Patent Application
20130017160
The present invention relates to a thickening additive composition comprising: (A) one or more substantially anhydrous solvent systems; and (B) a thickening agent, wherein the thickening agent comprising a strongly swellable, lightly to moderately crosslinked polyvinylpyrrolidone. The polyvinylpyrrolidone typically has an aqueous gel volume of about 15 to 150 mL/gm of polymer and/or a Brookfield viscosity in 5% aqueous solution of at least 10,000 cP at 25° C. Particularly, the present invention relates to the additive compositions meant to be added to the base composition to make personal care products for skin care, oral care, sun care, hair care and toiletries. More particularly, personal care compositions that are difficult to thicken include those that are substantially anhydrous or have low pH. The additive compositions described herein are intended to maintain desired viscosity, rheology and stability characteristics of the base composition.
The personal care category consists of a broad array of products that are fabricated in varied formulation types such as foundations, concealers, lipsticks, lotions, suncare, sunless tanning, face creams, liquid soaps, mascaras, and other color cosmetics and delivery systems. These products provide a wide range of perceived efficacies to the consumer, from “light” daily care products to therapeutic ointments and creams.
Creams, lotions and gels are frequently used topically for cosmetic or pharmaceutical use. Whether used to deliver a drug or as a skin moisturizer, the consistency and feel of the composition are important to the commercial success of the product. Stabilized compositions are important in formulating such products.
Aqueous cosmetic compositions often require thickeners. Thickeners which have been previously used in formulating creams, lotions and gels include several commercially available acrylic acid polymers and polyacrylamides. However, to obtain a target viscosity the manufacturers of these thickeners consistently recommend that the thickener be dispersed in water and then neutralized. Thus, in aqueous formulation systems acrylic acid polymers and polyacrylamides have been found quite useful and acceptable.
Unlike their aqueous counterparts, anhydrous systems are especially difficult to thicken and also may present formulation stability problems. Examples of various anhydrous systems that are difficult to thicken and stabilize include alcohols, esters, glycols, acids, oils, and hydrocarbons.
Many thickeners, also known as rheological modifiers, are characterized as natural, modified-natural and synthetic. Natural rheological modifiers include guar gum, pectin, casein, carrageenan, xanthan gum and alginates. Modified rheological modifiers include chemically modified celluloses, most particularly methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and carboxymethylcellulose. Synthetic thickeners include derivatives of the former categories, and also polyvinyl alcohols, polyacrylamides, polyvinylpyrrolidones, various polyethers, their copolymers as well as polyacrylic acids and their salts.
U.S. Pat. No. 5,422,112 discloses a thickener system including a combination of xanthan gum, magnesium aluminum silicate and polyacrylamide. The compositions are said to be particularly effective at low pH used especially for thickening alpha-hydroxy carboxylic acids and salts thereof.
Similarly, U.S. Pat. No. 5,874,095 claims an enhanced skin penetration system comprising a nonionic polyacrylamide of high molecular weight, for improved topical delivery of drugs at low pH.
Further, U.S. Pat. No. 6,774,100 reports an anhydrous composition having a viscosity greater than 1000 centipoise (cP) maintained with a thickening agent selected from the group consisting of acrylic acid polymers and polyacrylamides.
Some acrylic acid thickeners are described in U.S. Pat. Nos. 2,883,351; 2,956,046; 3,035,004; and 3,436,378.
Polyvinylpyrrolidone and its salts and esters being used as rheology modifier or as thickener in various personal care products are described in U.S. Pat. Nos. 6,436,380; 6,197,281; 6,333,039; 6,685,952; and 7,108,860.
U.S. Patent Application Publication No. 2003/0118620 discloses a thickening system for cosmetic compositions of low pH, comprising polysaccharide and taurate copolymer.
Nonetheless, acrylic, polyacrylamide, and silicone elastomers are widely acceptable thickener systems for aqueous system; there still exists a need for thickening a substantially anhydrous composition, which provides desired viscosity and stability.
