DE29824538U1 - Foam skin cream - Google Patents

Description

Foam skin cream
The invention relates to a foam skin cream.

The galenic principle of an emulsoid 2-phase system with lipophilic or hydrophobic components on the one hand and hydrophilic components on the other is already known for the production of foam preparations for skin care. Applying these foam preparations to the treated skin creates a two-dimensional two-phase network, the hydrophilic components bind to the keratin of the horny layer and allow sweat to evaporate, while the lipophilic components on the skin surface inhibit the penetration of moisture (including sweat that has penetrated through). Since the foam, unlike other creams that build up a barrier, absorbs within minutes, leaves no greasy traces on the work materials and prevents heat build-up or even maceration effects caused by sweat, the foam quickly became increasingly popular as a means of protection against odor-related moisture effects. Further details on the known foam skin creams can be found in particular in "Haut", issue 4, 1992 by R. Rudolph, L. Bade, B. Brüggemann.

In "hautnah derm" 10 (1994), 344 - 351, B. Kunze reports on fatty skin protection foams that are indicated for dry, sensitive skin and chronic rhagadiform eczema. The ingredients are also disclosed there. The skin protection foams described there protect against many occupational toxins, such as acidic permanent wave liquids in hairdressing, alkalis, oils, disinfectants, cleaning and dishwashing agents, but also against water, moisture, sweat, feces, urine and mineral dust.

EP O 598 412 also concerns skin protection foams which describe PTFE as the active principle.

DE-C-33 30 628 relates to skin protection and care lotions that contain silicone oils, partially neutralized stearic acid, fatty alcohols and their ethoxylated derivatives, ethoxylated wool fatty alcohols, cetylstearyl alcohol, Vaseline, thickeners and water. The lotions disclosed therein are said to be quickly absorbed without leaving an annoying greasy film on the skin for a long time.

Information on emulsifiers that can be used in skin care products can be found in DE-A-195 42 572. Emulsifiers are proposed there that contain 43 to 90% by weight of alkyl and/or alkenyl oligoglycosides and 10 to 57% by weight of fatty alcohols. These emulsifiers are particularly suitable for the production of storage-stable, highly viscous, sensorially light oil-in-water emulsions. The German utility model DE-U-9308050 relates to a skin protection foam as an agent against skin-aggressive agents. This foam consists of an aqueous emulsion that contains fatty acid esters with good skin compatibility and for producing a water vapor-permeable film, polyhydric alcohol for the stable dispersion of the active ingredients and regulation of the moisture of the film, emulsifiers to improve foam stability, surfactants to reduce surface tension and, if necessary, neutralizing agents for resins and emulsifiers. Gaseous hydrocarbons such as propane, butane or isobutane or mixtures thereof can be used as propellants. However, the foams described there do not contain any free fatty acids.

Aerosols are complex physical and chemical structures that do not form randomly.

special coordination of the components that form the foam. Even slight changes in the composition can lead to the foam collapsing, meaning that a mixture of substances that are otherwise effective cannot simply be formulated as a foam.

Skin creams are often perceived as unpleasant, especially when used at work, because the "greasy" components remain on the skin for too long and lead to annoying fingerprints or a general unpleasant feeling. The well-known skin foams have already provided some relief here, as they help prevent or reduce the skin from being overloaded with greasy substances. Nevertheless, it is desirable to find even greater acceptance among users, especially when skin protection products are used on a long-term basis.

The present invention is based on the technical problem of expanding the application spectrum of skin protection foams by providing a mixture which is widely accepted by the user, allowing a large number of admixtures of other substances without destroying the aerosol used or impairing the properties of the aerosol.

Surprisingly, the technical problem underlying the invention is solved by a basic mixture of a foam skin cream with the features of claim 1. Preferred embodiments of the foam skin cream according to the invention relate to subclaims 2 to 12.

