EP1635775A1

EP1635775A1 - Stable cosmetic emulsion with polyamide

Info

Publication number: EP1635775A1
Application number: EP04776319A
Authority: EP
Inventors: Tian X Wang; Carl C. Orr; Dexin Luo; Paul H. Marotta; Hernando Brieva; Shahan Nazar; Richard J. Castro
Original assignee: Color Access Inc
Current assignee: Color Access Inc
Priority date: 2003-06-09
Filing date: 2004-06-07
Publication date: 2006-03-22
Also published as: JP2007500749A; EP1635775A4; AU2004251705A1; CA2528605A1; AU2004251705C1; WO2005000252A1; AU2004251705B2; WO2005000252A9

Abstract

The present invention relates to a gelled cosmetic emulsion comprising an oil phase, an aqueous phase and a gelling system which contains at least one non-siloxane based polyamide in a sufficient amount to gel the emulsion. The polyamide can have an ester, acid, tertiary amide, or amine terminal end group. The emulsion is stabilized with a sugar-based emulsion stabilizer. The emulsions of the present invention are substantially transparent and when colorants are added the color is especially bright and clear. The emulsions are used in lipstick and mascara products as well as other gel and stick products.

Description

STABLE COSMETIC EMULSION WITH POLYAMIDE

Field of the Invention The invention relates to a cosmetic and personal care gel product that is gelled using a polyamide as a gelling agent in the oil phase. More specifically, the invention relates to a stable emulsion based compositions comprising a polyamide gelling agent in the oil phase.

Background of the Invention Many gelled cosmetic emulsions rely on gellants, waxes, fillers, heavy oils, and plasticizers for developing the structure to make a gel or stick composition. The structure built by these agents and materials give the product a balance of rigidity and firmness depending on the desired product. For example, the structure of lipstick is traditionally formed by a blend of wax and oil. However, these adjuvants, particularly waxes, have a disadvantage in that they contribute to opacity which diminishes the color of the pigment. The product therefore, has a dull, lackluster and pale appearance. To overcome this problem, enhanced amounts of pigment are added to the composition. Another drawback to the addition of wax is that it adheres poorly to the skin and compromises the longevity of wear of the product. For example, many commonly used cosmetic products, such as foundation, concealer, eyeliner, and lipstick, which contain these materials, are subject to fading, smudging, and flalcing. Such products also have a matte appearance that is not always desirable, addition, other adjuvants such as heavy oils can feel uncomfortable on the skin and have a distinct oily feel that may also be unpleasant. Therefore, to address these issues, alternative gelling agents have been sought and specific polyamides have been used to gel cosmetic products. The use of polyamides in cosmetic products has been known. For example, polyamide resins have been used in an anhydrous lipstick as disclosed in U.S. Patent No. 3,148,125. The method of making polyamides is disclosed in, for example, U.S. Patent No. 2,450,940. The polyamide resin has also been used in a deodorant or antiperspirant gel or stick as disclosed in U.S. Patent Nos. 4,275,054 and 5,500,209 because of its odor absorbing properties. None of these references, however, discloses an emulsion gelled with the non-siloxane based polyamide in combination with an ethylene oxide containing emulsion stabilizer. The stick, soft gel, or clear gel compositions disclosed in, for example,

U.S. Patent Nos. 6,051,216, 5,603,925, and 5,998,570 and European Patent Application Nos. EP 1 068 855 and EP 1 068 856 are unstable emulsions, single phase compositions, or use a siloxane based polyamide. The siloxane polyamides have been developed because of their alleged ability to, in addition to gel the composition, provide a less tacky composition. However, the siloxane based polyamides are not compatible with a wide variety of oils, for example, hydrocarbon oils, and because they are less tacky, their adhesion properties are significantly impaired, making them less desirable in products that require minimally an initial phase of adhesion during the application of the product to the skin or hair. Therefore, it is desirable to use other polyamides in cosmetic emulsion systems because products such as mascara, for example, need a certain degree of tackiness when being applied but afterwards, upon drying the tackiness of the mascara needs to transition to a comfortable feel on the lashes. Until now, it has not been known to fine-tune the tacky nature of a cosmetic dual phase product containing the polyamide resin as a gelling agent. The compositions heretofore have either been too tacky or not tacky enough for products that need to exhibit varying degrees of tackiness over time and during their use. Thus, the emulsions of the present invention gelled with a non-siloxane polyamide has heretofore not been known. A need for a stable cosmetic emulsion gelled by a polyamide resin system that adheres to the skin and functions in a variety of cosmetic emulsion systems still remains. The emulsion system of the present invention is also desirable because it allows water-soluble ingredients to be incorporated into the product containing the emulsion.