The present application is directed to personal care composition with improved thickening characteristics and associated stability. In accordance with certain aspects, one or more of the following benefits may be realized:
Accordingly, certain embodiments described herein may provide a thickening additive system and thus thickened personal care composition of sufficient aesthetic viscosity and skin feel.
In accordance with one aspect of the present invention, a thickening additive composition is provided wherein the composition comprises: (A) one or more substantially anhydrous solvent systems; and (B) a thickening agent, wherein the thickening agent comprises a strongly swellable, lightly to moderately crosslinked polyvinylpyrrolidone.
The polyvinylpyrrolidone in the thickening agent has an aqueous gel volume of about 15 to 150 mL/gm of polymer and/or a Brookfield viscosity in 5% aqueous solution of at least 10,000 cP at 25° C.
The substantially anhydrous solvent system typically comprises 15% or less of water, and it may include esters, glycols, acids, oils, emulsions and hydrocarbons; used either alone or in combination. The substantially anhydrous solvent system may further comprise other chemicals selected from the group consisting of salts, electrolytes, acids, bases, surfactants, cations, di-hydroxyacetone, and combinations thereof.
The additive composition may be added to a base composition to make personal care products, such as products for skin care, hair care, sun care, oral care and toiletries.
In accordance with another aspect of the invention, a personal care composition is provided comprising: (i) a personal care active; (ii) a cosmetically or dermatologically-acceptable carrier; and (iii) a thickening additive composition comprising (A) one or more substantially anhydrous solvent systems; and (B) a thickening agent.
Examples of personal care compositions include shampoos, body wash products, shaving cream, hand soap, bubble bath, bath gel, after-shave lotions, creams, moisturizers, sunscreens, liquid soaps, color cosmetics, acid peels, perms, hair color, sunless tanning and conditioners. The cosmetically or pharmaceutically acceptable carrier may be selected from the group consisting of a cream, a lotion, an emulsion, an oil, a spray, a gel, an aerosol, an aqueous or hydroalcoholic solution, a suspension, a powder, a serum, an ointment, a shampoo, a gel, a paste and a mousse.
In accordance with certain embodiments, the thickening additive composition comprises from about 0.5% to about 10% by weight of the composition, more particularly from about 1% to about 6% by weight of the composition.
Personal care compositions can be produced wherein the composition exhibits a viscosity of at least 7000 cP at 3% concentration of thickening additive composition, and a viscosity of at least 30,000 cP at 5% concentration.
The composition may further comprise at least one adjuvant such as a diluent, a lubricant, a surfactant, a flowing agent, an emollient, humectants, an antioxidant, a preservative, an antimicrobial agent, an antibiotic and an emulsifier.
The composition according to the present invention can be used in a great number of treatments, notably cosmetic and dermatological. They can be fabricated in the form of cosmetic compositions used for skin, lips and/or hair treatment, protection, care and make-up removal and/or cleaning, as well as for make-up applications on skin, lips, eye lashes and/or the body. The personal care composition may be formulated in the form of liquid, gel, semi solid, or solid.
Thickening additive compositions in accordance with some embodiments are effective in imparting improved viscosity, stability characteristics to the personal care composition and also maintain viscosity after exposure to high shear.
The thickening additive composition may increase and maintain the viscosity of compositions comprising acids. More particularly, the disclosed thickening additive composition may provide thickening to low pH personal care compositions.
Compositions disclosed herein may also provide stability to an anhydrous sun screen system. More particularly, the compositions may thicken the anhydrous sunscreen system and provide water resistance in sunscreen formulations.
The invention relates to improved thickening systems for cosmetic compositions, particularly to substantially anhydrous compositions, such as anhydrous creams, lotions and gels useful in the personal care industries. More particularly, this disclosure relates to a thickening additive composition comprising a substantially anhydrous solvent system, and a thickening agent. The additive composition enables the formulator to thicken non-aqueous systems creating anhydrous products and is applicable to a wide range of materials including esters, glycols, acids, mineral oil, vegetable oils, sunscreens and hydrocarbons; used either alone or in combination.
