U.S. patent application number 09/770753 was filed with the patent office on 2003-09-25 for compositions containing stabilized ascorbic acid and related methods.
This patent application is currently assigned to Revlon Consumer Products Corporation. Invention is credited to Guthauser, Bernadette, Moaddel, Teanoosh, Radice, William Joseph, Wolf, Barbara Ann.
Application Number | 20030180333 09/770753 |
Document ID | / |
Family ID | 46257458 |
Filed Date | 2003-09-25 |
United States Patent
Application |
20030180333 |
Kind Code |
A1 |
Moaddel, Teanoosh ; et
al. |
September 25, 2003 |
Compositions containing stabilized ascorbic acid and related
methods
Abstract
A composition in the form of an anhydrous emulsion having as a
dispersed phase ascorbic acid dissolved in a nonaqueous polar
organic solvent, and as the continous phase a nonaqueous nonpolar
organic solvent, as well as a method for dissolving ascorbic
acid.
Inventors: |
Moaddel, Teanoosh;
(Appleton, WI) ; Radice, William Joseph; (New
Brunswick, NJ) ; Wolf, Barbara Ann; (Scarsdale,
NY) ; Guthauser, Bernadette; (North Bergen,
NJ) |
Correspondence
Address: |
Julie Blackburn, Esq.
Revlon Consumer Products Corporation, Law Dept.
625 Madison Avenue
New York
NY
10022
US
|
Assignee: |
Revlon Consumer Products
Corporation
625 Madison Avenue
New York
US
10022
|
Family ID: |
46257458 |
Appl. No.: |
09/770753 |
Filed: |
January 25, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09770753 |
Jan 25, 2001 |
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09268159 |
Mar 15, 1999 |
|
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09268159 |
Mar 15, 1999 |
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08883671 |
Jun 27, 1997 |
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Current U.S.
Class: |
424/401 ;
514/474 |
Current CPC
Class: |
A61K 8/345 20130101;
A61Q 19/00 20130101; A61K 8/676 20130101; A61K 2800/52 20130101;
A61K 8/06 20130101; Y10S 514/937 20130101; A61K 2800/31
20130101 |
Class at
Publication: |
424/401 ;
514/474 |
International
Class: |
A61K 007/00; A61K
031/375 |
Claims
We claim:
1. A composition in the form of an anhydrous emulsion having as a
dispersed phase ascorbic acid dissolved by means of energy input,
in a nonaqueous polar organic solvent, and as the continuous phase
a nonaqueous nonpolar organic solvent.
2. The composition of claim 1 which is a cosmetic composition.
3. The composition of claim 1 comprising, by weight of the total
composition: 0.1-50% ascorbic acid. 5-98% of a nonaqueous polar
organic solvent, and 5-98% of a nonaqueous nonpolar organic
solvent.
4. The composition of claim 1 wherein the ascorbic acid is
completely dissolved in the nonaqueous polar organic solvent.
5. The composition of claim 1 comprising 5-35% by weight of
ascorbic acid.
6. The composition of claim 5 comprising 8-15% by weight of
ascorbic acid.
7. The composition of claim 1 comprising 1-35% ascorbic acid,
20-80% of a nonaqueous polar organic solvent, and 20-80% of a
nonaqueous nonpolar organic solvent.
8. The composition of claim 1 wherein the nonaqueous polar organic
solvent has an octanol/water partition coefficient of less than or
equal to -0.2 at 250 C.
9. The composition of claim 8 wherein the nonaqueous polar solvent
is selected from the group consisting of: a) polyols having three
or more hydroxyl groups per molecule, b) monomeric or polymeric
ethers, c) alcohols of the formula R(OH).sub.n d) diols e) sorbitan
derivatives, f) and mixtures thereof.
10. The composition of claim 1 wherein the nonaqueous nonpolar
organic solvent has an octanol/water partition coefficient of
greater than -0.2 at 25.degree. C.
11. The composition of claim 10 wherein the nonaqueous nonpolar
organic solvent is selected from the group consisting of: a)
silicones, b) fatty esters, c) glyceryl esters of fatty acids. d)
fatty acids, e) fatty alcohols, f) hydrocarbons, g) lanolin and
derivatives thereof, h) sterols, and i) mixtures thereof.
12. The composition of claim 9 wherein the nonaqueous polar solvent
is selected from the group consisting of polyols having three or
more carbon atoms, monomeric or polymeric ethers, and mixtures
thereof.
13. The composition of claim 11 wherein the nonaqueous nonpolar
solvent is selected from the group consisting of silicones, fatty
esters, hydrocarbons, and mixtures thereof.
14. A method for dissolving ascorbic acid in a nonaqueous polar
organic solvent, comprising the steps of: a) heating the nonaqueous
polar organic solvent to a temperature sufficient to dissolve
ascorbic acid in the nonaqueous polar organic solvent. b)
dissolving particulate ascorbic acid in the heated carrier
composition, and c) cooling the mixture.
15. The method of claim 14 wherein the nonaqueous polar organic
solvent is heated to a temperature of 70 to 170.degree. C.
16. The method of claim 15 wherein the temperature of the mixture
is cooled by reducing the temperature by 10 to 145.degree. C.
17. The method of claim 15 wherein the mixture is cooled to room
temperature.
18. The method of claim 15 wherein after cooling the mixture, it is
reheated to a temperature of 70 to 170.degree. C. and a second
nonaqueous polar organic solvent is added.
19. The method of claim 18 wherein after the addition of the second
nonaqueous polar organic solvent, the mixture is cooled.
20. The method of claim 19 wherein the mixture is cooled to room
temperature.
21. The method of claim 20 wherein the mixture is cooled to room
temperature by immersing in an ice water bath.
22. A method for dissolving ascorbic acid in nonaqueous polar
organic solvent comprising the steps of: a) heating a first
nonaqueous polar organic solvent to a temperature of 70 to 1700 C.,
b) dissolving ascorbic acid in the first solvent, c) cooling the
mixture, d) reheating the mixture to a temperature of 70 to
170.degree. C. e) adding a second nonaqueous polar organic solvent,
f) cooling the mixture.
22. The method of claim 21 wherein the composition is cooled to
room temperature.
23. The method of claim 21 wherein the first nonaqueous polar
organic solvent is a polyol having three or more carbon atoms.
24. The method of claim 21 wherein the second nonaqueous polar
organic solvent is a polymeric ether.
25. A cosmetic composition in the form of an anhydrous emulsion
having as the dispersed phase a nonaqueous nonpolar organic
solvent, and as the continuous phase ascorbic acid dissolved in a
nonaqueous polar organic solvent, said composition comprising, by
weight of the total composition: 0.1-50% ascorbic acid, 5-98% of a
nonaqueous polar organic solvent, and 5-98% of a nonaqueous
nonpolar organic solvent.
26. A method for making an anhydrous emulsion having as a dispersed
phase ascorbic acid dissolved in a nonaqueous polar organic
solvent, and as the continuous phase a nonaqueous nonpolar organic
solvent, said composition comprising, by weight of the total
composition: 0.1-40% ascorbic acid, 5-98% of a nonaqueous polar
organic solvent, 5-98% of a nonaqueous nonpolar organic solvent,
comprising the steps of: a) heating the nonaqueous polar organic
solvent to a temperature of about 80 to 120.degree. C., b)
dissolving particulate ascorbic acid in the heated carrier
composition, c) cooling the mixture.
27. The method of claim 26 wherein the mixture is then emulsified
into the nonaqueous nonpolar organic solvent.
28. A method for making an anhydrous emulsion having as the
dispersed phase a nonaqueous nonpolar organic solvent, and as the
continuous phase ascorbic acid dissolved in a nonaqueous polar
organic solvent, said composition comprising, by weight of the
total composition: 0.1-40% ascorbic acid, 5-98% of a nonaqueous
polar organic solvent, and 5-98% of a nonaqueous nonpolar organic
solvent, comprising the steps of: a) heating the nonaqueous
nonpolar organic solvent to a temperature of 80 to 120.degree. C.
b) dissolving particulate ascorbic acid in the heated composition
of (a), c) cooling the mixture.
29. The method of claim 28 wherein the nonaqueous nonpolar organic
solvent is emulsified into the mixture nonaqueous polar organic
solvent containing dissolved ascorbic acid.
Description
TECHNICAL FIELD
[0001] The invention pertains to the field of compositions,
particularly cosmetic compositions, containing ascorbic acid in
bioavailable form.
BACKGROUND OF THE INVENTION
[0002] It is well known that aging of the skin is due, at least in
part, to continual stretching and contraction of both the dermal
and epidermal layers of the skin and disruption of the collagen
bundles which provide support to the epidermis. Collagen consists
of long elastic polypeptide fibers interconnected by bridges which
provide the cohesion and stability of connective tissue. This
enables collagen to act as an elastic tissue in every direction and
retain water. Collagen aging manifests itself as a break in
connection between the collagen fibers. Age, severe weather, and
pollution accelerate the breaks and slow down renewal of the
collagen structure.
[0003] Ascorbic acid, or Vitamin C, has many known biological
functions. The L-ascorbic acid isomer is biologically active and is
known to stimulate the synthesis of collagen, act as a free radical
scavenger, and minimize lipid peroxidation and other forms of
cellular damage associated with aging
[0004] Ascorbic acid is a white, odorless, crystalline solid having
the empirical formula C.sub.6H.sub.8O.sub.6, a molecular weight of
about 176, and exhibits the following structural formula: 1
[0005] Ascorbic acid is highly soluble, but extremely unstable, in
water and rapidly decomposes to form dehydroascorbic acid. This
degradation is even more pronounced in the presence of oxygen. It
is known that ascorbic acid is much more stable in nonaqueous polar
solvents such as polyols, but unfortnately its solubility is
limited in such solvents and it generally is thought to be not
possible to obtain stable ascorbic acid solutions of more than
several percent by weight concentration. Since the anti-aging
effects of ascorbic acid are known to be dose-dependent, it is
desirable to make stable cosmetic compositions containing ascorbic
acid dispersed in a cosmetically acceptable carrier at a
concentration of greater than about 5 weight percent, preferably up
to 20 or 30 weight percent.
