GB2425060A - Strontium compounds in cosmetics - Google Patents

Abstract

Cosmetic compositions for topical application comprise strontium chloride or strontium acetate or hydrates thereof in an amount of up to 2.5% by weight. Strontium chloride hexahydrate in a Vaseline-based lotion is exemplified.

Description

COMPOSiTIONS The present invention relates to novel strontium-containing

compositions and their use in methods of cosmetic treatment.

Strontium compounds are known for topical use in the reduction of skin irritation. For example, both WO 97/48371 and WO 96/19 184 (Cosmederm) describe topical formulations containing strontium for preventing, reducing or eliminating the potential irritation caused by topical application of products containing irritating agents, especially cosmetic products containing hydroxy acids or other exfoliating agents. In the formulations described, the divalent strontium cation is provided at a concentration which is effective to reduce irritation to the skin. The concentrations of strontium salts that provide an optimum consumer benefit in terms of anti-irritant properties are approx. 4 to 6% by weight (approx.

190 to 280mM). Strontium nitrate is the preferred choice of anti-irritant agent and is generally used at a concentration of 250 mM (5.7% by weight).

US-A-5,866, 168 (L'Oreal) describes dermatological/pharmaceutical compositions comprising at least one lanthanide, manganese, tin, zinc, yttrium, cobalt, barium or strontium salt as a substance P antagonist. Such compositions are intended for use in the medical treatment and/or alleviation of pain associated with certain skin disorders, including skin ulcers, hypertrophic cicatrization and acne rosacea.

More recently, strontium compounds have been proposed for use in other methods of medical treatment. The use of strontium compounds to treat subdermal soft tissue pain is described in WO 03/028742 (Santosolve). WO 04/849920 (Santosolve) relates to strontium compounds for inflammatory treatment.

We have now surprisingly found that compositions containing certain strontium compounds in low concentrations are effective to enhance the cosmetic appearance and/or the personal well-being of a subject, preferably a human subject, when topically applied to the body.

Thus, viewed from one aspect the invention provides a cosmetic formulation comprising strontium in an amount of up to 2.5% by weight, together with a It. V

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* . I * * I I II * * III * * it I I t.* ** II II. St physiologically acceptable carrier or excipient, wherein the strontium is present in the form of strontium chloride, strontium acetate or a hydrate thereof Viewed from a further aspect the invention provides a method of cosmetic treatment of a human or non-human subject, preferably a human subject, said method comprising topically applying to said subject a composition comprising strontium in an amount of up to 2 5% by weight, wherein the strontium is present in the form of strontium chloride, strontium acetate or a hydrate thereof Viewed from a still further aspect the invention provides the use as a cosmetic preparation of a composition comprising strontium in an amount of up to 2.5% by weight, wherein the strontium is present in the form of strontium chloride, strontium acetate or a hydrate thereof.

The term "cosmetic" as used herein in relation to any product or method of treatment is intended to define a product or treatment which is used or intended for use solely for cosmetic purposes, i.e. to enhance or maintain the cosmetic appearance and/or the personal welfare of a human or non -human subject. Cosmetic treatment includes any method which serves (i) to maintain or alter (e.g. enhance) a subject's appearance; (ii) to protect a subject from environmental conditions such as sunlight, wind, extremes in temperature and/or humidity, etc.; or (iii) to produce a biological change in the subject's skin for cosmetic purposes. Cosmetic treatment specifically excludes any method of medical treament of a subject, in particular any method for treating or alleviating the symptoms of a disease.

The compositions according to the invention comprise strontium in the form of strontium chloride, strontium acetate or a hydrate thereof. Mixtures of any of these compounds may also be employed A preferred form of strontium is strontium chloride. Particularly preferably, this may be used in the form of strontium chloride hexahydrate.

The concentration of strontium in the compositions according to the invention will typically be up to about 2.1% by weight (w/w calculated as strontium), preferably in the range 0.5 to 2.1% by weight, more preferably 0.7 to 2.0% by weight, e.g. 1.0 to 2.0% by weight.

