WO2014205808A1

WO2014205808A1 - Topical composition for preventing or decreasing skin pigmentation and/or lightening skin tone and use thereof

Info

Publication number: WO2014205808A1
Application number: PCT/CN2013/078439
Authority: WO
Inventors: Liang Zhou; Severine Jeulin; Ludwig Baux; Jerome Senee
Original assignee: L'oreal
Priority date: 2013-06-28
Filing date: 2013-06-28
Publication date: 2014-12-31
Also published as: CN105307729B; CN105307729A

Abstract

The present invention relates to a topical composition comprising the combination of the extract of a plant in the family Paeoniaceae and at least one compound of formula (I), and use thereof for preventing or decreasing skin pigmentation and/or lightening skin tone, wherein R, R 2 and R 3 are as defined in the specification.

Description

Topical composition for preventing or decreasing skin pigmentation and/or lightening skin tone and use thereof

Field of the invention

The present invention relates to a topical composition for preventing or decreasing skin pigmentation and/or lightening skin tone. More particularly, the present invention relates to a topical composition comprising the combination of the extract of a plant in the family

Paeoniaceae and at least one compound of formula (I) according to the present application. The present invention also relates to use thereof for preventing or decreasing skin pigmentation and/or lightening skin tone.

Background of the invention

Skin pigmentation control remains one of the key factors to achieve Asian ideal skin.

Although a group of active ingredients with whitening efficacy have been successfully developed by L'Oreal and other cosmetic companies, it cannot effectively cater to

consumer's booming demand for "ingredients from natural origin" and integration of traditional medicines.

In prior art, in order to prevent or decrease skin pigmentation and/or lighten dark skin tone or spots on skin, active ingredients with melanogenesis inhibition activity were used in whitening cosmetic compositions. For instance, ascorbic acid and its derivatives, resorcinol derivatives, and botanical extracts have already been described.

In traditional medicine, founded on long history of medical and cosmetic use of herbs, there were frequently mention of some herbs able to prevent or even reduce skin pigmentation, among which Paeonia lactiflora root was especially highlighted for its significant skin whitening effects.

Paeonia lactiflora's skin whitening efficacy was especially achieved by association with other herbs through oral administration. Yet, finished products, containing Paeonia lactiflora extract for topical application, are already available in global market, and in particular prevailing in Asian market. In this aspect, a Chinese patent CN102247446 describes a composition to inhibit the activity of tyrosinase and prevent the production of melanin, which contains at least one whitening herb, like Paeonia lactiflora (white peony), licorice, ginseng etc.

Additionally, Japanese patents JP2002128657, JP2002265348 and Korean patent KR20090130584 separately described a few compositions for skin whitening benefit, which contain some associations of herbal extracts, including Paeonia lactiflora extract.

However, those whitening active ingredients bear some drawbacks/disadvantages upon application in cosmetic composition, such as: ascorbic acid is unstable in most cosmetic compositions and prone to be oxidized; or some botanical extracts, when formulated with an effective dose, normally resulted in unpleasant smell and color in the cosmetic composition.

Therefore there remains a need for product for preventing or decreasing skin pigmentation and/or lightening skin tone without above drawbacks/disadvantages.

Summary of the invention

This invention intends to remarkably inhibit melanin production through synergistic association of whitening active ingredients, hence by which this invention also indicates a solution to prevent and treat pigmentation of skin tone with credible safety.

According to one aspect of the present invention, there is provided a topical composition comprising the combination of the extract of a plant in the family Paeoniaceae and at least one compound of formula (I),

wherein:

Ri and R₃ are different from or identical to each other, independently selected from the group consisting of hydrogen, a linear or branched C-|-C₂o acyl carbonyl, a linear or branched C₂-C₂o alkenyl carbonyl, a linear or branched C -C₂o alkyl, a linear or branched C₂-C₂o alkenyl and a linear or branched C₂-C₂o alkynyl, preferably selected from the group consisting of hydrogen and a linear or branched C₁-C₁₀ alkyl, more preferably selected from the group consisting of hydrogen and a linear or branched C-|-C₄ alkyl, most preferably hydrogen; R₂ is selected from the group consisting of a linear or branched C1-C2₀ alkyl, a linear or branched C₂-C₂o alkenyl and a linear or branched C₂-C₂o alkynyl, preferably a linear or branched C1-C1₀ alkyl, more preferably a linear or branched C1-C4 alkyl or ethyl.

According to another aspect of the present invention, there is provided a cosmetic process for preventing or decreasing skin pigmentation and/or lightening skin tone comprising application of the topical composition according to the present invention.