[0006] Numerous patents and publications teach various ways of
stabilizing ascorbic acid. For example, European Patent Publication
No. 0 729 746 teaches an ascorbic acid delivery system comprised of
a two compartment kit. In the first compartment is an anhydrous
solution of ascorbic acid dissolved in a nonaqueous polar solvent
such as a polyol. In the second compartment is an alkaline aqueous
solution. The contents of the two compartments are mixed
immediately prior to use. The more alkaline aqueous solution
increases the pH of the anhydrous ascorbic acid containing solution
to provide a composition which does not tingle the skin.
[0007] U.S. Pat. No. 5,350,773 teaches stable liquid products used
for liquid human and animal food. The compositions are in the form
of anhydrous emulsions containing a nonpolar fatty material as the
dispersed phase and a polar nonaqueous solvent as the continuous
phase. Esters of ascorbic acid are used as the emulsifying
agent.
[0008] U.S. Pat. No. 5,427,814 teaches a method for protecting a
fat against oxidation by mixing ascorbic acid into a polar solvent,
and adding the mixture to a heated mixture of tocopherol and
lecithin. The polar solvent is then evaporated from the mixture by
subjecting the mixture to heat for a period of time.
[0009] U.S. Pat. No. 5,308,621 teaches a method for transdermal
administration of ascorbic acid. Fine particulate ascorbic acid is
suspended in a pharmaceutically acceptable carrier such as a
polyol. The compositions are topically applied and the particulate
ascorbic acid dissolves upon contact with skin and is absorbed into
the skin.
[0010] European Patent Publication No. 0 755 674 teaches stabilized
ascorbic acid compositions containing a water activity value of
less than 0.85. The compositions contain a minimum level of water,
in addition to a polyol and an oil.
[0011] U.S. Pat. No. 5,587,149 teaches ascorbic acid emulsion
compositions comprising ascorbic acid solubilized in a polyol as
the dispersed phase and oil as the continuous phase.
[0012] However, none of the above patents teach a stable anhydrous
ascorbic acid containing composition suitable for cosmetic
application where high levels of ascorbic acid are solubilized in
the composition and remain stable over protracted periods of time.
By "solubilized" it is meant either dissolved or emulsified, but
not merely suspended.
[0013] An object of the invention is to provide a method for
stabilizing ascorbic acid to enable its use in cosmetic products
which have anti-aging effects.
[0014] Another object of the invention is to provide a stabilized
ascorbic acid composition suitable for use in cosmetics.
[0015] Another object of the invention is to provide a stabilized
ascorbic acid composition containing ascorbic acid at significant
concentrations.
[0016] Another object of the invention is to provide a stabilized
ascorbic acid composition in an anhydrous emulsion form which
contains ascorbic acid at significant concentrations.
SUMMARY OF THE INVENTION
[0017] The invention comprises a composition in the form of an
anhydrous emulsion having as a dispersed phase, ascorbic acid
dissolved by means of energy input, in a nonaqueous polar organic
solvent, and as the continuous phase a nonaqueous nonpolar organic
solvent.
[0018] The invention comprises a composition in the form of an
anhydrous emulsion having as the dispersed phase a nonaqueous
nonpolar organic solvent, and as the continuous phase ascorbic acid
dissolved in a nonaqueous polar organic solvent.
[0019] The invention is also directed to a method for dissolving
ascorbic acid in a nonaqueous polar organic solvent comprising the
steps of:
[0020] a) heating the nonaqueous polar organic solvent to a
temperature sufficient to dissolve ascorbic acid,
[0021] b) dissolving particulate ascorbic acid in the heated
carrier composition, and
[0022] c) reducing the temperature of the mixture, preferably to
approximately room temperature.
[0023] The invention is also directed to a method for making an
anhydrous emulsion having as a dispersed phase ascorbic acid
dissolved in a nonaqueous polar organic solvent, and as the
continuous phase a nonaqueous nonpolar organic solvent, comprising
the steps of:
[0024] (a) heating the nonaqueous polar organic solvent to a
temperature sufficient to dissolve ascorbic acid,
[0025] (b) dissolving particulate ascorbic acid in the heated
nonaqueous polar organic solvent,
[0026] (c) reducing the temperature of the mixture, preferably to
approximately room temperature,
[0027] (d) emulsifying the ascorbic acid mixture into the
nonaqueous nonpolar organic solvent.
[0028] The invention also comprises a method for making an
anhydrous emulsion having as the dispersed phase a nonaqueous
nonpolar organic solvent, and as the continuous phase ascorbic acid
dissolved in a nonaqueous polar organic solvent, comprising the
steps of:
[0029] (a) heating the nonaqueous polar organic solvent to a
temperature sufficient to dissolve ascorbic acid,
[0030] (b) dissolving particulate ascorbic acid in the heated
nonaqueous polar organic solvent,
[0031] (c) reducing the temperature of the mixture, preferably to
room temperature,
[0032] (d) emulsifying the nonaqueous nonpolar organic solvent into
the solubilized ascorbic acid mixture.
[0033] The invention is directed to cosmetic compositions
comprising, by weight of the total composition:
[0034] 0.1-50% ascorbic acid,
[0035] 5-98% of a nonaqueous polar organic solvent,
[0036] 5-98% of a nonaqueous nonpolar organic solvent.
BACKGROUND OF THE INVENTION
[0037] Definitions
[0038] The term "ascorbic acid" when used in accordance with this
invention means L-ascorbic acid, the bioavailable form, and
derivatives thereof.
[0039] The term "partition coefficient" when used in accordance
with the invention means the octanol/water partition coefficient of
the solvent as calculated by the ACD/LogP software program marketed
by Advanced Chemistry Development, Inc. The software calculates the
partition coefficient based upon the molecular structure of the
solvent. Actual chemical measurement of partition coefficients may
be difficult. The partition coefficient is defined as, in the
equilibrium distribution of the solvent between two liquid phases,
one of which is water and the other of which is octanol, the ratio
of the solvent concentration in the octanol phase to the solvent
concentration in the water phase.
[0040] The term "polar" means, when used to characterize the
solvent, that the logarithm of the octanol/water partition
coefficient of the solvent as measured by the ACD/LogP software
program, is less than or equal to -0.2 at room temperature. Thus, a
polar solvent is one which is capable of solubilizing at least 2
weight percent or more of ascorbic acid at room temperature
(generally 25.degree. C.)
[0041] The term "nonpolar" means, with respect to the solvent, that
the logarithm of the octanol/water partition coefficient of the
solvent as measured by the ACD/LogP software program, is greater
than -0.2 at room temperature. Thus, a nonpolar solvent is one
which is capable of solubilizing less than 2 weight percent of
ascorbic acid at room temperature.
[0042] The term "anhydrous" means that no substantial amount of
water is added to the compositions of the invention. Trace amounts
of water (for example, supplied as an impurity in the raw materials
used to make the compositions of the invention) may still be
presents e.g. in an amount less than about 5% by weight of the
total composition, preferably less than 1 to 3% by weight of the
total composition.
[0043] The term "dissolved" or "dissolving" means that the ascorbic
acid is essentially solubilized or dissolved in the nonaqueous
polar organic solvent, and that the ascorbic acid will not exist to
any appreciable degree in the particulate or crystalline form.
[0044] The compositions of the invention may be liquid, semi-solid,
or solid at room temperature. The compositions exist in an
anhydrous emulsion form. The term "emulsion" is generally used in
the cosmetic art to mean water-in-oil or oil-in-water emulsions.
However, the compositions of the invention are anhydrous emulsions
wherein one anhydrous phase (`the dispersed phase`) is dispersed
into another anhydrous phase ("the continuous phase"). In the
anhydrous emulsions of the invention, the ascorbic acid dissolved
into the nonaqueous polar organic solvent forms the dispersed
phase. The nonaqueous nonpolar organic solvent forms the continuous
phase.
[0045] All percentages mentioned herein are percentages by weight
unless otherwise indicated.
[0046] The Nonaqueous Polar Organic Solvent
[0047] The anhydrous emulsions of the invention contain 1-99%,
preferably 20-80%, more preferably 40-60% by weight of the total
composition, of a nonaqueous polar organic solvent. A variety of
nonaqueous polar organic solvents are suitable for use in the
dispersed phase of the anhydrous emulsion. As mentioned above, a
solvent, in particular a nonaqueous solvent, is considered "polar"
in the context of the invention if the logarithm of the partition
coefficient of the solvent is less than or equal to -0.2 at room
temperature. Examples are as follows.
[0048] Polyols
[0049] Polyols are suitable nonaqueous polar organic solvents. For
purposes of this specification, polyols are defined as compounds
which contain three or more hydroxyl groups per molecule. Examples
of suitable polyols include fructose, glucamine, glucose, glucose
glutamate, glucuronic acid, glycerin, 1,2,6hexanetriol,
hydroxystearyl methylglucanine, inositol, lactose, malitol,
mannitol, methyl gluceth-10, methyl gluceth-20, methyl glucose
dioleate, methyl glucose sesquicaprylate/sesquicaprate, methyl
glucose sesquicocoate, methyl glucose sesquiisostearate, methyl
glucose sesquilaurate, methyl glucose sesquistearate, phytantriol,
riboflavin, sorbeth-6, sorbeth-20, sorbeth-30, sorbeth-40,
sorbitol, sucrose, thioglycerin, xylitol, and mix thereof. An
especially preferred polyol is glycerin.
[0050] Polymeric or Monomeric Ethers
[0051] Also suitable as the nonaqueous polar organic solvent are
homopolymeric or block copolymeric liquid ethers. Polymeric ethers
are preferably formed by polymerization of monomeric alkylene
oxides, generally ethylene or propylene oxides. Preferred monomeric
ethers are those exhibiting the structure below were n=1. Preferred
polymeric ethers exhibit the general structure below wherein n=2 to
20: 2
[0052] where R is H or C.sub.1-10 straight or branched chain alkyl,
and n is 1 to 20. Examples of such polymeric ethers include PEG,
PPG, and derivatives thereof.
