to be used for the present invention, in particular the microneedles of the microneedle sheet, have a Young modulus of 50 N/mm or more, preferably 55 N/mm or more, and more preferably 60 N/mm or more.

It may be preferable that the microneedle be capable of penetrating into a keratin substance, such as the skin or the lips, to a depth of 200 microns or less, preferably 180 microns or less, and more preferably 160 microns or less.

The microneedle is dissolvable. The“dissolvable microneedle” is meant that the microneedle can be broken down or disintegrated inside a keratin substance such as the skin or the lips by, for example, a natural moisturizing factor or external moisture.

The microneedle of the microneedle sheet to be used for the present invention comprises at least one water-soluble or water-dispersible polymer. Here, the terms“water-soluble” and “water-dispersible” mean soluble and dispersible respectively, when being contact with water. A single water-soluble or water-dispersible polymer may be used. Two or more water-soluble or water-dispersible polymers may be used in combination.

It is preferable that the water-soluble or water-dispersible polymer be soluble or dispersible in the skin or the lips. Thus, in one embodiment of the present invention, the water-soluble or water-dispersible polymer is capable of being dissolved or dispersed after insertion into a keratin substance such as the skin or the lips. Due to the solubility or dispersibility of the polymer, the microneedle of the microneedle sheet to be used for the present invention can effectively release an agent or agents, if present, in the microneedle.

It is preferable that the water-soluble or water-dispersible polymer be dissolvable in the surface layer of a keratin substance such as the skin or the lips.

The water-soluble or water-dispersible polymer may be selected from hyaluronic acids (in particular lower molecular weight hyaluronic acid), monosaccharides, disaccharides, oligosaccharides, polysaccharides (including derivatives thereof such as

hydroxymethylcellulose), dextrins, dextrans, polyethylene glycols, polyvinyl alcohols, poly(methyvinylether/maleic anhydride), polyvinylpyrrolidone, poly(methyl/vinyl

ether/maleic acid) (PMVE/MA) and esters thereof, poly(methyl/vinyl ether/maleic anhydride) (PMVE/MAH), and mixtures thereof.

The low molecular weight hyaluronic acid may have a molecular weight 100 kDa or less, preferably 70 kDa or less, and more preferably 50 kDa or less.

The polyvinylpyrrolidone may have a molecular weight between 1 kDa and 300 kDa, preferably between 5 kDa and 200 kDa, and more preferably between 7 kDa and 100 kDa.

The poly(methyl/vinyl ether/maleic acid) (PMVE/MA) and esters thereof, and

poly(methyl/vinyl ether/maleic anhydride) (PMVE/MAH) are known as Gantrez-type polymers.

The amount (solid basis) of the water-soluble or water-dispersible polymer(s) in the microneedle of the microneedle sheet to be used for the present invention may be 50% by weight or more, preferably 60% by weight or more, and more preferably 70% by weight or more, relative to the total weight of the microneedle. The amount (solid basis) of the water- soluble or water-dispersible polymer(s) in the microneedle of the microneedle sheet to be used for the present invention may be 100% by weight or less, preferably 90% by weight or less, and more preferably 80% by weight or less, relative to the total weight of the

microneedle. Thus, the amount (solid basis) of the water-soluble or water-dispersible polymer(s) in the microneedle of the microneedle sheet to be used for the present invention may be from 50% to 100% by weight, preferably from 60% to 90% by weight, and more preferably from 70% to 80% by weight, relative to the total weight of the microneedle.

It may be possible that the microneedle of the microneedle sheet to be used for the present invention comprise at least one material which is swellable, more preferably water-swellable, and even more preferably swellable in a keratin substance such as the skin or the lips. The above material may be a polymer which is swellable, more preferably water-swellable, and even more preferably swellable in the keratin substance. Here, the term“water-swellable” means swellable when being in contact with water. The above swellable material or polymer may have a high swellability such that it can swell to at least over 10 times in a l-hour in vitro incubation in a physiological saline solution or phosphate buffered saline, preferably at least 20 times in l-hour incubation, more preferably at least 30 times in l-hour incubation, even more preferably at least 40 times in l-hour incubation, and most preferably about 45-55 times in l-hour incubation.

It may be preferable that at least the distal end portion of the microneedle swell upon insertion into the keratin substance, more preferably within less than 1 hour, and even more preferably to at least 2 times within 24 hours after insertion into the keratin substance.

The above swellable material, preferably the above swellable polymer, may have a high viscoelasticity such that it can form a gel after the in vitro incubation in a physiological saline solution or phosphate buffered saline. The gel exhibits a high elastic modulus G’, a high viscous modulus G”, a Tangent (d) (Tangent (d) = G”/G’) of less than 1, and a high consistency G* (G*²=G’² + G”²) even at low frequency (0.01 Hz) in a dynamic frequency sweep test with a Rheometer.

In one embodiment, the above swellable material, preferably the swellable polymer, is not water-soluble or not water-dispersible.

In another embodiment, the above swellable material, preferably the swellable polymer, may be a hydrogel-forming polymer.

The above swellable polymer may be selected from high molecular weight hyaluronic acids, cross-linked hyaluronic acids, cross-linked polyethylene glycol, polyethylene glycol cross- linked poly-lactic acid or poly-glycolic acid or poly-lactic-co-glycolic acid or poly dioxanone, poly(styrene)-block-poly(acrylic acid), polyethylene glycol cross-linked PMVE/MA, cross- linked polyvinylpyrrolidone, sodium starch glycolate; cellulose; natural and synthetic gums; alginates; sodium polyacrylate PEG-crosslinked poly(methyl/vinyl ether/maleic acid)

(PMVE/MA) and esters thereof, PEG-crosslinked poly(methyl/vinyl ether/maleic anhydride) (PMVE/MAH) and esters thereof, and mixtures thereof.

The high molecular weight hyaluronic acid may have a molecular weight of more than 500 kDa, preferably more than 1000 kDa, and more preferably more than 2100 kDa, and preferably less than 10000 kDa.

Unless otherwise defined, the molecular weight here means a number average molecular weight. The poly(methyl/vinyl ether/maleic acid) (PMVE/MA) and esters thereof, and poly(methyl/vinyl ether/maleic anhydride) (PMVE/MAH) are known as Gantrez-type polymers.

The amount (solid basis) of the swellable material(s) in the microneedle of the microneedle sheet to be used for the present invention may be 1% by weight or more, preferably 5% by weight or more, and more preferably 10% by weight or more, relative to the total weight of the microneedle. The amount (solid basis) of the swellable material(s) in the microneedle of the microneedle sheet to be used for the present invention may be 30% by weight or less, preferably 25% by weight or less, and more preferably 20% by weight or less, relative to the total weight of the microneedle. Thus, the amount (solid basis) of the swellable material(s) in the microneedle of the microneedle sheet to be used for the present invention may be from 1% to 30% by weight, preferably from 5% to 25% by weight, and more preferably from 10% to 20% by weight, relative to the total weight of the microneedle.

If the microneedle of the microneedle sheet to be used for the present invention comprises at least one swellable material, preferably at least one swellable polymer, the microneedle may be swellable such that it can improve the aesthetic appearance of a keratin substance, preferably the skin, and more preferably the skin of the face, by reducing the appearance of wrinkles.

In other words, if the microneedle is swellable, it can swell in the skin to further increase the volume of the microneedle along with its absorption of, for example, water in the skin. Such volume expansion beneath the skin surface of a wrinkle site can effectively push the wrinkles from inside the skin and makes the wrinkles become shallower and wider. Thus, the wrinkles can be reduced or made less noticeable.

The apical separation distance between each of the individual microneedles on a substrate sheet can be modified to ensure the penetration of the skin or the lips by the microneedles while having a sufficiently small separation distance to provide high transdermal transport rates.

In one embodiment, the range of apical separation distances between microneedles can be in the range of 10-1000 pm, such as 30-800 pm or 50-600 pm. This may allow a compromise to be achieved between efficient penetration of the stratum comeum by as many microneedles as possible and the necessary margin for possible swelling of the microneedles if they are swellable.

In one embodiment, the density of microneedles may be from 100 to 2000 microneedles/cm², preferably 200 to 1000 microneedles/cm², and even more preferably 200 to 500

microneedles/ cm².

(Cosmetic Active Ingredient)

According to one embodiment, at least one of the microneedles of the microneedle sheet used for the present invention may comprise at least one cosmetic active ingredient. A single cosmetic active ingredient may be used. Two or more cosmetic active ingredients may be used in combination. The type of the cosmetic active ingredient is not limited. For example, an anti-aging agent may be used as the cosmetic active ingredient.

As examples of the anti-aging agent, mention may be made of anti-oxidant, moisturizers, free- radical scavengers, keratolytic agents, vitamins, anti-elastase and anti-collagenase agents, protides, fatty acid derivatives, steroids, trace elements, bleaching agents, extracts of algae and of planktons, enzymes and coenzymes, flavonoids and ceramides, and mixtures thereof.

