WO2021058469A1

WO2021058469A1 - Anhydrous compositions

Info

Publication number: WO2021058469A1
Application number: PCT/EP2020/076409
Authority: WO
Inventors: Guillaume Bernard LAURENT; Pascal Christian SIEBER
Original assignee: Dsm Ip Assets B.V.
Priority date: 2019-09-27
Filing date: 2020-09-22
Publication date: 2021-04-01

Abstract

The present invention relates to an anhydrous composition comprising ascorbic acid or a derivative thereof and porous silica beads having a particle size a Dv50 selected in the range of 8 to 15 µm and a specific surface area in the range of 100 to 300 m2/g. Preferably the highly porous silica beads moreover exhibit an oil absorption capacity selected in the range of 1.2 to 2.5 cc/g. Furthermore, the invention relates to the use of such beads to reduce the discoloration of anhydrous composition comprising ascorbic acid and/ or a derivative thereof.

Description

Anhydrous compositions

The present invention relates to an anhydrous composition comprising ascorbic acid or a derivative thereof and porous silica beads having a particle size a D_v50 selected in the range of 8 to 15 pm and a specific surface area in the range of 100 to 300 m²/g. Preferably the highly porous silica beads moreover exhibit an oil absorption capacity selected in the range of 1 .2 to 2.5 cc/g. Furthermore, the invention relates to the use of such beads to reduce the discoloration of anhydrous composition comprising ascorbic acid and/ or a derivative thereof.

Ascorbic acid (also known as vitamin C) as well as derivatives thereof are antioxidants that can benefit the skin when applied topically. Topical use of vitamin C may for example supplement sunscreen protection and provide additional anticarcinogenic protection. Furthermore, Vitamin C has been shown to result in clinically visible and statistically significant improvement in wrinkling in humans. Sodium ascorbyl phosphate on the other hand is for example effective for brightening an uneven skin tone.

Although topical vitamin C application can benefit the appearance and health of skin, problems limit the use of vitamin C as well as derivatives thereof in topical compositions. In particular, vitamin C and its derivatives can be difficult to stabilize in topical compositions. Thus, there is an ongoing need for substances which are able to the stabilize vitamin C and/ or derivatives thereof in cosmetic compositions, in particular when used in high concentration.

Surprisingly it has been found that the addition of specific porous silica beads to anhydrous composition comprising vitamin C or a derivative thereof significantly reduced the discoloration thereof upon storage. l Thus, the present invention relates to an anhydrous composition comprising vitamin C or a derivative thereof and porous silica beads having a particle size a D_v50 selected in the range of 8 to 15 pm and a specific surface area in the range of 100 to 300 m²/g.

Another subject matter of the invention is a method to reduce the discoloration of vitamin C or a derivative thereof in an anhydrous composition, said method comprising the step of adding to the anhydrous composition porous silica beads having a particle size D_v50 selected in the range of 8 to 15 pm and a specific surface area in the range of 100 to 300 m²/g and optionally appreciating the effect.

In a further embodiment the invention relates to the use of porous silica beads having a particle size Dv50 selected in the range of 8 to 15 pm and a specific surface area in the range of 100 to 300 m²/g to reduce the discoloration of an anhydrous composition comprising vitamin C or derivatives thereof.

In all embodiments of the present invention, the amount of the beads is preferably selected in the range from 1 to 30 wt.-%, more preferably in the range from 2 to 25 wt.-%, and most preferably in the range from 5 to 20 wt.-% based on the total weight of the composition. Further suitable ranges include 5 to 15 wt.-%, 7.5 to 15 wt.-%, 5 to 12 wt.-% and 7.5 to 12 wt.-%.

In all embodiments of the present invention, the amount (total) of the vitamin C or a derivative thereof is preferably selected in the range from 1 to 30 wt.-%, more preferably in the range from 5 to 25 wt.-%, and most preferably in the range from 7.5 to 20 wt.-%, based on the total weight of the composition. Further suitable ranges include 5 to 20 wt.-%, 7.5 to 20 wt.-% and 10 to 20 wt.-%.

