Stable O/W Nanoemulsions for Skin and Other Topics: Literature Findings

This month’s survey of recent patent and research literature describes moneymaking ideas for personal care product development, including stable o/w nanoemulsions for skin, inhibiting melanin production with pyrazolylpyrimidine, fluorescent pigment flakes for color cosmetics, enhancing the solubility of actives, and popping foam in aerosols, among others.

Skin and Skin Care
Oxidative stress protection: L’Oréal has disclosed cosmetic compositions comprising a Gentianaceae plant extract and at least one superoxide dismutase (SOD) to protect the skin against the effects of oxidative stress from UV radiation, toxins or pollution.1 An example is shown in Formula 1.

Soothing ellagic acid: Beiersdorf AG has patented an ellagic acid-containing skin care preparation for soothing stressed and slightly damaged, irritated skin.2 Synthetic ellagic acid or ellagic acid extracted from plants such as raspberries, pomegranate, strawberries, blackberries and walnuts was used in aftershave preparations and diaper creams, which were prepared in combination with other actives. No examples were given.

Concealing skin irregularities: Shiseido Co., Ltd. has disclosed a cosmetic preparation for concealing skin irregularities. The preparation contained 0.5–3.0% hydrocarbon wax, comprising: a 20–95% wax moiety constituted of hydrocarbons having 28–42 carbon atoms, and a 5.0–80.0% wax moiety constituted of hydrocarbons having 43 or more carbon atoms; where the content of a moiety constituted of 27 or fewer carbon atoms is 15% or lower. The preparation also contained 0.1–5.0% fumed silica and 5.0–40.0% silicone elastomer powder.3 An example is shown in Formula 2.

Pyrazolylpyrimidine to inhibit melanin: Shiseido Company Ltd. also has disclosed skin whitening agents comprising pyrazolylpyrimidine derivatives with excellent melanin production-inhibiting activity.4 An external preparation for the skin containing the compound also is disclosed. For example, 2-(3,5-dimethyl-1H-pyrazol-1-yl)-4,6-dimethylpyrimidine was prepared and tested in vitro for melanin production-inhibiting activities.

Hair and Hair Care

Protecting blond hair color: Beiersdorf AG has patented a surfactant-containing hair care preparation to protecting blond-colored hair from dye removal during washing.5 Ingredients in the composition included a pigment, cationic surfactant and bis-diglycerylpolyacyladipate-2 (bis-DGPAA). Cetyltrimethylammonium chloride is the preferred cationic quaternary surfactant, and the compositions are free of anionic surfactants. Thickening agents, cellulose derivatives, reflecting pigments and coated pigments can also be added. An example is shown in Formula 3.

Hair styling composition: Shiseido Co., Ltd. has disclosed emulsion-type hair styling preparations that exhibit excellent spreadability among other properties while also being non-tacky and imparting no “squeaky” feeling.6 Disclosed is a preparation comprising: preferably 0.1–10.0% w/w of a specific long-chain acylsulfonic acid salt type anionic surfactant such as sodium N-stearoyl-N-methyltaurate; 0.1–20.0% of a higher aliphatic alcohol; and one or selections of: 0.5–50% waxes, 0.1–8.0% hair styling resins, 0.1–8.0% powder components such as silicic acid anhydrides and/or water; and optionally, a liquid oil. An example of a hair styling composition is shown in Formula 4.

Oxidative hair dye: L’Oréal disclosed a hair dye composition containing 3-amino-2-methylamino-6-methoxypyridine or one of its additive salts with an acid, one or more additional oxidation dyes, and one or more quaternary diammonium polycondensates.7 An example of an oxidative hair dye composition is shown in Formula 5.


Fluorescent pigment flakes: L’Oréal also has patented a cosmetic composition comprising flakes containing: at least one fluorescent agent entrapped in a hybrid matrix of at least one metal oxide; at least one hydrophobic group linked to that metal oxide; and at least one organic surfactant in a cosmetically acceptable medium.8 Fluorescent flakes were prepared from a tetramethoxysilane and methyltrimethoxysilane polymer, dicocoylethyl hydroxyethylmonium methosulfate (and) propylene glycola, glycereth-25 PCA isostearate, hexylene glycol, and D&C Red 28 or D&C Orange 5. The fluorescent flakes were incorporated into a nail enamel that imparted a red-orange fluorescent color after application to the nails. The red flakes were also incorporated into a powder foundation and a lip gloss.

Antiperspirants and Deodorants

Interfacial microparticles for AP/Deo: L’Oréal has also disclosed deodorant and/or antiperspirant compositions containing interfacial microparticles and a process for the treatment of perspiration and/or body odors such as axillary odors.9 The compositions comprised at least a deodorant/antiperspirant active agent and interferential particles where at least 50% of the particles had a diameter less than 40 mum and more than 80 mum. An example of a roll-on antiperspirant is shown in Formula 6.

