EP4392007A1

EP4392007A1 - Ascorbic acid and human milk oligosaccahride compositions

Info

Publication number: EP4392007A1
Application number: EP22769128.4A
Authority: EP
Inventors: Stephan DOPPLER; Lise Anne KOHLER; Christine Mendrok-Edinger
Original assignee: DSM IP Assets BV
Current assignee: DSM IP Assets BV
Priority date: 2021-08-24
Filing date: 2022-08-23
Publication date: 2024-07-03
Also published as: CN117835960A; WO2023025796A1

Abstract

The present invention relates to cosmetic compositions comprising ascorbic acid or a salt thereof and at least one human milk oligosaccharide as well as to the use of at least one human milk oligosaccharide for suppressing discoloration of ascorbic acid or a salt thereof.

Description

ASCORBIC ACID AND HUMAN MILK OLIGOSACCAHRIDE COMPOSITIONS

Ascorbic acid, also known by its common name of Vitamin C, has long been recognized as an active substance benefiting skin appearance. Vitamin C reportedly increases the production of collagen in human skin tissue. Wrinkles and fine lines are thereby reduced. An overall healthier and younger-looking appearance results. Vitamin C has also found utility as an ultraviolet ray blocking or absorbing agent. Whitening or bleaching skin compositions have also employed Vitamin C utilizing its property of interference with the melanin formation process. There also is a belief that ascorbic acid interacts with the human immune system to reduce sensitivity to skin aggravating chemicals. Reduced levels of Vitamin C concentration on the skin have also been implicated with an increase in stress. From all of the foregoing perspectives, Vitamin C or ascorbic acid may provide significant benefit when topically applied.

Unfortunately, Vitamin C is a very unstable substance. Although it is readily soluble in water, rapid oxidation occurs in particular in aqueous media leading to unwanted discoloration.

Thus, there is an ongoing need for agents, which suppress the discoloration of Vitamin C such as in particular in the presence of water.

Human milk oligosaccharides’ (HMOs) are a family of structurally diverse unconjugated glycans that are highly abundant in and unique to human milk. Due to its specific characteristics these HMOs can be used in nutritional, pharmaceutical, cosmetic and medical applications.

In accordance with the present invention it has now surprisingly been found that the discoloration of aqueous compositions containing ascorbic can be effectively reduced by the addition of human milk oligosaccharides. Thus, in a first aspect, the present invention relates to cosmetic compositions comprising ascorbic acid or a salt thereof and at least one human milk oligosaccharide.

In a second aspect the present invention relates to the use of at least one human milk oligosaccharide for suppressing discoloration of ascorbic acid thereof or a salt, preferably in aqueous compositions and optionally appreciating the effect.

In a third aspect, the present invention relates to a method for reducing discoloration of compositions containing ascorbic acid or a salt thereof, said method comprising preparing a composition comprising ascorbic acid or a salt thereof, at least one human milk oligosaccharide and a cosmetically acceptable carrier, which carrier preferably comprises water, and optionally storing the respective composition for at least 1 , more preferably for at least 2 weeks, most preferably for at least 6 weeks.

In a further aspect the invention relates to the use of a combination of ascorbic acid or a salt thereof and at least one human milk oligosaccharide for the preparation of storage stable cosmetic composition. These compositions exhibit an excellent storage stability in view of preventing/suppressing discoloration compared to a control not comprising the HMO(s). Said compositions can be prepared by admixing ascorbic acid or a salt thereof and at least one human milk oligosaccharide into a cosmetically acceptable carrier, which carrier preferably comprises water.

The term ‘supress/ suppressing discoloration’ refers to a reduced discoloration of the composition according to the present invention compared to control. The suppression of discoloration according to the present invention is reflected by reduced a-values (according to the CIELAB colorspace) compared to the respective control not comprising the HMO upon storage, such as upon storage for at least 2 weeks (at RT (about 22°C) or in a thawcycle; in dark containers/ vials or at daylight in clear glass vials/ containers) as outlined in the example

The term ascorbic acid refers to ascorbic acid per se, preferably in the L-form as well as the respective salts thereof.

Suitable salts of ascorbic acid according to the present invention include, sodium, potassium, lithium, calcium, magnesium, barium, ammonium (such as e.g. triethanolamine) and protamine salts. Sodium, magnesium, potassium and ammonium salts being preferred.