[0053] Other examples of suitable polymeric ethers include
polyoxypropylene polyoxyethylene block copolymers having the
general formula: 3
[0054] wherein x is 1-200, y is 1-200 and z is 1-200. Such
compounds are sold under the CTFA name Meroxapol 105, 108, 171,
172, 174, 178, 251, 252, 254, 255, 258, 311, 312, and 314.
[0055] Mono- and Dihydric Alcohols
[0056] Also suitable for use as to the nonaqueous polar organic
solvent are mono- and dihydric alcohols of the general formula
R(OH).sub.n where n is 1 or 2 and R is a substituted or
unsubstituted saturated C.sub.2-10, preferably C.sub.1-8 alkyl, or
a substituted or unsubstituted alicyclic, bicyclic, or aromatic
ring, with the substituents selected from halogen, alkoxy, hydroxy,
and so on. Examples of suitable alcohols include monohydric
alcohols such as ethanol, isopropanol, hexyldecanol, benzyl
alcohol, propyl alcohol, and isopropyl alcohol, as well as dihydric
alcohols such as hexylene glycol, diethylene glycol, ethylene
glycol, propylene glycol, 1,2-butylene glycol, triethylene glycol,
dipropylene glycol, and mixtures thereof.
[0057] Sorbitan Derivatives
[0058] Sorbitan derivatives, which are defined as ethers or esters
of sorbitan, are also suitable polar solvents. Examples of suitable
sorbitan derivatives are the Polysorbates, which are defined as
stearate esters of sorbitol and sorbitan anhydrides, such as
Polysorbate 20, 21, 40, 60, 61, 65, 80, 81, and 85. Also suitable
are fatty esters of hexitol anhydrides derived from sorbitol, such
as sorbitan trioleate, sorbitan tristearate, sorbitan
sesquistearate, sorbitan stearate, sorbitan palmitate, sorbitan
oleate, and mixtures thereof.
[0059] Other nonaqueous polar solvents will also work in the
claimed compositions, provided the logarithm of the measured
partition coefficient of the solvent is less than -0.2 at room
temperature.
[0060] The Nonaqueous Nonpolar Organic Solvent
[0061] The anhydrous emulsions of the invention contain 1-99%,
preferably 20-80%, more preferably 4060%, by weight of total
composition, of a nonaqueous nonpolar organic solvent as the
continuous phase. Such solvents are defined as those where the
logarithm of the partition coefficient is greater than -0.2 at room
temperature. A variety of nonaqueous nonpolar organic solvents can
be used in the compositions of the invention.
[0062] Silicones
[0063] Silicones are suitable nonpolar compounds. The silicones may
be volatile or non-volatile. The term "volatile" means that the
silicone has a measureable vapor pressure, i.e. a vapor pressure of
at least 2 mm. of mercury at 20.degree. C. If volatile, the
silicone generally will have a viscosity of 0.5 to 25 centistokes
at 25.degree. C. Suitable volatile silicones include cyclic
silicones, linear silicones, or mixtures thereof. Cyclic silicones
(or cyclomethicones) are of the general formula: 4
[0064] wherein n 3-7, and R.sub.1 and R.sub.2 are each
independently H, C.sub.1-8 alkyl, aryl, aralkyl, alkenyl, or a
cylic or alicylic ring. Preferably R.sub.1 and R.sub.2 are each
independently H or CH.sub.3. Most preferably R.sub.1 and R.sub.2
are each CH.sub.3.
[0065] Linear volatile silicones in accordance with the invention
have the general formula:
(CH.sub.3).sub.3Si--O--[Si(CH.sub.3).sub.2--O].sub.n--Si(CH.sub.3).sub.3
[0066] where n=0-7, preferably 0-5.
[0067] Linear and cyclic volatile silicones are available from
various commercial sources including Dow Corning Corporation and
General Electric. The Dow Corning volatile silicones are sold under
the tradenames Dow Corning 244, 245, 344, and 200 fluids. These
fluids comprise octamethylcyclotetrasiloxane,
decamethylcyclopentasiloxane, hexamethyldisiloxane, and mixtures
thereof.
[0068] The silicone may also be nonvolatile, and in particular
water insoluble nonvolatile silicones. The term "nonvolatile" means
that the silicone has a vapor pressure of less than 2 mm. of
mercury at 20.degree. C. A variety of silicones fit this definition
including dimethicone, phenyl trimethicone, diphenyl dimethicone,
methicone, hexadecyl methicone, stearoxydimethicone, stearyl
dimethicone, cetyl dimethicone, and so on.
[0069] Cyclomethicone is the preferred silicone for use in the
compositions of the invention.
[0070] Esters
[0071] In addition to the sorbitan esters, other esters are also
suitable as the nonaqueous nonpolar organic solvent. In general
such esters have the formula RCO--OR wherein each R is
independently a C.sub.1-25 straight or branched chain saturated or
unsaturated alkyl, alkylcarbonyloxyalkyl, or alkoxycarbonylalkyl,
aryl, which may be substituted or unsubstituted with halogen,
hydroxyl, alkyl, and the like.
[0072] Examples of suitable esters include alkyl acetates, alkyl
behenates, alkyl lactates, alkyl benzoates, alkyl octanoates, alkyl
salicylates, and in particular C.sub.12-15 alkyl benzoate. Examples
of further esters are set forth on pages 502-506 of the CTFA
Cosmetic Ingredient Handbook, Second Edition, 1992, which is hereby
incorporated by reference.
[0073] Fats and Oils
[0074] Fats and oils are also suitable as the nonaqueous nonpolar
organic solvent. Preferably these materials are liquids or
semi-solids at room temperature. They are generally defined as
glyceryl esters of fatty acids (triglycerides), as well as the
synthetically prepared esters of glycerin and fatty acids having
the following general formula: 5
[0075] wherein R, R', and R" are each independently fatty acid
radicals. Examples of such materials include oils such as apricot
kernel oil, avocado oil, canola oil, olive oil, sesame oil, peanut
oil, soybean oil, trilinolenin, trilinolein, trioctanoin,
tristearin, triolein, sesame oil, rapeseed oil, sunflower seed oil,
and so on.
[0076] Fatty Acids
[0077] Fatty acids are also suitable as the nonaqueous nonpolar
organic solvent in the compositions of the invention. Preferably
the fatty acids are liquid or semi solid at room temperature. Fatty
acids are the carboxylic acids obtained by hydrolysis of animal or
vegetable fats and oils. Carboxylic acids having alkyl chains
shorter than about seven carbon atoms are not generally considered
fatty acids. Fatty acids have the general structure R--COOH where R
is a straight or branched chain saturated or unsaturated C.sub.7-65
alkyl. Examples of suitable fatty acids include arachidic acid,
arachidonic acid, behenic acid, capric acid, caproic acid, caprylic
acid, coconut acid, corn acid, cottonseed acid, hydrogenated
coconut acid, hydroxystearic acid, lauric acid, linoleic acid,
linolenic acid, linseed acid, myristic acid, oleic acid, palmitic
acid, palm kernel acid, soy acid, tallow acid, and the like.
[0078] Fatty Alcohols
[0079] Fatty alcohols may also be used as the nonaqueous nonpolar
organic solvent. Fatty alcohols are generally made by reducing the
fatty acid --COOH group to the hydroxyl function. They generally
have the formula RCH.sub.2OH. Examples of fatty alcohols are
behenyl alcohol, C.sub.9-11 alcohol, C.sub.12-13 alcohol,
C.sub.12-15 alcohol, C.sub.12-16 alcohol, caprylic alcohol,
cetearyl alcohol, cetyl alcohol, coconut alcohol, decyl alcohol,
lauryl alcohol, myristyl alcohol, oleyl alcohol, and the like.
[0080] Hydrocarbons
[0081] Hydrocarbons are also good nonaqueous nonpolar organic
solvents in accordance with the invention. Examples of suitable
hydrocarbons include C.sub.7-60 isoparaffins, ethane, heptane,
hexane, hydrogenated polyisobutene, isobutane, isododecane,
isoeicosane, isohexadecane, isopentane, microcrystalline wax,
mineral oil, mineral spirits, paraffin, petrolatum, petroleum
distillates, squalene, polyethylene, and mixtures thereof.
Preferred hydrocarbons are mineral oil and polyethylene.
[0082] Lanolin and Lanolin Derivatives
[0083] Also suitable as the nonaqueous nonpolar organic solvent are
lanolin and derivatives thereof. Examples of such materials include
acetylated hydrogenated lanolin, acetylated lanolin alcohol,
laneth, lanolin acid, lanolin oil, lanolin alcohol, lanolin wax,
and so on.
[0084] Other Ingredients
[0085] It may also be desired to include certain other ingredients
in the anhydrous emulsions of the invention, such as surfactants,
waxes, colorants, preservatives, and so on.
[0086] Surfactants
[0087] Silicone Surfactants
[0088] The compositions may contain 0.1-15%, preferably 0.5-10%,
more preferably 1-8% by weight of the total composition of one or
more surfactants. The term "surfactant" is defined, in accordance
with the invention, as a compound having at least one hydrophilic
moiety and at least one lipophilic moiety. The surfactants may be
silicone surfactants (also referred to as organosiloxane
emulsifiers) or organic surfactants.
[0089] Suitable silicone surfactants used in the compositions of
the invention may be liquid or solid at room temperature and are
generally a water-in-oil or oil-in-water type surfactants which are
preferably nonionic, having an Hydrophile/Lipophile Balance (HLB)
of 2 to 18. Preferably the organosiloxane is a nonionic surfactant
having an HLB of 2 to 12, preferably 2 to 10, most preferably 4 to
6. The HLB of a nonionic surfactant is the balance between the
hydrophilic and lipophilic portions of the surfactant and is
calculated according to the following formula:
HLB=7+11.7.times.log M.sub.w/M.sub.o
[0090] where M.sub.w is the molecular weight of the hydrophilic
group portion and M.sub.o is the molecular weight of the lipophilic
group portion.