Summary of the Invention The invention relates to gelled cosmetic compositions, and specifically, oil-in-water or water-in- oil emulsions, which comprises at least one sugar-based emulsion stabilizer and at least one non- siloxane based polyamide resin. The prepared emulsions, while they are not themselves clear, are substantially transparent after application to the skin. Use of the polyamide resin as a gelling agent per se is not new, however, its incorporation into the color compositions of the present invention containing, for example, alkylglucosides with about 8 to 16 carbon atoms, as an emulsion stabilizer is surprising. The cosmetic emulsions of the present invention also comprise a color component present in an amount greater than about 2.0 percent by weight of the composition. The ability to gel a color cosmetic emulsion with the polyamide resin as the primary gelling agent is particularly challenging because the polyamide is very polar and emulsions containing large quantities of polyamide tend to be tacky and are difficult to stabilize in the presence of colorants. The present invention also includes methods of making the emulsion systems of the present invention which can include multiple emulsion systems. The emulsion products are especially transparent and transfer resistant when they are applied to the skin and allowed to dry. The compositions containing these emulsions have an enhanced brightness and clarity with respect to their color on the skin after application thereon due to the transparent film that adheres to the skin without being tacky. The emulsion systems of the present invention dry faster than other polyamide containing systems, and are long wearing even after the water evaporates. In addition, gels and sticks made with the emulsion system of the present invention are less brittle, experience a substantial lack of syneresis, and have a creamier texture because the three-dimensional structure formed by the polyamide resin is interrupted partially by the water phase.