The present invention involves a strongly swellable, moderately crosslinked polyvinylpyrrolidone constitute a thickening system which can easily be utilized for formulating various personal care products. More particularly, the thickening systems are useful in personal care compositions with low pH or high acid content; sunscreens; emulsions; and oils. The resulting products showed improved viscosity and thickening properties, without stability issues.
The term “thickening additive composition” as used herein refers to a composition capable of providing thickness and rheological properties, particularly to substantially anhydrous solvent systems.
The term “personal care composition” as used herein refers to composition whose function is to maintain, restore or improve the appearance of skin and hair. Specific examples of personal care compositions include, but are not limited to, compositions with low pH or high acid content; sunscreens; emulsions; and oils.
Accordingly, a first element of the thickening additive composition according to the present invention is the thickening agent comprising strongly swellable, lightly to moderately crosslinked polyvinylpyrrolidone as described in commonly assigned U.S. Pat. Nos. 5,312,619 and 5,139,770, the contents of which are hereby incorporated by reference. The term “strongly swellable, lightly to moderately crosslinked PVP”, unless otherwise noted, specifically refers to polymer essentially consisting of lightly- to moderately-crosslinked poly(N-vinyl-2-pyrrolidone) having at least one of the following characteristics: (1) an aqueous swelling parameter defined by its gel volume from about 15 mL/g to about 300 mL/g, more particularly from about 15 mL/g to about 250 mL/g, and in other cases from about 15 mL/g to about 150 mL/g, or (2) a Brookfield viscosity of 5% crosslinked PVP in a liquid carrier comprising water at 25° C. of at least 2,000 cP, more particularly of at least about 5,000 cP, and in certain cases of at least about 10,000 cP. Disclosure for these parameter ranges is provided in U.S. Pat. No. 5,073,614 (incorporated herein by reference) and in Shih, J. S., et al. (1995). Synthesis methods for the crosslinked PVP are disclosed in a number of references, including U.S. Pat. Nos. 5,073,614; 5,654,385; and 6,177,068, the contents of which are hereby incorporated by reference. It is appreciated by a polymer scientist skilled in the art that the method of synthesis is immaterial, inasmuch as the produced polymer achieves at least one of the above defined parameters.
For example, U.S. patent '614 discloses different crosslinkers and crosslinker amounts that yield crosslinked PVP suitable for the present invention. The effect of crosslinker amount on swell volume and viscosity is graphically presented in Shih, J. S., et al. (1995). Thus, the crosslinked PVP may be produced by the precipitation polymerization method of the '614 patent, by the hydrogel method described in the '385 patent, or by the non-aqueous, heterogeneous polymerization method of the '068 patent. Certainly, other techniques are contemplated to synthesize this polymer, provided the product meets the aqueous swelling parameter and Brookfield viscosity requirements.
Final product viscosities may slightly vary for compositions containing crosslinked PVP made by these different methods. Nonetheless, these variations are within the scope of the invention, as the crosslinked PVPs thicken low pH compositions.
Unless otherwise specified, “strongly swellable, lightly to moderately crosslinked PVP” does not refer to swellable but water-insoluble crosslinked PVP, such as the type sold into commercial trade under the trade name Polyclar® by International Specialty Products, which differs from the above described crosslinked PVP.
Commercially available examples of strongly swellable, lightly to moderately crosslinked PVP include, but are not limited to, ACP-1120, ACP-1179, and ACP-1180, available from International Specialty Products (Wayne, N.J.).
As known to those skilled in the art, the precise amount of thickeners can vary depending upon the consistency and thickness of the composition which is desired. With reference to present invention, thickening agent/thickeners/rheology modifiers may be used in the amounts from about 0.01 to about 10% by weight of the composition. More particularly, the amount may range from 1% to about 6% by weight of the composition.