According to one aspect of the present invention, there is provided use of a combination of the extract of a plant in the family Paeoniaceae and at least one compound of formula (I) in producing a topical composition for preventing or decreasing skin pigmentation and/or lightening skin tone,

2

(I ) wherein:

Ri and R₃ are different from or identical to each other, independently selected from the group consisting of hydrogen, a linear or branched Ci-C₂₀ acyl carbonyl, a linear or branched C₂- C₂₀ alkenyl carbonyl, a linear or branched CrC₂₀ alkyl, a linear or branched C₂-C₂₀ alkenyl and a linear or branched C₂-C₂₀ alkynyl, preferably selected from the group consisting of hydrogen and a linear or branched C1-C1₀ alkyl, more preferably selected from the group consisting of hydrogen and a linear or branched C1-C4 alkyl, most preferably hydrogen;

R₂ is selected from the group consisting of a linear or branched C-|-C₂₀ alkyl, a linear or branched C₂-C₂₀ alkenyl and a linear or branched C₂-C₂₀ alkynyl, preferably a linear or branched C1-C1₀ alkyl, more preferably a linear or branched C-|-C₄ alkyl or ethyl.

The topical composition according to the present invention can be used to prevent or decrease skin pigmentation and/or lightening skin tone. Brief description of the drawing

While the specification concludes with claims distinctly pointing out the subject matter that applicant regards as his invention, it is believed that the invention will be better understood when taken in connection with the accompanying drawing in which:

Figure 1 illustrates measurement of the depigmentation activity (reduction of the production of melanin) of Paeonia lactiflora root extract, compound of formula (I) and their associations using normal human melanocytes in vitro assay. In Figure 1 , WP indicates "Paeonia lactiflora root extract", Lucinol is the positive control for depigmentation activity

Detailed description of the invention

The inventors of the present invention surprisely found that depigmentation effect of white peony extract is improved significantly once associated with some known compounds for example ascorbic acid derivative while compounds themselves do not show any

depigmentation effect, although depigmentation effect of paeoniflorin is not improved when associated with the same compounds.

Compound of formula (I)

The present invention comprises at least a compound of formula (I).

wherein:

R-i and R₃ are different from or identical to each other, independently selected from the group consisting of hydrogen, a linear or branched C-|-C₂o acyl carbonyl, a linear or branched C₂- C₂o alkenyl carbonyl, a linear or branched C-|-C₂o alkyl, a linear or branched C₂-C₂₀ alkenyl and a linear or branched C₂-C₂₀ alkynyl; R₂ is selected from the group consisting of a linear or branched C1-C20 alkyl, a linear or branched C₂-C₂o alkenyl and a linear or branched C₂-C₂o alkynyl.

Preferably, Ri and R₃ are different from or identical to each other, independently selected from the group consisting of hydrogen and a linear or branched C1-C1₀ alkyl;

Preferably, R₂ is selected from a linear or branched C1-C1₀ alkyl.

More preferably, Ri and R₃ are different from or identical to each other, independently selected from the group consisting of hydrogen and a linear or a branched C1-C4 alkyl.

More preferably, R₂ is selected from the group consisting of a linear or branched C1-C4 alkyl.

Most preferably, Ri and R₃ are hydrogen.

Most preferably, R₂ is or ethyl.

According to a preferred embodiment, R-i and R₃ are independently selected from hydrogen, linear or branched CrC₆ alkyl carbonyl, linear or branched C₂-C₆ alkenyl carbonyl, linear or branched C C₆ alkyl group, linear or branched C₂-C₆ alkenyl group, linear or branched C₃-C₆ alkynyl group ; R₂ is selected from linear or branched C-|-C₆ alkyl group, linear or branched C₂-C₆ alkenyl group.

According to a further preferred embodiment, Ri and R₃ are independently selected from hydrogen, linear or branched C-|-C₄ alkyl carbonyl, linear or branched C₂-C₄ alkenyl carbonyl, linear or branched C1-C4, linear or branched C₂-C₄ alkenyl group, linear or branched C₃-C₄ alkynyl group; R₂ is selected from linear or branched C1-C4 alkyl group, linear or branched C₂-C₄ alkenyl group.

According to a further preferred embodiment, R-i and R₃ is hydrogen, R₂ is ethyl.

Compound of formula (I) is commercial available or can be synthesized by known method in the art.

Compound of formula (I) is present in the composition according to the present invention in an amount of at least 0.04 g/L, preferably at least 0.25g/L.

Extract of a plant in the family Paeoniaceae

The composition of the present invention comprises an extract of a plant in the family Paeoniaceas. According to the present invention, the extract is obtained from a naturally grown part (preferably one or more selected from the group consisting of leaf, stem, root, flower, fruit and rhizome, more preferably root) and a cultivated part (preferably one or more selected from the group consisting of cells, tissues, organs and whole plant) of the plant.