Detailed Description of the Invention The gelling system of the present invention is at least one non-siloxane based polyamide resin and at least one sugar-based emulsion stabilizer. The polyamide resin as used herein is defined to be a polymer having recurring units of amide groups as an integral part of the main chain of the polymer and a terminal end group of acid, amine, or ester. The polyamide gelling agent can be used to produce a soft gel or a stick composition in an emulsified system. Therefore, it is preferable that the polyamide resin not be extensively cross-linked by hydrogen bonds. The polyamides are characterized as thermoplastics as opposed to thermosets. Based on complex fatty acids, esters, and amines, the polyamides used in the present invention are water insoluble. The polyamide is available in a solid form of 100 percent polyamide or as a percentage of polyamide in mineral oil, usually about 80 percent. Examples of commercially available polyamides which are useful in the present invention are Versamid 1655, by Cognis (formerly Henkel Corporation), Ambler, PA which is prepared from dimers of Ci₈ unsaturated fatty acids which are partially hydrogenated, azelaic acid (nonanedioic acid), ethylene diamine, hexamethylene diamine and stearic acid, Unirez and Uniclear, a series of polyamides from Arizona Chemicals Corporation, Jacksonville, FL or Elvamide from DuPont, DE a teφolymer of nylon 6, nylon 66, and nylon 610. Additional polyamides are disclosed in U.S. Patent Nos. 4,820,765, 5,719,255, 5,807,968, 6,111,055, and 6,054,517, the contents of which are incorporated herein by reference. These references fail to recognize the ability to make a stable emulsion product, and thus, fail to recognize the benefits of a water containing cosmetic emulsion incoφorating a polyamide gelling agent and an Cι_₅ alkylene oxide containing surfactant. For example, U.S. Patent No. 5,783,657 is an anhydrous system, and U.S. Patent No. 5,998,570 discloses that water is preferably removed when forming the polyamide, and compositions comprise a nonaqueous liquid as solvent, preferably a low-polarity liquid. The water phase of the cosmetic emulsion of the present invention comprises about 0.05 to 90.0 percent, and preferably 1.0 to 70.0 percent by weight of the emulsions. While the water phase is primarily water, it can take the form of a variety of aqueous solutions such as rose water, tea, and the like. Therefore, the water phase is well suited to deliver water-soluble actives and other water dispersible agents, such as for example, film-formers, surfactants, and emollients. The non-aqueous phase can include any type of cosmetically acceptable volatile or non-volatile oil including oily esters depending on the application of the product and the degree of gelling desired. Examples include, but are not limited to, hydrocarbon oil such as isododecane, silicone oils such as cyclomethicone, polyorganosiloxanes such as phenyl-methicones and dimethicones, castor oil, and hydrogenated vegetable oil. Preferably, in a mascara, the oil is volatile, such as for example, a volatile hydrocarbon oil or silicone oil; while a lipstick is a mixture of both volatile and non- olatile oils and the amounts of each depends on the type of lipstick desired. Suitable non-volatile hydrocarbons include, but are not limited, to isoparaffins, squalane, or petrolatum, or mixtures thereof. Regardless of the amount of volatile and/or non-volatile oil, the entire oil phase is present in an amount of about 5 to about 95 percent, preferably 10 to 80 percent by weight of the composition, and more preferably about 10 to 40 percent. The emulsions of the present invention are prepared by adding a gelling sufficient amount of the polyamide resin to the oil phase. The amount of polyamide resin used in the present invention is from about 1 to about 90 percent, preferably about 2 to 40 percent by weight of the composition. The amount of polyamide is a "gelling sufficient amount" and as used herein means an amount of polyamide in the oil phase to bring about an increase in the viscosity of the emulsion; preferably the viscosity increases by 25 percent, more preferably by 50 percent, and most preferably by 75 percent. This increase in viscosity is sufficient to form a thickened gel or form a solid having the hardness of a stick as the thickness of gels and sticks are known in the art. At lower levels, the polyamide aids in forming a gel, whereas, higher levels are used to make stick products. Although it is difficult to quantitatively distinguish between a cosmetic gel and stick, a gel is, in general, more viscous than a liquid; but, it is not as rigid or self-supporting as a stick. It is accepted by one of ordinary skill in the art that a gel maintains a certain degree of deformity, whereas, the stick is free-standing and is substantially rigid. Another component of the present invention is the emulsion stabilizer having a silicone backbone, containing a sugar based moiety, and being free of alkylene oxide units. Thus, the term sugar-based emulsion stabilizer as used herein refers to stabilizers that are based on saccharide and/or glyceryl moieties that have a silicone backbone and are free of alkylene oxide units. The sugar-based emulsion stabilizer can be non-ionic, cationic, anionic, or amphoteric. The nonionic sugar-based emulsion stabilizers that may be included in the present invention are selected from the group consisting of alkyl polyglycosides, alkyl glucose esters, aldobionamides, gluconamides, glyceramides, glyceroglycolipids, polyhydroxy fatty acid amides (glucamides), and mixtures thereof. Particularly, the Glucopon® and Plantaren® series of products from Henkel Corporation (Ambler, PA) are useful emulsion stabilizers in the present invention. Cationic sugar-based emulsion stabilizers are, for example, a cationic sugar surfactant containing at least one hydrocarbon group with 6-24 carbon atoms and at least one quaternary ammonium group where at least one substituent is an alkyleneoxy containing group which is connected to a saccharide residue by a glycosidic bond, as those disclosed in U.S. Patent Nos. 6,503,880, 6,432,907, and 5,773,595. Anionic and amphoteric surfactants are, for example, acylsucrose derivatives such as those disclosed in U.S. 6,184,196. Preferably, the emulsion stabilizer is one that has a certain ratio of sugar moiety to siloxane units (e.g., about 0.5 to 10 percent). It is suφrisingly discovered with the present invention that a stable emulsion comprising the polyamide resin as the gelling agent can be achieved. Although, it is known to gel oil based systems with the polyamide resin, until now, these systems have primarily