The term ‘anhydrous composition’ (used synonymously with ‘non-aqueous’) refers to compositions in that no water is added purposively to the composition. While formulations which are completely water free or which have only trace amounts of water are most desired, the term is meant to encompass total water contents of up to about 5 wt.-% as a certain amount of water associated with the various components may be contained in the composition. In one embodiment, the claimed compositions contain less than about 4 wt.-% water. In a further embodiment, the present compositions contain less than about 3 wt.-%, less than about 2 wt.- %, less than about 1 wt.-%, or less than about 0.5 wt.-% water. In one embodiment, the present compositions contain up to about 0.5 wt.-%, up to about 1 wt.-%, up to about 2 wt.-%, up to about 3 wt.-%, up to about 4 wt.-%, or up to about 5 wt.-% water. Preferably, the present compositions are completely anhydrous meaning that no water can be detected e.g. with Karl- Fischer titration.

Vitamin C and L-ascorbic acid are used herein interchangeably. Derivatives of L-ascorbic acid include L-ascorbic acid derivatized (modified by the substitution, addition, or deletion of a functional group) at the C2, C3, C5, or C6 position such as ethyl-ascorbic acid, ascorbyl-2- glucoside, ascorbyl-6-octanoate, ascorbyl-6-palmitate, ascorbyl-6-stearate, ascorbyl-2,6- dipalmitate, L-dehydroascrobic acid, ascorbyl phosphates, tetrahexaldecyl ascorbate and ascorbyl tetraisopalmitate/tetrahexyldecyl ascorbate. Furthermore, vitamin C may be obtained from vitamin C rich plant extracts. Such vitamin C rich plant extracts include Malpighia Glabra (Acerola) Fruit Extract, Terminalia Ferdinandiana Fruit Extract and Rosa Roxburghii Fruit Extract. In addition, extracts may be obtained from Vitamin C-rich fruits (or extracts therefrom), which include, without limitation, papaya, kiwi, strawberry, and orange.

Particularly suitable vitamin C derivatives according to the present invention are “ascorbyl phosphates”. The term ‘ascorbyl phosphate’ denotes metal salts of mono- and poly- phosphoric acid esters of ascorbic acid wherein the phosphorylated hydroxy group of the ascorbic acid molecule features one or more phosphoric acid (phosphate) units, and metal cations, e.g. sodium and/or magnesium or calcium ions, are also present. The term “poly” generally denotes 2 - 10, preferably 2 - 4, phosphate units. The ascorbyl phosphates may also be referred to in general as “ascorbyl (poly)phosphates” to embrace both mono- and polyphosphates. Typical ascorbyl phosphates for use in the present invention are L-ascorbic acid phosphate ester salts such as sodium ascorbyl phosphate, potassium ascorbyl phosphate, magnesium ascorbyl phosphate, calcium ascorbyl phosphate and sodium magnesium L-ascorbyl-2-monophosphate. The ascorbyl phosphates are essentially present in the form of a hydrate or a dihydrate. Commercially available ascorbyl phosphates comprise trisodium L-ascorbyl-2-monophosphate which is available as STAY-C^®50 from DSM Nutritional Products AG, (4303 Kaiseraugst, Switzerland) and magnesium L-ascorbyl phosphate (available from Showa Denko) and sodium magnesium L-ascorbyl-2-monophosphate. Preferred ascorbyl phosphates for all the purposes of the present invention are sodium or sodium magnesium or sodium calcium ascorbyl phosphate as well as mixtures thereof. Most preferred in all embodiments of the present invention is the use of trisodium L-ascorbyl-2- monophosphate dihydrate.

In one embodiment, the L-ascorbic acid or derivative thereof is a powdered solid. In an aspect of this embodiment, the L-ascorbic acid or derivative thereof does not dissolve significantly into the substantially anhydrous mixture of ingredients used in the present composition. In one aspect of this embodiment, the powdered L-ascorbic acid or derivative thereof is an ultra fine powder having an average particle size ranging from less than or equal to 100 microns, less than or equal to 75 microns, less than or equal to 50 microns, or less than or equal to 25 microns, less than or equal to 10 microns, or less than or equal to 5 microns. In one aspect, the present compositions include powdered L-ascorbic acid or a derivative thereof having an average particle size ranging from about 5 to 100 microns, from about 5 to 50 microns, from about 5 to 25 microns. In another aspect, the present compositions include powdered L- ascorbic acid or a derivative thereof having a particle size ranging from 5 to 100 microns, from 10 to 100 microns, from 10 to 50 microns, from 10 to 75 microns, from 10 to 25 microns, or from 5 to 10 microns.