[0091] Another method of calculating HLB is:
HLB=20(1-S/A)
[0092] where S is the saponification number of the surfactant and A
is the acid number of the surfactant.
[0093] The silicone surfactant or emulsifier used in the
compositions of the invention is a polymer containing a polymeric
backbone including repeating siloxy units that may have cyclic,
linear or branched repeating units, e.g. di(lower)alkylsiloxy
units, preferably dimethylsiloxy units. The hydrophilic portion of
the organosiloxane is generally achieved by substitution onto the
polymeric backbone of a radical that confers hydrophilic properties
to a portion of the molecule. The hydrophilic radical may be
substituted on a terminus of the polymeric organosiloxane, or on
any one or more repeating units of the polymer. In general, the
repeating dimethylsiloxy units of modified polydimethylsiloxane
emulsifiers are lipophilic in nature due to the methyl groups, and
confer lipophilicity to the molecule. In addition, longer chain
alkyl radicals, hydroxy-polypropyleneoxy radicals, or other types
of lipophilic radicals may be substituted onto the siloxy backbone
to confer further lipophilicity and organocompatibility. If the
lipophilic portion of the molecule is due in whole or part to a
specific radical, this lipophilic radical may be substituted on a
terminus of the organosilicone polymer, or on any one or more
repeating units of the polymer. It should also be understood that
the organosiloxane polymer in accordance with the invention should
have at least one hydrophilic portion and one lipophilic
portion.
[0094] The term "hydrophilic radical" means a radical that, when
substituted onto the organosiloxane polymer backbone, confers
hydrophilic properties to the substituted portion of the polymer.
Examples of radicals that will confer hydrophilicity are
hydroxy-polyethyleneoxy, hydroxyl, carboxylates, sulfonates,
sulfates, phosphates, or amines.
[0095] The term "lipophilic radical" means an organic radical that,
when substituted onto the organosiloxane polymer backbone, confers
lipophilic properties to the substituted portion of the polymer.
Examples of organic radicals which will conver lipophilicity are
C.sub.1-40 straight or branched chain alkyl, fluoro, aryl, aryloxy,
C.sub.1-40 hydrocarbyl acyl, hydroxy-polypropyleneoxy, or mixtures
thereof. The C.sub.1-40 alkyl may be non-interrupted, or interruped
by one or more oxygen atoms, a benzene ring, amides, esters, or
other functional groups.
[0096] The polymeric organosiloxane emulsifier used in the
invention may have any of the following general formulas:
M.sub.xQ.sub.y, or
M.sub.xT.sub.y, or
MD.sub.xD'.sub.yD".sub.zM
[0097] wherein each M is independently a substituted or
unsubstituted trimethylsiloxy endcap unit. If substituted, one or
more of the hydrogens on the endcap methyl groups are substituted,
or one or more methyl groups are substituted with a substituent
that is a lipophilic radical, a hydrophilic radical, or mixtures
thereof. T is a trifunctional siloxy unit having the empirical
formula RSiO.sub.15 or RSiO.sub.15. Q is a quadrifunctional siloxy
unit having the empirical formula SiO.sub.2, and D, D', D", x, y,
and z are as set forth below, with the proviso that the compound
contains at least one hydrophilic radical and at least one
lipophilic radical. Examples of emulsifiers used in the
compositions of the invention are of the general formula:
MD.sub.xD'.sub.yD".sub.zM
[0098] wherein the trimethylsiloxy endcap unit is unsubstituted or
mono-substituted, wherein one methyl group is substituted with a
lipophilic radical or a hydrophilic radical. Examples of such
substituted trimethylsiloxy endcap units include
(CH.sub.3).sub.2HPSiO, (CH.sub.3).sub.2LPSiO,
(CH.sub.3).sub.2CH.sub.2HPSiO, (CH.sub.3).sub.2CH.sub.2LPSiO,
wherein HP is a hydrophilic radical and LP is a lipophilic radical.
D, D', and D" are difunctional siloxy units substituted with
methyl, hydrogen, a lipophilic radical, a hydrophilic radical or
mixtures thereof. In this general formula:
[0099] x=0-5000, preferably 1-1000
[0100] y=0-5000, preferably 1-1000, and
[0101] z=0-5000, preferably 0-1000,
[0102] with the proviso that the compound contains at least one
lipophilic radical and at least one hydrophilic radical. Examples
of these polymers are disclosed in U.S. Pat. No. 4,698,178, which
is hereby incorporated by reference.
[0103] Particularly preferred is a linear silicone of the
formula:
MD.sub.xD'.sub.yD".sub.zM
[0104] wherein M=RRRSiO.sub.1/2
[0105] D and D'=RR'SiO.sub.2/2
[0106] D"=RRSiO.sub.2/2
[0107] x, y, and z are each independently 0-1000,
[0108] where R is methyl or hydrogen, and R' is a hydrophilic
radical or a lipophilic radical, with the proviso that the compound
contains at least one hydrophilic radical and at least one
lipophilic radical.
[0109] Most preferred is wherein
[0110] M=trimethylsiloxy
[0111] D=Si[(CH.sub.3)][(CH.sub.2).sub.nCH.sub.3]O.sub.2/2 where
n=1-40,
[0112] D'=Si [(CH.sub.3)][(CH.sub.2).sub.o--O-PE)]O.sub.2/2 where
PE is (--C.sub.2H.sub.4O).sub.a(--C.sub.3H.sub.6O).sub.bH, o=0-40,
a=1-100 and b=1-100, and
[0113] D"=Si (CH.sub.3).sub.2O.sub.2/2
[0114] Typical examples of preferred organosiloxane emulsifiers in
accordance with the invention include those set forth below: 6
[0115] wherein LP is a lipophilic radical
[0116] HP is a hydrophilic radical
[0117] x is 0-5000
[0118] y is 0-5000, and
[0119] z is 0-5000, with the proviso that the organosiloxane
contains at least on hydrophilic radical and at least one
lipophilic radical.
[0120] More preferred are compounds of the generic formula I
wherein LP is a lipophilic radical which is a C.sub.1-40 straight
or branched chain alkyl, HP is a hydrophilic radical containing
hydroxy-polyethyleneoxy, and z is at least 1. Most preferred is a
compound of the formula: 7
[0121] wherein p is 1040, preferably 12-20, most preferably 15,
and
[0122] PE is (--C.sub.2H.sub.4O)a(--C.sub.3H.sub.6O).sub.b--H
[0123] where x, y, z, a, and b are such that the maximum molecular
weight of the polymer is approximately 50,000. Organosiloxane
polymers useful in the compositions of the invention are
commercially available from Goldschmidt Corporation under the ABIL
tradename. The preferred polymer is cetyl dimethicone copolyol and
has the tradename ABIL WE 09 or ABIL WS 08. The cetyl dimethicone
copolyol may be used alone or in conjunction with other
non-silicone organic emulsifiers. Preferred is where the cetyl
dimethicone copolyol is in an admixture with other non-silicone
organic emulsifiers and emollients. In particular, blends of 25-50%
of the organosiloxane emulsifier, 25-50% of a non-silicone organic
emulsifier, and 25-50% by weight emollients or oils are preferred.
For example, the mixtures identified by the C.T.F.A. names cetyl
dimethicone copolyol (and) polyglyceryl 4-isostearate (and) hexyl
laurate, or cetyl dimethicone copolyol (and) polyglyceryl-3 oleate
(and) hexyl laurate both work well. These blends contain
approximately 25-50% of each ingredient, for example ABIL WE 09
contains approximately, by weight of the total ABIL composition,
25-50% cetyl dimethicone copolyol, 25-50%, polyglyceryl
4-isostearate, and 25-50% of hexyl laurate which is an emollient or
oil.
[0124] Another type of preferred organosiloxane emulsifier suitable
for use in the compositions of the invention are emulsifiers sold
by Union Carbide under the Silwet.TM. trademark. These emulsifiers
are represented by the following generic formulas:
(Me.sub.3Si).sub.y-2[(OSiMe.sub.2).sub.x/yO-PE].sub.y
[0125] wherein PE=--(EO).sub.m(PO).sub.nR
[0126] R=lower alkyl or hydrogen
[0127] Me=methyl
[0128] EO is polyethyleneoxy
[0129] PO is polypropyleneoxy
[0130] m and n are each independently 1-5000
[0131] x and y are each independently 0-5000, and 8
[0132] wherein
PE=--CH.sub.2CH.sub.2CH.sub.2O(EO).sub.m(PO).sub.nZ
[0133] Z=lower alkyl or hydrogen, and
[0134] Me, m, n, x, y, EO and PO are as described above.
[0135] with the proviso that the molecule contains a lipophilic
portion and a hydrophilic portion. Again, the lipophilic portion
can be supplied by a sufficient number of methyl groups on the
polymer backbone.
[0136] Particularly preferred is a Silwet.TM. polymer of the
following general formula: 9
[0137] Wherein n is 1-10, preferably 8.
[0138] Another preferred organosiloxane emulsifier for use in the
compositions of the invention is dimethicone copolyol.
[0139] Examples of other polymeric organosiloxane surfactants or
emulsifiers include amino/polyoxyalkyleneated polydiorganosiloxanes
disclosed in U.S. Pat. No. 5,147,578. Also suitable are
organosiloxanes sold by Goldschmidt under the ABIL trademark
including ABIL B-9806, as well as those sold by Rhone-Poulenc under
the Alkasil tradename. Also, organosiloxane emulsifiers sold by
Amerchol under the Amersil tradename, including Amersil ME-358,
Amersil DMC-287 and Amersil DMC-357 are suitable. Dow Corning
surfactants such as Dow Corning 3225C Formulation Aid, Dow Corning
190 Surfactant, Dow Corning 193 Surfactant, Dow Corning Q2-5200,
and the like are also suitable. In addition, surfactants sold under
the tradename Silwet by Union Carbide, and surfactants sold by Troy
Corporation under the Troysol tradename, those sold by Taiwan
Surfactant Co. under the tradename Ablusoft, those sold by Hoechst
under the tradename Arkophob, are also suitable for use in the
invention.