In accordance with certain embodiments, the compositions have a viscosity greater than about 7000 centipoise (cP) at 3% concentration when measured using a Brookfield viscometer at room temperature. It should be understood that all viscosities referred to herein are measured in this manner. In accordance with particular embodiments, the composition has a viscosity greater than 30,000 cP at 5% concentration. In particularly useful embodiments, the composition has a viscosity in the range of from about 1000 to about 100,000 centipoise. In other embodiments, the compositions have a viscosity in the range of about 10,000 cP to about 100,000 cP.
The substantially anhydrous solvents useful in the present compositions include esters, glycols, acids, oils, emulsions, and hydrocarbons; used either alone or in combination.
Useful glycols include, but are not limited to, propylene glycol, butylene glycol, diethylene glycol, dipropylene glycol, polyethylene glycol, glycerin, and mixtures thereof.
Useful oils include, but are not limited to, castor bean oil, castor oil, rapeseed oil, soybean oil, palm kernel oil, babassu kernel oil, coconut oil, and mixtures thereof.
Useful acids include, but are not limited to, alpha and beta hydroxy acid, alpha hydroxyethanoic acid, alpha hydroxyoctanoic acid alpha hydroxycaprylic acid, ascorbic acid, adipic acid, citric acid, caprylic acid, capric acid, glycolic acid, lactic acid, lauric acid, malic acid, mixed fruit acids, myristic acid, palmitic acid, salicylic acid, stearic acid, linoleic acid, linolenic acid, ricinoleic acid, oleic acid, elaidic acid, erucic acid, and mixtures thereof.
The substantially anhydrous solvent system may further comprise other chemicals such as salts, electrolytes, acids, bases, surfactants, cations, and di-hydroxyacetone.
The present application discloses compositions containing a “substantially anhydrous solvent system” together with a thickening agent, defined hereafter. The composition constitutes an additive composition which can easily be added to a base composition to make personal care products such as those for skin care, hair care, sun care, oral care and toiletries. The blended inventive product results in a thickening composition with equal or improved viscosity and thickening properties.
Within the context of the present invention, the resulting personal care composition is an anhydrous preparation, which will be understood by those of skill in the art, to mean that water has not been added as a component. However, water may be present in the composition via its presence in the formulation components and absorption from the atmosphere.
The compositions which include chemicals such as salts, electrolytes, acids, bases, surfactants, cations, and di-hydroxyacetone may have water, if any, in less than 15%, more particularly less than 10% and even more particularly less than 5%.
In another aspect, there is provided a personal care composition comprising a personal care active; (ii) a cosmetically or dermatologically-acceptable carrier; and (iii) thickening additive composition comprising (A) one or more substantially anhydrous solvent systems; and (B) a thickening agent, wherein the thickening agent comprises a strongly swellable, moderately crosslinked polyvinylpyrrolidone having an aqueous gel volume of about 15 to 150 mL/gm of polymer and a Brookfield viscosity in 5% aqueous solution of at least 10,000 cP at 25° C.
Examples of personal care compositions include, but are not limited to, shampoo, body wash products, shaving cream, hand soap, bubble bath, bath gel, after-shave lotions, creams, moisturizers, sunscreens, liquid soaps, color cosmetics, acid peels, perms, hair color, sunless tanning and conditioners.
In most embodiments, the personal care products of the invention comprise a personal care active ingredient which provides benefit to the user's body, e.g., to the hair or skin. Such materials are in general well-known to those persons of ordinary skill in the relevant personal care composition art, and may include moisturizing agents, antiperspirants, anti-bacterials, sunscreen agents, insect repellents, cleaning agents, hair conditioning agents, hair styling agents, anti-dandruff agents, hair growth promoters, hair dyes and pigments, anesthetics, lubricants, spermicides, soaps and perfumes.