The porous silica beads used according to the present invention may be prepared from sodium silicate by emulsion polymerization according to standard procedures such as e.g. via the sol- gel method. They silica beads may be used as such or may be further coated with a suitable coating agent such as e.g. a silicone oil. Suitable silicone oils include in particular non-volatile silicone oils such as dialkyl and alkyl aryl siloxanes as well as alkoxylated and / or aminated derivatives thereof, dihydroxypolydimethylsiloxanes and polyphenylalkylsiloxanes. Preferred silicone oils encompass dimethicone, dimethiconol, dimethicone copolyol, phenyl trimethicone, methicone, simethicone as well as mixtures thereof. Most preferably the silica beads are either uncoated or coated with dimethicone. Most advantageously, in all embodiments of the present invention the silica beads are not coated.

The particle size of the beads according to the invention (in volume %) is determined by a Coulter LS13320 or Malvern Mastersizer 2000 according to standard methods in the art. In number % the average particle size D_n50 ranges from 8 to 15 pm.

The specific surface area can be determined according to ISO 9277.

Particularly preferred in all embodiments of the present invention are beads having a particle size D_vO of greater than 0.3 pm, a D_V100 of less than 35 pm and a D_v50 selected in the range of 8 to 15 pm.

The oil absorption capacity (g/cc) refers to the amount of paraffin (in cc) absorbed by a specified amount (g) of the beads, i.e. the amount until the loose and dry powder disappears. It includes the oil absorption capacity of the dry particles existing between the inherent voids within and on the surface of the particles. The oil absorption capacity as referred to in the present invention is determined at 23°C by weighting 2g of the respective beads into a 20 ml beaker glass. Then liquid paraffin (Paraffinum Perliquidum PH. EUR. CAS 8042-47-5) is added. After addition of 4 to 5 drops of paraffin to the powder, mixing is performed using a spatula, and addition of paraffin is continued until conglomerates of oil and powder have formed. From this point, the paraffin is added one drop at a time and the mixture is then triturated with the spatula. The addition of oil is stopped when the loose and dry powder completely disappears and a highly viscous white to transparent homogeneous gel is obtained. The oil absorption capacity (cc/g) is then calculated by the volume of paraffin used (in cc) per g of the respective beads.

In all embodiments of the present invention the oil absorption capacity of the silica beads is preferably selected in the range of 1.2 to 2.0 cc/g, more preferably in the range of 1.3 to 1 .8 cc/g.

Suitable porous silica beads according to the present invention are e.g. obtainable as VALVANCE™ Touch 210 at DSM Nutritional Products Ltd Kaiseraugst.

Preferred anhydrous compositions according to the invention are skin care preparations or functional preparations intended for topical application.

The term "topical" is understood here to mean external application to keratinous substances, which are in particular the skin, scalp, eyelashes, eyebrows, nails, mucous membranes and hair.

According to an advantageous embodiment of the invention the topical anhydrous compositions constitute cosmetic composition and are intended for topical application to the skin.

As the compositions according to the invention are intended for topical application, they comprise a physiologically acceptable medium, that is to say 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.

The term cosmetically acceptable carrier refers to all carriers and/or excipients and/or diluents conventionally used in cosmetic compositions suitable for preparing anhydrous formulations.

Examples of skin care preparations are, in particular, light protective preparations (sunscreens), anti-ageing preparations, preparations for the treatment of photo-ageing, body/face oils, body/face butters, body/face balms, body lotions, body gels, treatment creams, skin protection ointments, skin powders, moisturizing gels, moisturizing sprays, face and/or body moisturizers, skin-tanning preparations (i.e. compositions for the artificial/sunless tanning and/or browning of human skin), as well as skin lightening preparations as well as BB and CC Creams.

Examples of functional preparations are cosmetic or pharmaceutical 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.

Preferably, the compositions according to the present invention are in the form of an oil, gel, paste, balm, lotion, creme, or aerosolized oil, gel, lotion or creme.

In a particular embodiment the compositions according to the invention are skin care preparations, such as (body) milks, lotions, hydrodispersions, foundations, creams, creamgels, serums, toners or gels.

In a further particular embodiment, the compositions according to the invention are not emulsions. Thus, the compositions preferably comprise less than 5 wt.-%, more preferably 3 wt.-%, most preferably less than 1 wt.-% of an emulsifier or a surfactant or both. Most preferably, the compositions according to the present invention do not include emulsifiers or surfactants, or both, in particular none which has been purposively added.