Preferably, the (total) amount of ascorbic acid or a salt thereof in the compositions according to the present invention is selected in the range from 0.001 to 50 wt. %, preferably from 0.01 to 20 wt. %, most preferably from 0.1 to 15 wt. %, such as e.g. from 0.1 to 10 wt.-%, from 0.5 to 10 wt.-%, from 0.5 to 7.5 wt.-%, from 0.5 to 5 wt.-% or from 1 to 5 wt.-%, based on the total weight of the composition.

The term ‘human milk oligosaccharides’ (HMOs) refers to a family of structurally diverse unconjugated glycans that are highly abundant in and unique to human milk. Originally, HMOs were proposed to be prebiotic "bifidus factors," or human milk glycans found to promote growth in Bifidobacterial species of the gut and found uniquely in the stool of breast fed infants compared to formula fed infants.

HMOs are composed of the five monosaccharides glucose (Glc), galactose (Gal), N- acetylglucosamine (GIcNAc), fucose (Fuc) and sialic acid (Sia), with N- acetylneuraminic acid (Neu5Ac) as the predominant if not only form of Sia. More than two hundred different HMOs have been identified so far. The most important ones are 2'-fucosyllactose (2'FL), lacto-N-neotetraose (LNnT), 3-fucosyllactose (3FL), difucosyllactose (DFL), Lacto-N-fucopentaose I (LNFP I), 3'Sialyllactose Sodium Salt (3'SL), 6'Sialyllactose Sodium Salt (6'SL), and Lacto-N-Tetraose (LNT).

HMOs can be isolated from breast milk or they can be produced chemically or biochemically. HMOs are available commercially from a variety of producers.

For the purpose of the present invention the source of the HMO is not essential. It is clear that HMOs from different sources can be used.

Particularly suitable HMO’s in all embodiments of the present invention are fucosylated HMO’s such as in particular a1-2 respectively a1 -3 fucosylated HMO’s; sialylated HMO’s such as in particular sialyllactoses, as well as lacto-N-(neo)tetraoses as well as any mixtures thereof.

Particularly preferred fucosylated HMO’s according to the present invention are 2'-fucosyllactose (CAS No: 41263-94-9), 3-fucosyllactose (CAS No: 41312-47-4), difucosyllactose (also known as Lactodifucotetraose; CAS No: 20768-11 -0) and Lacto- N-fucopentaose I (CAS No: 7578-25-8).

Particularly preferred sialylated HMO’s according to the present invention are sialyllactoses as well as salts thereof (preferably the sodium salts) such as in particular 3’sialyllactose, 6’sialyllactose as well as the respective sodium salts thereof (CAS No’s: 35890-39-2 (3’sialyllactose); 128596-80-5 (3’sialyllactose sodium salt); 35890-39-2 (6’sialyllactose); 157574-76-0 (6’sialyllactose sodium salt)).

Particularly preferred lacto-N-(neo)tetraoses according to the present invention are lacto-N-tetraose (CAS No: 141 16-68-8) and lacto-N-neotetraose (CAS No: 13007-32- 4), which are highly abundant neutral core HMO’s in human milk.

Most preferred human milk oliogsaccharides according to the present invention are 2'-fucosyllactose, 3-fucosyllactose, difucosyllactose, lacto-N-fucopentaose I, 3'sialyllactose sodium salt, 6'sialyllactose sodium salt, lacto-N-neotetraose and lacto- N-tetraose as well as mixtures thereof, such as in particular 2'-fucosyllactose, 3- fucosyllactose, difucosyllactose, 3'sialyllactose sodium salt, 6'sialyllactose sodium salt, lacto-N-neotetraose and lacto-N-tetraose.

The total amount of human milk oligosaccharide(s) in the compositions according to the present invention is preferably selected in the range from 0.01 to 10 wt.-%, more preferably in the range from 0.1 to 7.5 wt.-%, most preferably in the range from 0.2 to 5 wt.-%, based on the total weight of the composition. Further suitable ranges are from 0.25 to 2.5 wt.-%, from 0.5 to 2 wt.-%, from 0.1 to 1 wt.-%, from 0.25 to 0.75 wt.-% and from 0.3 to 0.6 wt.-%. Particularly preferred ranges according to the present invention are from 0.1 to 5 wt.-%, more preferably from 0.25 to 5 wt.-%, such as from 0.3 to 5 wt.-%.

In all embodiments of the present invention, preferably the use level (in weight-%) of the human milk oligosaccharide is higher than the one of ascorbic acid ora salt thereof, i.e. the human milk oligosaccharide(s) is/are used in excess.