The amount of the cosmetic active ingredient(s) in the microneedle of the microneedle sheet used for the present invention is not limited, and may be from 0.01% to 10% by weight, preferably from 0.05% to 5% by weight, and more preferably from 0.1% to 1% by weight, relative to the total weight of the microneedle.

It is also possible that the amount of the cosmetic active ingredient(s) in the microneedle of the microneedle sheet to be used for the present invention be less than 0.01% by weight, relative to the total weight of the microneedle. In one embodiment, the microneedle of the microneedle sheet according to the present invention may include no cosmetic active ingredient.

(Substrate Sheet)

The microneedle sheet according to the present invention comprises a substrate sheet on which the microneedles are present or placed.

The substrate sheet of the microneedle sheet to be used for the present invention may be dissolvable or non-dissolvable.

It is preferable that the substrate sheet of the microneedle sheet to be used for the present invention be dissolvable in water or disintegrable in water.

The substrate sheet of the microneedle sheet to be used for the present invention may comprise at least one water-soluble or water dispersible polymer, as explained above. In other words, the above explanations for the water-soluble or water-dispersible polymer which is comprised in the microneedles of the microneedle sheet can apply to the water-soluble or water-dispersible polymer which may be comprised in the substrate sheet.

For example, the amount (solid basis) of the water-soluble or water-dispersible polymer(s) in the substrate sheet of the microneedle sheet to be used for the present invention may be 50% by weight or more, preferably 60% by weight or more, and more preferably 70% by weight or more, relative to the total weight of the substrate sheet. The amount (solid basis) of the water- soluble or water-dispersible polymer(s) in the substrate sheet of the microneedle sheet to be used for the present invention may be 100% by weight or less, preferably 90% by weight or less, and more preferably 80% by weight or less, relative to the total weight of the substrate sheet. Thus, the amount (solid basis) of the water-soluble or water-dispersible polymer(s) in the substrate sheet of the microneedle sheet to be used for the present invention may be from 50% to 100% by weight, preferably from 60% to 90% by weight, and more preferably from 70% to 80% by weight, relative to the total weight of the substrate sheet.

The substrate sheet and the microneedles may be separated or integrated. For example, the substrate sheet and the microneedles may comprise at least one common water-soluble or water dispersible polymer. Thus, in one embodiment, the substrate sheet and the microneedles can be a single element comprising at least one common water-soluble or water-dispersible polymer. Preferably, the single element can be prepared by using the same water-soluble or water-dispersible polymer(s).

On the other hand, the substrate sheet may be different or distinct from the microneedles. For example, the substrate sheet and the microneedles may be made from different materials. In this case, the substrate sheet may be, for example, chosen from masks, wipes, patches, and in general all types of porous substrate sheets. Preferably, these substrate sheets have an oblong structure, namely with a thickness smaller than the dimensions of the plane in which they are defined.

The substrate sheet may be cut so as to be in the form of a patch, a disc, a mask, a towel, a glove, a precut roll, or any other form suitable for a cosmetic use.

(Preparation)

There is no limitation regarding how to prepare the microneedle sheet to be used for the present invention. It is possible to prepare the microneedle sheet to be used for the present invention based on conventional technology such as molding, 3D printing and droplet bom air blowing.

The microneedle sheet to be used for the present invention can be prepared, for example, by a process comprising the steps of molding a composition comprising at least one water-soluble or water-dispersible polymer, as explained above.

In one embodiment, the microneedle sheet to be used for the present invention can be prepared by a process comprising the steps of

(a) providing a mold with cavities corresponding to a negative of the microneedles,

(b) filling a composition comprising at least one water-soluble or water-dispersible

polymer, as explained above, into the cavities,

(c) solidifying the composition, for example, by drying at room temperature (and

optionally heating) for a period of time such as several hours to form the

microneedles, and

(d) removing the microneedle sheet from the mold.

The mold may be made from organic materials such as polyamides and silicones and inorganic materials such as aluminum and iron.

At least one evaporable liquid ingredient may be included in the above composition, if necessary, in order to enhance the fluidity of the composition. Examples of the evaporable liquid ingredient are not limited, but may preferably be water and alcohol such as ethanol.

The amount of the evaporable liquid ingredient(s) may be 10% by weight or more, preferably 20% by weight or more, and more preferably 30% by weight or more, relative to the total weight of the composition. The amount of the evaporable liquid ingredient(s) may be 98% by weight or less, preferably 95% by weight or less, and more preferably 90% by weight or less, relative to the total weight of the composition. Thus, the amount of the evaporable liquid ingredient(s) may be from 10% to 98% by weight, preferably from 20% to 95% by weight, and more preferably from 30% to 90% by weight, relative to the total weight of the composition.

The amount of the water-soluble or water-dispersible polymer(s) in the above composition, which is preferably capable of flowing, and more preferably is in the form of a liquid, may be from 2% to 90% by weight, preferably from 5% to 50% by weight, and more preferably from 5% to 30% by weight relative to the total weight of the composition.

If necessary, the above composition may include at least one additional polymer such as the above-explained swellable polymer and/or at least one cosmetic active ingredient as explained above.

The shape of the microneedle sheet to be used for the present invention is not limited, and it may be any shape such as the shape of the lips or a shape suitable for application under the eyes, depending on the application target of the microneedle sheet.

{Composition}

The composition to be used for the cosmetic process according to the present invention is in the form of an O/W emulsion and comprises at least one oil and water.

The composition may be used as a pre-treatment composition for a keratin substance.

(Oil)

The composition to be used for the present invention comprises at least one oil. If two or more oils are used, they may be the same or different.

Here,“oil” means a fatty compound or substance which is in the form of a liquid or a paste (non-solid) at room temperature (25°C) under atmospheric pressure (760 mmHg). As the oils, those generally used in cosmetics can be used alone or in combination thereof. These oils may be volatile or non-volatile.

The oil may be a non-polar oil such as a hydrocarbon oil, a silicone oil, or the like; a polar oil such as a plant or animal oil and an ester oil or an ether oil; or a mixture thereof.

The oil may be selected from the group consisting of oils of plant or animal origin, synthetic oils, silicone oils, hydrocarbon oils, and fatty alcohols.

As examples of plant oils, mention may be made of, for example, linseed oil, camellia oil, macadamia nut oil, com oil, mink oil, olive oil, avocado oil, sasanqua oil, castor oil, safflower oil, jojoba oil, sunflower oil, almond oil, rapeseed oil, sesame oil, soybean oil, peanut oil, and mixtures thereof.

As examples of animal oils, mention may be made of, for example, squalene and squalane.

As examples of synthetic oils, mention may be made of alkane oils such as isododecane and isohexadecane, ester oils, ether oils, and artificial triglycerides. The ester oils are preferably liquid esters of saturated or unsaturated, linear or branched Ci- C₂₆ aliphatic monoacids or polyacids and of saturated or unsaturated, linear or branched Ci- C₂₆ aliphatic monoalcohols or polyalcohols, the total number of carbon atoms of the esters being greater than or equal to 10.

Preferably, for the esters of monoalcohols, at least one from among the alcohol and the acid from which the esters of the present invention are derived is branched.

Among the monoesters of monoacids and of monoalcohols, mention may be made of ethyl palmitate, ethyl hexyl palmitate, isopropyl palmitate, dicaprylyl carbonate, alkyl myristates such as isopropyl myristate or ethyl myristate, isocetyl stearate, 2-ethylhexyl isononanoate, isononyl isononanoate, isodecyl neopentanoate, and isostearyl neopentanoate.

Esters of C₄-C₂₂ dicarboxylic or tricarboxylic acids and of Ci-C₂₂ alcohols, and esters of monocarboxylic, dicarboxylic, or tricarboxylic acids and of non-sugar C₄-C₂₆ dihydroxy, trihydroxy, tetrahydroxy, or pentahydroxy alcohols may also be used.

Mention may especially be made of: diethyl sebacate; isopropyl lauroyl sarcosinate;

diisopropyl sebacate; bis(2-ethylhexyl) sebacate; diisopropyl adipate; di-n-propyl adipate; dioctyl adipate; bis(2-ethylhexyl) adipate; diisostearyl adipate; bis(2-ethylhexyl) maleate; triisopropyl citrate; triisocetyl citrate; triisostearyl citrate; glyceryl trilactate; glyceryl trioctanoate; trioctyldodecyl citrate; trioleyl citrate; neopentyl glycol diheptanoate; diethylene glycol diisononanoate.

As ester oils, one can use sugar esters and diesters of C₆-C₃₀ and preferably Ci₂-C₂₂ fatty acids. It is recalled that the term“sugar” means oxygen-bearing hydrocarbon-based compounds containing several alcohol functions, with or without aldehyde or ketone functions, and which comprise at least 4 carbon atoms. These sugars may be monosaccharides, oligosaccharides, or polysaccharides.