The active personal care ingredients (and other ingredients of the personal care compositions as described below) can be categorized by the benefit they provide or by their postulated mode of action. However, it is to be understood that the active personal care ingredients (and other ingredients) useful herein can in some instances provide more than one benefit or operate via more than one mode of action. Therefore, classifications herein are made for the sake of convenience and are not intended to limit the active to that particular application or applications listed.
Examples of substances that may suitably be included in the personal care products according to the present invention as active personal care ingredients include the following:
(1) perfumes and fragrances, which give rise to an olfactory response in the form of a fragrance, and deodorant perfumes which, in addition to providing a fragrance response, can also reduce body malodor;
(2) skin coolants, such as menthol, menthyl acetate, menthyl pyrrolidone carboxylate, N-ethyl-p-menthane-3-carboxamide and other derivatives of menthol, which give rise to a tactile response in the form of a cooling sensation on the skin;
(3) emollients, such as isopropylmyristate, silicone oils, mineral oils and vegetable oils, which give rise to a tactile response in the form of an increase in skin lubricity;
(4) deodorants other than perfumes, whose function is to reduce the level of or eliminate micro flora at the skin surface, especially those responsible for the development of body malodor, including precursors of deodorants;
(5) antiperspirant actives, whose function is to reduce or eliminate the appearance of perspiration at the skin surface;
(6) moisturizing agents, that keep the skin moist by either adding moisture or preventing from evaporating from the skin;
(7) cleansing agents, that remove dirt and oil from the skin;
(8) sunscreen active ingredients that protect the skin and hair from UV and other harmful light rays from the sun;
(9) hair treatment agents that condition hair, clean hair, detangle hair, act as styling agents, anti-dandruff agents, hair growth promoters, hair dyes and pigments, hair perfumes, hair relaxers, hair bleaching agents, hair moisturizers, hair oil treatment agents and antifrizzing agents;
(10) oral care agents, that clean, whiten, deodorize and protect the teeth and gum;
(11) denture adhesives, that provide adhesion properties to dentures;
(12) beauty aids, such as powders, pigments and colorants; and
(13) medicinal agents.
Further examples of skin benefit agents include abrasives; absorbents; aesthetic components such as opacifying agents and pearlescent aids such as ethylene glycol distearate and TiO2 coated mica; essential oils; skin sensates; cosmetic and drug astringents such as clove oil, menthol, camphor, eucalyptus oil, eugenol, menthyl lactate and witch hazel distillate; anti-acne agents such as resorcinol, sulfur, salicylic acid, benzoyl peroxide, erythromycin and zinc; anti-caking agents; antimicrobial agents such as iodopropyl butylcarbamate; antioxidants; cosmetic biocides; external analgesics; pH modifiers such as citric acid, sodium citrate, succinic acid, phosphoric acid, sodium hydroxide and sodium carbonate; skin bleaching and lightening agents such as hydroquinone, kojic acid, ascorbic acid, magnesium ascorbyl phosphate and ascorbyl glucosamine; skin soothing and/or healing agents such as panthenol and derivatives like ethyl panthenol, aloe vera, pantothenic acid and its derivatives, allantoin; bisabolol and dipotassium glycyrrhizinate; retinoids such as retinol palmitate); tocopheryl nicotinate; skin treating agents; vitamins and derivatives thereof; and other similar materials.
Humectants have been described as agents that control the moisture exchange between the product and air, both in the container and on the skin. Humectants have also been described as compounds that prevent drying of skin or that increase the water content of the top layers of skin (e.g., hygroscopic compounds).
Suitable moisturizing agents include hydrophobic agents, hydrophilic agents and combinations thereof Examples of moisturizing agents are allantoin, glycerol, polyglycerylmethacrylate, panthenol, polyols, ceramide, borage oil (linoleic acid), tocopherol (Vitamin E), tocopherol linoleate, dimethicone, hyaluronic acid, sodium peroxylinecarbolic acid (sodium PCA), wheat protein (e.g., laurdimonium hydroxypropyl hydrolyzed wheat protein), hair keratin amino acids, panthenol; primrose oil; GLA 3 and other fish oils that may include, for example, the omega-3 and omega-6 oils and/or linoleic acid; and flax seed oil, and mixtures thereof. Other moisturizing agents can also be used.