Accordingly, in all embodiments of the present invention, it is preferred that the weightratio (w/w) between the human milk oligosaccharide(s) and the ascorbic acid or a salt thereof is selected in the range from 50:1 to 1 :5 or from 50:1 to 1 :1 , more preferably in the range from 25:1 to 1 :5 or from 25:1 to 1 :1 , most preferably in the range from 15:1 to 1 :5 or from 15:1 to 5:1 . Further preferred ranges are from 10:1 to 7.5:1 , from 10:1 to 5:1 , from 10:1 to 2:1 , from 10:1 to 1 :5, from 5:1 to 1 :5, from 10:1 to 1 :2 and from 5:1 to 1 :2.

Preferably, in all embodiments of the present invention, the compositions are free of mannose, i.e. do not contain any mannose.

The term ‘cosmetic composition’ as used herein refers to cosmetic compositions which are used to treat, care for or improve the appearance of the skin and/or the scalp.

In all embodiments according to the present invention including all compositions, methods and uses as disclosed herein, the compositions preferably are aqueous compositions, i.e. compositions which comprise water.

Advantageously, in all embodiments of the present invention the water content in the compositions according to the present invention is selected in the range from 30 to 90 wt.-%, preferably from 40 to 90 wt.-%, more preferably from 45 to 90 wt.-% such as most preferably from 50 to 90 wt.-%, based on the total weight of the composition. Further suitable ranges are from 30 to 75 wt.-%, from 30 to 70 wt-%, from 30 to 60 wt.- % and from 40 to 60 wt.-%.

In a particular embodiment, the compositions according to the present invention are cosmetic compositions intended to be topically applied to mammalian keratinous tissue such as in particular to human skin or the human scalp. Such compositions are also called dermatological compositions. Thus, preferably in all embodiments of the present invention the cosmetic compositions are topical cosmetic (i.e. dermatological) compositions with all the definitions and preferences as given herein.

The topical cosmetic compositions according to the present invention may be leave- on or rinse-off compositions, and include any product applied to the skin and/ or scalp of a human body, primarily for improving appearance, cleansing, odor control or general aesthetics. Preferably the topical cosmetic compositions of the present invention are leave-on compositions. It is well understood that the cosmetic compositions according to the invention intended for topical application comprise a physiologically acceptable medium, i.e. a medium compatible with keratinous substances, such as the skin, mucous membranes, and keratinous fibers. In particular, the physiologically acceptable medium is a cosmetically acceptable carrier. In all embodiments of the present invention it is preferred that the carrier comprises water.

The term ‘cosmetically respectively dermatologically acceptable carrier’ (also referred to herein as carrier) refers to all vehicles/ carriers conventionally used in cosmetic compositions, i.e. which are suitable for topical application to the keratinous tissue, have good aesthetic properties, are compatible with the actives present in the composition, and will not cause any unreasonable safety or toxicity concerns. Such carriers are well-known to one of ordinary skill in the art, and can include one or more compatible liquid(s) or solid filler diluent(s), excipient(s), additive(s) or vehicle(s) which are suitable for application to skin.

The exact amount of carrier will depend upon the actual level of the active ingredients and of any other optional ingredients that one of ordinary skill in the art would classify as distinct from the carrier (e.g., other active ingredients).

The compositions of the present invention preferably comprise from about 50% to about 99.999%, more preferably from about 60% to about 99.99%, still more preferably from 75% to about 99%, and most preferably, from about 80% to about 98% such as about 90% to about 98%, by weight of the composition, of a carrier, based on the total weight of the composition.

In a particular advantageous embodiment, the carrier consists furthermore of at least 30 wt. %, more preferably of at least 40 wt.-%, most preferably of at least 45 wt.-% of water, such as in particular of 50 to 90 wt.-% of water.

The cosmetic compositions in accordance with the invention can be in the form of a liquid, lotion, a thickened lotion, a gel, a cream, a milk, an ointment, a paste, a powder, a make-up, or a solid tube stick and can be optionally be packaged as an aerosol and can be provided in the form of a mousse such as an aerosol mousse, a foam or a spray foam, a spray, a stick. Preferably the ascorbic acid or a salt thereof and the respective HMO(s) are formulated into lotions, creams, gels, and tonics. These product forms may be used for a number of applications, including, but not limited to, hand and body lotions, facial moisturizers, anti-ageing preparations, make-ups including foundations, and the like. Any additional components required to formulate such products vary with product type and can be routinely chosen by one skilled in the art.