been single phase, i particular, stable dual phase compositions, and especially, stable cosmetic emulsions, have not been known to contain a non-siloxane based polyamide gelling agent as they experience stability problems. The non-siloxane based polyamides are known to be tacky. Therefore, their use is limited and most appropriate for coatings, paints, inks, epoxies, adhesives and the like. Their use in cosmetics has also been limited primarily to single phase systems such as anhydrous lipsticks and deodorants. However, the ability to formulate these types of cosmetics is quite different than the challenges presented by formulating a cosmetic emulsion, especially a stable emulsion in a color cosmetic. The method of preparing the emulsions of the present invention entails basic steps known in the art for preparing emulsions. The non-siloxane based polyamide and the other ingredients in the oil phase may be prepared separately but are combined or added to the oil phase before combining with the aqueous phase to make the emulsion. The present emulsions, containing the gelling system, can be prepared with the polyamide as the primary gelling agent in the gelling system or with other naturally derived or synthetic gellants or thickening agents, known and commonly used by one skilled in the art, such as for example, cetyl dimethicone copolyol, acrylates copolymer, dextrin fatty acid esters, carbopols, dibenzyl monosorbitol acetal, polyethylene wax, beeswax, carnauba wax, candilla wax, bayberry wax, rice wax, acylglutamic acid diamide, esters, fatty alcohols, and the like can be used in the oil phase of the present invention. Preferably, however, the compositions of the present invention are wax-free. Suφrisingly, it has been found that the presence of a sugar-based surfactant stabilizes the emulsion system containing the polyamide as the gelling agent. Considering the difficulty of formulating a cosmetic emulsion, and in addition, the difficulty of incoφorating the non-siloxane polyamide gelling agent in the emulsion, it is suφrising that greater stability is achieved using the sugar-based emulsifier. While not wishing to be bound to any particular theory, it is believed that stability and enhanced gelling is achieved with the sugar-based emulsifier because it is capable of hydrogen bonding with the polyamide gelling agent. The emulsion stabilizer can be a single surfactant or a combination of surfactants. The emulsion stabilizers aid in rendering the polyamide resin compatible in the dual phase system, and enhance not only the stability of the emulsion containing the non-siloxane based polyamide resin as the gelling agent, but may also affect the gelling activity of the polyamide resin. Because the polyamide resin is water-insoluble when used as a gelling agent in the emulsion, with commonly used cosmetic oils stability problems are known to arise. In particular, agglomeration occurs or the phases separate in a short time, for example, in about few hours to about a few months. However, the present invention has discovered that this problem can be remedied with the emulsion stabilizer which can be present in the oil phase, the water phase, or both. As a result, the polyamide resin is rendered compatible in the emulsion stabilizer at room temperature and/or at elevated temperature, hi addition, the emulsion is stable for about 6 months, preferably about 1 year, The active ingredients incoφorated in the emulsions of the present invention having a polyamide as the gelling agent preferably do not include antiperspirant actives especially those that are acidic metal salts. Examples of actives that can be used in the present invention include, but are not limited to, sunscreen actives, whitening agents, such as for example, antioxidants, antimicrobials, analgesics, anesthetics, anti-acne agents, antidermatitis agents, antipruritic agents, anti-inflammatory agents, antihyperkeratolytic agents, anti-dry skin agents, antipsoriatic agents, antiseborrheic agents, antiaging agents, antiwrinkle agents, self-tanning agents, wound-healing agents, corticosteroids, or hormones. The incoφoration of the active in the formulation is determined by its solubility and/or stability in combination with non-siloxane polyamide gelled emulsions of the present invention. The term "sunscreen" as used herein refers to any material which is capable of protecting skin from ultraviolet radiation having a wavelength of from about 280 to about 400 nm, by effectively absorbing such radiation, and/or reflecting or scattering such radiation away from the surface of skin. Examples of sunscreens with which the compositions of the present invention can be combined in this context are titanium dioxide, zinc oxide, benzophenones, octyl dimethyl PABA, amyldimethyl PABA, octyl methoxycinnaniate, 2-ethoxy p-methoxycinnamate, oxybenzone, homosalate, phenyl salicylate, avobenzene, glyceryl p-arninobenzoate, ethyl-p-glycosylimido benzoate and the like, hi a formulation, the sunscreen agent is used in the amounts normally used for that agent. Preferably, the active is non- acidic. The selection of the mode of delivery for additional active ingredients, however, is limited to the mode of delivery chosen for the compositions. The cosmetic product can be, but is not limited to, a lipstick, lip gloss or other lip product, a solid, or gel fragrance or perfume product, cleanser, toner, an eye product, such as a mascara, eyeliner or an eye gel, compact emulsion foundation, concealer, moisturizing skin lotion or cream, hair stick or gel, and any other makeup, or skin or sun care product that is in a gel or stick form. In a preferred embodiment, the product is a mascara or lipstick product. The base of the lipstick or mascara has sufficient clarity such that the color is bright and luminous, i.e., they are transparent, semi-transparent, or translucent. The products of the present invention are long wearing, non-smudging, and non-flaking. Further, the clear cosmetic product can contain other optional components as long as they do not interfere with the gelling properties of the polyamide. Examples include, but are not limited to, one or more preservatives such as, for example, propyl paraben, butyl paraben, mixtures thereof, or isoforms thereof, as well as butyl hydroxy toluene or butyl hydroxy anisol (BHT or BHA); fragrances (such as pinene); flavoring agents; wateφroofing agents (such as PVP/eicosene copolymer); surfactants, such as silicone copolyols or fatty acid glycerol esters; and oil-soluble actives, such as tocopherol and its derivatives or retinol and its derivatives; and the like. The invention is further illustrated by the following non-limiting examples.