In accordance with the present invention, the compositions according to the invention may comprise further (active) ingredients such as ingredients for skin lightening; tanning prevention; treatment of hyperpigmentation; preventing or reducing acne, wrinkles, lines, atrophy and/or inflammation; chelators and/or sequestrants; anti-cellulites and slimming (e.g. phytanic acid), firming, moisturizing and energizing, self-tanning, soothing, as well as agents to improve elasticity and skin barrier and/or further UV-filter substances conventionally used in anhydrous compositions. The cosmetically active ingredients useful herein can in some instances provide more than one benefit or operate via more than one mode of action.

The topical cosmetic compositions of the invention can also contain usual cosmetic adjuvants and additives, such as preservatives/antioxidants, fatty substances/oils, organic solvents, silicones, thickeners, softeners, emulsifiers, sunscreens, antifoaming agents, moisturizers, aesthetic components such as fragrances, surfactants, fillers, sequestering agents, anionic, cationic, nonionic or amphoteric polymers or mixtures thereof, propellants, acidifying or basifying agents, dyes, colorings/colorants, abrasives, absorbents, essential oils, skin sensates, astringents, antifoaming agents, pigments or nanopigments, e.g. those suited for providing a photoprotective effect by physically blocking out ultraviolet radiation, or any other ingredients usually formulated into such compositions. Such cosmetic ingredients commonly used in the skin care industry, which are suitable for use in the compositions of the present invention, are e.g. 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.

If nothing else is stated, the ingredients, etc. mentioned in the following are suitable for topical 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 chosen by a skilled person in this field. The necessary amounts of such cosmetic and dermatological adjuvants and additives can, based on the desired product, easily be determined by the skilled person. The mode of addition can easily be adapted by a person skilled in the art.

Of course, one skilled in this art will take care to select the above mentioned optional additional ingredients, adjuvants 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.

In a particular advantageous embodiment, the compositions according to the invention comprise at least 40 wt.-% of oil, more preferably at least 50 wt.-% of oil, most preferably at least 60 wt.-% of oil, such as at least 70 wt.-% of oil, based on the total weight of the composition.

Suitable oils encompass all oils commonly used in cosmetic application. The term oil as used herein also encompasses waxes. Particular advantageous oils according to the present invention encompass triglycerides, alcohols, fatty acids, esters, hydrocarbons, silicones, ethers, essential oils, botanically derived oils and oily extracts.

Non-limiting triglycerides include those identified in other sections of this specification and those known to a person of ordinary skill in the art. Examples of such triglycerides include small, medium, and large chain triglycerides. In certain aspects, the triglyceride is a medium chain triglyceride (e.g., caprylic/capric triglyceride).

Further particular suitable oils according to the present invention encompass argan oil, almond oil, avocado oil, baobab oil, limnanthes alba seed oil, butyrospermum parkii butter, cera alba, coco nucifera oil, simmondsia chinensis seed oil, prunus amygdalus dulcis oil, glycine soja oil, olus oil, hydrogenated castor oil, ricinnus communis seed oil, helianthus annus seed cera, shorea robusta resin rhus verniciflua peel cera, jojoba esters, acacia decurrens flower cera and helianthus annuus seed cera, macadamia oil, caprylic/capric triglyceride, octydodecanol, isopropyl myristate, isopropyl palmitate, ethylhexyl palmitate, dibutyl adipate, glycol distearate, dicaprylyl ether, PPG-15 steary ether, ozokerite, beeswax, candelilla cera, copernicia cerifera cera, cetyl esters, cetearyl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, stearic acid, hydroxystearic acid, glyceryl stearate, C12-16 alcohol, coconut alkanes, palmitic acid, myristic acid, squalane, mineral oil, cera microcristallina, parafinum liquidum, petrolatum, hydrogenated polyisobutene, coco caprylate, coco-caprylate/caprate, C15-19 alkane, C12-15 alky benzoate, dimethicone, cyclopentasiloxane, cyclohexasiloxane as well as mixtures thereof.

Particularly advantageously the oil is selected from the group consisting of caprylic/ capric triglyceride, argan oil, butyrospermum parkii butter, spent grain wax, cera alba, heliantus annus seed cera, shorea robusta resin rhus verniciflua peel cera, jojoba esters, acacia decurrens flower cera and helianthus annuus seed cera as well as mixtures thereof.

In another particular embodiment, the compositions can include vitamin E. The vitamin E can be tocopherol or tocopheryl acetate. The compositions can include vitamin A. The vitamin A can be vitamin A palmitate, retinyl palmitate, or retinoic acid.