The foam skin cream according to the invention is available through

Preparation of a phase I by melting at 75 ⁰ C a mixture containing fatty acids, in particular C _i2 -C ₂₂ fatty acids, optionally unsaturated and/or polyunsaturated fatty acids, emulsifiers, coemulsifiers, such as triceteareth-4-phosphate,

followed by a measured addition while stirring to a

Phase II, tempered to 75 ⁰ C, which is obtained from an aqueous mixture containing moisturizers such as propylene glycol and/or polyhydric alcohols, in particular glycerin, emulsifiers such as alkyl sarcosinates, and skin care additives such as allantoin,

whereby a homogeneous mixing of phases I and II is to be established and the dosed addition is carried out at a temperature of 75 ⁰ C,

after addition, the temperature is maintained at 75 ⁰ C for a period of between 5 and 20 minutes, after which

the temperature of the mixture thus obtained is reduced to a temperature between 30 and 40 ⁰ C with constant stirring,

Adjusting the pH value to 7.6 to 8.2, preferably with a skin-compatible basic organic compound and filling the resulting mixture into dosage forms with the addition of a propellant gas.

The product obtained by the process can be used directly as a foam skin cream in the commercial sector to protect against or reduce the absorption of carcinogenic substances such as polycyclic aromatic hydrocarbons. This mixture is

already able to provide effective protection to people whose skin is exposed to carcinogenic substances such as polycyclic aromatic compounds. Furthermore, the mixture is suitable for providing protection to people against the effects of acids, alkalis (not above pH 11), dishwashing and washing detergents, sweat, urine, stool, rubber gloves, dust, house dust, machines, drilling and cooling oils, fats, paints/varnishes, plaster and other substances and chemicals, particularly aggressive substances and chemicals.

The foam skin cream according to the invention contains fatty acids, in particular C ₁₂ - C 22 fatty acids, which may optionally additionally contain unsaturated and/or polyunsaturated fatty acids. Suitable fatty acids that are saturated are in particular the naturally occurring C ₁₂ - C ₂₀ fatty acids, in particular stearic acid and palmitic acid. Myristic acid can also be used. Suitable unsaturated fatty acids are in particular those with up to three unsaturated bonds in the hydrocarbon chain. Unsaturated fatty acids are found, for example, in fractions of coconut fat. Suitable coemulsifiers are known coemulsifiers, in particular triceteareth-4-phosphate, sodium laureth-4-phosphate or oleth-3, as well as other lipophilic emulsifiers based on low-ethoxylated fatty alcohols.

Phase I may also contain liquid paraffin.
Emulsifiers to be used in Phase I are those based on
Fatty alcohol base and base of partial esters of fatty acids in
Particularly preferred fatty alcohols are cetearyl alcohol.
For example, glyceryl stearate is used as a partial ester of a fatty acid
used.

The moisturizers that can be used in Phase II are in particular propylene glycol and/or polyhydric alcohols such as glycerin. In Phase II

Emulsifiers that are particularly used are alkyl sarcosinates, such as lauroyl, lauryl and cetyl sarcosinates.

The mixture obtainable according to claim 1 also serves as a basis for further foam skin creams which can be used in a wide range of areas to protect the skin and alleviate dermatological dysfunctions.

If desired, one or more preservatives can be added to the foam skin cream according to the invention. Substances such as methyldibromoglutaronitrile and/or phenoxyethanol have proven particularly useful as preservatives. These substances can be added in amounts of 0.01 to 1% by weight.

Preferably, the emulsifiers, fatty acids, co-emulsifiers, moisturizers and skin care products, especially allantoin, panthenol, etc. are used in the following quantities:

4 to 15 wt.% oil-in-water emulsifier,

1 to 10 wt.% fatty acid, in particular 4 to 7 wt.%, preferably 4.5 to 6 wt.%

0.4 to 2.3 wt.% co-emulsifier

1 to 10 wt.% moisturizer

0.05 to 1 wt.% skin care products and

Water to balance to 100% w/w.