[0140] Also suitable as surfactants are various organic surfactants
such as anionic, nonionic, amphoteric, zwitterionic, or cationic
surfactants.
[0141] The compositions of the invention comprise 0.5-20%,
preferably 0.5-15%, more preferably 0.5-10%, of a surfactant.
Suitable surfactants may be anionic, nonionic, amphoteric, or
zwitterionic.
[0142] Anionic Surfactants
[0143] Anionic surfactants include alkyl and alkyl ether sulfates
generally having the formula ROSO.sub.3M and
RO(C.sub.2H.sub.4O).sub.xSO.- sub.3M wherein R is alkyl or alkenyl
of from about 10 to 20 carbon atoms, x is 1 to about 10 and M is a
water soluble cation such as ammonium, sodium, potassium, or
triethanolamine cation.
[0144] Another type of anionic surfactant which may be used in the
compositions of the invention are water soluble salts of organic,
sulfric acid reaction products of the general formula:
R.sub.1--SO.sub.3-M
[0145] wherein R.sub.1 is chosen from the group consisting of a
straight or branched chain, saturated aliphatic hydrocarbon radical
having from about 8 to about 24 carbon atoms, preferably 12 to
about 18 carbon atoms; and M is a cation. Examples of such anionic
surfactants are salts of organic sulfuric acid reaction products of
hydrocarbons such as n-paraffins having 8 to 24 carbon atoms, and a
sulfonating agent, such as sulfur trioxide.
[0146] Also suitable as anionic surfactants are reaction products
of fatty acids esterified with isethionic acid and neutralized with
sodium hydroxide. The fatty acids may be derived from coconut oil,
for example.
[0147] In addition, succinates and succinimates are suitable
anionic surfactants. This class includes compounds such as disodium
N-octadecylsulfosuccinate; tetrasodium
N-(1,2-dicarboxyethyl)-N-octadecyl- sulfosuccinate; and esters of
sodium sulfosuccinic acid e.g. the dihexyl ester of sodium
sulfosuccinic acid, the dioctyl ester of sodium sulfosuccinic acid,
and the like.
[0148] Other suitable anionic surfactants include olefin sulfonates
having about 12 to 24 carbon atoms. The term "olefin sulfonate"
means a compound that can be produced by sulfonation of an alpha
olefin by means of uncomplexed sulfur trioxide, followed by
neutralization of the acid reaction mixture in conditions such that
any sulfones which have been formed in the reaction are hydrolyzed
to give the corresponding hydroxy-alkanesulfonates. The
alpha-olefin from which the olefin sulfonate is derived is a
mono-olefin having about 12 to 24 carbon atoms, preferably about 14
to 16 carbon atoms.
[0149] Other classes of suitable anionic organic surfactants are
the beta-alkoxy alkane sulfonates or water soluble soaps thereof
such as the salts of C.sub.10-20 fatty acids, for example coconut
and allow based soaps. Preferred salts are ammonium, potassium, and
sodium salts.
[0150] Still another class of anionic surfactants include N-acyl
amino acid surfactants and salts thereof (alkali, alkaline earth,
and ammonium salts) having the formula: 10
[0151] wherein R.sub.1 is a C.sub.8-24 alkyl or alkenyl radical,
preferably C.sub.10-18; R.sub.2 is H, C.sub.1-4 alkyl, phenyl, or
--CH.sub.2COOM; R.sub.3 is CX.sub.2-- or C.sub.1-2 alkoxy, wherein
each X independently is H or a C.sub.1 alkyl or alkylester, n is
from 1 to 4, and M is H or a salt forming cation as described
above. Examples of such surfactants are the N-acyl sarcosinates,
including lauroyl sarcosinate, myristoyl sarcosinate, cocoyl
sarcosinate, and oleoyl sarcosinate, preferably in sodium or
potassium forms.
[0152] Nonionic Surfactants
[0153] The composition can contain one or more nonionic
surfactants. Nonionic surfactants are generally compounds produced
by the condensation of alkylene oxide groups with a hydrophobic
compound. Classes of nonionic surfactants are:
[0154] (a) Long chain dialkyl sulfoxides containing one short chain
alkyl or hydroxy alkyl radical of from about 1 to 3 carbon atoms
and one long hydrophobic chain which may be an alkyl, alkenyl,
hydroxyalkyl, or ketoalkyl radical containing from about 8 to 20
carbon atoms, from 0 to 10 ethylene oxide moieties, and 0 or 1
glyceryl moiety.
[0155] (b) Polysorbates, such as sucrose esters of fatty acids.
Examples of such materials include sucrose cocoate, sucrose
behenate, and so on.
[0156] (c) Polyethylene oxide condensates of alkyl phenols, for
example the condensation products of alkyl phenols having an alkyl
group of 6 to 20 carbon atoms With ethylene oxide being present in
amounts of about 10 to 60 moles of ethylene oxide per mole of alkyl
phenol.
[0157] (d) Condensation products of ethylene oxide with the
reaction product of propylene oxide and ethylene diamine.
[0158] (e) Condensation products of aliphatic alcohols having 8 to
18 carbon atoms with ethylene oxide, for example a coconut
alcohol/ethylene oxide condensate having 10 to 30 moles of ethylene
oxide per mole of coconut alcohol, the coconut alcohol fraction
having 10 to 14 carbon atoms.
[0159] (f) Long chain tertiary amine oxides such as those
corresponding to the general formula:
R.sub.1R.sub.2R.sub.3NO
[0160] wherein R.sub.1 contains an alkyl, alkenyl or
monohydroxyalkyl radical ranging from about 8 to 18 carbon atoms in
length, from 0 to about 10 ethylene oxide moieties, and from 0 to
about 1 glyceryl moiety and R.sub.2 and R.sub.3 are each alkyl or
monohydroxyalkyl groups containing from about 1 to about 3 carbon
atoms.
[0161] (g) Long chain tertiary phosphine oxides corresponding to
the general formula:
RR.sub.1 R.sub.2PO
[0162] wherein R contains an alkyl, alkenyl, or monohydroxyalkyl
radical having 8 to 18 carbon atoms, from 0-10 ethylene oxide
moieties and 0 or 1 glyceryl moiety, and R.sub.2 and R.sub.3 are
each alkyl or monohydroxyalkyl group containing from about 1 to 3
carbon atoms.
[0163] (h) Alkyl polysaccharides having a hydrophobic group of 6 to
30, preferably 10, carbon atoms and a polysaccharide group such as
glucose, galactose, etc. Suitable alkyl polysaccharides are octyl,
nonydecyl, undecyldodecyl, tridecyl, tetradecyl, pentadecyl,
hexadecyl, heptadecyl, and octadecyl, di-, tri-, tetra-, penta-,
and hexaglucosides, galactosides, lactosides, giucoses,
fructosides, fructoses, and so on.
[0164] (i) Polyethylene glycol (PEG) glyceryl fatty esters, having
the formula
RC(O)OCH.sub.2CH(OH)CH.sub.2(OCH.sub.2CH.sub.2).sub.nOH
[0165] wherein n is 5-200 and RC(O) is a hydrocarbylcarbonyl group
wherein R is preferably an aliphatic radical having 7 to 19 carbon
atoms.
[0166] (j) Other nonionic surfactants that may be used include
C.sub.10-18 alkyl(C.sub.1-6)polyhydroxy fatty acid amides such as
C.sub.12-18 methylglucamides, N-alkoxy polyhydroxy fatty acid
amides, N-propyl through N-hexyl C.sub.12-19 glucamides and so
on.
[0167] Amphoteric Surfactants
[0168] Amphoteric surfactants that can be used in the compositions
of the invention are generally described as derivatives of
aliphatic secondary or tertiary amines wherein one aliphatic
radical is a straight or branched chain alkyl of 8 to 18 carbon
atoms and the other aliphatic radical contains an anionic group
such as carboxy, sulfonate, sulfate, phosphate, or phosphonate.
[0169] Suitable amphoteric surfactants may be imidazolinium
compounds having the general formula: 11
[0170] wherein R.sup.1 is C.sub.8-22 alkyl or alkenyl, preferably
C.sub.12-16; R.sup.2 is hydrogen or CH.sub.2CO.sub.2M, R.sup.3 is
CH.sub.2CH.sub.2OH or CH.sub.2CH.sub.2OCH.sub.2CHCOOM; R.sup.4 is
hydrogen, CH.sub.2CH.sub.2OH, or
CH.sub.2CH.sub.2OCH.sub.2CH.sub.2COOM, Z is CO.sub.2M or
CH.sub.2CO.sub.2M, n is 2 or 3, preferably 2, M is hydrogen or a
cation such as an alkali metal, alkaline earth metal, ammonium, or
alkanol ammonium. cation. Examples of such materials are marketed
under the tradename MIRANOL, by Miranol, Inc.
[0171] Also suitable amphoteric surfactants are monocarboxylates or
dicarboxylates such as cocamphocarboxypropionate,
cocoamphocarboxypropion- ic acid, cocamphocarboxyglycinate, and
cocoamphoacetate.
[0172] Other types of amphoteric surfactants include
aminoalkanoates of the formula
R--NH(CH.sub.2).sub.nCOOM
[0173] or iminodialkanoates of the formula:
R--N[(CH.sub.2).sub.mCOOM].sub.2
[0174] and mixtures thereof; wherein n and m are 1 to 4, R is
C.sub.8-22 alkyl or alkenyl, and M is hydrogen, alkali metal,
alkaline earth metal, ammonium or alkanolammonium. Examples of such
amphoteric surfactants include n-alkylaminopropionates and
n-alkyliminodipropionates, which are sold under the trade name
MIRATAINE by Miranol, Inc. or DERIPHAT by Henkel, for example
N-lauryl-beta-amino propionic acid, N-lauryl-beta-imino-dipropionic
acid, or mixtures thereof.