Numerous sunscreen agents are suitable for use in the personal care compositions of the present invention. Examples include, p-aminobenzoic acid, its salts and its derivatives, anthranilates, salicylates, cinnamic acid derivatives, dihydroxy cinnamic acid derivatives, trihydroxy cinnamic acid derivatives, dibenzalacetone, dibenzalacetophenone, naphtholsulfonates, dihydroxynaphtholic acid and its salts, coumarin derivatives, diazoles, quinine salts, quinoline derivatives, hydroxy- and methoxy-substituted benzophenones, uric and vilouric acids, tannic acid and its derivatives, hydroquinone and benzophenones. In accordance with this invention, an effective amount will normally be from about 0.01 to about 10% by weight, more particularly from about 0.1 to about 5% by weight, based on the weight of the composition.
Typically, the active ingredient in deodorant-antiperspirant compositions is a basic aluminum compound. Examples of such materials are aluminum chlorhydroxide, basic aluminum bromide, iodide or nitrate, and basic aluminum hydroxy chloride-zirconyl hydroxy oxychloride.
Cleaning agents are typically anionic, cationic, non-ionic or amphoteric surfactants. Typical anionic surfactants are carboxylates, sulfonates, sulfates or phosphates, e.g. fatty acid soaps, salts of lauryl sulfate and salts of lauryl ether sulfate. Examples of cationic surfactants are aliphatic mono, di and polyamines derived from fatty and rosin acids, amine oxides, ethoxylated alkyl amines and imidazolines. Examples of non-ionic surfactants are polyoxyethylene surfactants, alkylphenol ethoxylates, carboxylic acid esters, e.g., mono and diglycerides, polyoxyethylene esters and fatty acid diethanolamine condensates. Amphoteric surfactants are those containing combinations of the anionic and cationic groups described above, particularly those containing both acid carboxyls and basic nitrogen groups. Typical amphoteric surfactants are imidazolines and betaines, e.g., lauric and myristic imidazolines and betaines, and amidopropylbetaines.
A variety of medicinal agents also may be present as active ingredients in the compositions of the invention. Non-limiting examples are anti-acne additives, anti-cellulite agents, antihistamines, anti-inflammatory agents, antimicrobials, spermicides, antiseptics, antifungal agents and antiviral agents, and local anesthetics.
Examples of cosmetically or pharmaceutically acceptable carriers include, but are not limited to, a cream, a lotion, an emulsion, an oil, a spray, a gel, a aerosol, an aqueous or hydra-alcoholic solution, a suspension, a powder, a serums, an ointment, a shampoo, a gel, a paste and a mousse.
The composition may also include one or more adjuvants such as co-solvents, (e.g., alcohol, acetone, propylene carbonates), a diluent, a lubricant, an associative thickener, a surfactant, a flowing agent, an emollient, humectants, an antioxidant, a preservative, an antimicrobial agent, an antibiotic and an emulsifier.
The thickening additive compositions in accordance with this disclosure can be easily prepared by conventional methods known to persons of ordinary skill in the art, such as, simple mixing or blending using physical means or heat blending.
In one aspect, where acids and alcohols are included in the anhydrous solvent system, the acid or alcohol can be simply mixed with the moderately cross linked polyvinylpyrrolidone, using homogenizers at room temperature. This additive composition may be added to a base composition containing a personal care active and other adjuvants. This is particularly useful when the personal care composition is heat liable. The order of addition of the ingredients is not critical. In accordance with certain embodiments, the personal care active may be added to a dermatological or cosmetically acceptable carrier. Then, sufficient thickening additive composition may be added with stirring to provide a composition having the desired viscosity. Other optional adjuvants can then be added with continued stirring.