The plant in the family Paeoniaceae is a plant of the Paeonia L. genus, preferably one or more selected from the group consisting of Paeonia lactiflora Pall., Paeonia anomala ssp. Veitchii (Lynch) D. Y. Hong, Paeonia suffruticosa Andrews, Paeonia ostii T. Hong & J. X. Zhang, Paeonia rockii, Paeonia decomposita and Paeonia delavayi, and more preferably Paeonia lactiflora Pall.

The extract of the present invention can be obtained following the conventional methods. The root of plant was crushed and washed, then submit to an alcoholic extraction, the liquor parts were filter out and concentrated to centrifuge in order to removal impurity. The extracts were applied to a resin column, and eluting gradually by water and alcohol in order to get final extracts. This final extracts were concentrated and spray dried to obtain products.

It is preferred that the extract is paeonia lactiflora root extract.

In a preferred embodiment, the paeonia lactiflora root extract contains no less than 40% Paeoniflorin.

It is found that although the improved whitenning effect according to the present application is not determined by paeoniflorin, higher amount of paeoniflorin is preferred as far as the improved whitenning effect is considered.

According to an embodiment, in the combination of the extract of a plant in the family Paeoniaceae and at least one compound of formula (I), the ratio by weight of the extract to the at least one compound of formula (I) is 1 :0.003-1 , preferably 1 :0.070-1 , and more preferably 1 :0.25-1.

According to an embodiment, the combination is present in the composition from 0.05% to 20% by weight, with respect to the total weight of the topical composition.

According to a preferred embodiment, the combination is present in the composition from 1 % to 10% by weight, with respect to the total weight of the topical composition.

According to yet another preferred embodiment, the combination is present in the

composition from 2% to 6% by weight, with respect to the total weight of the topical composition. Optionally the remaining part of the composition is a cosmetically acceptable medium.

According to an embodiment, the topical composition according to the present invention further comprises a compound of formula (I I),

(II) wherein:

R₄ is selected from the group consisting of hydrogen, an alkali metal ion, a linear or branched C1-C20 alkyl, a linear or branched C₂-C₂o alkenyl and a linear or branched C₂-C₂o alkynyl;

R₅ and R₆ are different from or identical to each other, independently selected from the group consisting of hydrogen, a linear or branched Ci-C₂₀ alkyl, a linear or branched C₂-C₂₀ alkenyl and a linear or branched C₂-C₂₀ alkynyl.

Preferably, R₄ is selected from the group consisting of hydrogen and a linear or branched C C10 alkyl.

Preferably, R₅ and R₆ are different from or identical to each other, independently selected from the group consisting of hydrogen and a linear or branched C1-C1₀ alkyl.

More preferably, R₄ is selected from the group consisting of hydrogen and a linear or branched C-|-C₄ alkyl.

More preferably, R₅ and R₆ are different from or identical to each other, independently selected from the group consisting of hydrogen and a linear or branched C1-C4 alkyl.

Most preferably, R₄ is hydrogen.

Most preferably, one of R₅ and R₆ is methyl and the other is hydrogen. According to a preferred embodiment, R₄ is selected from the group consisting of hydrogen, a linear or branched C1-C10 alkyl; R₅ and R₆ are different from or identical to each other, independently selected from the group consisting of hydrogen and a linear or branched C C10 alkyl.

According to a further preferred embodiment, R₄ is selected from the group consisting of hydrogen, a linear or branched Ci-C₆ alkyl; R₅ and R₆ are different from or identical to each other, independently selected from the group consisting of hydrogen and a linear or branched Ci-C₆ alkyl.

According to a further preferred embodiment, R₄ is selected from the group consisting of hydrogen, a linear or branched C1-C4 alkyl; R₅ and R₆ are different from or identical to each other, independently selected from the group consisting of hydrogen and a linear or branched C1-C4 alkyl.

According to a further preferred embodiment, R₄ is hydrogen, R₅ is methyl and R₆ is hydrogen.

According to an embodiment, compound of formula (II) is selected from linear or branched C1-C10 alkyl ester of ferulic acid.

According to an embodiment, R₄ is selected from ethyl and isooctyl, R₅ and R₆ are hydrogen.

According to an embodiment, the compound of formula (II) comprises 0.01 %-10%wt%, preferably0.05%-5%wt%, and more preferably 0.05%-3%wt%, with respect to the total weight of the topical composition.

Physically acceptable medium

Besides the compounds indicated previously, a composition according to the invention may further comprise a physiologically acceptable medium.

The term "physiologically acceptable medium" is intended to denote a medium that is particularly suitable for applying a composition according to the invention to the skin.

The physiologically acceptable medium is generally adapted to the nature of the support onto which the composition is to be applied, and also to the form in which the composition is to be packaged.

Aqueous phase The composition according to the invention may comprise an aqueous phase.

The aqueous phase comprises water. A water that is suitable for use in the invention may be a floral water such as cornflower water and/or a mineral water such as Vittel water, Lucas water or La Roche Posay water and/or a spring water.