Examples of suitable sugars that may be mentioned include sucrose (or saccharose), glucose, galactose, ribose, fucose, maltose, fructose, mannose, arabinose, xylose, and lactose, and derivatives thereof, especially alkyl derivatives, such as methyl derivatives, for instance methylglucose.

The sugar esters of fatty acids may be chosen especially from the group comprising the esters or mixtures of esters of sugars described previously and of linear or branched, saturated or unsaturated C6-C30 and preferably Ci₂-C₂₂ fatty acids. If they are unsaturated, these compounds may have one to three conjugated or non-conjugated carbon-carbon double bonds.

The esters according to this variant may also be selected from monoesters, diesters, triesters, tetraesters, and polyesters, and mixtures thereof.

These esters may be, for example, oleates, laurates, palmitates, myristates, behenates, cocoates, stearates, linoleates, linolenates, caprates, and arachidonates, or mixtures thereof such as, especially, oleopalmitate, oleostearate, and palmitostearate mixed esters, as well as pentaerythrityl tetraethyl hexanoate. More particularly, use is made of monoesters and diesters and especially sucrose, glucose, or methylglucose monooleates or dioleates, stearates, behenates, oleopalmitates, linoleates, linolenates, and oleostearates.

An example that may be mentioned is the product sold under the name Glucate® DO by the company Amerchol, which is a methylglucose dioleate.

As examples of preferable ester oils, mention may be made of, for example, diisopropyl adipate, dioctyl adipate, 2-ethylhexyl hexanoate, ethyl laurate, cetyl octanoate, octyldodecyl octanoate, isodecyl neopentanoate, myristyl propionate, 2-ethylhexyl 2-ethylhexanoate, 2- ethylhexyl octanoate, 2-ethylhexyl caprylate/caprate, methyl palmitate, ethyl palmitate, isopropyl palmitate, dicaprylyl carbonate, isopropyl lauroyl sarcosinate, isononyl

isononanoate, ethylhexyl palmitate, isohexyl laurate, hexyl laurate, isocetyl stearate, isopropyl isostearate, isopropyl myristate, isodecyl oleate, glyceryl tri(2-ethylhexanoate),

pentaerythrithyl tetra(2-ethylhexanoate), 2-ethylhexyl succinate, diethyl sebacate, and mixtures thereof.

As examples of artificial triglycerides, mention may be made of, for example, capryl caprylyl glycerides, glyceryl trimyristate, glyceryl tripalmitate, glyceryl trilinolenate, glyceryl trilaurate, glyceryl tricaprate, glyceryl tricaprylate, glyceryl tri(caprate/caprylate), and glyceryl tri(caprate/caprylate/linolenate).

As examples of silicone oils, mention may be made of, for example, linear

organopolysiloxanes such as dimethylpolysiloxane, methylphenylpolysiloxane,

methylhydrogenpolysiloxane, and the like; cyclic organopolysiloxanes such as

cyclohexasiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane,

dodecamethylcyclohexasiloxane, and the like; and mixtures thereof.

Preferably, the silicone oil is chosen from liquid polydialkylsiloxanes, especially liquid polydimethylsiloxanes (PDMS) and liquid polyorganosiloxanes comprising at least one aryl group.

These silicone oils may also be organomodified. The organomodified silicones that can be used in accordance with the present invention are silicone oils as defined above and comprise in their structure one or more organofunctional groups attached via a hydrocarbon-based group.

Organopolysiloxanes are defined in greater detail in Walter Noll’s Chemistry and Technology of Silicones (1968), Academic Press. They may be volatile or non-volatile.

When they are volatile, the silicones are more particularly chosen from those having a boiling point of between 60°C and 260°C, and even more particularly from:

(i) cyclic polydialkylsiloxanes comprising from 3 to 7 and preferably 4 to 5 silicon

atoms. These are, for example, octamethylcyclotetrasiloxane sold in particular under the name Volatile Silicone® 7207 by Union Carbide or Silbione® 70045 V2 by Rhodia, decamethylcyclopentasiloxane sold under the name Volatile Silicone® 7158 by Union Carbide, Silbione® 70045 V5 by Rhodia, and

dodecamethylcyclopentasiloxane sold under the name Silsoft 1217 by Momentive Performance Materials, and mixtures thereof. Mention may also be made of cyclocopolymers of the type such as dimethylsiloxane/methylalkylsiloxane, such as Silicone Volatile® FZ 3109 sold by the company Union Carbide, of the formula:

Mention may also be made of mixtures of cyclic polydialkylsiloxanes with organosilicon compounds, such as the mixture of octamethylcyclotetrasiloxane and tetratrimethylsilylpentaerythritol (50/50) and the mixture of

octamethylcyclotetrasiloxane and oxy-l,r-bis(2,2,2’,2’,3,3’- hexatrimethylsilyloxy)neopentane; and

(ϋ) linear volatile polydialkylsiloxanes containing 2 to 9 silicon atoms and having a viscosity of less than or equal to 5x 10 ⁶ m²/s at 25°C. An example is

decamethyltetrasiloxane sold in particular under the name SH 200 by the company Toray Silicone. Silicones belonging to this category are also described in the article published in Cosmetics and Toiletries, Vol. 91, Jan. 76, pp. 27-32, Todd & Byers, Volatile Silicone Fluids for Cosmetics. The viscosity of the silicones is measured at 25°C according to ASTM standard 445 Appendix C.

Non-volatile polydialkylsiloxanes may also be used. These non-volatile silicones are more particularly chosen from polydialkylsiloxanes, among which mention may be made mainly of polydimethylsiloxanes containing trimethylsilyl end groups.

Among these polydialkylsiloxanes, mention may be made, in a non-limiting manner, of the following commercial products:

- the Silbione^® oils of the 47 and 70 047 series or the Mirasil^® oils sold by Rhodia, for instance the oil 70 047 V 500 000;

the oils of the Mirasil^® series sold by the company Rhodia;

the oils of the 200 series from the company Dow Coming, such as DC200 with a viscosity of 60 000 mm²/s; and

- the Viscasil^® oils from General Electric and certain oils of the SF series (SF 96, SF

18) from General Electric.

Mention may also be made of polydimethylsiloxanes containing dimethylsilanol end groups known under the name dimethiconol (CTFA), such as the oils of the 48 series from the company Rhodia.

Among the silicones containing aryl groups, mention may be made of polydiarylsiloxanes, especially polydiphenylsiloxanes and polyalkylarylsiloxanes such as phenyl silicone oil. The phenyl silicone oil may be chosen from the phenyl silicones of the following formula:

in which

Ri to Rio, independently of each other, are saturated or unsaturated, linear, cyclic or branched C1-C30 hydrocarbon-based radicals, preferably Ci-Ci₂ hydrocarbon-based radicals, and more preferably Ci-C₆ hydrocarbon-based radicals, in particular methyl, ethyl, propyl, or butyl radicals, and

m, n, p, and q are, independently of each other, integers of 0 to 900 inclusive, preferably 0 to 500 inclusive, and more preferably 0 to 100 inclusive,

with the proviso that the sum n+m+q is other than 0.

Examples that may be mentioned include the products sold under the following names:

the Silbione® oils of the 70 641 series from Rhodia;

the oils of the Rhodorsil® 70 633 and 763 series from Rhodia;

the oil Dow Coming 556 Cosmetic Grade Fluid from Dow Coming;

the silicones of the PK series from Bayer, such as the product PK20;

certain oils of the SF series from General Electric, such as SF 1023, SF 1154, SF 1250, and SF 1265.

As the phenyl silicone oil, phenyl trimethicone (Ri to Ri₀ are methyl; p, q, and n = 0; m=l in the above formula) is preferable.

The organomodified liquid silicones may especially contain polyethyl eneoxy and/or polypropyleneoxy groups. Mention may thus be made of the silicone KF-6017 proposed by Shin-Etsu, and the oils Silwet® L722 and L77 from the company Union Carbide.

Hydrocarbon oils may be chosen from:

linear or branched, optionally cyclic, C₆-Ci₆ lower alkanes. Examples that may be mentioned include hexane, undecane, dodecane, tridecane, and isoparaffins, for instance isohexadecane, isododecane, and isodecane; and

linear or branched hydrocarbons containing more than 16 carbon atoms, such as liquid paraffins, liquid petroleum jelly, polydecenes and hydrogenated

polyisobutenes such as Parleam®, and squalane.

As preferable examples of hydrocarbon oils, mention may be made of, for example, linear or branched hydrocarbons such as isohexadecane, isododecane, squalane, mineral oil (e.g., liquid paraffin), paraffin, vaseline or petrolatum, naphthalenes, and the like; hydrogenated polyisobutene, isoeicosan, and decene/butene copolymer; and mixtures thereof.

The term“fatty” in the fatty alcohol means the inclusion of a relatively large number of carbon atoms. Thus, alcohols which have 4 or more, preferably 6 or more, and more preferably 12 or more carbon atoms are encompassed within the scope of fatty alcohols. The fatty alcohol may be saturated or unsaturated. The fatty alcohol may be linear or branched.