[0175] Zwitterionic surfactants are also suitable for use in the
compositions of the invention. The general formula for such
surfactants is: 12
[0176] wherein R.sub.2 contains an alky, alkenyl or hydroxy alkyl
radical of from about 8 to about 18 carbon atoms, from 0 to about
10 ethylene oxide moieties and 0 or I glyceryl moiety; Y is
selected from the group consisting of nitrogen, phosphorus, and
sulfur atoms; R.sub.3 is an alkyl or monohydroxyalkyl group
containing about 1 to 3 carbon atoms; X is 1 when Y is a sulfur
atom, and 2 when Y is a nitrogen or phosphorus atom; R.sub.4 is an
alkylene or hydroxyalkylene of from about 1 to about 4 carbon
atoms, and Z is a radical selected from the group consisting of
carboxylate, sulfonate, sulfate, phosphonate, and phosphate
groups.
[0177] Zwitterionics include betaines, for example higher alkyl
betaines such as coco dimethyl carboxymethyl betaine, lauryl
dimethyl carboxymethyl betaine, lauryl dimethyl alphacarboxyethyl
betaine, cetyl dimethyl carboxymethyl betaine, lauryl
bis-(2-hydroxyethyl)carboxymethyl betaine, stearyl
bis-(2-hydroxypropyl)carboxymethyl betaine, oleyl dimethyl
gamma-carboxylethyl betaine, and mixtures thereof. Also suitable
are sulfo- and amido-betaines such as coco dimethyl sulfopropyl
betaine, stearyl dimethyl sulfopropyl betaine, and the like.
[0178] Cationic surfactants and/or polymers may be incorporated
into the compositions of the invention. If so, 0.01-15%, preferably
0.05-10%, preferably 0.10-8% of a cationic ingredients is
suggested. Suitable cationic ingredients include cationic polymers,
quaternary ammonium salts, or the salts of fatty amines. Quaternary
ammonium salts have the formula: 13
[0179] wherein R.sub.1 is hydrogen, an aliphatic group of 1 to 22
carbon atoms, or aromatic, aryl, or alkaryl group having 12 to 22
carbon atoms; R.sub.2 is an aliphatic group having 1-22 carbon
atoms; R.sub.3 and R.sub.4 are each alkyl groups of from 1 to 3
carbon atoms, and X is an anion selected from halogen, acetate,
phosphate, nitrate and methyl sulfate radicals. The aliphatic
groups may contain, in addition to carbon and hydrogen atoms, ether
linkages as well as amido groups.
[0180] Suitable quaternary ammonium compounds may be mono-long
chain alkyl, di-long chain alkyl, tri-long chain alkyl, and the
like. Examples of such quaternary ammonium salts include
behenalkonium chloride, behentrimonium chloride, behentrimonium
methosulfate, benzalkonium chloride, benzethonium chloride, benzyl
triethyl ammonium chloride, cetalkonium chloride, cetrimonium
chloride, cetrimonium bromide, cetrimonium methosulfate,
cetrimonium tosylate, cetylpyridinium chloride,
dibehenyudiarachidyl dimonium chloride. dibehenyldimonium chloride,
dibehenyldimonium methosulfate, dicapryl/dicaprylyl dimonium
chloride, dicetyldimonium chloride, and mixtures thereof.
[0181] Other quaternary ammonium salts useful as the cationic
surfactant are compounds of the general formula: 14
[0182] wherein R.sub.1 is an aliphatic group having 16 to 22 carbon
atoms, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are the same
or different and are selected from H and alkyls having 1 to 4
carbon atoms and X is an anion as above defined.
[0183] Also, quaternary imidazolinium salts having the following
general formula are also suitable: 15
[0184] wherein R.sub.5 is hydrogen or a C.sub.1-4 alkyl; R.sub.6 is
a C.sub.1-4 alkyl; R.sub.7 is a C.sub.8-22 alkyl; and R.sub.8 is
hydrogen, or a C.sub.1-22 alkyl; and X is an anion as defined
above.
[0185] Also suitable as the cationic surfactant are salts of fatty
primary, secondary, or tertiary amines, wherein the substituted
groups have 12 to 22 carbon atoms. Examples of such amines include
dimethyl stearamine, dimethyl soyamine, stearylamine,
myristylamine, tridecylamine, ethyl stearamine, and so on.
[0186] Also suitable as the cationic ingredient are cationic
polymers such as:
[0187] (a) Quaternary derivatives of cellulose ethers such as
polymers sold under the tradename JR-125, JR-400, JR-30M. Preferred
is Polyquaternium 10, which is a polymeric quaternary ammonium salt
of hydroxyethyl cellulose reacted with a trimethyl ammonium
subsituted epoxide.
[0188] (b) Copolymers of vinylpyrrolidone having monomer units of
the formula: 16
[0189] wherein R is hydrogen or methyl, preferably methyl;
[0190] y is 0 or 1, preferably 1
[0191] R.sup.2 is O or NH, preferably NH;
[0192] R.sup.3 is C.sub.xH.sub.2x where x is 2 to 18, or
--CH.sub.2--CHOH--CH--, preferably C.sub.xH.sub.2x where x is
2;
[0193] R.sup.4 is methyl, ethyl, phenyl, or C.sub.1-4 substituted
phenyl, preferably methyl; and
[0194] R.sup.5 is methyl or ethyl, preferably methyl.
[0195] (c) Homopolymer of dimethyldiallylammonium chloride, or
copolymer of dimethyldiallylammonium chloride and acrylamide. Such
compounds are sold under the tradename MERQUAT.TM. by Merck and
Company.
[0196] (d) Homopolymers or copolymers derived from acrylic or
methacrylic acid wherein the monomer units are selected from the
group consisting of acrylamide, methylacrylamide,
diacetone-acrylamide, acrylamide or methacrylamide substituted on
the nitrogen by lower alkyl, alkyl esters of acrylic acid and
methacrylic acid, vinylpyrrolidone, and vinyl esters.
[0197] Examples of cationic polymers that can be used in the
compositions of the invention are the cationic polymers disclosed
in U.S. Pat. Nos. 5,240,450 and 5,573,709, which are hereby
incorporated by reference.
[0198] Waxes
[0199] The compositions of the invention may contain 0.1-25%,
preferably 0.5-20%, more preferably 1-15% by weight of the total
composition of wax. Suitable waxes have a melting point of 35 to
120.degree. C., and can be animal waxes, plant waxes, mineral
waxes, silicone waxes, synthetic waxes, and petroleum waxes.
Examples of waxes in accordance with the invention include
bayberry, beeswax, candelilla, carnauba, ceresin, cetyl esters,
hydrogenated jojoba oil, hydrogenated jojoba wax, hydrogenated
microcrystalline wax, hydrogenated rice bran wax, japan wax, jojoba
butter, jojoba esters, jojoba wax, lanolin wax, microcrystalline
wax, mink wax, montan acid wax, montan wax, ouricury wax,
ozokerite, paraffin, PEG-6 beeswax, PEG-8 beeswax, rice bran wax,
shellac wax, spent grain wax, sulfurized jojoba oil, synthetic
beeswax, synthetic candelilla wax, synthetic carnauba wax,
synthetic japan wax, synthetic jojoba oil, ethylene homo- or
copolymers, stearoxy dimethicone, dimethicone behenate, stearyl
dimethicone, and the like, as well synthetic homo- and copolymer
waxes such as PVP/eicosene copolymer, PVP/hexadecene copolymer, and
the like.
[0200] Branched Chain Silicone Resins
[0201] It may be desireable to include one or more branched chain
silicone resins in the compositions of the invention. If so, a
range of 0.001-20%, preferably 0.01-15%, more preferably
0.1-10%0/by weight of the total composition is suggested. Examples
of suitable silicone resins include siloxy silicate polymers having
the following general formula:
[(RR'R").sub.3SiO.sub.1/2].sub.x[SiO.sub.2].sub.y
[0202] wherein R, R' and R" are each independently a C.sub.1-10
straight or branched chain alkyl or phenyl, and x and y are such
that the ratio of (RR'R").sub.3SiO.sub.1/2 units to SiO.sub.2 units
is 0.5 to 1 to 1.5 to 1.
[0203] Preferably R, R' and R" are a C.sub.1-6 alkyl, and more
preferably are methyl and x and y are such that the ratio of
(CH.sub.3).sub.3SiO.sub- .1/2 units to SiO.sub.2 units is 0.75 to
1. Most preferred is this trimethylsiloxy silicate containing 2.4
to 2.9 weight percent hydroxyl groups which is formed by the
reaction of the sodium salt of silicic acid, chlorotrimethylsilane,
and isopropyl alcohol. The manufacture of trimethylsiloxy silicate
is set forth in U.S. Pat. Nos. 2,676,182; 3,541,205; and 3,836,437,
all of which are hereby incorporated by reference. Trimethylsiloxy
silicate as described is available from Dow Corning Corporation
under the tradename 2-0749 and 2-0747, which is a blend of about
40-60% volatile silicone and 40-60% trimethylsiloxy silicate. Dow
Corning 2-0749 in particular, is a fluid containing about 50%
trimethylsiloxy silicate and about 50% cyclomethicone. The fluid
has a viscosity of 200-700 centipoise at 25.degree. C., a specific
gravity of 1.00 to 1.10 at 25.degree. C., and a refractive index of
1.40-1.41.
[0204] Other branched chain silicone resins are silicone esters
comprising units of the general formula
R.sub.aR.sup.E.sub.bSiO.sub.[4-(a+b)/2] or
R.sup.13.sub.xR.sup.E.sub.ySiO.sub.1/2, wherein R and R.sup.13 are
each independently an organic radical such as alkyl, cycloalkyl, or
aryl, or, for example, methyl, ethyl, propyl, hexyl, octyl, decyl,
aryl, cyclohexyl, and the like. a is an number ranging from 0 to 3,
b is a number ranging from 0 to 3, a+b is a number ranging from 1
to 3, x is a number from 0 to 3, y is a number from 0 to 3 and the
sum of x+y is 3, and wherein R.sup.E is a carboxylic ester
containing radical. Preferred R.sub.E radicals are those wherein
the ester group is formed of one or more fatty acid moieities (e.g.
of about 6, often about 6 to 30 carbon atoms) and one or more
aliphatic alcohol moieities (e.g. of about 10 to 30 carbon atoms).