If the cosmetic compositions of the present invention are formulated as an aerosol and applied to the skin as a spray-on product, a propellant is added to the composition.

The cosmetic compositions according to the present invention can be prepared by conventional methods in the art such as e.g. by admixing ascorbic acid and/ or a salt thereof and the respective HMO(s) with all the definitions and preferences given herein with the cosmetically acceptable carrier.

The cosmetic composition may comprise further ingredients, which may form part of the carrier. Such ingredients are particularly surfactants, emulsifiers, thickeners, and oils. Such suitable surfactants, emulsifiers, thickeners, and oils are well known to a person skilled in the art.

The cosmetic compositions of the invention (including the carrier) may comprise further conventional (cosmetic) adjuvants and additives, such as preservatives/antioxidants, fatty substances/oils, water, organic solvents, silicones, thickeners, softeners, emulsifiers, antifoaming agents, aesthetic components such as fragrances, surfactants, fillers, anionic, cationic, non-ionic or amphoteric polymers or mixtures thereof, propellants, acidifying or basifying agents, dyes, colorings/colorants, abrasives, absorbents, chelating agents and/ or sequestering agents, essential oils, skin sensates, astringents, pigments or any other ingredients usually formulated into such compositions.

If nothing else is stated, the excipients, additives, diluents, etc. mentioned in the following are suitable for the compositions according to the present invention. The necessary amounts of the cosmetic and dermatological adjuvants and additives can, based on the desired product, easily be determined by the skilled person. The additional ingredients can either be added to the oily phase, the aqueous phase or separately as deemed appropriate. The mode of addition can easily be adapted by a person skilled in the art based on the respective composition.

Examples of cosmetic excipients, diluents, adjuvants, additives as well as active ingredients commonly used in the skin care industry which are suitable for use in the cosmetic compositions of the present invention are for example described in the International Cosmetic Ingredient Dictionary & Handbook by Personal Care Product Council (http://www.personalcarecouncil.org/), accessible by the online INFO BASE (http://online.personalcarecouncil.org/jsp/Home.jsp), without being limited thereto.

The cosmetically active ingredients useful herein can in some instances provide more than one benefit or operate via more than one mode of action.

Of course, one skilled in this art will take care to select the above mentioned optional additional ingredients, adjuvants, diluents and additives and/or their amounts such that the advantageous properties intrinsically associated with the combination in accordance with the invention are not, or not substantially, detrimentally affected by the envisaged addition or additions.

The cosmetic compositions according to the present invention are in particular skin care preparations, functional preparations and/or hair care preparations such as most in particularly skin or hair care preparations.

Examples of skin care preparations are, in particular, light protective preparations (sun care preparations), anti-ageing preparations, preparations for the treatment of photoageing, body oils, body lotions, body gels, treatment creams, skin protection ointments, moisturizing preparations such as moisturizing gels or moisturizing sprays, face and/or body moisturizers, make-up as well as skin lightening preparations.

Examples of functional preparations are cosmetic compositions containing active ingredients such as hormone preparations, vitamin preparations, vegetable extract preparations, anti-ageing preparations, and/or antimicrobial (antibacterial or antifungal) preparations without being limited thereto. Examples of hair care preparations which are suitable according to the invention and which may be mentioned are shampoos, hair conditioners (also referred to as hair rinses), hairdressing compositions, hair tonics, hair regenerating compositions, hair lotions, water wave lotions, hair sprays, hair creams, hair gels, hair oils, hair pomades or hair brilliantines. Accordingly, these are always preparations which are applied to the hair and the scalp for a shorter or longer time depending on the actual purpose for which they are used.

In a preferred embodiment, the cosmetic compositions according to the present invention are emulsions and/or gels. Even more preferably, the cosmetic compositions are emulsions which contain an oily phase and an aqueous phase such as in particular O/W, W/O, Si/W, W/Si, O/W/O, W/O/W multiple or a pickering emulsions.

The amount of the oily phase (i.e. the phase containing all oils and fats including the polar oils) present in such emulsions such as in particular O/W, W/O, Si/W, W/Si, O/W/O, W/O/W multiple or a pickering emulsions is preferably at least 10 wt.-%, such as in the range from 10 to 60 wt.-%, preferably in the range from 15 to 50 wt.-%, most preferably in the range from 15 to 40 wt.-%, based on the total weight of the composition.