In another aspect, where sunscreens and oils constitute at least a part of the anhydrous solvent system, heat can be applied, provided there is no detrimental effect on the personal care actives.
In particular embodiments, sunscreen or combination of sunscreens when used in association with the thickening additive composition have shown viscosity as well stability excellence.
In yet other embodiments, the present thickening additive composition is highly effective for low pH personal care compositions. It is particularly useful for building viscosity in relatively acidic compositions, especially those containing C1-C25 alpha-or beta-hydroxycarboxylic acids.
Beyond building viscosity, the thickening system of this invention has the further advantage of stabilizing oil and water emulsions and providing a good skin-feel.
In another embodiment, oils containing surfactant were thickened with the thickening additive composition, which may also contain X-Tend™ 226 (ISP).
The following examples are presented to illustrate specific embodiments of the present compositions and methods. These examples should not be interpreted as limitations upon the scope of the invention.
Table 1 shows thickening of water, ethanol and combination of water and ethanol solvent system. The results were illustrated in
Table 2 shows Compatibility testing of the various alcohol and water based gels in the presence of acids and their homologues bases/salts; solvent=water, light-to-moderately crosslinked PVP=5%.
The low pH compositions, according to the present disclosure are made by mixing thickening agent i.e. strongly swellable, lightly to moderately crosslinked polyvinylpyrrolidone with alcohol/Deionized water/mixture of the two. This is followed by adding to it the various acidic components, such as salicylic acid and glycolic acid, with continuous homogenization. The viscosity of the resulting composition is measured using a Brookfield LVT viscometer.
The low pH compositions expressed as percents of total weight of the entire composition are reported in Table 3, and the corresponding results in Table 4.
The personal care compositions, which are substantially anhydrous, according to the present disclosure may be made by mixing thickening agent i.e. strongly swellable, lightly to moderately crosslinked polyvinylpyrrolidone with one or more substantially anhydrous solvent systems followed by adding it to the various personal care compositions. The viscosity of the resulting composition is measured using a Brookfield LVT viscometer.
The sunscreen compositions expressed as percents of total weight of the entire composition are reported in Table 5, and the corresponding results in Table 6.
In Examples 8-10, thickening agent is first dispersed in alcohol and then added to a hot mixture of sunscreen oils. The mixture was continuously mixed until smooth and free of lumps and a gel was obtained. Compositions with the concentration of 5% lightly to moderately crosslinked polyvinylpyrrolidone (Example 3) exhibited better gel consistency and a viscosity of 110,000 cP.
In Example 11, thickening agent is first dispersed in sunscreen oils with heating and homogenization. The gel so obtained was cooled to 45° C. This is followed by addition of alcohol and fragrance with continuous mixing and the temperature was maintained at 30° C. The composition has shown high SPF value of 45 (on Labspere using 25 mg) or SPF of 41.4 (on Optimetrics SPF 290 Analyzer using 25 mg). The in-vitro water resistance value obtained was 97.64 (Std. Deviation of 6.12).
Anhydrous VOC-Free
High SPF Gel With experimental Polymer ACP 1120
11691-120B
Appearance | Yellow-green colored, clear gel
Viscosity | 49,000 cps (RVT/TD/10 RPM)
Example 14 provides a broad spectrum, high SPF gel which is very water resistant, and has good rub resistance. The composition is a non alcohol formulation for non VOC regulations. It is non-greasy, with minimal shine.
Having described the invention in detail and by reference to disclosed embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention as defined in the following claims:
This application claims the benefit of U.S. Provisional App. Ser. No. 61/159,284 filed Mar. 11, 2009 and U.S. Provisional App. Ser. No. 61/167,727 filed Apr. 8, 2009, the contents of which are hereby incorporated by reference.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US10/26973 | 3/11/2010 | WO | 00 | 5/17/2012 |
| Number | Date | Country | |
|---|---|---|---|
| 61159284 | Mar 2009 | US | |
| 61167727 | Apr 2009 | US |
