U.S. patent application number 15/880764 was filed with the patent office on 2019-08-01 for salicylic acid gel.
The applicant listed for this patent is Michael Davies, Chris Gerlach. Invention is credited to Michael Davies, Chris Gerlach.
Application Number | 20190231657 15/880764 |
Document ID | / |
Family ID | 67393059 |
Filed Date | 2019-08-01 |
![](/patent/app/20190231657/US20190231657A1-20190801-C00001.png)
United States Patent
Application |
20190231657 |
Kind Code |
A1 |
Gerlach; Chris ; et
al. |
August 1, 2019 |
SALICYLIC ACID GEL
Abstract
A salicylic acid gel contains salicylic acid, a thickener, and a
stabilizer compound. The gel may be diluted and/or incorporated
into final skin care products.
Inventors: |
Gerlach; Chris; (Buford,
GA) ; Davies; Michael; (Dacula, GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Gerlach; Chris
Davies; Michael |
Buford
Dacula |
GA
GA |
US
US |
|
|
Family ID: |
67393059 |
Appl. No.: |
15/880764 |
Filed: |
January 26, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K 31/16 20130101;
A61Q 19/00 20130101; A61K 47/18 20130101; A61K 31/60 20130101; A61Q
5/006 20130101; A61K 2300/00 20130101; A61K 2300/00 20130101; A61K
8/368 20130101; A61K 8/342 20130101; A61K 8/365 20130101; A61K
9/0014 20130101; A61K 47/38 20130101; A61Q 5/02 20130101; A61K
31/60 20130101; A61K 8/42 20130101; A61Q 19/10 20130101; A61K 8/042
20130101; A61K 8/86 20130101; A61K 47/10 20130101; A61Q 19/007
20130101; A61K 9/06 20130101; A61K 8/731 20130101; A61K 31/16
20130101 |
International
Class: |
A61K 8/04 20060101
A61K008/04; A61K 31/60 20060101 A61K031/60; A61K 47/10 20060101
A61K047/10; A61K 47/38 20060101 A61K047/38; A61K 47/18 20060101
A61K047/18; A61K 31/16 20060101 A61K031/16; A61Q 19/00 20060101
A61Q019/00; A61Q 5/00 20060101 A61Q005/00; A61Q 5/02 20060101
A61Q005/02; A61K 9/06 20060101 A61K009/06; A61K 8/365 20060101
A61K008/365; A61K 8/42 20060101 A61K008/42; A61K 8/86 20060101
A61K008/86; A61K 8/34 20060101 A61K008/34; A61K 8/73 20060101
A61K008/73 |
Claims
1. A salicylic acid gel consisting of salicylic acid, at least one
thickener, and a stabilizing amount of at least one nitrogen
compound selected from the group consisting of alkoxylated amides,
alkoxylated amines, alkylamido alkylamines, amides, amine oxides,
and amines, wherein the salicylic acid comprises at least 1 wt % of
the total weight of the gel and the thickener comprises at least 1
wt % of the gel.
2. The salicylic acid gel of claim 1 consisting of at least 20 wt %
salicylic acid based on total weight of the gel.
3. The salicylic acid gel of claim 1 consisting of at least 30 wt %
salicylic acid based on total weight of the gel.
4. The salicylic acid gel of claim 1 wherein the nitrogen compound
is cocamidopropyl dimethylamine.
5. The salicylic acid gel of claim 1 consisting of at least 5 wt %
thickener based on the total weight of the gel.
6. The salicylic acid gel according to claim 1 wherein the
thickener is at least one selected from the group consisting of
agar, align, pectin, bentonite, chitosan, cellulose, carrageenan,
chitin, cassia gum, cetyl glycol, clay, croscarmellose, dextrin,
xanthangum, gelatin, hectorite, silica, hydroxyethylcellulose,
hydroxypropylcellulose, methylcellulose, microcrystalline
cellulose, pectin, polyester-5, polyether-1, polyglycerin-20,
polyglycerin-40, sclerotium gum, sodium stearate, starch, beeswax,
ceresin, an alcohol, or a polyethylene glycol.
7. The salicylic acid gel according to claim 1 wherein the
thickener is at least one alcohol selected from the group
consisting of cetearyl alcohol, cetyl alcohol, decyl alcohol,
lauryl alcohol, polyvinyl alcohol, and stearyl alcohol.
8. The salicylic acid gel according to claim 1 wherein the
thickener is at least one polyethylene glycol selected from the
group consisting of PEG-450, PEG-800, PEG-2M, PEG-5M, PEG-7M,
PEG-9M, PEG-14M, PEG-20M, PEG-23M, PEG-25M, PEG-45M, PEG-65M,
PEG-90M, PEG-115M, PEG-160M, and PEG-180M.
9. A salicylic acid gel of claim 1 where the thickener is PEG-450,
stearyl alcohol, or hydroxypropylcellulose.
10. A salicylic acid gel according to claim 1 consisting of
salicylic acid, cocamidopropyl dimethylamine, and one selected from
the group consisting of PEG-450, stearyl alcohol, and
hydroxypropylcellulose.
11. An acne treatment product comprising the salicylic acid gel
according to claim 1 and a solvent wherein the concentration of the
salicylic acid is 0.5 to 2 wt % based on total weight of the acne
treatment product.
12. A wart treatment product comprising the salicylic acid gel
according to claim 1 and a solvent wherein the concentration of the
salicylic acid is 5 to 40 wt %, based on total weight of the wart
treatment product.
13. A skin tag remover product comprising the salicylic acid gel
according to claim 1 and a solvent wherein the concentration of the
salicylic acid is 5 to 40 wt %, based on total weight of the skin
tag remover product.
