US3906106A - Material for the physiological treatment and refatting of human skin - Google Patents

Abstract

A composition for topical application containing one or more esters formed from an aliphatic, branch chain, fatty alcohol having at least 8 carbon atoms in the molecule and a hydroxy fatty acid. The composition itself can be applied directly to the skin or can be added to cosmetic or pharmaceutical products and provides an irritation reducing, refattening effect on the skin.

Description

United States Patent [191 Jacobi [451 Sept. 16, 1975 MATERIAL FOR THE PHYSIOLOGICAL TREATMENT AND REFA'ITING OF HUMAN SKIN [75] Inventor: Otto K. Jacobi, Wiesbaden,

Germany [73] Assignee: Kolmar Laboratories, Inc., Port Jervis, NY.

[22] Filed: Oct. 23, 1968 [21] App]. No.: 770,116

[52] 11.5. CI. 424/312; 252/106; 252/107 [51] Int. Cl. A61K 31/23 [58] Field of Search 424/312; 252/106, 107,

[56] References Cited FOREIGN PATENTS OR APPLICATIONS 1,048,820 12/1963 United Kingdom 424/312 Primary Examiner-V. D. Turner Attorney, Agent, or Firm-Andrus, Sceales, Starke and Sawall [5 7 ABSTRACT 6 Claims, N0 Drawings MATERIAL FOR THE PHYSIOLOGICAL TREATMENT AND REFATIING OF HUMAN SKIN The present invention relates to a composition for topical application containing one or more esters of a branch chain, aliphatic fatty alcohol and a hydroxy fatty acid which, when applied to the skin, reduces irritation and prevents defatting of the skin.

It is recognized that soaps and detergents when applied to the skin, drastically defat the skin. The result of this defatting action is a dry, chapped, scaling skin condition which in some cases can even be eczematic in nature.

Recently, detergents have been used more extensively in cosmetic preparations. Detergents are used in relatively high concentrations in detergent cleaners for the skin to remove makeup and clean the face, as well as in shampoos, foam and bubble bath preparations, and socalled detergent cakes. These cosmetic products containing detergents not only defat the skin but at the same time have a high irritation effect on the skin.

In the past, various attempts have been made to prevent the drastic defatting action of detergents or surface active agents. Various types of fatty materials such as oils, fats. lanolin, petrolatum and the like have been used in combination with soaps and detergents in an effort to prevent this defatting effect. It was hoped that the addition of the fat-like materials would prevent the defatting effect by depositing or precipitating the fatlike materials on the skin surface to replace the sebum which had been removed by the defatting action of the detergents. However, the addition of fat and fat-like materials to the surface active agents has not been satisfactory and the effect has been nil.

Other attempts have been made to incorporate esters of fatty acids and low molecule primary mono alcohols with surface active agents. Esters such as isopropyl myristate, butyl myristate, propyl myristate, propyl palmitate, ethyl palmitate, ethyl myristate, and the like have been used in the past. These esters have not shown any anti-defatting effect, and as these esters are formed from short chain molecule alcohols, the esters actually increased the irritation to the skin. Moreover, the low molecule alcohol fatty acid esters also possess a solvent effect, and this solvent action serves to increase the defatting effect of the detergent and consequently also increases the irritation. While fatty acids such as myristic or palmitic do occur in human sebum, the low molecule alcohols which have been used in the past in the esters, namely, ethanol, propanol, isopropanol and butanol, are not part of the skin metabolism. Consequently, these materials are foreign to the cells of the living skin and provide additional irritation.

The present invention is a material for topical application which contains an ester of a branch chain, aliphatic, fatty alcohol and a hydroxy fatty acid. The ester is particularly adapted to be combined with a surface active agent. such as a soap or detergent and when applied to the skin, the ester acts to prevent defatting of the skin, and in some cases, a film of fat-like material is deposited on the skin surface after the detergent composition has been rinsed from the skin. As a further advantage, the ester substantially reduces the irritational effect of the detergent or soap on the skin.

The esters of the branch chain, aliphatic fatty alcohols and hydroxy fatty acids are generally used in an amount of 0.05 to 50 percent by weight of the soap or detergent and preferably from 0.5 to 10 percent. The soaps to which the esters are added are conventional types which are metallic salts of fatty acids. Generally, the metal salt will take the form of an alkali metal, such as sodium and potassium, and the fatty acids contain from 12 to 20 carbon atoms. Sodium salts of coconut fatty acids are the most commonly used soaps.