Examples of such acid moieities include those derived from
branched-chain fatty acids such as isostearic, or straight chain
fatty acids such as behenic. Examples of suitable alcohol moieties
include those derived from monohydric or polyhydric alcohols, e.g.
normal alkanols such as n-propanol and branched-chain etheralkanols
such as (3,3,3-trimethylolpropoxypropane. Preferably the ester
subgroup (i.e. the group containing the carboxylic ester) will be
linked to the silicon atom by a divalent aliphatic chain that is at
least 2 or 3 carbon atoms in length, e.g. an alkylene group or a
divalent alkyl ether group. Most preferably that chain will be part
of the alcohol moiety, not the acid moiety. More particularly, the
cross-linked silicone ester can be a liquid or solid at room
temperature. Preferably it will have a waxy feel and a molecular
weight of no more than about 100,000 daltons.
[0205] Such silicone resins having the above formula are disclosed
in U.S. Pat. No. 4,725,658 and U.S. Pat. No. 5,334,737, which are
hereby incorporated by reference. These ingredients are
commercially available from General Electric under the tradenames
SF 1318 and SF 1312, respectively.
[0206] Pigments and Powders
[0207] The composition of the invention may contain 0.001-35%,
preferably 0.01-20% more preferably 0.1-10%, by weight of the total
composition, of dry particulate matter having a particle size of
0.02 to 200, preferably 0.5 to 100, microns. The particulate matter
may be colored or non-colored (for example white). Suitable powders
include bismuth oxychloride, titanated mica, fumed silica,
spherical silica, polymethylmethacrylate, micronized teflon, boron
nitride, acrylate copolymers, aluminum silicate, aluminum starch
octenylsuccinate, bentonite, calcium silicate, cellulose, chalk,
corn starch, diatomaceous earth, fuller's earth, glyceryl starch,
hectorite, hydrated silica, kaolin, magnesium aluminum silicate,
magnesium trisilicate, maltodextrin, montmorillonite,
microcrystalline cellulose, rice starch, silica, talc, mica,
titanium dioxide, zinc laurate, zinc myristate, zinc rosinate,
alumina, attapulgite, calcium carbonate, calcium silicate, dextran,
kaolin, nylon, silica silylate, silk powder, sericite, soy flour,
tin oxide, titanium hydroxide, trimagnesium phosphate, walnut shell
powder, or mixtures thereof. The above mentioned powders may be
surface treated with lecithin, amino acids, mineral oil, silicone
oil or various other agents either alone or in combination, which
coat the powder surface and render the particles more lipophilic in
nature.
[0208] The powder component also may comprise various organic and
inorganic pigments. The organic pigments are generally various
aromatic types including azo, indigoid, triphenylmethane,
anthraquinone, and xanthine dyes which are designated as D&C
and FD&C blues, browns, greens, oranges, reds, yellows, etc.
Organic pigments generally consist of insoluble metallic salts of
certified color additives, referred to as the Lakes. Inorganic
pigments include iron oxides, ultramarines, chromium, chromium
hydroxide colors, and mixtures thereof.
[0209] The composition may contain a mixture of both pigmented and
non-pigmented powders. The percentage of pigments used in the
powder component will depend on the type of cosmetic being
formulated.
[0210] Sunscreens
[0211] The compositions of the invention may contain 0.001-20%,
preferably 0.01-10%, more preferably 0.05-8% of one or more
sunscreens. A sunscreen is defined as an ingredient that absorbs at
least 85 percent of the light in the UV range at wavelengths from
290 to 320 nanometers, but transmit UV light at wavelengths longer
than 320 nanometers. Sunscreens generally work in one of two ways.
Particulate materials, such as zinc oxide or titanium dioxide, as
mentioned above, physically block ultraviolet radiation. Chemical
sunscreens, on the other hand, operate by chemically reacting upon
exposure to UV radiation. Suitable sunscreens that may be included
in the compositions of the invention are set forth on page 582 of
the CTFA Cosmetic Ingredient Handbook, Second Edition, 1992, as
well as U.S. Pat. No. 5,620,965, both of which are hereby
incorpated by reference. Examples of such sunscreen materials are
p-aminobenzoic acid (PABA), cinoxate, diethanolamine
p-methoxycinnamate (DEA-methoxycinnamate), Digalloyl trioleate,
dioxybenzone (Benzophenone-8), ethyl 4-[bis-(hydroxypropyl)]
amnobenzoate (ethyl dihydroxypropyl PABA),
2-ethythexyl-2-cyano-3,3-diphenylacrylate (octocrylene), ethylhexyl
p-methoxycinnamate (Octyl methoxycinnamate), 2-ethylhexyl
salicylate (Octyl salicylate), glyceryl aminobenzoate (Glyceryl
PABA), homosalate, lawsone with dihydroxyacetone, menthyl
anthranilate, oxybenzone (Benzophenone-3), Padimate A (Pentyl
Dimethyl PABA), Padimate 0, (Octyl Dimethyl PABA),
2-Phenylbenzimidazole-5-sulfoni- c acid (Phenylbenzimidazole
Sulfonic acid), Red Petrolatum, Sulisobenzone (Benzophenone4),
triethanolamine salicylate (TEA-Salicylates), and so on.
[0212] Preservatives
[0213] The composition may contain 0.0001-8%, preferably 0.001-6%,
more preferably 0.005-5% by weight of the total composition of
preservatives. A variety of preservatives are suitable, including
such as benzoic acid, benzyl alcohol, benzylhemiformal,
benzylparaben, 5-bromo-5-nitro-1,3-diox- ane,
2-bromo-2-nitropropane-1,3-diol, butyl paraben, calcium benzoate,
calcium propionate, captan, chlorhexidine diacetate, chlorhexidine
digluconate, chlorhexidine dihydrochloride, chloroacetamide,
chlorobutanol, p-chloro-m-cresol, chlorophene, chlorothymol,
chloroxylenol, m cresol, o-cresol, DEDM Hydantoin, DEDM Hydantoin
dilaurate, dehydroacetic acid, diazolidinyl urea,
dibromopropamidine diisethionate, DMDM Hydantoin, and all of those
disclosed on pages 570 to 571 of the CTFA Cosmetic Ingredient
Handbook, Second Edition, 1992, which is hereby incorporated by
reference.
[0214] Vitamins and Antioxidants
[0215] The compositions of the invention may contain vitamins
and/or coenzymes, as well as antioxidants. If so, 0.001-10%,
preferably 0.01-8%, more preferably 0.05-5% by weight of the total
composition are suggested. Suitable vitamins include the B vitamins
such as thiamine, riboflavin, pyridoxin, and so on, as well as
coenzymes such as thiamine pyrophoshate, flavin adenin
dinucleotide, folic acid, pyridoxal phosphate, tetrahydrofolic
acid, and so on. Also Vitamin A and derivatives thereof are
suitable. Examples are Vitamin A palmitate, acetate, or other
esters thereof, as well as Vitamin A in the form of beta carotene.
Also suitable is Vitamin E and derivatives thereof such as Vitamin
E acetate, nicotinate, or other esters thereof. In addition,
Vitamins D and K are suitable.
[0216] Suitable antioxidants are ingredients which assist in
preventing or retarding spoilage. Examples of antioxidants suitable
for use in the compositions of the invention are potassium sulfite,
sodium bisulfite, sodium erythrobate, sodium metabisulfite, sodium
sulfite, propyl gallate, cysteine hydrochloride, butylated
hydroxytoluene, butylated hydroxyanisole, and so on.
[0217] Alpha or Beta Hydroxy Acids, Alpha Keto Acids
[0218] It may be desired to add one or more alpha or beta hydroxy
acids or alpha ketoacids to the compositions of the invention.
Suggested ranges are 0.01-20%, preferably 0.1-15%, more preferably
0.5-10% by weight of the total composition. Suitable alpha hydroxy
acids and alpha ketoacids are disclosed in U.S. Pat. No. 5,091,171,
which is hereby incorporated by reference. Such alpha hydroxy acids
are as follows:
[0219] a) Organic carboxylic acids where one hydroxyl group is
attached to the alpha carbon atom of the acid. The general
structure of such alpha hydroxy acids may be represented by the
following formula:
(Ra)(Rb)C(OH)COOH
[0220] wherein Ra and Rb are H, F, Cl, Br, alkyl, aralkyl, or aryl
group of saturated, unsaturated, straight or branched chain or
cyclic form having 1-10 carbon atoms, and in addition Ra or Rb may
carry OH, CHO, COOH and alkoxy groups having 1 to 9 carbon
atoms.
[0221] The second group of alpha hydroxy acids may be represented
by the following formula:
(Ra)CO COO(Rb)
[0222] wherein Ra and Rb are H, alkyl, aralkyl, or aryl groups of
straight or branched chain saturated or unsaturated alkyl having 1
to 10 carbon atoms, and in addition Ra may carry F, Cl, Br, I, OH,
CHO, COOH, and alkoxy groups having 1 to 10 carbon atoms.
[0223] The alpha hydroxy acids may exist in the keto acid form, or
the ester form. Examples of such alpha hydroxy acids include
glycolic acid, malic acid, pyruvic acid, mandelic acid, lactic
acid, methyllactic acid, and so on.
[0224] Also beta hydroxy acids such as salicylic acid, and
derivatives thereof may be included in the compositions of the
invention.
[0225] The Method
[0226] The anhydrous emulsions of the invention are made by first
subjecting the nonaqueous polar organic solvent to an input of
energy, preferably heat energy. In particular, the nonaqueous polar
organic solvent is heated to a temperature sufficient to dissolve
the ascorbic acid. A temperature above room temperature is
generally required to achieve solubilization of ascorbic acid to
any appreciable degree. Preferably, the nonaqueous polar organic
solvent is heated to a temperature of about 70 to 170, more
preferably about 80 to 120, more preferably about 90-110, and most
preferably about 95-105.degree. C. The heat energy required may
depend on conditions such as the pressure at which the nonaqueous
polar organic solvent is maintained. For example, if the pressure
of the nonaqueous polar organic solvent is increased above standard
pressure at room temperature, the temperature required to dissolve
appreciable levels of ascorbic acid in the solvent is
correspondingly less. Conversely, if the nonaqueous polar organic
solvent is maintained at a pressure which is less than the standard
pressure at room temperature, the temperature required to dissolve
appreciable levels of ascorbic acid may be correspondingly greater.