Porous polyamide odor absorption: Henkel AG & Co. has disclosed porous polyamide particle-containing deodorants and/or antiperspirants with improved fragrance effects and odor absorption.10 The compositions contain at least one deodorant/antiperspirant active, 0.0001–5.0% w/w fragrance, and 0.1–10% w/w porous polyamide beads in a carrier. The beads were characterized by: a medium particle diameter of 1-30 mum; a specific surface according to BET of 5 m2/g or larger; oil absorption capacity (boiled linseed oil) of 200 mL/100 g or larger; crystallinity of 40% or larger; and a 1.0-1.5 ratio of volume medium particle diameter to average medium particle diameter. An example of a w/o sprayable emulsion is shown in Formula 7.


Radiation-photostabilizing formulations: L’Oréal has also disclosed cosmetic compositions containing a combination of at least one dibenzoylmethane derivative and at least one neutral N-acylamino acid ester derivative, as well as a process for radiation-photostabilizing the dibenzoylmethane derivative with an effective amount of the neutral N-acylamino acid ester derivative.11 The radiation-photostabilizing process is designed to improve the efficacy of the composition with respect to UVA rays. An example is shown in Formula 8.

Interesting Compositions and Raw Materials

Popping foam in aerosols: Daizo Co., Ltd. has disclosed an aerosol composition in which the forming foam generates a long-lasting popping sound and imparts a cooling effect to skin.12 The composition comprises a liquid and a liquefied gas. The liquid contains 3.0–30.0% oily base materials, water-soluble polymers and surfactants. The liquefied gas, at a weight ratio 50:50–10:90, comprised an inorganic-organic balance of materials of 0.2–0.5. An aerosol container was packed with a liquid composition comprising: hydroxyethylcellulose, PEG-20 sorbitan cocoateb, cyclomethicone, methylpentanediol dineopentanoatec, talc, ethyl alcohol, methylparaben, disodium EDTA and water; and a 40:60 isobutane-butane liquefied petroleum gas mixture. Foams sprayed from the container generated a large popping sound when rubbed on a palm.

Phosphoric acid ester formulation: Clariant International Ltd. has disclosed cosmetic, pharmaceutical or dermatological compositions containing phosphoric acid esters and hydrophobically modified, cross-linked anionic polymers.13 Specifically, the invention relates to compositions comprising: one or more anionic, cross-linked and/or hydrophobically modified polymers, where the hydrophic modification is carried out by a hydrocarbon group with 6–50 carbon atoms; and one or more phosphoric acid esters. A phosphoric acid ester was prepared from 12.7 g phosphoric acid and 701.3 g ceteareth-50. The phosphoric acid ester product was formulated into a vitamin C gel at 1.0% w/w with additional 1.5% w/w ceteareth-25d; 3.0% w/w ascorbic acid; 1.2% w/w ammonium acryloyldimethyltaurate/beheneth-25 methacrylate crosspolymere, and a water balance to 100% w/w.

Enhancing actives solubility: Dow Global Technologies Inc. has disclosed a method to enhance the aqueous solubility of poorly soluble actives using methoxypolyethylene glycol.14 The method combined an active compound of aqueous solubility ≤ 10 mg/mL with enough methoxypolyethylene glycol to increase the aqueous solubility of the active compound. Enhancement of aqueous solubility for this combination may be significantly greater than that of an active compound in combination with an equivalent amount of polyethylene glycol. Enhanced solubility was shown where a small amount of water was also included. This invention may be used in a variety of industries including pharmaceutical, agricultural, antimicrobial and personal care.

Lipids for pollen allergy protection: Beiersdorf AG has patented the use of lipid components in pharmaceutical and topical cosmetic formulations to protect against pollen allergies.15 A disclosed preparation comprised a lipid phase where one or more lipids had a viscosity of approximately 40–25,000 mPas. An example is shown in Formula 9.

Flexible, porous, dissolvable product form: The Procter & Gamble Company has disclosed personal care compositions in flexible, porous and dissolvable solid structures.16 The disclosed compositions comprise 23–75% surfactant, 10–50% water-soluble polymer and an optional 1.0–15.0% plasticizer. The company also has described a process for preparing the compositions. An example of a dissolvable, porous, solid cleanser is shown in Formula 10. It is prepared by mixing and heating the ingredients, vigorously aerating the mixture, spreading the mixture into molds, and drying the mixture.

Moisturizing composition for surgical gloves: Evonik Goldschmidt GmbH has disclosed a moisturizing liquid liner composition for a barrier layer such as surgical gloves.17 The moisturizing liner contains a hydrophobic moiety and an emulsifier. Nitrile gloves treated with a formulation of: 4.0% polyglyceryl-4 isostearate (and) cetyl PEG/PPG-10/1 dimethicone (and) hexyl lauratef, 46.0% cyclomethicone, 47% cetyl dimethiconeg, 1.0% quaternium-80h, and 2.0% dimethicone (350 cst) provided an increase in hand moisturization, compared with untreated gloves.