A preferred foam skin cream according to the invention has
1 to 3% by weight of glyceryl stearate,

3 to 6 wt.% cetearyl alcohol,

4 to 6 wt.% stearic acid,
0.5 to 2 wt.% paraffin,

0.4 to 2.3 wt.% triceteareth-4-phosphate,

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1.5 to 4% by weight of propylene glycol,
1.3 to 4.2 wt.% glycerin,
1 to 3% by weight of cetyl sarcosinate,
0.05 to 1 wt.% allantoin and
Water to balance to 100 wt.%.

In a further preferred embodiment, the foam skin cream according to the invention additionally contains a silicone-containing substance, such as dimethicone. This substance is added to phase I. It is preferably present in amounts of 0.05 to 1% by weight.

The foam skin cream according to the invention can furthermore additionally contain in phase I one or more moisturising substances, such as decyl oleate, isohexadecane, stearic acid glycol esters, coconut fatty acid ethanolamide, corn oil, peanut oil, almond oil, sesame oil, olive oil, jojoba oil, soybean oil, wool wax alcohols, paraffin, medium-chain triglycerides, oleic acid oleyl esters, white petrolatum, macrogol glycerol hydroxystearate, hydrogenated castor oil, castor oil communis, avocado oil, wheat germ oil,

Palmitic acid isopropyl ester, cetyl palmitate imitation, myristic acid myristil ester and/or octyldodecanol.

In particular, the foam skin cream contains amounts of 0.5 to 2% by weight of decyl oleate and/or 0.5 to 2% by weight of octyldecanol or another of the above-mentioned moisturising substances if the product is to be used on normal skin. The total amount of moisturising substances should be such that the skin protection foam is not destroyed. An amount of about 4% by weight of moisturising substances is sufficient for normal to slightly dry skin. If dry skin is to be treated with the foam skin cream according to the invention, amounts of 3 to 6% by weight of a component of the moisturising substances, such as in particular decyl oleate and/or octyldecanol, are recommended. If more than one component is used, the

The total amount of moisturizing ingredients should not exceed around 12% for slightly dry skin. If even more dry skin is being treated, the amount of moisturizing substance is around 6 to 9% by weight when using a component such as decyl oleate and 6 to 9% by weight when using octyldecanol. The amount of moisturizing substance can then be up to 20% by weight.

The latter foam skin creams, like the products without silicone-containing substances, are suitable for the care and protection of the skin, especially against aggressive substances such as dishwashing and washing detergents, sweat, urine, stool, rubber gloves, dust, house dust, machine, drilling and cooling oils, greases, paints/varnishes, plaster and other substances and chemicals, especially aggressive substances and chemicals.

The foam skin creams are also suitable for treating dermatological diseases or alleviating them. Dermatological diseases such as allergic contact eczema type I and IV, cumulative-subtoxic eczema, toxic-irritant eczema, microbial-dysregulatory eczema, atopic dermatitis, atopic palmoplantar eczema, dyshidrosis, hyperhidrosis, contact urticaria, intertriginous eczema in hemorrhoids, various weeping fungal infections, e.g. interdigital mycosis, perleches, psoriasis vulgaris, leg ulcers, cholinergic urticaria, diaper rash are particularly suitable.

It may be appropriate to include, in addition to the moisturising substances, substances that can increase the moisture content of the skin. These hydrating substances include in particular urea, ethoxydiglycol, sodium chloride, magnesium chloride, sorbitol, dexphanthenol, sodium lactate, allantoin, hyaluronic acid, vitamin E, linolenic acid. The amount of these substances may be 1 to 20% by weight or more of the substances in question, depending on the severity of the disease to be treated.

These quantities also apply in particular to urea, which can also be present in quantities of 3 to 15% by weight, or 12.5 - 15% by weight. The foam skin cream according to the invention can also be used for psoriasis.

A particularly important field of application is the prevention and treatment of diabetic feet. Due to the side effects of diabetes, diabetics suffer from dry skin, which in the course of the disease leads to damage to the extremities, and may even require amputation in long-term diabetics. The prophylactic use of skin protection products, which improve skin parameters in diabetics, can prevent the development of diabetic feet.