The fatty alcohol may have the structure R-OH wherein R is chosen from saturated and unsaturated, linear and branched radicals containing from 4 to 40 carbon atoms, preferably from 6 to 30 carbon atoms, and more preferably from 12 to 20 carbon atoms. In at least one embodiment, R may be chosen from Ci₂-C₂₀ alkyl and Ci₂-C₂₀ alkenyl groups. R may or may not be substituted with at least one hydroxyl group.

As examples of the fatty alcohol, mention may be made of lauryl alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, behenyl alcohol, undecylenyl alcohol, myristyl alcohol, octyldodecanol, hexyldecanol, oleyl alcohol, linoleyl alcohol, palmitoleyl alcohol,

arachidonyl alcohol, erucyl alcohol, and mixtures thereof.

It is preferable that the fatty alcohol be a saturated fatty alcohol.

Thus, the fatty alcohol may be selected from straight or branched, saturated or unsaturated C₆- C₃₀ alcohols, preferably straight or branched, saturated C₆-C₃₀ alcohols, and more preferably straight or branched, saturated Ci₂-C₂₀ alcohols.

The term“saturated fatty alcohol” here means an alcohol having a long aliphatic saturated carbon chain. It is preferable that the saturated fatty alcohol be selected from any linear or branched, saturated C₆-C₃₀ fatty alcohols. Among the linear or branched, saturated C₆-C₃₀ fatty alcohols, linear or branched, saturated Ci₂-C₂₀ fatty alcohols may preferably be used.

Any linear or branched, saturated Ci₆-C₂₀ fatty alcohols may be more preferably used.

Branched Ci₆-C₂o fatty alcohols may be even more preferably used.

As examples of saturated fatty alcohols, mention may be made of lauryl alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, behenyl alcohol, undecylenyl alcohol, myristyl alcohol, octyldodecanol, hexyldecanol, and mixtures thereof. In one embodiment, cetyl alcohol, stearyl alcohol, octyldodecanol, hexyldecanol, or a mixture thereof (e.g., cetearyl alcohol) as well as behenyl alcohol, can be used as a saturated fatty alcohol.

According to at least one embodiment, the fatty alcohol used in the composition to be used for the present invention is preferably chosen from cetyl alcohol, octyldodecanol, hexyldecanol, and mixtures thereof.

It may be preferable that the oil be chosen from ester oils, hydrocarbon oils, silicone oils, fatty alcohols, and mixtures thereof.

The amount of the oil(s) in the composition to be used for the present invention may be 1% by weight or more, preferably 5% by weight or more, and more preferably 10% by weight or more, relative to the total weight of the composition. The amount of the oil(s) in the composition to be used for the present invention may be 30% by weight or less, preferably 25% by weight or less, and more preferably 20% by weight or less, relative to the total weight of the composition. The amount of the oil(s) in the composition to be used for the present invention may be from 1% to 30% by weight, preferably from 5% to 25% by weight, and more preferably from 10% to 20% by weight, relative to the total weight of the composition.

The oil(s) can form a fatty phase of the composition to be used for the present invention. As the composition to be used for the present invention is in the form of an O/W emulsion, the oil(s) can form dispersed fatty phases in the O/W emulsion.

(Water)

The composition to be used for the cosmetic process according to the present invention comprises water.

The amount of the water may be 50% by weight or more, preferably 55% by weight or more, and more preferably 60% by weight or more, relative to the total weight of the composition. The amount of the water may be 95% by weight or less, preferably 90% by weight or less, and more preferably 85%. by weight or less, relative to the total weight of the composition.

The amount of water in the composition to be used for the present invention may range from 50% to 95% by weight, preferably from 55% to 90% by weight, and more preferably from 60% to 85% by weight, relative to the total weight of the composition.

The water can form an aqueous phase of the composition to be used for the present invention.

As the composition to be used for the present invention is in the form of an O/W emulsion, the water can form continuous aqueous phases in the O/W emulsion.

(Surfactant)

The composition to be used for the present invention may include at least one surfactant. If two or more surfactants are used, they may be the same or different.

Any surfactant may be used for the present invention. The surfactant used in the present invention may be selected from the group consisting of anionic surfactants, amphoteric surfactants, cationic surfactants, and nonionic surfactants. Two or more surfactants may be used in combination. Thus, a single type of surfactant or a combination of different types of surfactants may be used.

Anionic Surfactants

According to the present invention, the type of anionic surfactant is not limited. It is preferable that the anionic surfactant be selected from the group consisting of (C₆-C₃₀)alkyl sulfates, (C₆-C₃₀)alkyl ether sulfates, (C₆-C₃o)alkylamido ether sulfates, alkylaryl polyether sulfates, and monoglyceride sulfates; (C₆-C₃o)alkylsulfonates, (C₆-C₃₀)alkylamide sulfonates, (C₆-C₃o)alkylaryl sulfonates, a-olefm sulfonates, and paraffin sulfonates; (C₆-C₃o)alkyl phosphates; (C₆-C₃₀)alkyl sulfosuccinates, (C₆-C₃₀)alkyl ether sulfosuccinates, and (C₆- C₃₀)alkylamide sulfosuccinates; (C₆-C₃₀)alkyl sulfoacetates; (C₆-C₂₄)acyl sarcosinates; (C₆- C₂₄)acyl glutamates; (C₆-C₃₀)alkylpolyglycoside carboxylic ethers; (C₆- C₃₀)alkylpolyglycoside sulfosuccinates; (C₆-C₃₀)alkyl sulfosuccinamates; (C₆-C₂₄)acyl isethionates; N-(C₆-C₂₄)acyl taurates; C₆-C₃₀ fatty acid salts; coconut oil acid salts or hydrogenated coconut oil acid salts; (C₈-C₂₀)acyl lactylates; (C₆-C₃₀)alkyl-D-galactoside uronic acid salts; polyoxyalkylenated (C₆-C₃₀)alkyl ether carboxylic acid salts;

polyoxyalkylenated (C₆-C₃₀)alkylaryl ether carboxylic acid salts; and polyoxyalkylenated (C₆- C₃₀)alkylamido ether carboxylic acid salts. It is more preferable that the anionic surfactant be selected from salts of (C₆-C₃₀)alkyl sulfate or polyoxyalkylenated (C₆-C₃₀)alkyl ether carboxylic acid salts.

In at least one embodiment, the anionic surfactants are in the form of salts such as salts of alkali metals, for instance sodium; salts of alkaline-earth metals, for instance magnesium; ammonium salts; amine salts; and amino alcohol salts. Depending on the conditions, they may also be in acid form.

Amphoteric Surfactants

According to the present invention, the type of amphoteric surfactant is not limited. The amphoteric or zwitterionic surfactants can be, for example (non-limiting list), amine derivatives such as aliphatic secondary or tertiary amine, and optionally quatemized amine derivatives, in which the aliphatic radical is a linear or branched chain comprising 8 to 22 carbon atoms and containing at least one water-solubilizing anionic group (for example, carboxylate, sulphonate, sulphate, phosphate, or phosphonate).

The amphoteric surfactant may preferably be selected from the group consisting of betaines and amidoaminecarboxylated derivatives.

The betaine-type amphoteric surfactant is preferably selected from the group consisting of alkylbetaines, alkylamidoalkylbetaines, sulfobetaines, phosphobetaines, and

alkylamidoalkylsulfobetaines, in particular, (C₈-C₂₄)alkylbetaines, (C₈-C₂₄)alkylamido(Ci- C₈)alkylbetaines, sulphobetaines, and (C₈-C₂₄)alkylamido(Ci-C₈)alkylsulphobetaines. In one embodiment, the amphoteric surfactants of betaine type are chosen from (C₈- C₂₄)alkylbetaines, (C₈-C₂₄)alkylamido(Ci-C₈)alkylsulphobetaines, sulphobetaines, and phosphobetaines.

Non-limiting examples that may be mentioned include the compounds classified in the CTFA dictionary, 9th edition, 2002, under the names cocobetaine, laurylbetaine, cetylbetaine, coco/oleamidopropylbetaine, cocamidopropylbetaine, palmitamidopropylbetaine, stearamidopropylbetaine, cocamidoethylbetaine, cocamidopropylhydroxysultaine, oleamidopropylhydroxysultaine, cocohydroxysultaine, laurylhydroxysultaine, and cocosultaine, alone or as mixtures.

The betaine-type amphoteric surfactant is preferably an alkylbetaine and an

alkylamidoalkylbetaine, in particular cocobetaine and cocamidopropylbetaine.