The energy source may be standard heat as well as heat radiation
from sources such as long and short microwaves, infrared radiation,
sonication, microfluidization, and the like.
[0227] While maintaining the temperature, the ascorbic acid is
added to the nonaqueous polar organic solvent with stirring until
dissolved. The temperature of the mixture is then reduced, i.e. the
mixture is cooled, by reducing the temperature by 10 to 145.degree.
C., more preferably by 20 to 100.degree. C., most preferably by 40
to 95.degree. C. Most preferably the mixture is cooled to room
temperature. It is preferred to cool the mixture to room
temperature quickly, for example by plunging a container of the
mixture into an ice water bath until the mixture attains room
temperature.
[0228] In the preferred embodiment of the invention, one of the
nonaqueous polar organic solvents is heated in a vessel to about
100.degree. C. The ascorbic acid is added with stirring until
dissolved. The vessel containing the mixture is then plunged into
an ice water bath and held there until it has cooled to room
temperature. Then, the mixture is reheated to a temperature of
70-170.degree., 80-110.degree., preferably 95-105.degree., more
preferably about 100.degree. C. and the second nonaqueous polar
organic solvent is added with stirring. The mixture is then rapidly
cooled to room temperature by putting it into an ice water
bath.
[0229] It has been discovered that the rapid cooling appears to
promote solubilization of the ascorbic acid into the nonaqueous
polar organic solvent. In addition, adding the nonaqueous polar
organic solvents one at a time followed by rapid cooling, promotes
the highest level of stability and solubility of ascorbic acid in
the nonaqueous polar organic solvent. Most unexpectedly,
concentrations of solubilized ascorbic acid up to 25% have been
achieved using solvents which normally provide very low solubility
of ascorbic acid.
[0230] The ascorbic acid solubilized in the nonaqueous polar
organic solvent is emulsified into the nonaqueous nonpolar organic
solvent at room temperature by homogenizing by using standard
homogenizing equipment such as the Eppenbach Homo-mixer. In the
case where the ascorbic acid dissolved in the nonaqueous polar
organic solvent forms the continuous phase, the nonaqueous nonpolar
organic solvent is emulsified into the ascorbic acid mixture at
room temperature using homogenization.
EXAMPLE 1
[0231] An anhydrous emulsion suitable as a skin lotion, was made in
accordance with the invention as follows:
1 w/w % Cetyl dimethicone copolyol 3.00 (surfactant) Hydrogenated
castor oil 5.00 (wax) Polyethylene 1.00 (wax)
Polyglyceryl-4-isostearate 1.50 (surfactant) Polyethylene/mineral
oil 15.00 (wax/nonpolar organic solvent) (6:94) Cyclomethicone
12.00 (nonpolar organic solvent) C.sub.12-15 alkyl benzoate 12.50
(nonpolar organic solvent) Glycerine 33.40 (polar organic solvent)
PEG-6 6.70 (polar organic solvent) Ascorbic acid 10.00
[0232] The glycerine was heated to a temperature of 100.degree. C.
The ascorbic acid was added to the glycerine while maintaining the
temperature at 100.degree. C., while stirring until dissolved. The
solution was then put into an ice water bath until the mixture
cooled to room temperature. The mixture was a clear solution. The
mixture was then heated back up to 100.degree. C., and the PEG-6
was added to the hot mixture with stirring. The mixture was then
put into an ice water bath again until cooled to room
temperature.
[0233] The remaining ingredients were separately mixed, yielding a
nonpolar solvent phase, and the ascorbic acid/glycerine/PEG-6
mixture was dispersed into the nonpolar solvent phase by
homogenizing using an Eppenbach Homo-mixer.
EXAMPLE 2
[0234] An anhydrous emulsion suitable for use as a skin lotion was
made as follows:
2 w/w % Dimethicone copolyol/cyclomethicone 10.50
(surfactant/nonpolar (10:90) organic solvent) Cetyl dimethicone
copolyol 1.00 (surfactant) Trihydroxystearin/cyclomethicone 9.50
(nonpolar organic (17.5:82.5) solvent/nonpolar organic solvent)
Dimethiconol/cyclomethicone 2.00 (surfactant/nonpolar (13:87)
organic solvent) PEG-6 31.00 (polar organic solvent) Glycerin 35.40
(polar organic solvent) Ascorbic acid 10.60
[0235] The glycerin was heated to a temperature of 100.degree. C.
The ascorbic acid was added to the heated mixture while maintaining
the temperature at 100.degree. C., and stirring until dissolved.
The mixture was then put into an ice water bath until the mixture
cooled to room temperature. The mixture was then heated back up to
100.degree. C., and the PEG-6 was added to the hot mixture with
stirring. The mixture was then put into an ice water bath until
cooled to room temperature.
[0236] The remaining ingredients were separately mixed, and the
ascorbic acid/glycerine/PEG-6 mixture was dispersed into the
nonpolar phase by homogenizing.
EXAMPLE 3
[0237] Anhydrous emulsions suitable for use as a skin treatment
lotion and cream were prepared as follows:
3 1 2 Ascorbic acid 10.00 10.00 PEG-6 (nonaqueous polar organic
solvent) 33.7 6.7 Glycerine (nonaqueous polar organic solvent) 33.3
33.3 Octyl methoxycinnamate (sunscreen) 7.5 -- Safflower oil
(nonaqueous nonpolar organic solvent) 7.5 -- Tocopheryl acetate
(vitamin) 1.0 -- Polyacrylamide/C13-14 isoparaffin/laureth-7 1.0 --
Sorbitan oleate (surfactant) 2.7 -- Polysorbate 80 (nonaqueous
polar organic solvent) 3.3 -- Steareth-21 (surfactant) -- 12.0
Steareth-2 (surfactant) -- 4.0 Polysorbate 20 (nonaqueous polar
organic solvent) -- 1.0 Glyceryl stearate (nonaqueous nonpolar
organic solvent) -- 8.0 Cetyl alcohol (nonaqueous nonpolar organic
solvent) -- 4.0 C12-15 alkyl benzoate -- 16.6 Preservatives --
0.4
[0238] The glycerine was heated to a temperature of 100.degree. C.
The ascorbic acid was added to the heated mixture while maintaining
the temperature at 100.degree. C. and stirring until dissolved. The
mixture was then put into an ice water bath until the mixture
cooled to room temperature. The mixture was then heated back up to
100.degree. C., and the PEG-6 was added to the hot mixture with
stirring. The mixture was then put into an ice water bath until
cooled to room temperature.
[0239] The remaining ingredients were separately mixed, and
dispersed into the ascorbic acid/glycerine/PEG-6 mixture by
homogenizing. Sample 1 provided a pourable translucent gel-like
emulsion. Sample 2 provided a non-pourable opaque cream.
EXAMPLE 4
[0240] The solubility of ascorbic acid in various solvents was
correlated with the octanol/water partition coefficient of the
solvent. The partition coefficient of each solvent was measured
using a software program marketed by Advanced Chemistry
Development, Inc., called the ACD/LogP program, which calculates
the partition coefficient from the molecular structure of the
solvent. The solubility of the ascorbic acid was determined by
heating the solvent to a temperature in excess of 100.degree. C.,
preferably in the range of 105 to 110.degree. C. while monitoring
with a thermometer. Measured amounts (in weight percent, i.e. 1%,
2%, 3%, 4%, 5%, up to 20%, 25%, etc.) of ascorbic acid were added
to separate tubes containing the hot solvent while mixing. After
the ascorbic acid dissolved, the samples were cooled to room
temperature. The solubility of ascorbic acid in the particular
solvent was the maximum weight percent of ascorbic acid that could
be solubilized in the solvent before the solution turned cloudy and
crystal formation occurred at room temperature after one month. In
other words, the solubility was determined to be the maximum weight
percent of ascorbic acid that could be solubilized in the solvent,
where the solution remained clear and no microscopic evidence of
crystal formation was evident at room temperature after one
month.
[0241] The results are set forth below:
4 Solvent Ascorbic Acid Solubility wt % LogP Ethylene glycol 25
-1.69 1,2-propanediol 17 -1.34 1,2-butanediol 9 -0.81
1,2-pentanediol 3 -0.28 1,2-hexanediol 1 0.25 Diethylene glycol 21
-1.51 Triethylene glycol 17 -1.50 Glycerine 17 -2.41 Polyethylene
glycol 300 8 -1.46 Polyethylene glycol 400 7 -1.43 Polyethylene
glycol 600 5 -1.39 Dipropylene glycol 9 -0.82 Polypropylene glycol
n = 6 3 0.97 Polyglycol EP530 0.1 9.25 Synalox PB-200 fluid (n =
14) 0.5 5.79 Glyceryl monooleate 0.1 6.91 Glyceryl stearate 0.1
7.43 Diglycerol 18 -2.86
[0242] The solvents which exhibit octanol/water partition
coefficients of less than -0.2 may be used as the nonaqueous polar
organic solvent. The solvents which exhibit octanol/water partition
coefficients of greater than -0.2 may be used as the nonaqueous
nonpolar organic solvent.
EXAMPLE 5
[0243] Stability studies were performed on the formula of Example
2, containing 10.6% ascorbic acid, as follows:
5 Time Temperature % Ascorbic Acid Remaining 5 months 25.degree. C.
9.6% 5 months 40.degree. C. 9.6% 5 months 50.degree. C. 6.6%
[0244] It can be seen that the ascorbic acid in the formula of
Example 2 exhibits good stability at room temperature and at
elevated temperatures.
[0245] While the invention has been described in connection with
the preferred embodiment, it is not intended to limit the scope of
the invention to the particular form set forth, but, on the
contrary, it is intended to cover such alternatives, modifications
and equivalents as may be included within the spirit and scope of
the invention as defined by the appended claims.
* * * * *