The detergent may be any commonly used surface active agent. Examples of detergents which can be used are alkali metal alkyl sulfates, designated by the formula ROSO X where R is an aliphatic hydrocarbon having a carbon range of 10 to 18, and including both saturated and unsaturated forms, and X is an alkali metal selected from the group consisting of sodium, p0- tassium, lithium and the like. A specific example is sodium lauryl sulfate.

Another group of surfactants or detergents which can be employed is the alkali metal alkylol sarcosinates which have the general formula RCON (CH CH COOX where R is an aliphatic hydrocarbon group having a carbon content of 12 to 18 and X is a hydrogen atom or a water soluble salt-forming cation such as sodium, potassium, lithium and the like.

Acetylenic glycols, such as those disclosed in U.S. Pat. No. 2,997,447, can also be used as the surfactant.

Other detergents or surfactants which can be employed are the water soluble higher alkyl aryl sulfonates, particularly those having about 8 to 15 carbon atoms in the alkyl group. lt is preferred to use the higher alkyl benzene sulfonate detergent for optimum effects though other similar detergents having a mononuclear aryl nucleus, such as toluene, xylene, or phenol, may also be used. The higher alkyl substituent on the aromatic nucleus may be branched or straightchained in structure. examples of such groups being nonyl, decyl, dodecyl, tridecyl and pentadecyl groups derived from polymers of lower mono-olefins, decyl, keryl and the like.

The sulfate and sulfonate detergents can be used in the form of their water soluble salts, such as the alkali metal and nitrogen-containing, e.g. lower alkylolamine salts. Examples are the sodium, potassium, ammonium, isopropanolamine, mono and tri-ethanolamine salts of said higher alkyl benzene sulfonate, higher alkyl sulfate and the like. In commercial practice, it is preferred to use the alkali metal and/or ammonium salts.

Further suitable non-ionic detersive materials are the higher fatty acid alkanolamides, such as the monoethanolamides, diethanolamides and isopropanolamides wherein the acyl radical has about 10 to 18 carbon atoms. Examples are coconut (or equivalent lauric). capric and myristic diethanolamide, monoethanolamide and isopropanolamide.

It should be emphasized that the particular soap or detergent to which the ester is added is not critical to the invention and the action of the ester in reducing the defatting effect will be displayed with all commonly used soaps and detergents.

The alcohol to be employed in forming the ester is a branch chain. aliphatic, primary, secondary or tertiary fatty alcohol having a total of 8 to 20 carbon atoms in the molecule. Alcohols containing less than 8 carbon atoms in the molecule are not akin to the skin and are foreign to the cells metabolism. Alcohols having 20 carbon atoms or less in the molecule are preferred in order to provide an oily or paste-like consistency for the alcohol.

The alcohol can be saturated or unsaturated. The branches are alkyl groups containing 1 to 4 carbon atoms, such as ethyl, methyl, propyl, isopropyl, butyl and iso-butyl. The branches can be located on any of the carbon atoms of the straight chain.

Specific examples of alcohols which can be employed are as follows: 4,6,8-tri-methyl-oleyl-alcohol; a-ethylhexanol; 3.4di-isopropyll-hexadecanol; 2,6-dimethyll-octanol; 2,6-dimethyll -octcnol; 3,7,12,14-tetrabutyll -octadecanol; 3 ,4-dipropyll -decanol; 3 ,5- diethyll -undccanol; 5-methl-7-ethyll -tridecanol; 2,6- ,8-tri-isobutyl-l-octadecanol, and the like.

The fatty acid employed to form the ester can be a straight or branch chain fatty acid containing from 5 to carbon atoms in the straight or primary chain. If a branch chain fatty acid is employed, the branch is an alkyl group containing from 1 to 4 carbon atoms and can be located on any of the carbons of the straight chain.

The fatty acids can be either saturated or unsaturated and contain at least one hydroxy group which can be located anywhere-along the length of the straight carbon chain.

Specific examples of acids which can be employed to form the esters are follows: l2-hydroxyoctadecenoic acid; tri-hydroxy-stearic acid; dihydroxy-stearic acid; a-hydroxy-n-docosanoic acid; ahydroxyn-tetracosanoic acid; a-hydroxy-nhexacosanoic acid; 3-hydroxy-S-butyl-heptadecanoic acid; 3-hydroxy-3-propyl-octadecanoic acid; 3- hydroxy-3-ethyl-nonadecanoic acid, and the like.