Among the amidoaminecarboxylated derivatives, mention may be made of the products sold under the name Miranol, as described in U.S. Pat. Nos. 2,528,378 and 2,781,354 and classified in the CTFA dictionary, 3rd edition, 1982 (the disclosures of which are incorporated herein by reference), under the names Amphocarboxyglycinates and

Amphocarboxypropionates, with the respective structures:

Ri-CONHCH₂CH₂-N⁺(R₂)(R₃)(CH₂COO ) in which:

Ri denotes an alkyl radical of an acid Ri-COOH present in hydrolysed coconut oil, a heptyl, nonyl, or undecyl radical,

R₂ denotes a beta-hydroxyethyl group, and DPT/ ID 9 M 9 /025265

WO 2020/004428 PCT/JP2019/025265

R₃ denotes a carboxymethyl group; and

Ri'-CONHCH₂CH₂-N (B)(C) in which:

B represents -CH₂CH₂OX',

C represents -(CH₂)_Z-Y', with z=l or 2,

X' denotes a -CH₂CH₂-COOH group, -CH₂-COOZ’, -CH₂CH₂-COOH, -CH₂CH₂-COOZ’, or a hydrogen atom,

V denotes -COOH, -COOZ’, -CH₂-CH0H-S0₃Z’, or a -CH₂-CH0H-S0₃H radical,

Z’ represents an ion of an alkaline or alkaline earth metal such as sodium, an ammonium ion, or an ion issued from an organic amine, and

Rf denotes an alkyl radical of an acid Rf-COOH present in coconut oil or in hydrolysed

linseed oil, an alkyl radical, such as a C₇, C9, Cn, or Ci₃ alkyl radical, a C_l7 alkyl radical and its iso form, or an unsaturated C17 radical.

It is preferable that the amphoteric surfactant be selected from (C₈-C₂₄)-alkyl

amphomonoacetates, (C₈-C₂₄)alkyl amphodiacetates, (C₈-C₂₄)alkyl amphomonopropionates, and (C₈-C₂₄)alkyl amphodipropionates

These compounds are classified in the CTFA dictionary, 5th edition, 1993, under the names

Disodium Cocoamphodiacetate, Disodium Lauroamphodiacetate, Disodium

Caprylamphodiacetate, Disodium Capryloamphodiacetate, Disodium Cocoamphodipropionate, Disodium Lauroamphopropionate, Disodium Caprylamphodipropionate, Disodium

Caprylamphodipropionate, Lauroamphodipropionic acid, and Cocoamphodipropionic acid.

By way of example, mention may be made of the cocoamphodiacetate sold under the trade

name Miranol® C2M concentrate by the company Rhodia Chimie.

Cationic Surfactants

According to the present invention, the type of cationic surfactant is not limited. The cationic surfactant may be selected from the group consisting of optionally polyoxyalkylenated,

primary, secondary, or tertiary fatty amine salts, quaternary ammonium salts, and mixtures

thereof.

Examples of quaternary ammonium salts that may be mentioned include, but are not limited to:

those of general formula (I) below:

wherein

Ri, R₂, R₃, and R₄, which may be identical or different, are chosen from linear and branched aliphatic radicals comprising from 1 to 30 carbon atoms and optionally comprising

heteroatoms such as oxygen, nitrogen, sulfur, and halogens. The aliphatic radicals may be

chosen, for example, from alkyl, alkoxy, C₂-C₆ polyoxyalkylene, alkylamide, (Ci₂- C₂₂)alkylamido(C₂-C₆)alkyl, (Ci₂-C₂₂)alkylacetate, and hydroxyalkyl radicals; and aromatic radicals such as aryl and alkylaryl; and X is chosen from halides, phosphates, acetates, lactates, (C₂-C₆) alkyl sulfates, and alkyl- or alkylaryl-sulfonates;

quaternary ammonium salts of imidazoline, for instance those of formula (II) below:

wherein:

R₅ is chosen from alkenyl and alkyl radicals comprising from 8 to 30 carbon atoms, for example fatty acid derivatives of tallow or of coconut;

R₆ is chosen from hydrogen, C1-C4 alkyl radicals, and alkenyl and alkyl radicals comprising from 8 to 30 carbon atoms;

R₇ is chosen from C₁-C₄ alkyl radicals;

R₈ is chosen from hydrogen and C₁-C₄ alkyl radicals; and

X is chosen from halides, phosphates, acetates, lactates, alkyl sulfates, alkyl sulfonates, and alkylaryl sulfonates. In one embodiment, R₅ and R₆ are, for example, a mixture of radicals chosen from alkenyl and alkyl radicals comprising from 12 to 21 carbon atoms, such as fatty acid derivatives of tallow, R₇ is methyl, and R₈ is hydrogen. Examples of such products include, but are not limited to, Quatemium-27 (CTFA 1997) and Quatemium-83 (CTFA 1997), which are sold under the names "Rewoquat®" W75, W90, W75PG, and W75HPG by the company Witco;

diquatemary ammonium salts of formula (III):

wherein:

R.9 is chosen from aliphatic radicals comprising from 16 to 30 carbon atoms;

Rio is chosen from hydrogen or alkyl radicals comprising from 1 to 4 carbon atoms or the group (Ri _6a)(Ri 7a)(Ri _8a)N⁺(CH₂)₃ ;

Rn, RI₂, Rn, R_I4, Ri_6a, Rn_a, and Ri_8a, which may be identical or different, are chosen from hydrogen and alkyl radicals comprising from 1 to 4 carbon atoms; and

X is chosen from halides, acetates, phosphates, nitrates, ethyl sulfates, and methyl sulfates.

An example of one such diquatemary ammonium salt is FINQUAT CT-P of FINETEX

(Quatemium-89) or FINQUAT CT of FINETEX (Quatemium-75); and

quaternary ammonium salts comprising at least one ester function, such as those of formula

wherein: R₂₂ is chosen from Ci-C₆ alkyl radicals, and Ci-C₆ hydroxyalkyl and dihydroxyalkyl radicals; R.23 is chosen from:

the radical below:

linear and branched, saturated and unsaturated Ci-C₂2 hydrocarbon-based radicals R₂₇, and hydrogen,

R₂₅ is chosen from:

the radical below:

linear and branched, saturated and unsaturated C_]-C₆ hydrocarbon-based radicals R₂9, and hydrogen,

R₂4, R₂₆, and R₂₈, which may be identical or different, are chosen from linear and branched, saturated and unsaturated, C₇-C_2i, hydrocarbon-based radicals;

r, s, and t, which may be identical or different, are chosen from integers ranging from 2 to 6; each of rl and tl, which may be identical or different, is 0 or 1, and r2+rl=2r and tl+2t=2t; y is chosen from integers ranging from 1 to 10;

x and z, which may be identical or different, are chosen from integers ranging from 0 to 10;

X is chosen from simple and complex, organic and inorganic anions; with the proviso that the sum x+y+z ranges from 1 to 15, that when x is 0, R₂₃ denotes R₂₇, and that when z is 0, R₂₅ denotes R₂9. R₂₂ may be chosen from linear and branched alkyl radicals. In one embodiment, R₂₂ is chosen from linear alkyl radicals. In another embodiment, R₂₂ is chosen from methyl, ethyl, hydroxyethyl, and dihydroxypropyl radicals, for example methyl and ethyl radicals. In one embodiment, the sum x+y+z ranges from 1 to 10. When R₂₃ is a hydrocarbon-based radical R₂₇, it may be long and comprise from 12 to 22 carbon atoms, or short and comprise from 1 to 3 carbon atoms. When R₂₅ is a hydrocarbon-based radical R₂9, it may comprise, for example, from 1 to 3 carbon atoms. By way of a non-limiting example, in one embodiment, R₂₄, R₂₆, and R₂₈, which may be identical or different, are chosen from linear and branched, saturated and unsaturated, Cn-C_2i hydrocarbon-based radicals, for example from linear and branched, saturated and unsaturated Cn-C_2i alkyl and alkenyl radicals. In another

embodiment, x and z, which may be identical or different, are 0 or 1. In one embodiment, y is equal to 1. In another embodiment, r, s, and t, which may be identical or different, are equal to 2 or 3, for example equal to 2. The anion X may be chosen from, for example, halides, such as chloride, bromide, and iodide; and Ci-C₄ alkyl sulfates, such as methyl sulfate.

However, methanesulfonate, phosphate, nitrate, tosylate, an anion derived from an organic acid, such as acetate and lactate, and any other anion that is compatible with the ammonium comprising an ester function, are other non-limiting examples of anions that may be used according to the present invention. In one embodiment, the anion X is chosen from chloride and methyl sulfate.

In another embodiment, the ammonium salts of formula (IV) may be used, wherein:

R₂₂ is chosen from methyl and ethyl radicals,

x and y are equal to 1 ;

z is equal to 0 or 1 ;

r, s, and t are equal to 2;

R₂₃ is chosen from: the radical below:

O

R₂₆ C

methyl, ethyl, and Ci₄-C₂₂ hydrocarbon-based radicals, and hydrogen;

R₂₅ is chosen from:

the radical below:

and hydrogen;

R24, R26, and R₂₈, which may be identical or different, are chosen from linear and branched, saturated and unsaturated, Ci₃-Ci₇ hydrocarbon-based radicals, for example from linear and branched, saturated and unsaturated, Ci₃-Ci₇ alkyl and alkenyl radicals.