The aqueous phase may also comprise water-miscible organic solvents (at room

temperature: 25°C), for instance monoalcohols containing from 2 to 6 carbon atoms, such as ethanol or isopropanol; polyols especially containing from 2 to 20 carbon atoms, preferably containing from 2 to 10 carbon atoms and preferentially containing from 2 to 6 carbon atoms, such as glycerol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, dipropylene glycol or diethylene glycol; glycol ethers (especially containing from 3 to 16 carbon atoms) such as mono-, di- or tripropylene glycol (C1 -C4)alkyl ethers, mono-, di- or triethylene glycol (C1-C4)alkyl ethers, and mixtures thereof.

The aqueous phase may also comprise stabilizers, for example sodium chloride, magnesium dichloride or magnesium sulfate.

The aqueous phase may also comprise any water-soluble or water-dispersible compound that is compatible with an aqueous phase, such as gelling agents, film-forming polymers, thickeners or surfactants, and mixtures thereof.

In particular, a composition of the invention may comprise an aqueous phase in a content ranging from 1 % to 80% by weight, especially from 5% to 50% and more particularly from 10% to 45% by weight relative to the total weight of the composition.

Fatty phase

A cosmetic composition in accordance with the present invention may comprise at least one liquid and/or solid fatty phase.

According to one embodiment, the composition according to the present invention is in the form of an emulsion.

In particular, a composition of the invention may comprise at least one liquid fatty phase, especially at least one oil as mentioned below.

The term "oil" means any fatty substance that is in liquid form at room temperature (20-25°C) and at atmospheric pressure.

A composition of the invention may comprise a liquid fatty phase in a content ranging from 1 % to 90%, in particular from 5% to 80%, in particular from 10% to 70% and more particularly from 20% to 50% by weight relative to the total weight of the composition.

The fatty phase that is suitable for preparing the cosmetic compositions according to the invention may comprise hydrocarbon-based oils, silicone oils, fluoro oils or non-fluoro oils, or mixtures thereof.

The oils may be volatile or non-volatile.

They may be of animal, plant, mineral or synthetic origin. The term "non-volatile oil" means an oil that remains on the skin or the keratin fibre at room temperature and atmospheric pressure. More specifically, a non-volatile oil has an

evaporation rate strictly less than 0.01 mg/cm2/min.

To measure this evaporation rate, 15 g of oil or of oil mixture to be tested are placed in a crystallizing dish 7 cm in diameter, which is placed on a balance in a large chamber of about 0.3 m3 that is temperature-regulated, at a temperature of 25°C, and hygrometry-regulated, at a relative humidity of 50%. The liquid is allowed to evaporate freely, without stirring it, while providing ventilation by means of a fan (Papst-Motoren, reference 8550 N, rotating at 2700 rpm) placed in a vertical position above the crystallizing dish containing said oil or said mixture, the blades being directed towards the crystallizing dish, 20 cm away from the bottom of the crystallizing dish. The mass of oil remaining in the crystallizing dish is measured at regular intervals. The evaporation rates are expressed in mg of oil evaporated per unit of area (cm2) and per unit of time (minutes).

The term "volatile oil" means any non-aqueous medium that is capable of evaporating on contact with the skin or the lips in less than one hour, at room temperature and atmospheric pressure. The volatile oil is a cosmetic volatile oil, which is liquid at room temperature. More specifically, a volatile oil has an evaporation rate of between 0.01 and 200 mg/cm2/min, limits included.

For the purposes of the present invention, the term "silicone oil" means an oil comprising at least one silicon atom, and especially at least one Si-0 group.

The term "fluoro oil" means an oil comprising at least one fluorine atom.

The term "hydrocarbon-based oil" means an oil mainly containing hydrogen and carbon atoms.

The oils may optionally comprise oxygen, nitrogen, sulfur and/or phosphorus atoms, for example in the form of hydroxyl or acid radicals.

Volatile oils

The volatile oils may be chosen from hydrocarbon-based oils containing from 8 to 16 carbon atoms, and especially C8-C16 branched alkanes (also known as isoparaffins), for instance isododecane (also known as 2,2,4,4,6-pentamethylheptane), isodecane and isohexadecane, for instance the oils sold under the trade names Isopar® or Permethyl®.

Volatile oils that may also be used include volatile silicones, for instance volatile linear or cyclic silicone oils, especially those with a viscosity of less than or equal to 8 centistokes (cSt) (8 x 10-6 m2/s), and especially containing from 2 to 10 silicon atoms and in particular from 2 to 7 silicon atoms, these silicones optionally comprising alkyl or alkoxy groups containing from 1 to 10 carbon atoms. As volatile silicone oils that may be used in the invention, mention may be made especially of dimethicones with viscosities of 5 and 6 cSt,

octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, heptamethylhexyltrisiloxane, heptamethyloctyltnsiloxane, hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane and

dodecamethylpentasiloxane, and mixtures thereof.