Furthermore, skin-care substances such as polyunsaturated fatty acids (PUFA) can be added to the foam skin cream according to the invention. Omega-6 fatty acids, such as those known from evening primrose oil and borage oil, are particularly suitable. Both synthetic omega-6 fatty acids and those from the plant extracts mentioned can be used.

Furthermore, soothing substances such as chamomile extract are considered as a further fraction that can be added to the foam skin cream according to the invention.

Vitamins that are effective for the skin, such as vitamins A, E and F, can also be added to the foam skin cream according to the invention in effective amounts. The addition of the following substances has proven particularly effective for the treatment and prevention of diaper rash: 3 to 7% by weight calendula extract, 3-7% by weight witch hazel extract, 3-7% by weight chamomile extract, 3-7% by weight tea tree oil extract, 1-5% by weight decyl oleate, 1-5% by weight octyldodecanol.

- 10 -

A process for producing the foam skin protection cream according to the invention comprises the following steps:

a phase I is prepared by melting a mixture containing fatty acids, in particular C ₁₂ - C ₂₂ fatty acids, optionally unsaturated and/or polyunsaturated fatty acids, coemulsifiers such as triceteareth-4-phosphate, at 75 ⁰ C, this phase is dosed with stirring to a

Phase II melted at 75 ⁰ C, which is obtained from an aqueous mixture containing moisturizers such as propylene glycol and/or polyhydric alcohols, in particular glycerin, emulsifiers such as alkyl sarcosinates, and skin care additives such as allantoin, is added,

whereby a homogeneous mixing of phases I and II is to be achieved and the dosed addition takes place at a temperature of 75 ⁰ C.

After adding phase I to phase II, the temperature is maintained at 75 ⁰ C for a period of between 5 and 20 minutes, after which

the temperature of the mixture thus obtained is reduced to a temperature between 30 and 40 ⁰ C with constant stirring.

The pH value is adjusted to 7.6 to 8.2, preferably with a skin-compatible basic organic compound, and the filling is carried out with the addition of a propellant gas.

The invention is explained in more detail using the following example:

- 11 -

Example

The skin protection cream according to the invention is produced in a heatable and coolable closed apparatus with a self-discharging homogenizer and a heatable dosing funnel (preferably a Koruma multi-purpose apparatus).

Phase I is prepared in a heatable dosing funnel by melting a mixture containing 2% by weight glyceryl stearate, 4% by weight cetearyl alcohol, 5% by weight stearic acid, 1% by weight paraffin, 1% by weight triceteareth-4-phosphate at 75°C. This phase is added in measured amounts, with stirring, to phase II placed in a heatable and coolable closed apparatus with a self-discharging homogenizer. This phase consists of an aqueous mixture containing 2.5% by weight propylene glycol, 2.5% by weight glycerin, 2% by weight sodium lauroyl sarcosinate and 0.3% by weight allantoin. The amount of water is 79.7% by weight. A homogeneous mixture of phases I and II must be achieved. ;

Phase I is added in measured amounts at a temperature of 75°C. Both phases are brought together at a constant medium stirring speed, ensuring that the homogenization is uniform. The temperature is kept at 75°C for between 5 and 20 minutes. The resulting mixture is cooled to a temperature between 30 and 40 ^° C while stirring constantly.

After reaching a temperature of 40 ⁰ C, the other substances can be added. The pH value can also be adjusted to a value between 7.8 and 8.0. 2-amino-2-methyl-lpropanol is used for this purpose. It is stirred for a sufficiently long time until the pH value has stabilized and then the filling is carried out in suitable containers.

Storage containers or filled into the corresponding spray containers. 91% active ingredient is filled with 9% butane/propane.