In one embodiment, the hydrocarbon-based radicals are linear.

Non-limiting examples of compounds of formula (IV) that may be mentioned include salts, for example chloride and methyl sulfate, of diacyloxyethyl-dimethylammonium, of

diacyloxyethyl-hydroxyethyl-methylammonium, of monoacyloxyethyl-dihydroxyethyl- methylammonium, of triacyloxyethyl-methylammonium, of monoacyloxyethyl-hydroxyethyl- dimethyl-ammonium, and mixtures thereof. In one embodiment, the acyl radicals may comprise from 14 to 18 carbon atoms, and may be derived, for example, from a plant oil, for instance palm oil and sunflower oil. When the compound comprises several acyl radicals, these radicals may be identical or different.

These products may be obtained, for example, by direct esterification of optionally

oxyalkylenated triethanolamine, triisopropanolamine, alkyldiethanolamine, or

alkyldiisopropanolamine onto fatty acids or onto mixtures of fatty acids of plant or animal origin, or by transesterification of the methyl esters thereof. This esterification may be followed by a quatemization using an alkylating agent chosen from alkyl halides, for example methyl and ethyl halides; dialkyl sulfates, for example dimethyl and diethyl sulfates; methyl methanesulfonate; methyl para-toluenesulfonate; glycol chlorohydrin; and glycerol

chlorohydrin.

Such compounds are sold, for example, under the names Dehyquart® by the company Cognis, Stepanquat® by the company Stepan, Noxamium® by the company Ceca, and "Rewoquat® WE 18" by the company Rewo-Goldschmidt.

Other non-limiting examples of ammonium salts that may be used in the compositions according to the present invention include the ammonium salts comprising at least one ester function described in U.S. Pat. Nos. 4,874,554 and 4,137,180.

Among the quaternary ammonium salts mentioned above that may be used in the

compositions according to the present invention include, but are not limited to, those corresponding to formula (I), for example tetraalkylammonium chlorides, for instance dialkyldimethyl ammonium and alkyltrimethylammonium chlorides in which the alkyl radical comprises from about 12 to 22 carbon atoms, such as behenyltrimethylammonium,

distearyldimethylammonium, cetyltrimethylammonium, and benzyldimethylstearylammonium chloride; palmitylamidopropyltrimethylammonium chloride; and stearamidopropyldimethyl(myristyl acetate)ammonium chloride, sold under the name "Ceraphyl® 70" by the company Van Dyk.

According to one embodiment, the cationic surfactant that may be used in the compositions of the present invention is chosen from quaternary ammonium salts, for example from

behenyltrimethylammonium chloride, cetyltrimethylammonium chloride, Quatemium-83, Quatemium-87, Quatemium-22, behenylamidopropyl-2,3- dihydroxypropyldimethylammonium chloride, palmitylamidopropyltrimethylammonium chloride, and stearamidopropyldimethylamine.

Nonionic Surfactants

The nonionic surfactants are compounds well known in and of themselves (see, e.g., in this regard, "Handbook of Surfactants" by M. R. Porter, Blackie & Son publishers (Glasgow and London), 1991, pp. 116-178). Thus, they can, for example, be chosen from alcohols, alpha- diols, alkylphenols and esters of fatty acids, these compounds being ethoxylated,

propoxylated or glycerolated and having at least one fatty chain comprising, for example, from 8 to 30 carbon atoms, it being possible for the number of ethylene oxide or propylene oxide groups to range from 2 to 50, and for the number of glycerol groups to range from 1 to 30. Maltose derivatives may also be mentioned. Non-limiting mention may also be made of copolymers of ethylene oxide and/or of propylene oxide; condensates of ethylene oxide and/or of propylene oxide with fatty alcohols; polyethoxylated fatty amides comprising, for example, from 2 to 30 mol of ethylene oxide; polyglycerolated fatty amides comprising, for example, from 1.5 to 5 glycerol groups, such as from 1.5 to 4; ethoxylated fatty acid esters of sorbitan comprising from 2 to 30 mol of ethylene oxide; ethoxylated oils of plant origin; fatty acid esters of sucrose; fatty acid esters of polyethylene glycol; polyethoxylated fatty acid mono or diesters of glycerol (C₆-C₂₄)alkylpolyglycosides; N-(C₆-C₂₄)alkylglucamine derivatives; amine oxides such as (Cio-Ci₄)alkylamine oxides or N-(Cio- Ci₄)acylaminopropylmorpholine oxides; and mixtures thereof.

The nonionic surfactants may preferably be chosen from monooxyalkylenated,

polyoxyalkylenated, monoglycerolated or polyglycerolated nonionic surfactants. The oxyalkylene units are more particularly oxyethylene or oxypropylene units, or a combination thereof, and are preferably oxyethylene units.

Examples of monooxyalkylenated or polyoxyalkylenated nonionic surfactants that may be mentioned include:

monooxyalkylenated or polyoxyalkylenated (C₈-C₂4)alkylphenols,

saturated or unsaturated, linear or branched, monooxyalkylenated or polyoxyalkylenated C₈- C₃o alcohols,

saturated or unsaturated, linear or branched, monooxyalkylenated or polyoxyalkylenated C₈- C30 amides,

esters of saturated or unsaturated, linear or branched, C₈-C₃₀ acids and of polyalkylene glycols, monooxyalkylenated or polyoxyalkylenated esters of saturated or unsaturated, linear or branched, C₈-C₃₀ acids and of sorbitol,

saturated or unsaturated, monooxyalkylenated or polyoxyalkylenated plant oils,

condensates of ethylene oxide and/or of propylene oxide, inter alia, alone or as mixtures.

The surfactants preferably contain a number of moles of ethylene oxide and/or of propylene oxide of between 1 and 100 and most preferably between 2 and 50. Advantageously, the nonionic surfactants do not comprise any oxypropylene units.

According to one of the embodiments of the present invention, the polyoxyalkylenated nonionic surfactants are chosen from polyoxyethylenated fatty alcohol (polyethylene glycol ether of fatty alcohol), polyoxyethylenated fatty ester (polyethylene glycol ester of fatty acid), and mixtures of polyoxyethylenated fatty alcohol and polyoxyethylenated fatty ester.

Examples of polyoxyethylenated fatty alcohol (or C₈-C₃₀ alcohols) that may be mentioned include the adducts of ethylene oxide with lauryl alcohol, especially those containing from 2 to 50 oxyethylene units and more particularly those containing from 2 to 20 oxyethylene units (Laureth-2 to Laureth-20, as the CTFA names); the adducts of ethylene oxide with behenyl alcohol, especially those containing from 2 to 50 oxyethylene units and more particularly those containing from 2 to 20 oxyethylene units (Beheneth-2 to Beheneth-20, as the CTFA names); the adducts of ethylene oxide with cetearyl alcohol (mixture of cetyl alcohol and stearyl alcohol), especially those containing from 2 to 30 oxyethylene units (Ceteareth-2 to Ceteareth-30, as the CTFA names); the adducts of ethylene oxide with cetyl alcohol, especially those containing from 2 to 30 oxyethylene units (Ceteth-2 to Ceteth-30, as the CTFA names); the adducts of ethylene oxide with stearyl alcohol, especially those containing from 2 to 50 oxyethylene units and more particularly those containing from 2 to 20 oxyethylene units (Steareth-2 to Steareth-20, as the CTFA names); the adducts of ethylene oxide with isostearyl alcohol, especially those containing from 2 to 50 oxyethylene units (Isosteareth-2 to Isosteareth-50, as the CTFA names); and mixtures thereof. Examples of polyoxyethylenated fatty esters that may be mentioned include the adducts of ethylene oxide with esters of lauric acid, palmitic acid, stearic acid or behenic acid, and mixtures thereof, especially those containing from 9 to 100 oxyethylene units, such as PEG-9 to PEG-50 laurate (as the CTFA names: PEG-9 laurate to PEG-50 laurate); PEG-9 to PEG-50 palmitate (as the CTFA names: PEG-9 palmitate to PEG-50 palmitate); PEG-9 to PEG-50 stearate (as the CTFA names: PEG-9 stearate to PEG-50 stearate); PEG-9 to PEG-50 palmitostearate; PEG-9 to PEG-50 behenate (as the CTFA names: PEG-9 behenate to PEG-50 behenate); polyethylene glycol 100 EO monostearate (CTFA name: PEG- 100 stearate); and mixtures thereof. According to one preferred embodiment of the present invention, the composition to be used for the present invention comprises at least one polyoxyethylenated fatty alcohol.

According to a more preferred embodiment, the composition to be used for the present invention contains at least one fatty alcohol comprising from 2 to 9 ethyleneoxide units and at least one fatty alcohol comprising from 10 to 30 ethyleneoxide units.