Stable o/w nanoemulsions for skin: Shiseido Co., Ltd. has disclosed the composition and manufacture of o/w nanoemulsions containing polyalkylene glycol dineopentanoates with excellent stability and skin application properties.18 The nanoemulsions, with 30–1,000 nm particle sizes, are suggested for lotions, creams and hair conditioners and are manufactured by preparing o/w microemulsion compositions with: nonionic surfactants having a hydrophilic-lipophilic balance (HLB) ≤ 5, polyalkylene glycol dineopentanoates, a water content ≤ 70% w/w, nonionic surfactants with a HLB ≥ 9, and polyoxyethylene-polyoxyalkylene random copolymer dialkyl ethers and/or polyhydric alcohol-polyoxyalkylene glycol-polyethylene glycol copolymer alkyl ethers and adding them to aqueous media containing potassium 4-methoxysalicylate.

The polyoxyethylene-polyoxyalkylene random copolymer dialkyl ethers were structured as:


where AO = C3-4 oxyalkylene; EO = oxyethylene; m, n = 1-70; the ratio of EO/(EO + AO) is 50–100%; and R1,2 = C1-4 hydrocarbyl.

The polyoxyethylene-polyoxyalkylene random copolymer dialkyl ethers were arranged as:


where Y = polyhydric alcohol residue; k = 3-6; EO, AO = C3-4 oxyalkylene; a, b = 1-70; and R = C1-4 hydrocarbyl.

A nanoemulsion containing: 0.3% ethoxylated hydrogenated castor oilj, 0.2% tripropylene glycol dineopentanoate, 0.01% PEG-20 glyceryl isostearatek, 0.2% pentaerythritol-POE-POP copolymer tetra-Me ether and 1.0% of the disclosed o/w microemulsion composition showed a particle size of 48 nm and good stability after storage at RT for one month.

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1. FR 2,926,991, Cosmetic composition to protect skin and/or its superficial body growths against the effects of oxidative stress, L’Oréal, France (Aug 7, 2009)
2. DE 102,008,008,540, Ellagic acid-containing skin care preparation for soothing stressed and irritated skin, Beiersdorf AG, Germany (Aug 13, 2009)
3. WO 2009 98,839, Cosmetic preparation for concealing irregularities, Shiseido Co Ltd, Japan (Aug 13, 2009)
4. WO 2009 99,192, Skin whitening agents comprising pyrazolylpyrimidine derivatives, Shiseido Company Ltd, Japan (Aug 13, 2009) 5. DE 102,008,005,411, New surfactant-containing hair care preparation for protecting blond colored hair from dye removal during washing, Beiersdorf AG, Germany (Jul 30, 2009)
6. JP 2009 173,601, Emulsion-type hair-dressing preparation, Shiseido Co Ltd, Japan (Aug 6, 2009)
7. FR 2,926,987, Hair dye composition containing 3-amino-2-methylamino 6-methoxypyridine, another oxidation dye, and a quaternary diammonium polycondensate, L’Oréal, France (Aug 7, 2009)
8. WO 2009 95,808, A cosmetic composition, L’Oréal, France (Aug 6, 2009)
9. FR 2,926,978, Deodorant and/or antiperspirant composition containing interferential microparticles; process for makeup and treatment of perspiration and/or body odors in particular axillary odors, L’Oréal, France (Aug 7, 2009)
10. DE 102,008,008,780, Porous polyamide particle-containing deodorants and/or antiperspirants with improved fragrance effect and odor absorption, Henkel AG & Co KGaA, Germany (Aug 13, 2009)
11. WO 2009 98,139, Cosmetic composition containing a dibenzoylmethane derivative and a neutral N-acylamino acid ester derivative; Process for photostabilizing the dibenzoylmethane derivative, L’Oréal, France (Aug 13, 2009)
12. JP 2009 173,613, Aerosol compositions which form foams generating popping sound, Daizo Co Ltd, Japan (Aug 6, 2009)
13. WO 2009 95,197, Cosmetic and dermatological compositions containing phosphoric acid esters and hydrophobically modified cross-linked anionic polymers, Clariant International Ltd, Switzerland (Aug 6, 2009)
14. WO 2009 91,622, Method to enhance aqueous solubility of poorly soluble actives using methoxypolyethylene glycol, Dow Global Technologies Inc, USA (Jul 23, 2009)
15. EP 2,082,733, Use of lipid components in pharmaceutical and cosmetic topical formulations against pollen allergies, Beiersdorf AG, Germany (Jul 29, 2009)
16. WO 2009 95,891, Personal care composition in the form of a flexible, porous, dissolvable solid structure, The Procter & Gamble Company, USA (Aug 6, 2009)
17. WO 2009 95,351, Moisturizing liquid liner for barrier layer, Evonik Goldschmidt GmbH, Germany (Aug 6, 2009)
18. JP 2009 179,584, Oil-in-water nanoemulsions containing polyalkylene glycol dineopentanoates with excellent stability and skin application properties and their manufacture, Shiseido Co Ltd, Japan (Aug 13, 2009)

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