The oil phase according to the invention preferably comprises oils selected from butylenglykoldicaprylatAdicaprat, propylenglykoldicaprylatZ-dicaprat, dicaprylylether, C s-Alkylbenzoat, Ci_8-38-fatty acid triglyceride, dibutyladipate, cyclomethicone, dimethicone, 2-phenylethylbenzoat, isopropyl lauroyl sarkosinate, caprylic/ capric triglyceride as well as mixtures thereof.

The amount of the aqueous phase present in such emulsions is preferably at least 20 wt.-%, such as in the range from 20 to 90 wt.-%, preferably in the range from 30 to 80 wt.-%, most preferably in the range from 30 to 70 wt.-%, based on the total weight of the composition.

Advantageously in all emulsions of the present invention the ratio of oily phase to aqueous phase is selected in the range of 40:60 to 30 to 70.

In one particular advantageous embodiment, the cosmetic compositions according to the present invention are in the form of an oil-in-water (O/W) emulsion comprising an oily phase dispersed in an aqueous phase in the presence of an O/W emulsifier. The preparation of such O/W emulsions is well known to a person skilled in the art.

If the cosmetic composition according to the invention is an O/W emulsion, then it contains advantageously at least one O/W- or Si/W-emulsifier selected from the list of, glyceryl stearate citrate, glyceryl stearate SE (self-emulsifying), stearic acid, salts of stearic acid, polyglyceryl-3-methylglycosedistearate. Further suitable emulsifiers are phosphate esters and the salts thereof such as cetyl phosphate (e.g. as Amphisol® A from DSM Nutritional Products Ltd.), diethanolamine cetyl phosphate (e.g. as Amphisol® DEA from DSM Nutritional Products Ltd.), potassium cetyl phosphate (e.g. as Amphisol® K from DSM Nutritional Products Ltd.), sodium cetearylsulfate, sodium glyceryl oleate phosphate, hydrogenated vegetable glycerides phosphate and mixtures thereof. Further suitable emulsifiers are sorbitan oleate, sorbitan sesquioleate, sorbitan isostearate, sorbitan trioleate, cetearyl glucoside, lauryl glucoside, decyl glucoside, sodium stearoyl glutamate, sucrose polystearate and hydrated polyisobutene. Furthermore, one or more synthetic polymers may be used as an emulsifier. For example, PVP eicosene copolymer, acrylates/C 10-30 alkyl acrylate crosspolymer, and mixtures thereof.

The at least one O/W, respectively Si/W emulsifier is preferably used in an amount of 0.5 to 10 wt. %, in particular in the range of 0.5 to 6 wt.-%, such as more in particular in the range of 0.5 to 5 wt.-%, such as most in particular in the range of 1 to 4 wt.-%, based on the total weight of the cosmetic composition.

Particular suitable O/W emulsifiers to be used in the cosmetic compositions according to the invention encompass phosphate ester emulsifiers such as advantageously 8-10 alkyl ethyl phosphate, C9-15 alkyl phosphate, ceteareth-2 phosphate, ceteareth-5 phosphate, ceteth-8 phosphate, ceteth-10 phosphate, cetyl phosphate, C6-10 pareth- 4 phosphate, C12-15 pareth-2 phosphate, C12-15 pareth-3 phosphate, DEA- ceteareth-2 phosphate, DEA-cetyl phosphate, DEA-oleth-3 phosphate, potassium cetyl phosphate, deceth-4 phosphate, deceth-6 phosphate and trilaureth-4 phosphate.

A particular suitable O/W emulsifier to be used in the cosmetic compositions according to the invention is potassium cetyl phosphate e.g. commercially available as Amphisol® K at DSM Nutritional Products Ltd Kaiseraugst. Another particular suitable class of O/W emulsifiers are non-ionic self-emulsifying systems derived from olive oil e.g. known as (INCI Name) cetearyl olivate and sorbitan olivate (chemical composition: sorbitan ester and cetearyl ester of olive oil fatty acids) sold under the tradename OLIVEM 1000.

In one particular embodiment, the invention relates to cosmetic compositions with all the definitions and preferences given herein in the form of O/W emulsions comprising an oily phase dispersed in an aqueous phase in the presence of an O/W emulsifier wherein the O/W emulsifier is potassium cetyl phosphate. The amount of oily phase in such O/W emulsions is preferably at least 10 wt.-%, more preferably in the range of 10 to 60 wt.-%, most preferably in the range of 15 to 50 wt.-%, such as in the range of 15 to 40 wt.-%, based on the total weight of the composition.