The strontium compounds herein described may be dissolved or dispersed in any appropriate vehicle, e.g. a physiologically acceptable carrier or excipient such as I., * * , I I I I S S I I, S I ** 1.: 15. : *

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those described herein Preferred carriers and excipients are those which are non - irritating to the skin. Although the strontium compounds herein described may be employed as the sole active component of a cosmetic formulation, preferably these will be used in a conventional cosmetic formulation in order to further enhance the cosmetic properties of the product. Examples of such products which contain safe (i.e. non-irritating) cosmetics to which the strontium compounds may be added include the following.

Vaseline Intensive Care Extra Strength Body Lotion (Lilleborg AS, Oslo, Norway) contains: water, glycerin, petrolatum, paraffinum liquidum, stearic acid, glycol stearate, stearamide AMP, cetyl acetate, acetylated lanolin alcohol, glyceryl stearate, triethanolamine, dimethicone, magnesium aluminum silicate, PEG-40 stearate, cetyl alcohol, perfume, methylparaben, propylparaben, carbomer, disodium EDTA, DMDM and hydantoin.

Natusan Baby Lotion (Johnson & Johnson, Dusseldorf, SCA Hygiene Products AS, T nsberg, Norway) contains: water, paraffinum liquidum, petrolatum, Elaeis Guineensis oil, lanolin, glycerin, glycine soya oil, helianthus annusus seed oil, dimethicone, cetyl alcohol, stearyl alcohol, acrylates/C1030 alkyl acrylate crosspolymer, carbomer, sodium hydroxide, phenoxyethanol, methylparaben, propylparaben and perfume.

Wella Balsam Shampoo (Wella AS, Darmstadt, Germany) contains: water, cetearyl alcohol, cetrimonium chloride, dimethicone, phenoxyethanol, perfume, isopropyl alcohol, methylparaben, CL 77891, buxus chinensis, citrus dulcis and pyrus malus.

Natusan pH 5.5 Shampoo (Johnson & Johnson, Maidenhead, UK, SCA Hygiene Products AS, T nsberg, Norway) contains: water, ammonium lauryl sulphate, ammonium laureth sulphate, cocamidopropyl betaine, glycol distearate, lauramide MBA, methylparaben, tetrasodium EDTA, sodium benzoate, guar hydroxypropyltrimonium chloride, BHT, silicone, guanternium-13, acrylamidopropylirimonjum chioride/acryl amide copolymer, panthenol, PEGi 4M, tee * * S * S I S * * a * * S I SI * .: .:. . : . : I * * S IS. IS PEG-4, wheat amino acids, phytantriol, citric acid, iodopropynyl butylcarbamate, propylene glycol, quatemium-80, sodium chloride, polysorbate 20, PEG-4 laurate, PEG-4 dilaurate and perfume.

Vaseline intensive Care Mild Shower Gel (Chesbrough Pond Inc., USA, Lilleborg AS, Oslo, Norway) contains: water, sodium laureth sulfate, glycerin, cocamidopropyl betaine, glycol distearate, perfume, lanolin alcohol, stearic acid, PPG-9, actylates/C1030 alkyl acrylate crosspolymer, guar hydroxypropyltrimonium chloride, PEG-40 hydrogenated castor oil, laureth-4, aloe barbadensis, potassium sorbate, sodium benzoate, tocopheryl acetate, citric acid, sodium hydroxide and sodium chloride.

Some of the cosmetic products mentioned above contain certain components that might be regarded as skin irritants when used at high concentrations. However, in the products listed, these are not present in an amount sufficient to irritate the skin.