EXAMPLES Lipstick with Polvamide Gelling As ^rent

The lipstick is prepared by combining Phase I ingredients together and heating them to about 99°C for about 2 hours. Phase II ingredients are combined and ground in a homogenizer at about 3000 φm for about 10 minutes. The homogenized Phase II ingredients are added to Phase I and together the combination is heated to 80°C. Phase HI is added to the combined Phase I and Phase II ingredients at a temperature of about 80°C by mixing. Adjust pH of combination with to about 7.35. The lipstick can be made by pouring the combination into a lipstick mold or by following any known technique for making a lipstick.

Claims

What we claim is:

1. A cosmetic composition comprising an emulsion of an aqueous phase and a non-aqueous phase, and a gelling system of at least one sugar-based emulsion stabilizer and at least one non- siloxane based polyamide resin.

2. The composition of claim 1 wherein the composition further comprises a color component present in an amount greater than 2.0 percent by weight of the composition.

3. The composition of claim 2 wherein the color component is present in an amount greater than

5.0 percent by weight of the composition.

4. The composition of claim 1 wherein the polyamide resin further comprises a terminal end group selected from the group consisting of ester, amine, tertiary amide, and acid.

5. The composition of claim 1 wherein said polyamide resin is present in a gelling sufficient amount.

6. The composition of claim 5 wherein said polyamide resin is present in an amount of about 1 to 90 percent by weight of the composition.

7. The composition of claim 1 wherein said emulsion further comprises about 0.01 to about 10 percent surfactant.

8. The composition of claim 7 wherein said emulsion stabilizer is selected from the group consisting of non-ionic, cationic, anionic, and amphoteric sugar-based surfactants.

9. The composition of claim 1 wherein said non-aqueous phase further comprises volatile oil.

10. The composition of claim 2 in the form of a lipstick.

11. The composition of claim 10 further comprising an alkanolamide of a fatty acid.

12. The composition of claim 2 in the form of a mascara.

13. The composition of claim 12 wherein said emulsion is wax-free. 10

14. A stable cosmetic emulsion comprising a colorant component present in an amount greater than about 2.0 percent by weight of the composition, an aqueous phase, and an oil phase wherein the aqueous phase contains at least a gelling sufficient amount of at least one non-siloxane based polyamide resin having a terminal end group selected from the group consisting of amine, acid, tertiary amide, and ester, and at least one non-ionic, cationic, anionic, or amphoteric sugar-based surfactant

15. The emulsion of claim 14 wherein said emulsion is wax-free.

16. The emulsion of claim 15 further comprising a colorant component present in an amount greater than about 5.0 percent.

17. The emulsion of claim 16 further comprising one or more active ingredients.

18. The method of making a cosmetic emulsion comprising the steps of adding a gelling sufficient amount of a non-siloxane based polyamide resin to at least an aqueous phase, and dispersing the aqueous phase with a non-aqueous phase, at least one sugar-based emulsion stabilizer, and a colorant component present in an amount greater than about 2.0 percent. ,

19. The method of claim 18 wherein the step of dispersing further comprises the aqueous phase as the dispersant phase.

20. The method of claim 19 wherein the polyamide further comprises a terminal end group selected from the group consisting of ester, amine, tertiary amide and acid.

21. The method of claim 20 wherein the emulsion is wax-free.

22. The method of claim 21 wherein the emulsion is added to a formulation for a mascara or a lipstick.

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