Preferably, the cosmetic compositions according to the invention further comprise at least one fatty alcohol (co-emulsifier), such as in particular cetyl alcohol, cetearyl alcohol and/ or behenyl alcohol. The total amount of one or several fatty alcohols on the compositions according to the invention is preferably selected in the range of about 0.1 to 10.0 wt.-%, in particular in the range of about 0.5 to 6.0 wt.-% with respect to the total weight of the composition.

Preferably, the compositions according to the invention comprise a thickener in particular if the composition is in the form of an emulsion to assist in making the consistency of a product suitable. Preferred thickeners are aluminiumsilicates, xanthan gum, hydroxypropylmethylcellulose, hydroxyethylcellulose, polyacrylates such as carbopole® (e.g. Carbopole 980, 981 , 1382, 2984, 5984) or mixtures thereof. Further preferred thickeners encompass acrylate/Cio.30 alkyl acrylate copolymers (such as e.g. Pemulen TR 1 , Pemulen TR 2, Carbopol 1328 by. NOVEON) as well as Aristoflex AVC (INCI: Ammonium Acryloyldimethyltaurate/VP Copolymer).

The cosmetic compositions according to the present invention advantageously comprise a preservative. When present, the preservative is preferably used in an amount of 0.1 to 2 wt.-%, more preferably in an amount of 0.5 to 1 .5 wt.-%, based on the total weight of the composition.

The cosmetic compositions according to the invention in general have a pH in the range of 3 to 10, preferably a pH in the range of 3 to 8 and most preferably a pH in the range of 3 to 7.5 such as in the range of 3 to 6.5. The pH can easily be adjusted as desired with suitable acids, such as e.g. citric acid, or bases, such as sodium hydroxide (e.g. as aqueous solution), triethanolamine (TEA Care), Tromethamine (Trizma Base) and Aminomethyl Propanol (AMP-Ultra PC 2000), according to standard methods in the art. It is well understood, that ascorbic acid may be present in the composition as a salt, dependent on the final pH of the composition.

In a particular advantageous aspect, the compositions according to the present invention are free of any parabenes, benzethoniumchlorid, piroctone olamine, lauroylarginat, methylisothiazolinon, chlormethylisothiazolinon, bronopol, benzalkoniumchloride, formaldehyd releasing compounds, salicylic acid, triclosan, DMDM hydantoin, chlorphenesin and IPBC (lodopropinylbutyl carbamate), such as in particular free of methylchloroisothiazolinone.

The amount of the cosmetic composition to be applied to the skin is not critical and can easily be adjusted by a person skilled in the art. Preferably the amount is selected in the range of 0.1 to 3 mg/cm² skin, such as preferably in the range of 0.1 to 2 mg/cm² skin and most preferably in the range of 0.5 to 2 mg/cm² skin.

The following examples are provided to further illustrate the compositions and effects of the present invention. These examples are illustrative only and are not intended to limit the scope of the invention in any way.

Examples

The formulations as outlined in table 1 were prepared and then stored in clear glass vials as outlined below. The colour stability was assessed against a control (reference) by measuring the ‘a values’ (CIELAB system), which is an indicator of the discoloration of the sample: the higher the a-value, the higher the discoloration.

HMO’s Abbreviation

2’-FL: 2’-Fucosyllactose

3-FL: 3-Fucosyllactose

3’SL: 3'-Sialyllactose sodium salt

6’SL: 6'-Sialyllactose sodium salt

LNnT : Lacto-N-neotetraose

LNT : Lacto-N-tetraose FL/DFL: 2’-Fucosyllactose/ Difucosyllactose mixture (> 75% 2'-FL; > 5% DFL)

Table 1 : Formulation

Mix A and stir until a clear solution is obtained Add B at room temperature to A and stir until a clear solution is obtained

Adjust the pH to 9.0 with aqueous NaOH

Add C until the pH is at pH 3.0 (approx. 0.5-2 wt.-%)

Table 2: Colour stability upon storage (a-values) at RT/ stored dark

Table 3: Colour stability upon storage (a-values) at RT/ exposed to daylight

Table 4: Colour stability upon storage (a-values) thaw cycle

As can be retrieved from tables 2-4, the addition of the respective HMO’s led to an effective reduction of the respective a-values compared to the respective controls.