According to one embodiment, a composition of the invention may comprise from 1 % to 80% by weight, or even from 5% to 70% by weight, or even from 10% to 60% by weight and especially from 15% to 50% by weight of volatile oil relative to the total weight of the composition.

Non-volatile oils

The non-volatile oils may be chosen especially from non-volatile hydrocarbon-based, fluoro and/or silicone oils.

Non-volatile hydrocarbon-based oils that may especially be mentioned include:

hydrocarbon-based oils of animal origin, such as perhydrosqualene,

hydrocarbon-based oils of plant origin, such as phytostearyl esters, such as

phytostearyl oleate, phytostearyl isostearate and lauroyl/octyldodecyl/phytostearyl glutamate (Ajinomoto, Eldew PS203), triglycerides formed from fatty acid esters of glycerol, in particular in which the fatty acids may have chain lengths ranging from C4 to C36 and especially from C18 to C36, these oils possibly being linear or branched, and saturated or unsaturated; these oils may especially be heptanoic or octanoic triglycerides, shea oil, alfalfa oil, poppy oil, winter squash oil, millet oil, barley oil, quinoa oil, rye oil, candlenut oil, passionflower oil, shea butter, aloe vera oil, sweet almond oil, peach stone oil, groundnut oil, argan oil, avocado oil, baobab oil, borage oil, broccoli oil, calendula oil, camelina oil, canola oil, carrot oil, safflower oil, flax oil, rapeseed oil, cotton oil, coconut oil, marrow seed oil, wheatgerm oil, jojoba oil, lily oil, macadamia oil, corn oil, meadowfoam oil, St John's Wort oil, monoi oil, hazelnut oil, apricot kernel oil, walnut oil, olive oil, evening primrose oil, palm oil, blackcurrant pip oil, kiwi seed oil, grapeseed oil, pistachio oil, winter squash oil, pumpkin oil, musk rose oil, sesame oil, soybean oil, sunflower oil, castor oil and watermelon seed oil, and mixtures thereof, or alternatively caprylic/capric acid triglycerides, such as those sold by the company Stearineries Dubois or those sold under the names Miglyol 810®, 812® and 818® by the company Dynamit Nobel,

linear or branched hydrocarbons of mineral or synthetic origin, such as liquid paraffins and derivatives thereof, petroleum jelly, polydecenes, polybutenes, hydrogenated polyisobutene such as Parleam, and squalane;

synthetic ethers containing from 10 to 40 carbon atoms;

synthetic esters, for instance the oils of formula RaCOORb, in which Ra represents a linear or branched fatty acid residue containing from 1 to 40 carbon atoms and Rb represents a hydrocarbon-based chain, which is especially branched, containing from 1 to 40 carbon atoms, on condition that the sum of the number of carbon atoms in the chains R1 and R2 is greater than or equal to 10. The esters may be chosen especially from fatty acid esters of alcohols, for instance cetostearyl octanoate, isopropyl alcohol esters, such as isopropyl myristate, isopropyl palmitate, ethyl palmitate, 2-ethylhexyl palmitate, isopropyl stearate, isopropyl isostearate, isostearyl isostearate, octyl stearate, hydroxylated esters, for instance isostearyl lactate, octyl hydroxystearate, diisopropyl adipate, heptanoates, and especially isostearyl heptanoate, alcohol or polyalcohol octanoates, decanoates or ricinoleates, for instance propylene glycol dioctanoate, cetyl octanoate, tridecyl octanoate, 2-ethylhexyl 4-diheptanoate, 2- ethylhexyl palmitate, alkyl benzoates, polyethylene glycol diheptanoate, propylene glycol 2-diethylhexanoate, and mixtures thereof, C12-C15 alcohol benzoates, hexyl laurate, neopentanoic acid esters, for instance isodecyl neopentanoate, isotridecyl neopentanoate, isostearyl neopentanoate, octyldodecyl neopentanoate, isononanoic acid esters, for instance isononyl isononanoate, isotridecyl isononanoate, octyl isononanoate, hydroxylated esters, for instance isostearyl lactate and diisostearyl malate,

polyol esters and pentaerythritol esters, for instance dipentaerythrityl

tetra hyd roxystea rate/tetra isostearate,

esters of diol dimers and of diacid dimers, such as Lusplan DD-DA5® and Lusplan DD- DA7® sold by the company Nippon Fine Chemical and described in patent application US 2004-175 338,

copolymers of a diol dimer and of a diacid dimer and esters thereof, such as dilinoleyl diol dimer/dilinoleic dimer copolymers and esters thereof, for instance Plandool-G, copolymers of polyols and of diacid dimers, and esters thereof, such as Hailuscent ISDA or the dilinoleic acid/butanediol copolymer,

fatty alcohols that are liquid at room temperature, with a branched and/or unsaturated carbon-based chain containing from 12 to 26 carbon atoms, for instance 2- octyldodecanol, isostearyl alcohol, oleyl alcohol, 2-hexyldecanol, 2-butyloctanol and 2- undecylpentadecanol;