The strontium compounds herein described are not intended for use in preventing or reducing the irritation which may be associated with any conventional cosmetic products. Where any potentially skin irritating components are present in the formulations according to the invention, these will generally be present in sufficiently low concentrations that these do not irritate the skin. Such concentrations will depend on the nature of the skin irritant but typically will be of the order of less than 5% by weight, preferably less than 3% by weight, e g. less than 2% by weight. Most preferably, the compositions of the invention will be substantially free from any skin irritating components. For example, any such components will be present in an amount of less than 1% by weight, e. g. less than 0.5% by weight.

As used herein, the terms "skin irritating component" and "skin irritant" are used interchangeably to define any compound which when topically applied to a human or non-human subject (e g. when applied to the surface of the skin) at a given concentration will irritate the skin. Symptoms of skin irritation may include itching (pruritus), inflammation, stinging, burning, tightness of the skin, erythema or 551 * I I 5 U * * I 5 * I I US 8 5 8 * I t * * : * * * * * 5 I I * ass 55 oedema Skin irritants may include not only components of cosmetic products which may be considered inert, e.g. fragrances, preservatives, solvents, etc, but also active components of the products such as exfoliants and skin cell renewal agents, anti- perspirant compounds, skin protective agents, chemical sunscreen agents, etc. Known skin irritants include, for example, those compounds conventionally used as exfoliants and/or cell renewal agents to reduce the occurrence or severity of skin wrinkles, and anti-acne agents. Such compounds include carboxylic acids such as aipha-hydroxy acids (e.g. lactic acid, glycolic acid), beta-hydroxy acids (e.g. salicylic acid), retinoids (e.g. tretinoin, retinol); peroxides (e.g. benzoyl peroxide); and organic alcohols.

In a preferred embodiment of the invention the strontium compounds herein described are not provided in any conventional anti-aging or anti-wrinkle product, e.g. one containing aipha-hydroxy acids, beta-hydroxy acids or a retinoid Preferably, the compositions in accordance with the invention will thus be substantially free from any anti-aging or anti-wrinkle agents Other known skin irritants include the following: - acetyl choline and its salts - spironolactone - methotrexate - aminocapric acid - chinophen and its salts or derivatives - trichloro-acetic acid - epinephrine - rauwolfia serpentia (in any form) - alkyne alcohols - allyl isothicyanate nalorphine - aniline - procainamide - benzidine - 4-aminosalicylic acid toluidines

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- xylidines - anthracene oil - antibiotics - antimony compoumds apomorphine - arsenic - atropa belladonna L. - atropine - benzene beryllium - brompheniramine - tetracaine - tolbutamine - tetracaine tolbutamide - cadmium - carbon disuiphide - catalase 2,2,2-trichloroethane4, 1-diol - chlorine - chioroethane - curare hydrogen cyanide - dichloroethane - dichioroethylene - dimethylamine disulfiram - ephedrine - ethylene oxide - fluorouracil - progestogens hexachioroethane If. * I * I I I * I I I I * * I I t * : . . 1

III

- hyoscyamus niger L. - iodine - ipecacuanha - barbiturates - mercuiy metaldehyde - nicotine - amy! nitites - nitrobenzene - noraclrenajjne oestrogens - picric acid - radioactive substances - gold salts glucocorticosteroids - strychnine - neodymium compounds - tellurium compounds - tetrachloroethylene - carbon tetrachioride - thallium compounds - yohimbine - dimethylsulfoxide - 4-tert-butylphenol - dioxane chloroform - coaltar Included in this listing of compounds are salts, esters and other derivatives which form any of the above-mentioned compounds in vivo.