Specific examples of esters formed by the reaction of the branch chain aliphatic, primary fatty alcohols and the hydroxy fatty acids are as follows: IZ-hydroxyoctadecanyl-a-ethyl-hexanate; IZ-hydroxyoctadecenyl-2,o-dimethyl-oetanate; a-hydroxy-nhexacosanyl-3.7, l 2, l 4-tetrabutyl-octadecanate; ahydroxy-n-docosanyl-2.6,X-tri-isobutyl-octadecanate; di-hyd'roxy-stearyl-3,S-diethyl-undecanate; B-methyll2-hydroxystearyl-a-ethyl-hexanate; a-ethyll 2- hydroxy-octadecanyl-Z,6-dimethyl-octanate; trihydroxy-stearyl-a-ethyl-hexanate; l2-hydroxyoctadecenyl-3 ,S-diethyl-undecanate; 2,5-butyll 0, l 2- di-hydoxy-hexadecanyl-a-ethyl-hexadecanate, and the like.

The manner of preparing the esters is not critical and generally the acids and alcohols are merely reacted in equimolar amounts.

As previously noted many cosmetic products contain substantial amounts of detergents and because of the high percentage of detergents are irritating to the skin. As an example, the following conventional cosmetic products contain the listed detergents and have the following irritation index:

, Table l-Continued Bath sulfate 4M) 4. l 7

Skin Anionie-tli-hasie-aeid- Cleanser half-ester sulfonate 55.0 3.52

Facial Substituted alkyl- Cleanser amine of lanolin-acids 52.0 5.23

Cleansing Lauryl-eyelo-imidiniuni- Lotion l-ethoxy-ethionie acid- Z-ethionic-aeid. di-

sodium salt 20.0 4.45

Cleanser l.auryl-eyelo-imidinium- (iel l-ethoxy-cthionic acid- Z-ethionic-aeid. disodium salt 25.0

+ Amphotcric surfactant containing Carboxyl and Amine groups 25.0 5.46

Pearl I Sodium-lauryl-sult'ate 50.0 5. l 3 Cleanser lsopropylmyristate l()().() .75

The irritation index is calculated according to the method set forth in the book Appraisal oft/1e Safety of Chemicals in Foods, Drugs and Cosmetics. An irritation index of O to 2 is slightly irritating, an index of 2 to 5, moderate irritation. and an index above 6, severe irritation.

From Table l it can be observed that many conventional cosmetic products contain substantial quantities of detergents which, when applied to the skin, cause defatting of the skin and irritation.

A series of tests were conducted to compare the defatting effect on human skin of (i) conventional detergents alone, (ii) detergents combined with conventional fatty materials, and (iii) detergents combined with the esters of branch chain, aliphatic. primary, fatty alcohols and hydroxy fatty acids. In making these comparative tests, sodium lauryl sulfate was employed as the detergent, and triglycerides, such as caster oil or peaunut oil, and esters of straight chain alcohols, such as octanol, were used as the conventional fatty materials.

In carrying out these tests a 10 cm area of the skin on the outside of the lower arm of a test subject was defatted by wiping the area with defatted, ether-soaked cottonballs. The cottonballs were extracted with ether, the ether evaporated under vacuum, and the remaining sebum residue was dried in an oven at C until a constant weight was reached. This determined the skin surface sebum content.

A neighboring skin arca of the same size was then treated with one of the aqueous detergent solutions. For this purpose a glass cylinder was fixed to the skin, with the skin forming the bottom of the cylinder. 5 ml test solutions were introduced into the cylinder and moved over the skin surface by shaking the arm for a period of 10 minutes. The detergent solutions were then removed from the cylinder and the skin was rinsed three times with 5 ml of distilled water. After rinsing, the cylinder was removed and the skin dried with a warm air current. Following the drying, the sebum content of the treated skin was determined in the same manner previously described. The results of this comparision are shown in the following table:

Table ll Sebum content Test of 10 cm'-' skin '7 Sebum /1 Surface No. Treating Solution surface Lost fat gained l. none 2.3 mg

5'7! sodium lauryl sulfate 2.1 mg 8.7

2. none 4 5 mg 4.5% sodium lauryl sulfate 0.5% olive oil 2 5 mg 28.6

3. none '5 5 mg 4.5'/r sodium lauryl sulfate 0.5% peanut oil 2 2 mg 37.