As examples of monoglycerolated or polyglycerolated nonionic surfactants,

monoglycerolated or polyglycerolated C₈-C₄₀ alcohols are preferably used. In particular, the monoglycerolated or polyglycerolated C₈-C₄₀ alcohols correspond to the following formula:

R0-[CH₂-CH(CH₂0H)-0]_m-H or R0-[CH(CH₂0H)-CH₂0]_m-H in which R represents a linear or branched C₈-C₄o and preferably C₈-C₃₀ alkyl or alkenyl radical, and m represents a number ranging from 1 to 30 and preferably from 1.5 to 10.

As examples of compounds that are suitable in the context of the present invention, mention may be made of lauryl alcohol containing 4 mol of glycerol (INCI name: Polyglyceryl-4 Lauryl Ether), lauryl alcohol containing 1.5 mol of glycerol, oleyl alcohol containing 4 mol of glycerol (INCI name: Polyglyceryl-4 Oleyl Ether), oleyl alcohol containing 2 mol of glycerol (INCI name: Polyglyceryl-2 Oleyl Ether), cetearyl alcohol containing 2 mol of glycerol, cetearyl alcohol containing 6 mol of glycerol, oleocetyl alcohol containing 6 mol of glycerol, and octadecanol containing 6 mol of glycerol.

The alcohol may represent a mixture of alcohols in the same way that the value of m represents a statistical value, which means that, in a commercial product, several species of polyglycerolated fatty alcohol may coexist in the form of a mixture.

Among the monoglycerolated or polyglycerolated alcohols, it is preferable to use the C₈/Ci₀ alcohol containing 1 mol of glycerol, the Cio/Ci₂ alcohol containing 1 mol of glycerol and the Ci₂ alcohol containing 1.5 mol of glycerol.

The monoglycerolated or polyglycerolated C₈-C₄₀ fatty esters may correspond to the following formula:

R’0-[CH₂-CH(CH₂0R”^,)-0]_m-R” or R’0-[CH(CH₂0R’”)-CH20]m-R” in which each of R’, R” and R’” independently represents a hydrogen atom, or a linear or branched C₈-C₄o and preferably C₈-C₃o alkyl-CO- or alkenyl-CO-radical, with the proviso that at least one of R’, R” and R’” is not a hydrogen atom, and m represents a number ranging from 1 to 30 and preferably from 1.5 to 10.

Examples of polyoxyethylenated fatty esters that may be mentioned include the adducts of ethylene oxide with esters of lauric acid, palmitic acid, stearic acid or behenic acid, and mixtures thereof, especially those containing from 9 to 100 oxyethylene units, such as PEG-9 to PEG-50 laurate (as the CTFA names: PEG-9 laurate to PEG-50 laurate); PEG-9 to PEG-50 palmitate (as the CTFA names: PEG-9 palmitate to PEG-50 palmitate); PEG-9 to PEG-50 stearate (as the CTFA names: PEG-9 stearate to PEG-50 stearate); PEG-9 to PEG-50 palmitostearate; PEG-9 to PEG-50 behenate (as the CTFA names: PEG-9 behenate to PEG-50 behenate); polyethylene glycol 100 EO monostearate (CTFA name: PEG- 100 stearate); and mixtures thereof.

Preferably, the nonionic surfactant may be a nonionic surfactant with an HLB from 8 to 18. The HLB is the ratio between the hydrophilic part and the lipophilic part in the molecule.

This term HLB is well known to those skilled in the art and is described in“The HLB system. A time-saving guide to emulsifier selection” (published by ICI Americas Inc., 1984).

The amount of the surfactant(s) in the composition to be used for the present invention may be 0.01% by weight or more, preferably 0.05% by weight or more, and more preferably 0.1% by weight or more, relative to the total weight of the composition. The amount of the surfactant(s) in the composition to be used for the present invention may be 10% by weight or less, preferably 8% by weight or less, and more preferably 5% by weight or less, relative to the total weight of the composition. The amount of the surfactant(s) in the composition to be used for the present invention may be from 0.01% to 10% by weight, preferably from 0.05% to 8% by weight, and more preferably from 0.1% to 5% by weight, relative to the total weight of the composition.

(Polyol)

The composition to be used for the present invention includes at least one polyol phase including at least one polyol. Two or more polyols may be used in combination. Thus, a single type of polyol or a combination of different types of polyols may be used.

It is preferable that the polyol be in the form of a liquid at ambient temperature such as 25 °C under atmospheric pressure (760 mmHg or 10⁵ Pa).

The term“polyol” here means an alcohol having two or more hydroxy groups, and does not encompass a saccharide or a derivative thereof. The derivative of a saccharide includes a sugar alcohol which is obtained by reducing one or more carbonyl groups of a saccharide, as well as a saccharide or a sugar alcohol in which the hydrogen atom or atoms in one or more hydroxy groups thereof has or have been replaced with at least one substituent such as an alkyl group, a hydroxyalkyl group, an alkoxy group, an acylgroup or a carbonyl group.

Polyols used in the present invention are liquid at ambient temperature such as 25°C under atmospheric pressure (760 mmHg or 10⁵ Pa).

The polyol may be a C₂-C₂₄ polyol, preferably a C₂-C9 polyol, comprising at least 2 hydroxy groups, and preferably 2 to 5 hydroxy groups.

The polyol may be a natural or synthetic polyol. The polyol may have a linear, branched or cyclic molecular structure.

The polyol may be selected from glycerins and derivatives thereof, and glycols and derivatives thereof. The polyol may be selected from the group consisting of glycerin, diglycerin, polyglycerin, ethyleneglycol, diethyleneglycol, propyleneglycol,

dipropyleneglycol, butyleneglycol, pentyleneglycol, hexyleneglycol, C₆-C₂₄

polyethyleneglycol, 1, 3-propanediol, l,4-butanediol, and l,5-pentanediol.

The amount of the polyol(s) in the composition to be used for the present invention may be 0.01% by weight or more, preferably 0.05% by weight or more, and more preferably 0.1% by weight or more, relative to the total weight of the composition. The amount of the polyol(s) in the composition to be used for the present invention may be 10% by weight or less, preferably 8% by weight or less, and more preferably 5% by weight or less, relative to the total weight of the composition. The amount of the polyol(s) in the composition to be used for the present invention may be from 0.01% to 10% by weight, preferably from 0.05% to 8% by weight, and more preferably from 0.1 % to 5% by weight, relative to the total weight of the composition.

In one embodiment, the (weight) amount of the polyol(s) in the total (weight) amount of the polyol(s) and water may be 10% by weight or more, preferably 15% by weight or more, and more preferably 20% by weight or more. In another embodiment, the (weight) amount of the polyol(s) in the total (weight) amount of the polyol(s) and water may be 40% by weight or less, preferably 35% by weight or less, and more preferably 30% by weight or less. Thus, the (weight) amount of the polyol(s) in the total (weight) amount of the polyol(s) and water may be from 10% to 40% by weight, preferably from 15% to 35% by weight, and more preferably from 20% to 30% by weight.

(Optional Ingredients)

The pH of the composition to be used for the present invention may be adjusted to the desired value using acidifying or basifying agents commonly used in cosmetic compositions.

The water phase of the composition to be used for the present invention may preferably be neutral or acidic. Therefore, it is preferable that the pH of the water phase of the composition be from 1 to 7, more preferably from 2 to 6, and even more preferably from 3 to 5.

Among the acidifying agents, mention may be made, by way of example, of mineral or organic acids such as hydrochloric acid, ortho-phosphoric acid, sulfuric acid, carboxylic acids such as acetic acid, tartaric acid, citric acid, and lactic acid, and sulfonic acids.

Among the basifying agents, mention may be made, by way of example, of ammonium hydroxide, alkali metal carbonates, alkanolamines such as mono-, di- and triethanolamines and also their derivatives, sodium or potassium hydroxide and compounds of the formula below:

wherein

W denotes an alkyl ene such as propylene optionally substituted by a hydroxyl or a Ci-C₄ alkyl radical, and R_a, R_t>, R_c and R_d independently denote a hydrogen atom, an alkyl radical or a Ci-C₄ hydroxyalkyl radical, which may be exemplified by l,3-propanediamine and derivatives thereof.

The acidifying or basifying agent may be used in an amount ranging from 0.001% to 15% by weight, preferably from 0.01% to 10% by weight, and more preferably from 0.1% to 5% by weight, relative to the total weight of the composition.

The composition to be used for the present invention may also contain various adjuvants conventionally used in cosmetic compositions, such as anionic, non-ionic, cationic, and amphoteric or zwitterionic polymers, antioxidants, thickeners, sequestering agents, fragrances, dispersing agents, conditioning agents, film-forming agents, ceramides, preservatives and opacifying agents.

(Preparation)

The composition to be used for the present invention can be prepared by mixing oil(s) and water, as essential ingredients, and optional ingredient(s), if necessary, as explained above. The method and means to mix the above essential and optional ingredients are not limited. Any conventional method and means can be used to mix the above essential and optional ingredients to prepare the composition to be used for the present invention.

[Kit, Process, and Use]

The present invention also relates to a kit comprising:

and

a composition in the form of an O/W emulsion.