The topical compositions according to the invention in general have a pH in the range of 3 to 10, preferably a pH in the range of 4 to 8 and most preferably a pH in the range of 4 to 7.5. 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.

The amount of the topical 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.

Example:

The formulations as outlined in table 1 have been prepared and stored for 3 months at Room Temperature (RT), 40°C and 50°C. The colour stability was assessed by measuring the L* a* b* values at to and after 3 months storage.

The L* a* b* measurement determines a possible color change of formulations. The L* a* b* system is also referred to as the CIELAB system. It can be visualized as a cylindrical coordinate system in which the axis of the cylinder is the lightness variable L* ranging from 0% to 100%, and the radii are the chromaticity variables a*and b* Variable a* is the green (negative) to red (positive) axis, and variable J * is the blue (negative) to yellow (positive) axis.

Based on these values, the DE values can be calculated. The DE value reflects the difference of the overall color of a formulation over storage time.

The higher the DE value the stronger the difference of color.

In this example, DE values after 3 months storage versus to have been calculated.

Table 1

¹Silica beads SB 700 (Myoshi): Particle size 7 pm, Specific surface area 400-700m²/g ²Valvance Touch 210 (DSM Nutritional Products Ltd): Particle size 8-15 pm, Specific surface area 170m²/g

Surprisingly, the use of a Silica as defined by the invention showed a better color stability of the formula during the 3 months storage at the different temperatures.

Claims

1. An anhydrous composition comprising vitamin C or a derivative thereof and porous silica beads having a particle size a D_v50 selected in the range of 8 to 15 pm and a specific surface area in the range of 100 to 300 m²/g.

2. The anhydrous composition according to claim, characterized in that the oil absorption capacity of the porous silica beads is selected in the range of 1.3 to 1.8 cc/g.

3. The anhydrous composition according to claim 1 or 2, characterized in that the porous silica beads are uncoated.

4. The anhydrous composition according to any one of claims 1 to 3, characterized in that the vitamin C or derivative thereof is vitamin C.

5. The anhydrous composition according to any one of claims 1 to 4, characterized in that the amount of the porous silica beads selected in the range from 1 to 30 wt.-%, preferably in the range from 2 to 25 wt.-%, most preferably in the range from 5 to 20 wt.- %, based on the total weight of the composition.

6. The anhydrous composition according to any one of claims 1 to 5, characterized in that the amount of the vitamin C or a derivative thereof is selected in the range from 1 to 30 wt.-%, preferably in the range from 5 to 25 wt.-%, most preferably in the range from 7.5 to 20 wt.-%, based on the total weight of the composition.

7. The anhydrous composition according to claim 6, characterized in that the composition comprises at least 40 wt.-%, preferably at least 50 wt.-% of oil, most preferably at least 60 wt.-%, based on the total weight of the composition of at least one oil.

8. The anhydrous composition according to any one of claims 1 to 7, characterized in that the at least one oil is selected from triglycerides and botanical oils.

9. The anhydrous composition according to claim 7, characterized in that the oil is selected from the group of caprylic/ capric triglyceride, argan oil, butyrospermum parkii butter, spent grain wax, cera alba, heliantus annus seed cera, shorea robusta resin rhus verniciflua peel cera, jojoba esters, acacia decurrens flower cera and helianthus annuus seed cera as well as mixtures thereof.

10. The anhydrous composition according to any one of claims 1 to 9, characterized in that the composition is in the form of an oil, gel, paste, lotion, creme, or aerosolized oil, gel, lotion or creme.

11 . The anhydrous composition according to any one of claims 1 to 10, characterized in that the composition is substantially free of any emulsifier and/ or surfactant.

12. The anhydrous composition according to any one of claims 1 to 11 , characterized in that the composition further comprises an additional active ingredient.

13. The anhydrous composition of claim 12, wherein the additional active ingredient is vitamin E or a derivative thereof.

14. Use of porous silica beads having a particle size D_v50 selected in the range of 8 to 15 pm and a specific surface area in the range of 100 to 300 m²/g to reduce the discoloration of an anhydrous composition comprising vitamin C or derivatives thereof.

15. A method to reduce the discoloration of vitamin C or a derivative thereof in an anhydrous composition, said method comprising the step of adding to the anhydrous composition porous silica beads having a particle size D_v50 selected in the range of 8 to 15 pm and a specific surface area in the range of 100 to 300 m²/g and optionally appreciating the effect.