C12-C22 higher fatty acids, such as oleic acid, linoleic acid or linolenic acid, and mixtures thereof,

dialkyl carbonates, the two alkyl chains possibly being identical or different, such as dicaprylyl carbonate sold under the name Cetiol CC® by Cognis,

oils of high molar mass, in particular having a molar mass ranging from about 400 to about 10 000 g/mol, in particular from about 650 to about 10 000 g/mol, in particular from about 750 to about 7500 g/mol and more particularly ranging from about 1000 to about 5000 g/mol. As oils of high molar mass that may be used in the present invention, mention may especially be made of oils chosen from:

lipophilic polymers,

linear fatty acid esters with a total carbon number ranging from 35 to 70, hydroxylated esters,

aromatic esters,

C24-C28 branched fatty acid or fatty alcohol esters,

silicone oils,

oils of plant origin, and

mixtures thereof;

optionally partially hydrocarbon-based and/or silicone fluoro oils, for instance

fluorosilicone oils, fluoropolyethers and fluorosilicones as described in document EP-A- 847 752;

silicone oils, for instance linear or cyclic non-volatile polydimethylsiloxanes (PDMS); polydimethylsiloxanes comprising alkyl, alkoxy or phenyl groups, which are pendant or at the end of a silicone chain, these groups containing from 2 to 24 carbon atoms;

phenyl silicones, for instance phenyl trimethicones, phenyl dimethicones, phenyl trimethylsiloxy diphenyl siloxanes, diphenyl dimethicones, diphenyl methyldiphenyl trisiloxanes and 2-phenylethyl trimethylsiloxy silicates, and

mixtures thereof.

According to one particular embodiment, the fatty phase of the composition according to the invention can contain only volatile compounds.

Adjuvants

The composition according to the invention may further comprise additional adjuvants commonly used in the envisaged application field.

Mention may be made especially of water; organic solvents, especially Ci-C₆ alcohols and C2-C1₀ carboxylic acid esters; carbon-based and/or silicone oils, of mineral, animal and/or plant origin; waxes, pigments, fillers, colorants, surfactants, emulsifiers, co-emulsifiers;

cosmetic or dermatological active agents, UV-screening agents, polymers, hydrophilic or lipophilic gelling agents, thickeners, preserving agents, fragrances, bactericides, ceramides, odour absorbers, antioxidants.

These additional adjuvants may be present in the composition in a proportion of from 0.001 % to 80% by weight and especially from 0.1 % to 40% by weight relative to the total weight of the composition. Depending on their nature, these adjuvants may be introduced into the fatty phase or into the aqueous phase of the composition, or into lipid vesicles. In any case, these adjuvants, and the proportions thereof, will be chosen by a person skilled in the art such that the advantageous properties of the compounds according to the invention are not, or are not substantially, adversely affected by the envisaged addition.

Galenic form

This composition may be in any galenical form normally used in the cosmetic or

pharmaceutical field, and especially in the form of an optionally gelled aqueous or aqueous- alcoholic solution, a dispersion, optionally a two-phase dispersion, of the lotion type, an oil-in- water or water-in-oil or multiple emulsion (for example W/O/W or 0/W/O), an aqueous gel, a dispersion of oil in an aqueous phase with the aid of spherules, these spherules possibly being polymer nanoparticles such as nanospheres and nanocapsules or, better still, lipid vesicles of ionic and/or nonionic type; aqueous or oily gels. These compositions are prepared according to the usual methods. According to this invention, a composition in the form of an emulsion, especially an oil-in-water emulsion, is preferably used.

The composition may be more or less fluid and may have the appearance of a white or coloured cream, an ointment, a milk, a lotion, a serum, a paste, a gel or a mousse. It may optionally be applied in aerosol form. It may also be in solid form, in particular in the form of a stick.

When the composition is an emulsion, the proportion of the fatty phase may range from 5% to 80% by weight and preferably from 8% to 50% by weight relative to the total weight of the composition. The emulsifier and the co-emulsifier may be present in a proportion ranging from 0.3% to 30% by weight and preferably from 0.5% to 20% by weight relative to the total weight of the composition.

The composition used according to the invention may constitute a skincare composition, and especially a cleansing, protecting, medicated or care cream for the face, the hands, the feet, the major anatomical folds or the body (for example day creams, night creams, makeup- removing creams, foundation creams or antisun creams); a fluid foundation, a makeup- removing milk, a protective or care body milk or an antisun milk; a skincare lotion, gel or mousse, such as a cleansing lotion.