The composition in the form an O/W emulsion may be contained in any container such as a vessel which is commonly used for cosmetic purposes.

The kit can preferably be used for performing a cosmetic process according to the present invention.

According to the above process and use according to the present invention, the microneedles of a microneedle sheet can rapidly dissolve or disintegrate. In other words, the microneedles of a microneedle sheet can dissolve or disintegrate in a short period of time. Thus, the microneedles of a microneedle sheet can disappear easily, when the microneedle sheet is used, and do not remain in a keratin substance for a long period of time.

Therefore, the above process or use according to the present invention can reduce the time required for a cosmetic process using a microneedle sheet.

The above explanations for the microneedle sheet and the composition for the cosmetic process according to the present invention can also apply to those in the kit, process, and use according to the present invention.

EXAMPLES

The present invention will be described in a more detailed manner by way of examples.

However, these examples should not be construed as limiting the scope of the present invention. The examples below are presented as non-limiting illustrations in the field of the present invention.

[Microneedle Patch]

A microneedle sheet was prepared using sodium hyaluronate with an average molecular weight of 70,000 Dalton. The microneedle sheet had a plurality of microneedles on a substrate sheet with a density of 324 needles/cm². Each microneedle had the shape of a cone with a length or height of 200 pm and a base diameter of 200 pm. The pitch of the microneedles was 60 pm.

The microneedle sheet was prepared by a standard mold casting process. Sodium hyaluronate was dissolved in water, and an aqueous solution of sodium hyaluronate thus obtained was poured into the cavities of a mold which correspond to the shape of microneedles. After drying at room temperature to remove water, microneedles in the cavities were removed from the mold as a microneedle sheet having a plurality of microneedles on a substrate sheet.

The microneedle sheet was cut such that it had the shape of a patch to be applied under the eyes.

[Compositions]

(Composition 1) An O/W emulsion was prepared by mixing the ingredients shown in Table 1. The numerical values for the amounts of the ingredients are all based on“% by weight” as active raw materials.

Table 1

(Composition 2)

An O/W emulsion was prepared by mixing the ingredients shown in Table 2. The numerical values for the amounts of the ingredients are all based on“% by weight” as active raw materials.

Table 2

(Composition 3)

A W/O emulsion was prepared by mixing the ingredients shown in Table 3. The numerical values for the amounts of the ingredients are all based on“% by weight” as active raw materials.

Table 3

(Composition 4) An aqueous gel was prepared by mixing the ingredients shown in Table 4. The numerical values for the amounts of the ingredients are all based on“% by weight” as active raw materials.

Table 4

[Evaluations]

(Example 1)

The O/W emulsion according to Composition 1 was applied to a porcine skin in an amount of 2 mg/cm².

Just after the application of the O/W emulsion, the microneedle patch thus prepared as above was applied on the skin. The behavior of the microneedles of the microneedle patch was observed by optical coherence tomography.

Just after the application of the microneedle patch, the penetration of the microneedles into the skin was observed. After 14 minutes, it was observed that the microneedles in the skin were dissolved and disappeared.

(Example 2)

The O/W emulsion according to Composition 2 was applied to a porcine skin in an amount of 2 mg/cm².

Just after the application of the microneedle patch, the penetration of the microneedles into the skin was observed. After 6 minutes, it was observed that the microneedles in the skin were dissolved and disappeared.

(Comparative Example 1)

The W/O emulsion according to Composition 3 was applied to a porcine skin in an amount of 2 mg/cm².

Just after the application of the W/O emulsion, the microneedle patch thus prepared as above was applied on the skin. The behavior of the microneedles of the microneedle patch was observed by optical coherence tomography. Just after the application of the microneedle patch, the penetration of the microneedles into the skin was observed. After 1 minute, however, it was observed that the microneedles were pushed back from the skin. Even after 20 minutes, the presence of the microneedles was observed. Thus, the microneedles were not dissolved and did not disappear.

(Comparative Example 2)

The aqueous gel according to Composition 4 was applied to a porcine skin in an amount of 2 mg/cm².

Just after the application of the aqueous gel, the microneedle patch thus prepared as above was applied on the skin. The behavior of the microneedles of the microneedle patch was observed by optical coherence tomography.

It was observed that the microneedles were dissolved and disappeared immediately after the application of the microneedle patch on the skin. It was not possible for the microneedles to enter into the skin.

(Results)

Examples 1 and 2 demonstrate that the microneedles were able to penetrate into the skin. The microneedles were maintained in a state where they were inserted in the skin. In other words, the microneedles were not pushed away from the skin.

Examples 1 and 2 also demonstrate that the application of the O/W emulsion onto the skin before applying the microneedle sheet onto the skin accelerated the dissolution of the microneedles of the microneedle sheet. The accelerated dissolution of the microneedles can reduce the time required for a cosmetic process using the microneedle sheet.

Comparative Example 1 demonstrates that the application of the W/O emulsion onto the skin before applying the microneedle sheet onto the skin could not accelerate the dissolution of the microneedles. Even the insertion of the microneedles could not be maintained when the W/O emulsion had been applied onto the skin before applying the microneedle sheet onto the skin.

Comparative Example 2 demonstrates that the application of the aqueous gel onto the skin before applying the microneedle sheet onto the skin caused too rapid dissolution of the microneedles. Even the insertion of the microneedles was not possible because the microneedles had been dissolved and disappeared before being inserted into the skin.

Claims

1. A cosmetic process for a keratin substance such as the skin or the lips, comprising the steps of:

applying onto the keratin substance at least one composition in the form of an oil/water emulsion; and

applying onto the keratin substance, to which the composition has been applied, a microneedle sheet comprising a substrate sheet and a plurality of microneedles on the substrate sheet, wherein the microneedles comprise at least one water-soluble or water-dispersible polymer.

2. The cosmetic process according to Claim 1, wherein the microneedle has a height of from 50 to 1000 microns, preferably from 100 to 750 microns, and more preferably from 150 to 500 microns.

3. The cosmetic process according to Claim 1 or 2, wherein the microneedle is in the shape of a cone.

4. The cosmetic process according to Claim 3, wherein the base of the cone of the

microneedle has a diameter of from 50 to 350 microns, preferably from 100 to 300 microns, and more preferably from 150 to 250 microns.

5. The cosmetic process according to Claim 3 or 4, wherein the ratio of (the height of the cone)/(the diameter of the base of the cone) of the microneedle is 1 or more, preferably 1.5 or more, and more preferably 2.0 or more.

6. The cosmetic process according to any one of Claims 1 to 5, wherein the water- soluble or water-dispersible polymer is selected from hyaluronic acids,

monosaccharides, disaccharides, oligosaccharides, polysaccharides, dextrins, dextrans, polyethylene glycols, polyvinyl alcohols, poly(methyvinylether/maleic anhydride), polyvinylpyrrolidone, poly(methyl/vinyl ether/maleic acid) (PMVE/MA) and esters thereof, poly(methyl/vinyl ether/maleic anhydride) (PMVE/MAH), and mixtures thereof.

7. The cosmetic process according to any one of Claims 1 to 6, wherein the water- soluble or water-dispersible polymer has a molecular weight of from 10,000 to 200,000 Dalton, preferably from 30,000 to 150,000 Dalton, and more preferably from 50,000 to 100,000 Dalton.

8. The cosmetic process according to any one of Claims 1 to 7, wherein the

composition comprises water in an amount of from 50% to 95% by weight, preferably from 55% to 90% by weight, and more preferably from 60% to 85% by weight, relative to the total weight of the composition.

9. The cosmetic process according to any one of Claims 1 to 8, wherein the

composition comprises at least one polyol.

10. The cosmetic process according to Claim 9, wherein the amount of the polyol is from 1% to 20% by weight, preferably from 3% to 15% by weight, and more preferably from 5 to 10% by weight, relative to the total weight of the composition.

11. The cosmetic process according to any one of Claims 1 to 10, wherein the microneedle sheet is applied onto the keratin substance without a step of drying the composition on the keratin substance.

12. The cosmetic process according to any one of Claims 1 to 1 1, wherein at least one of the microneedles comprises at least one cosmetic active ingredient.

13. A kit comprising:

a microneedle sheet comprising a substrate sheet and a plurality of microneedles on the substrate sheet, wherein the microneedles comprise at least one water-soluble or water-dispersible polymer;

and

a composition in the form of an oil/water emulsion.

14. A process for accelerating the dissolution of microneedles of a microneedle sheet comprising a substrate sheet and the microneedles on the substrate sheet, wherein the microneedles comprise at least one water-soluble or water-dispersible polymer, comprising the step of:

contacting the microneedles with a composition in the form of an oil/water emulsion before the use of the microneedle sheet.

15. A use of a composition in the form of an oil/water emulsion, in order to accelerate the dissolution of microneedles of a microneedle sheet comprising a substrate sheet and the microneedles on the substrate sheet, wherein the microneedles comprise at least one water-soluble or water-dispersible polymer, before the use of the microneedle sheet.