Claims (12)

1. Foam skin cream available through - Preparation of a phase I by melting at 75°C a mixture containing fatty acids, in particular C ₁₀ - C ₂₂ fatty acids, optionally unsaturated and/or polyunsaturated fatty acids, emulsifiers, coemulsifiers, such as triceteareth-4-phosphate,
followed by a measured addition while stirring to a - Phase II tempered to 75°C, which is obtained from an aqueous mixture containing moisturizers such as propylene glycol and/or polyhydric alcohols, in particular glycerin, emulsifiers such as alkyl sarcosinates, and skin care additives such as allantoin, - whereby a homogeneous mixing of phases I and II is to be achieved and the dosed addition is carried out at a temperature of 75°C, - after addition, the temperature is maintained at 75°C for a period of between 5 and 20 minutes, after which - the temperature of the mixture thus obtained is reduced to a temperature between 30 and 40°C with constant stirring, - Adjusting the pH value to 7.6 to 8.2, preferably with a skin-compatible basic organic compound and filling the resulting mixture into dosage forms with the addition of a propellant gas. 2. Foam skin cream according to claim 1, wherein the mixture of phases I and II is mixed with a preservative while stirring at 30 to 40°C. 3. Foam skin cream according to claim 1 or 2 containing 4 to 15 wt.% oil-in-water emulsifier,
1 to 10 wt.% fatty acid,
0.4 to 2.3 wt.% co-emulsifier
1 to 10 wt.% moisturizer
0.05 to 1 wt.% skin care products and
Water to balance to 100% w/w. 4. Foam skin cream according to one of claims 1 to 3 containing
1 to 3% by weight of glyceryl stearate,
3 to 6 wt.% cetearyl alcohol,
4 to 6 wt.% stearic acid,
0.5 to 2 wt.% paraffin,
0.4 to 2.3 wt.% triceteareth-4-phosphate,
1.5 to 4% by weight of propylene glycol,
1.3 to 4.2 wt.% glycerin,
1 to 3% by weight of cetyl sarcosinate,
0.05 to 1 wt.% allantoin and
Water to balance to 100% w/w. 5. Foam skin cream according to one of claims 1 to 4, additionally containing in phase I a silicone-containing compound, such as dimethicone, preferably in amounts of 0.05 to 1 wt.%. 6. Foam skin cream according to one of claims 1 to 5, additionally containing in phase T one or more moisturizing substances, such as decyl oleate, isohexadecane, stearic acid glycol esters, coconut fatty acid ethanolamide, corn oil, peanut oil, almond oil, sesame oil, olive oil, jojoba oil, soybean oil, wool wax alcohols, paraffin, medium-chain triglycerides, oleic acid oleyl esters, white petrolatum, macrogol glycerol hydroxystearate, hydrogenated castor oil, castor oil communis, avocado oil, wheat germ oil, palmitic acid isopropyl ester, cetyl palmitate, myristic acid myristil ester and/or octyldodecanol. 7. Foaming skin cream according to claim 6, containing
0.5 to 2 wt.% decyl oleate and/or
0.5 to 2 wt.% octyldecanol. 8. Foam skin cream according to claim 6, containing
3 to 6 wt.% decyl oleate and/or
3 to 6 wt.% octyldecanol. 9. Foam skin cream according to claim 6, containing
6 to 9 wt.% decyl oleate and/or
6 to 9 wt.% octyldecanol. 10. Foam skin cream according to one of claims 1 to 9, containing in phase II additional hydrating (moisture-binding) agents such as urea, ethoxydiglycol, sodium chloride, magnesium chloride, sorbitol, dexpanthenol, sodium lactate, preferably 1 to 20% by weight of urea. 11. Foam skin cream according to one of claims 1 to 10, containing polyunsaturated fatty acids, such as w-6 fatty acids, soothing substances, such as chamomile extract, and/or skin-effective vitamins. 12. Foam skin cream according to one of claims 6 to 10, containing
3-7 wt.% calendula extract,
3-7 wt.% witch hazel extract,
3-7% by weight chamomile extract,
3-7 wt.% tea tree oil extract,
1-5 wt.% decyl oleate,
1-5 wt.% octyldodecanol.