4. none 2.7 mg

4.5% sodium lauryl sulfate 0.5% castor oil 2 2 mg 18.5

5. none 3.1 m

4.5% sodium lauryl sulfate .57r Octyl-lZ-hydroxy steumtc v 1.) mg 38.8

6. none Y 3.1 mg

4.59 sodium laurl sulfate .57: Octyl-ricinolcutu 2.4 mg 22.6

7. none 2.7 mg

4.5)? sodium lauryl sulfate 0.5: ethyl-hcxyll 2- hydroxy-stcurutc 3.] mg +l4.8

8. none 2.5 mg

4.5% sodium lauryl sulfate 0.5% 2.6 dinicthyloctvl- IZ-hyd roxystcaratc 2.8 mg +ll0 nonc 2.5 mg

4.5% sodium lauryl sulfate 0.57/ u-cthyl-hcxylricinolcutc 2.5 mg 0 0 l0. none 2.8 mg M 4.5% sodium lauryl sulfate 0.5?! 2.11 dimcthyl-octy-L n'cinoleutc 2.8 mg 0 n 0 From Test No. 1 above it can. be seen that treating the skin with an aqueous solution of 5 percent sodium lau ryl sulfate resulted in an 8.7 percent sebum loss, while Tests Nos. 2 and 3, which incorporated olive oil and peanut oil respectively, along with the sodium lauryl sulfate resulted in a substantially greater percentage of sebum loss, namely 28.6 percent and 37.2 percent.

With respect to Test No. 4, the combination of sodium lauryl sulfate and caster oil resulted in a loss of 18.5 percent of the sebum, while treating the skin with the combination of sodium lauryl sulfate and esters of straight chain fatty alcohols'and hydroxy fatty acids resulted in a sebum loss of 38.8 percent and 22.6 percent as shown in Tests Nos. 5 and 6. I I

Tests Nos. 7-10 in Table II were prepared in accordance with the invention and include the addition of an ester of a branch chain aliphatic, fatty alcohol and a hydroxy fatty acid. Morespecifically, the treating solution of Test No. 7 did not result in any loss of the sebum of the skin and in fact resulted in the deposit of a fat film as evidenced by the 14.8 percent increase in fat as shown in the table. Similarly, treating the skin with the solution of Test No. 8 also resulsted in a l2 percent increase in the surface fat. ln tests Nos. 9 and 10 there I was no loss of sebum, but in these tests there was no additional deposit of fat on the skin.

The following table shows the decrease of primary irritation of sodium lauryl sulfate by the addition of aliphatic, branch chain, fatty alcohol esters of hydroxy fatty acids.

Table III Test Irritation No. Aqueous Treating Solution Index I. L471 sodium lauryl sulfate 4.28 2. 57: sodium lauryl sulfate 3.56 3. 4.57: sodium lauryl sulfate 0.5?! 2.6-dimcthyl-octyl-hydroxy- 3,06

stearate 4. 4.5% sodium lauryl sulfate 0.571 a-ethyl-hexyl-ricinoleate 2.73 5. 4.57: sodium lauryl sulfate 0.571 2.6-dimcthyl-octyl-ricinoleate 2.57 6. 4.5)? sodium lauryl sulfate 0.5V: a-ethyl-hexyll Z-hydroxy SICIIIUIC.

The irritation index was calculated according to the method set forth in Appraisal oft/1e Sujl'ty f Chemicals in FOOt/S, Drugs and Cosmetics.

As shown in Table lll. a 1.4 percent aqueous solution of sodium lauryl sulfate provided an irritation index of 4.28. while a greater quantity of the detergent, namely 5 percent. in Test No. 2 resulted in a lesser irritation index of 3.56. The addition of the branch chain aliphatic, fatty alcohol esters of hydroxy fatty acids. as shown in Tests Nos. 3. 4. 5. and 6. in all cases substantially reduced the irritation index over that provided by the sodium lauryl sulfate alone. as shown in Test No. 2. The smaller amount of the detergent in Tests Nos. 3-6. as compared to Test No. 2 did not contribute to the reduced irritation level, for by comparing Test No. l and Test No. 2 it indicates that a decrease in the percentage of detergent results in an increase. and not a decrease. in irritation.

The results of Table lll show the unusual and unexpected property of the esters of aliphatic. branch chain. fatty alcohols and hydroxy fatty acids in reducing the irritational effect of the detergent on human skin.

The following examples illustrate various products incorporating soaps and detergents and the esters of aliphatic. branch chain, fatty alcohols and hydroxy fatty acids with the amounts given in weight per cent.

di-hydroxy-stcaryl-3 .S-diethyl-undecanate -Continued glycerol I071 methyl parabcn 0. l7! sodium cctyl sulfate 5.091 distilled water 70.971 7. Dishwashing Detergent distilled water 70% alkyl polyglycolether sulfate l7r sodium lauryl sulfate 10%' ethanol 57: l 2-hydroxy-octadecanyl-a-ethyl-hcxanate 5'7: 8. Laundrv Detergent dodecylbcnzyl sulfate l07r tetrapropylenc-henZene-sulfatc l0/( tri-sodium-phosphate 40% sodium carbonate carhoxymcthylcellulosc 2% l2-hydroxy-octadecenyl-Z.o-dimethyl-octanate 571 distilled water I07! sodium tripolyphosphate 1371 It is contemplated that the esters of aliphatic, branch chain, fatty alcohols and hydroxy fatty acids can be applied directly to the skin or can be combined with any material which acts to defat human skin. such as surface active agents. solvents. astringcnts. and the like. Moreover. the esters can be used in a wide variety of cosmetic and pharmaceutical products as well as cleansing products. such as laundry and dishwashing detergents, as illustrated by the above Examples.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