Preferably, the compositions according to the invention will be substantially free from any of the above-mentioned compounds, for example these will be present *1I * * t I 0 0 I I S * * * I SI I I I * * * I P V * I, * I I * S V I * i.. IS in an amount of less than I % by weight, more preferably less than 0 1% by weight, e g less than 0.0 1% by weight The formulations herein described will generally be prepared by simple mixing of an appropriate amount of the chosen strontium compound into the chosen formulation vehicle, optionally together with any cosmetic components as are desired Suitable topical vehicles and vehicle components for use with the formulations according to the invention are well known in the field of cosmetics and include such vehicles as solvents (e.g. water, organic solvents such as alcohols, glycols), lipid-based materials such as fatty acids, acylglycerols, phosphoglycerides; protein-based materials such as collagen and gelatin, silicone-based materials such as cyclomethicone, dimethicone; hydrocarbon-based materials such as petrolatum and squalene; anionic, cationic and amphoteric surfactants and soaps, sustained release vehicles such as microsponges and polymer matrices; stabilizing and suspending agents; and emulsifying agents Other components may be provided to improve the stability or effectiveness of the formulations such as preservatives, redox agents (e.g. antioxidants), skin penetration enhancers, sustained release materials, viscosity modifiers, pH modifiers, etc. Other components which may be present include perfumes, sunscreens, odour absorbers and colourants. The amounts of these various adjuvants and additives are those conventionally used in the cosmetic field and may range, for example, from 0.01 to 20% of the total weight of the formulation.

The compositions according to the invention may be used as cosmetic preparations, in particular as skin and hair products. in use, these will be topically applied to the body of a human or non-human animal, preferably to a human. For example, these may be administered directly onto the skin's surface (on any area of the skin), onto the hair (wet or dry hair) and/or onto the nails.

The compositions may be provided in a variety of forms, including solids (e.g. soaps or cleansing bars), liquids, emulsions, semi-solids (e.g. creams, gels, lotions or pastes), powders or aerosols. Examples of topical products used as cosmetics and to which the strontium compounds herein described may be added include skin care products such as moisturising creams and lotions, skin cleansers and toners, exfoliants and skin cell renewal agents, anti-wrinkle products, fragrances * I * I I I I 1 I I S I I * * * * I I I

I I I S

-I. II such as perfumes, deodorants and anti-perspirants, shaving products such as shaving creams and after-shaves; depilatories and other hair removal products; sunbathing products such as tanning lotions, sunscreens, sunbiocks and after-sun products; artificial tanning products; skin-whitening products, cleansing products such as toilet soaps and gels, bath products such as bath and shower compositions, after-bath compositions; eye care products such as eye lotions and make-up removers; make- up products such as foundations, blushers, eye shadows and eye liners, lipsticks, mascaras, powders; products for application to the lips such as lip balms and sticks; hair care and treatment products such as shampoos, conditioners, colourants, dyes, bleaches, permanent-waving or straightening compositions; baby products such as wet wipes, lotions, oils, shampoos, powders; products for intimate hygiene such as deodorants and douches; skin or facial peels and masks; and products for nail care such as nail hardeners and nail varnishes.

The present invention is further illustrated by the following nonlimiting

Example.

Example 1: Preparation of strontium chloride (2% strontium) containing product Strontium chloride hexahydrate (6.05 g) was mixed into Vaseline Intensive Care Extra Strength Body Lotion (Lilleborg AS, Oslo, Norway) (94g) using a mortar and pestle. The lotion was filled into a plastic vial.

The lotion contained 2% (w/w) strontium. St. V I,

Claims (3)

1. I S I, I I * S * * * I I I .: I;. *. 11 II - 10 - Claims 1 A cosmetic

   formulation comprising strontium in an amount of up to 2.5% by weight, preferably up to about 2 1% by weight, together with a physiologically acceptable carrier or excipient, wherein the strontium is present in the form of strontium chloride, strontium acetate or a hydrate thereof.
2. 2 A method of cosmetic treatment of a human or non-human subject, preferably a human subject, said method comprising topically applying to said subject a composition comprising strontium in an amount of up to 2. 5% by weight, preferably up to about 2.1% by weight, wherein the strontium is present in the form of strontium chloride, strontium acetate or a hydrate thereof
3. 3. The use as a cosmetic preparation of a composition comprising strontium in an amount of up to 2 5% by weight, preferably up to about 2. 1% by weight, wherein the strontium is present in the form of strontium chloride, strontium acetate or a hydrate thereof