According to one aspect of the present invention, there is provided a cosmetic process for preventing or decreasing skin pigmentation and/or lightening skin tone comprising application of the topical composition according to the present invention to the skin. According to one aspect of the present invention, there is provided use of a combination of the extract of a plant in the family Paeoniaceae and at least one compound of formula (I) in producing a topical composition for preventing or decreasing skin pigmentation and/or lightening skin tone,

n₂

(I ) wherein:

Ri and R₃ are different from or identical to each other, independently selected from the group consisting of hydrogen, a linear or branched C1-C2₀ acyl carbonyl, a linear or branched C₂- C2₀ alkenyl carbonyl, a linear or branched C1-C2₀ alkyl, a linear or branched C₂-C₂o alkenyl and a linear or branched C₂-C₂o alkynyl, preferably selected from the group consisting of hydrogen and a linear or branched C1-C1₀ alkyl, more preferably selected from the group consisting of hydrogen and a linear or branched C1-C4 alkyl, most preferably hydrogen;

R₂ is selected from the group consisting of a linear or branched Ci-C₂₀ alkyl, a linear or branched C₂-C₂₀ alkenyl and a linear or branched C₂-C₂₀ alkynyl, preferably a linear or branched C1-C1₀ alkyl, more preferably a linear or branched C1-C4 alkyl or ethyl.

Unless otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about."

Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contain certain errors necessarily resulting from the standard deviation found in their respective measurements. The following examples are intended to illustrate the invention without limiting the scope as a result. The percentages are given on a weight basis.

Examples

Example 1 : Preparation examples

The following examples were prepared (inv exp stands for invention examples):

from KAO)

STEARYL ALCOHOL (NACOL^® 18 1.50 1.50 98 from SASOL)

STEARIC ACID (RADIACID 0461 3.00 3.00 from OLEON)

CYCLOHEXASILOXANE 7.00 7.00 (XIAMETER PMX-0246

CYCLOHEXASILOXANE from DOW

CORNING)

HYDROGENATED 2.00 2.00 POLYISOBUTENE (PARLEAM from

NOF CORPORATION)

CAPRYLYL GLYCOL (multiple 0.30 0.30 suppliers, 199602 HYDROLITE CG

from SYMRISE) c POLYACRYLAMIDE andC13-14 1.70 1.70

ISOPARAFFIN andLAURETH-7

(SEPIGEL 305 from SEPPIC)

D PAEONIA LACTI FLORA ROOT 1.00 1.00

EXTRACT (RADIX PAEONIAE

ALBA P.E. from GUILIN LAYN

NATURAL INGREDIENTS)

3-O-ETHYL ASCORBIC ACID ((actyl 0.50 1.00 C, CORUM 9515 from CORUM) )

The above mentioned examples are prepared following the steps of: 1 . adding glycerin, propylene glycol, phenoxyethanol and sodium hydroxide in the water under the temperature of 75 ^°C , stirring the mixture until homogeneous.

2. heating phase B to the temperature of 75 ^°C , adding phase B to phase A under turbine; speed: 2000 rpm; machine brand: Turboptest TM 2004; supplier: VMI Turbotest.

3. cooling down the temperature of the mixture obtained in step 2 to 60 ^°C , adding phase C to the mixture under turbine; speed: 2000 rpm; machine brand: Turboptest TM 2004; supplier: VMI Turbotest.

4. adding phase D to the mixture obtained in step 3 under the temperature of 25 ^°C , mixing the ingredients until homogeneous. Adjust the pH of phase D until pH of 4.3.

Example 2: Evaluation examples

Evaluations of the effects for preventing or decreasing skin pigmentation and/or lightening skin tone of the examples are performed.

The measurement of the depigmentation activity (reduction of the production of melanin) of Paeonia lactiflora root extract, compound of formula (I) wherein R-i and R₃ is hydrogen, R₂ is ethyl and their associations using normal human melanocytes in vitro assay as follows.

Firstly, normal human melanoyctes are grown and distributed in 384 plates. After 24 hours, the culture medium was replaced with medium containing raw materials (Paeonia lactiflora root extract,compound of formula (I) or their associations) to be evaluated. The cells were incubated 72 hours before final measurement of optical density which measures the amount of melanin produced by melanocytes.

It can be seen from figure 1 that the positive reference, Lucinol, at the concentration of 1 g/L inhibits the production of melanin by melanocytes (100% depigmentation activity), compound of formula (I) alone showed no activity in this model below concentration of 1 g/L (0% depigmentation activity); while Paeonia lactiflora root extractalone showed a medium inhibitory effect of production of melanin at the same concentration (49% depigmentation activity).