The same experiment has been performed, using lower use levels of the respective HMO’s. The results are outlined in tables 5: Table 5: Colour stability upon storage (a-values) at RT; 2 weeks at various use levels

As can be retrieved from the results outlined in table 5, also lower use levels of the HMO result in a colour stabilization of ascorbic acid.

Claims

Claims . A cosmetic composition for topical application comprising ascorbic acid or a salt thereof and at least one human milk oligosaccharide (HMO). . The cosmetic composition according to claim 1 , wherein the at least one human milk oligosaccharide is selected from the group consisting of fucosylated HMOs; sialylated HMOs, lacto-N-(neo)tetraoses as well as any mixtures thereof. . The cosmetic composition according to claim 1 , wherein the at least one human milk oligosaccharide is selected from the group consisting of 2'-fucosyllactose, 3- fucosyllactose, difucosyllactose, lacto-N-fucopentaose I, 3'sialyllactose sodium salt, 6'sialyllactose sodium salt, lacto-N-neotetraose and lacto-N-tetraose as well as mixtures thereof. . The cosmetic composition according to any one of the preceding claims, wherein the total amount of ascorbic acid and/ or a salt thereof is selected in the range from 0.01 to 20 wt. %, preferably from 0.1 to 15 wt. %, most preferably from 0.1 to 10 wt.-%, based on the total weight of the composition. . The cosmetic composition according to any one of the preceding claims, wherein the total amount of the human milk oligosacharide(s) is selected in the range from 0.01 to 10 wt.-%, more preferably in the range from 0.1 to 7.5 wt.-%, most preferably in the range from 0.2 to 5 wt.-%, based on the total weight of the composition. . The cosmetic composition according to any one of the preceding claims, wherein the weight-ratio between the human milk oligosaccharide(s) and the ascorbic acid and/or a salt thereof is selected in the range from 50:1 to 1 :5, more preferably in the range from 25:1 to 1 :5, most preferably in the range from 15:1 to 1 :2. . The cosmetic composition according to any one of the preceding claims, wherein the composition comprises a carrier consisting of at least 30 wt. %, more preferably of at least 40 wt.-%, most preferably of at least 45 wt.-% of water, such as in particular of 50 to 90 wt.-% of water. 8. The cosmetic composition according to any one of the preceding claims, wherein the composition is an O/W emulsion comprising an oily phase dispersed in an aqueous phase.

9. Use of at least one human milk oligosaccharide for suppressing discoloration of ascorbic acid or a salt thereof, preferably in aqueous compositions.

10. The use according to claim 9, wherein the human milk oligosaccharide is selected from the group consisting of 2 -fucosyllactose, 3-fucosyllactose, difucosyllactose, lacto-N-fucopentaose I, 3'sialyllactose sodium salt, 6'sialyllactose sodium salt, lacto-N-neotetraose and tacto-N-tetraose as well as mixtures thereof.

1 1 . A method for reducing discoloration of compositions containing ascorbic acid or a salt thereof, comprising preparing a composition comprising ascorbic acid and/ or a salt thereof, at least one human milk oligosaccharide and a cosmetically acceptable carrier.

12. The method according to claim 1 1 , wherein the at least one human milk oligosaccharide is selected from the group consisting of 2'-fucosyllactose, 3- fucosyllactose, difucosyllactose, lacto-N-fucopentaose I, 3'sialyllactose sodium salt, 6'sialyllactose sodium salt, lacto-N-neotetraose and tacto-N-tetraose as well as mixtures thereof.

13. The method according to claim 1 1 to 12, wherein the total amount of ascorbic acid and/or a salt thereof is selected in the range from 0.01 to 20 wt. %, preferably from 0.1 to 15 wt. %, most preferably from 0.1 to 10 wt.-%, based on the total weight of the composition.

14. The method according to any one of claims 11 to 13, wherein the total amount of human milk oligosacharide(s) is selected in the range from 0.01 to 10 wt.-%, preferably in the range from 0.1 to 7.5 wt-%, most preferably in the range from 0.2 to 5 wt.-%, based on the total weight of the composition.

15. The method according to anyone of claims 11 to 14, wherein the carrier consists of at least 30 wt. %, more preferably of at least 40 wt.-%, most preferably of at least 45 wt.-% of water, such as in particular of 50 to 90 wt.-% of water.