1 claim:

1. A composition for topical application, comprising a topical surface active material capable of substantially defatting human skin when applied to said skin. and having incorporated therein an ester of an aliphatic branch chain fatty alcohol and a hydroxy fatty acid, said alcohol containing from 8 to carbon atoms in the molecule and said branch chain being an alkyl group containing from 1 to 4carbon atoms, said acid containing from 5 to 20 carbon atoms. said ester acting to prevent the defatting action of said material and to substantially reduce the irritational effect of said material on said skin. said ester being present in an amount of 0.05 to percent by weight of said material.

2. The composition of claim 1, wherein said fatty acid is selected from the group consisting of a straight chain fatty acid and a branch chain fatty acid.

3. The composition of claim 1, wherein said estei' is 2.6-dimethyl-octyll 2-hydroxy stearate.

4. A method of preventing the defatting effect of topical surface active materials on human skin, comprising the step of contacting the skin with the combination of a topical surface active material selected from the group consisting of soaps and detergents and an effective amount of an ester of an aliphatic branch chain fatty alcohol and a hydroxy fatty acid. said alcohol containing from 8 to 20 carbon atoms in the molecule and said branch chain being an alkyl group containing from 1 to 4 carbon atoms. said acid containing from 5 to 20 carbon atoms in the molecule. said ester being present in an amount of 0.05 to 50 percent by weight of said material. said ester acting to prevent the defatting action of the surface active material and to substantially reduce the irritational effect of said material on the skin.

5. The method of claim 4, wherein said fatty acid is selected from the group consisting of a straight chain fatty acid and a branch chain fatty acid.

6. The method of claim 4, wherein said alcohol and acid are saturated or unsaturated.

Claims (6)

1. A COMPOSITION FOR TOPICAL APPLICATION, COMPRISING A TOPICAL SURFACE ACTIVE MATERIAL CAPABLE OF SUBSTANTIALLY DEFATTING HUMAN SKIN WHEN APPLIED TO SAID SKIN, AND HAVING INCORPORATED THEREIN AN ESTER OF AN ALIPHATIC BRANCH CHAIN FATTY ALCOHOL AND A HYDROXY FATTY ACID, SAID ALCOHOL CONTAINING FROM 8 TO 20 CARBON ATOMS IN THE MOLECULE AND SAID BRANCH CHAIN BEING AN AKYL GROUP CONTAINING FROM 1 TO 4 CARBON ATOMS, SAID ACID CONTAINING FROM 5 TO 20 CARBON ATOMS, SAID ESTER ACTING TO PREVENT THE DEFATTING ACTION OF SAID MATERIAL AND TO SUBSTANTIALLY REDUCE THE IRRITATIONAL EFFECT OF SAID MATERIAL ON SAID SKIN, SAID ESTER BEING PRESENT IN AN AMOUNT OF 0.05 TO 50 PERCENT BY WEIGHT OF SAID MATERIAL.

2. The composition of claim 1, wherein said fatty acid is selected from the group consisting of a straight chain fatty acid and a branch chain fatty acid.

3. The composition of claim 1, wherein said ester is 2,6-dimethyl-octyl-12-hydroxy stearate.

4. A method of preventing the defatting effect of topical surface active materials on human skin, comprising the step of contacting the skin with the combination of a topical surface active material selected from the group consisting of soaps and detergents and an effective amount of an ester of an aliphatic branch chain fatty alcohol and a hydroxy fatty acid, said alcohol containing from 8 to 20 carbon atoms in the molecule and said branch chain being an alkyl group containing from 1 to 4 carbon atoms, said acid containing from 5 to 20 carbon atoms in the molecule, said ester being present in an amount of 0.05 to 50 percent by weight of said material, said ester acting to prevent the defatting action of the surface active material and to substantially reduce the irritational effect of saId material on the skin.

5. The method of claim 4, wherein said fatty acid is selected from the group consisting of a straight chain fatty acid and a branch chain fatty acid.

6. The method of claim 4, wherein said alcohol and acid are saturated or unsaturated.