It can also be seen from figure 1 that an unexpected significant improved whitenning effectimproved whitenning effect between Paeonia lactiflora root extract and compound of formula (I) was observed: when 1 g/L Paeonia lactiflora rootextract is mixed with 0.25 g/L compound of formula (I), the activity of Paeoni lactifloa root extract was increased by +49% to reach 72% depigmentation activity, and this improved whitenning effectimproved whitenning effect can be amplified in a compound of formula (I) dose-dependent way.

Claims

We claim:

1. A topical composition comprising the combination of the extract of a plant in the family Paeoniaceae and at least one compound of formula (I)

wherein:

Ri and R₃ are different from or identical to each other, independently selected from the group consisting of hydrogen, a linear or branched C1-C2₀ acyl carbonyl, a linear or branched C2-C2₀ alkenyl carbonyl, a linear or branched Ci-C₂o alkyl, a linear or branched C₂-C₂o alkenyl and a linear or branched C₂-C₂o alkynyl, preferably selected from the group consisting of hydrogen and a linear or branched C1-C1₀ alkyl, more preferably selected from the group consisting of hydrogen and a linear or branched C1-C4 alkyl, most preferably hydrogen;

2. The topical composition according to claim 1 , wherein the extract is obtained from a naturally grown part, preferably one or more selected from the group consisting of leaf, stem, root, flower, fruit and rhizome, more preferably root, and a cultivated part, preferably one or more selected from the group consisting of cells, tissues, organs and whole plant of the plant.

3. The topical composition according to claim 1 or 2, wherein the plant in the family

Paeoniaceae is a plant of the Paeonia L. genus, preferably one or more selected from the group consisting of Paeonia lactiflora Pall., Paeonia anomala ssp. Veitchii (Lynch) D. Y.

Hong, Paeonia suffruticosa Andrews, Paeonia ostii T. Hong & J. X. Zhang, Paeonia rockii, Paeonia decomposita and Paeonia delavayi, and more preferably Paeonia lactiflora Pall.

4. The topical composition according to any one of the preceding claims 1 to 3, wherein in the combination, the ratio by weight of the extract to the at least one compound of formula (I) is 1 :0.003-1 , preferably 1 :0.070-1 , and more preferably 1 :0.25-1 .

5. The topical composition according to any one of the preceding claims 1 to 4, wherein the combination is present in the composition from 0.05% to 20% by weight, preferably from 1 % to 10% by weight, and more preferably from 2% to 6% by weight, with respect to the total weight of the topical composition, optionally the remaining being a physically acceptable medium.

6. The topical composition according to any one of the preceding claims 1 to 5, further comprising at least one additional adjuvant.

7. The topical composition according to any one of the preceding claims 1 to 6, further comprising a compound of formula (II),

wherein:

R₄ is selected from the group consisting of hydrogen, an alkali metal ion, a linear or branched C C₂o alkyl, a linear or branched C₂-C₂o alkenyl and a linear or branched C₂-C₂o alkynyl, preferably selected from the group consisting of hydrogen and a linear or branched C-I-C-IO alkyl (preferably a linear or branched C-|-C₄ alkyl), more preferably hydrogen;

R₅ and R₆ are different from or identical to each other, independently selected from the group consisting of hydrogen, a linear or branched Ci-C₂₀ alkyl, a linear or branched C₂-C₂₀ alkenyl and a linear or branched C₂-C₂₀ alkynyl, preferably selected from the group consisting of hydrogen and a linear or branched C-I-C-IO alkyl, preferably a linear or branched Ci-C₄ alkyl; preferably one of R₅ and R₆ is methyl and the other is hydrogen.

8. The topical composition according to any one of the preceding claims 1 to 7, wherein the compound of formula (II) is present in the composition from 0.01 % to 10% by weight, preferably from 0.05% to 5% by weight, and more preferably from 0.05% to 3% by weight, with respect to the total weight of the topical composition.

9. A cosmetic process for preventing or decreasing skin pigmentation and/or lightening skin tone comprising application of the topical composition according to any one of claims 1 to 8 to the skin.

10. Use of a combination of the extract of a plant in the family Paeoniaceae and at least one compound of formula (I) in producing a topical composition for preventing or decreasing skin pigmentation and/or lightening skin tone,

2

(I ) wherein:

Ri and R₃ are different from or identical to each other, independently selected from the group consisting of hydrogen, a linear or branched C1-C2₀ acyl carbonyl, a linear or branched C2-C2₀ alkenyl carbonyl, a linear or branched C1-C2₀ alkyl, a linear or branched C₂-C₂o alkenyl and a linear or branched C₂-C₂o alkynyl, preferably selected from the group consisting of hydrogen and a linear or branched C1-C1₀ alkyl, more preferably selected from the group consisting of hydrogen and a linear or branched C1-C4 alkyl, most preferably hydrogen;