Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Cosmetic – antiperspirant – dentifrice
Reexamination Certificate
2000-02-18
2002-07-23
Hartley, Michael G. (Department: 1617)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Cosmetic, antiperspirant, dentifrice
C424S070240, C424S489000, C510S101000, C514S680000
Reexamination Certificate
active
06423323
ABSTRACT:
This application is a 371 of PCT/EP/98/05232 filed Aug, 18, 1998
The present invention relates to a foam skin cream, uses of the foam skin protection cream and a process for its preparation.
The galenic principle of an emulsoid two-phase system having lipophilic or hydrophobic components and, on the other hand, hydrophilic components has been known for the production of foam preparations for skin care. The application of these foam preparations to the treated skin forms a two-dimensional two-phase network, the hydrophilic components bind to the keratin of the horny layer and enable the evaporation of sweat while the lipophilic components inhibit the permeation of moisture (including the penetrated sweat) on the skin surface. As the foam, in contrast to other creams building a barrier, is absorbed in less than a minute, does not leave any grease traces on the working materials and prevents heat built-up or even maceration effects from the action of sweat, the foam has enjoyed rapidly growing popularity as a protective agent against occupational action of moisture. Further details about the per se known foam skin creams can be seen, in particular, from “Haut”,issue 4, 1992, by R. Rudolph, L. Bade, B. Brüggemann.
In “hautnah derm” 10 (1994), 344-351, B. Kunze reports lipid-containing skin protection foams which are indicated for dry sensitive skin and chronical-rhagadiform eczemas. Ingredients are also disclosed therein. The skin protection foams described therein are protective against a lot of occupational noxious matters, such as acid permanent waving liquids in the hairdresser's trade, lyes, oils, disinfectants, cleaning and rinsing agents, but also against water, moisture, sweat, feces, urine and mineral dusts.
EP 0 598 412 also relates to skin protection foams; PTFE is described as an active principle.
DE-C-33 30 628 relates to skin protection and care lotions containing silicone oils, partially neutralized stearic acid, fatty alcohols and their ethoxylated derivatives, ethoxylated wool alcohols, cetyl/stearyl alcohol, vaseline, thickeners and water. The lotions disclosed therein are said to be quickly absorbed without leaving an annoying grease film on the skin for extended periods of time.
Information about emulsifiers which can be employed in skin care agents are found in DE-A-195 42 572. This reference suggests emulsifiers which contain from 43 to 90% by weight of alkyl and/or alkenyl oligoglycosides and from 10 to 57% by weight of fatty alcohols. These emulsifiers are particularly suitable for the preparation of highly viscous, sensorily light oil-in-water emulsions having a long shelf life. The German utility model DE-U9308050 relates to a skin protection foam used against skin-aggressive agents. This foam consists of an aqueous emulsion containing fatty acid esters with good skin compatibility for the production of a moisture-permeable film, polyhydric alcohol for stably dispersing the active agents and controlling the humidity of the film, emulsifiers for improving foam stability, surfactants for reducing the surface tension and optionally neutralizing agents for resins and emulsifiers. Gaseous hydrocarbons may be used as propellants, for example, propane, butane or isobutane and mixtures thereof. However, the foams described do not contain any free fatty acids.
Aerosoles are complicated physical-chemical structures which do not form under arbitrary circumstances. In Particular, a special balance between the foam-forming components is important. Slight shifts in the composition may already result in a collapse of the foam; thus, a formulation of per se active substances may not be capable of being formulated as a foam without further provisions.
Especially in occupational applications, skin creams are often found unpleasant because the “fatting” components remain too long on the skin and lead to annoying finger traces or generally to an unpleasant feeling. This has been remedied to some extent by the per se known skin foams since they help preventing or reducing overload of the skin with the fatting matters. Nevertheless, it is desirable to find even more acceptance by the user, especially in the long-term use of skin protection agents.
It has been the object of the present invention to extend the application range of skin protection foams by providing a formulation which is highly accepted by the user, the admixture of a wide variety of other substances being allowed without destroying the aerosol employed or deteriorating the properties of the aerosol.
The object of the invention is surprisingly achieved by a base formulation of a foam skin cream having the features disclosed and claimed in the present application, including preferred embodiments of the foam skin cream according to the invention, uses of the foam skin cream according to the invention, and a process for preparing the base of a foam skin cream according to the invention.
The foam skin cream according to the invention can be obtained by
preparing a phase I by melting at 75° C. a mixture containing fatty acids, especially C
12
-C
22
fatty acids, optionally unsaturated and/or polyunsaturated fatty acids, emulsifiers, coemulsifiers, such as triceteareth-4-phosphate, followed by metering it with stirring to
a phase II temperature-controlled at 75° C. obtained from an aqueous mixture containing moisturizers, such as propylene glycol and/or polyhydric alcohols, especially glycerol, emulsifiers, such as alkyl sarcosinates, and skin care additives, such as allantoin;
wherein homogeneous mixing of phases I and II is provided and said metering is performed at a temperature of 75° C.;
after the metered addition, the temperature is maintained at 75° C. for a period of between 5 and 20 minutes; whereupon
the temperature of the thus obtained mixture is lowered to a temperature of between 30 and 40° C. with constant stirring;
the pH value is adjusted to from 7.6 to 8.2, preferably with a skin-compatible basic organic compound, and the mixture obtained is filled into dosage forms with the addition of a propellant.
At the one hand, the product obtainable according to this process can be directly employed as a foam skin cream in the industrial field for the protection from or reduction of the absorption of cancerogenic substances, such as polycyclic aromatic hydrocarbons. This mixture is capable of providing effective protection for persons whose skin has already been exposed to cancerogenic substances, such as polycyclic aromatic hydrocarbons. In addition, the mixture is suitable for providing protection to persons from the action of acids, lyes (not above pH 11), scouring agents and detergents, sweat, urine, stool, rubber gloves, dusts, house dust, machine, drilling and cooling oils, greases, paints/varnishes, gypsum and other substances and chemicals, especially aggressive substances and chemicals.
The foam skin cream according to the invention contains fatty acids, especially C
12
-C
22
fatty acids, and may optionally additionally contain unsaturated and/or polyunsaturated fatty acids. Useful fatty acids which are saturated include, in particular, the naturally occurring C
12
-C
22
fatty acids, especially stearic acid and palmitic acid. Myristic acid may also be used. Useful unsaturated fatty acids include, in particular, those having up to three unsaturated bonds in their hydrocarbon chain. Unsaturated fatty acids are found, for example, in fractions of coconut fat. Useful coemulsifiers include per se known coemulsifiers, especially triceteareth-4-phosphate, sodium laureth-4-phosphate or oleth-3 and other lipophilic emulsifiers based on fatty alcohols with a low degree of ethoxylation.
Phase I may additionally contain paraffinum liquidum. Emulsifiers to be used in phase I may include those based on fatty alcohols and those based on partial esters of fatty acids. Particularly preferred fatty alcohols include cetearyl alcohol. Glyceryl stearate, for example, may be employed as a partial ester of a fatty acid.
The moisturizers to be used in phase II include, in particular, propylene glycol and/or polyhydric
Hartley Michael G.
Jacobson & Holman PLLC
Neubourg Stephanie
Willis Michael A.
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