14. A lotion for skin exfoliation comprising the salicylic acid gel
according to claim 1 and a solvent wherein the concentration of the
salicylic acid is 0.2 to 10 wt % based on total weight of the
lotion.
15. An anti-dandruff shampoo comprising the salicylic acid gel
according to claim 1 and a solvent wherein the concentration of the
salicylic acid is 1.8 to 3 wt % based on total weight of the
shampoo.
16. A salicylic acid gel comprising salicylic acid, at least one
thickener, and a stabilizing amount of at least one nitrogen
compound selected from the group consisting of alkoxylated amides,
alkoxylated amines, alkylamido alkylamines, amides, amine oxides,
and amines, wherein the salicylic acid comprises at least 30 wt %
of the total weight of the gel, wherein no solvent is present in
the gel.
17. The salicylic acid gel of claim 16 comprising 40 to 55 wt %
salicylic acid based on total weight of the gel.
18. The salicylic acid gel of claim 16 wherein the nitrogen
compound is cocamidopropyl dimethylamine and the thickener is
PEG-450, stearyl alcohol, or hydroxypropylcellulose.
19. An acne treatment product comprising the salicylic acid gel
according to claim 16 and a solvent wherein the concentration of
the salicylic acid is 0.5 to 2 wt % based on total weight of the
acne treatment product.
20. A wart treatment product comprising the salicylic acid gel
according to claim 16 and a solvent wherein the concentration of
the salicylic acid is 5 to 40 wt %, based on total weight of the
wart treatment product.
21. A skin tag remover product comprising the salicylic acid gel
according to claim 16 and a solvent wherein the concentration of
the salicylic acid is 5 to 40 wt %, based on total weight of the
skin tag remover product.
22. A lotion for skin exfoliation comprising the salicylic acid gel
according to claim 16 and a solvent wherein the concentration of
the salicylic acid is 0.2 to 10 wt % based on total weight of the
lotion.
23. An anti-dandruff shampoo comprising the salicylic acid gel
according to claim 16 and a solvent wherein the concentration of
the salicylic acid is 1.8 to 3 wt % based on total weight of the
shampoo.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 14/329,063, filed Jul. 11, 2014, which application claims
benefit of U.S. 61/990,144 filed May 8, 2014 and is a continuation
in part of PCT/US13/62561 filed Sep. 30, 2013 which is a
continuation in part of U.S. Ser. No. 13/789,780 filed Mar. 8, 2013
(now U.S. Pat. No. 8,828,979 issued Sep. 9, 2014), which claims
benefit of U.S. 61/615,956 filed Mar. 27, 2012, each application
hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a stable gel of salicylic acid, and
products produced therefrom.
BACKGROUND OF THE INVENTION
[0003] Salicylic acid, also known as 2-hydroxybenzenecarboxylic
acid, is a monohydroxybenzoic acid. Its salts and esters are known
as salicylates. Salicylic acid has the formula:
##STR00001##
[0004] Salicylic acid is also known for providing pain relief when
applied as a liniment, for example
[0005] Salicylic acid is used in many skin-care products. For
example, salicylic acid is well known for its use in anti-acne
treatments. In addition to the treatment of acne, salicylic acid is
also used in products for treatment of psoriasis, calluses, corns,
skin tags, keratosis pilaris, and warts. It works as a keratolytic,
bacteriocide and comedolytic agent. Salicylic acid is also used in
shampoos for treatment of dandruff and as a chemical exfoliant.
[0006] Salicylic acid can cause burns if applied in high
concentrations. Typically, over-the-counter limits are 2% for
topical treatments (that remain on the skin) and 3% for cleansers
or shampoo (products that are washed off) Higher concentrations
(e.g. up to 40 wt %) may be used for wart and skin tag removal but
should be applied cautiously and only to the wart and not the
surrounding skin.
[0007] Salicylic acid is poorly soluble in water. It is therefore
difficult to prepare solutions of salicylic acid that remain
precipitate-free.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention is directed to a stable salicylic acid
gel consisting of salicylic acid, a thickener, and a stabilizer
compound, wherein the salicylic acid is present in at least 1 wt %
based on total weight of the gel. The present invention is further
directed to a salicylic acid solution comprising the salicylic acid
gel, a thickener, and a solvent. The present invention is further
directed to products prepared with the salicylic acid gel or with
dilute solutions of the gel.
[0009] The present invention is further directed to a stable
salicylic acid gel comprising salicylic acid, a thickener, and a
stabilizer compound, wherein the salicylic acid comprises at least
30 wt %, based on total weight of the gel. The present invention is
further directed to a salicylic acid solution comprising the
salicylic acid gel and a solvent. The present invention is further
directed to products prepared with the salicylic acid gel or with
dilute solutions of the gel in solvent. The present invention is
further directed to a salicylic acid gel consisting of salicylic
acid, a thickener, and a stabilizer compound, wherein the salicylic
acid comprises at least 30 wt %, based on total weight of the
gel.
[0010] In further aspects, the salicylic acid gel prepared in
accordance with any aspect above is combined with ingredients to
form various products including body or hand lotions, skin
exfoliation products, skin tag removers, anti-dandruff shampoos,
wart medications, and anti-acne medications.
[0011] Further aspects are directed to making a solution or skin
care product comprising mixing the salicylic acid gel in accordance
with any aspect defined above with a solvent.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Aspects of the invention are directed to a gel of salicylic
acid, at least one thickener, and at least one stabilizer compound
selected from nitrogen compounds. One aspect is particularly
directed to a stable, concentrated gel. The concentrated gel allows
relatively large amounts of salicylic acid to be shipped and stored
in a safe and stable manner. A higher concentration of salicylic
acid further allows smaller shipping and storage space. Another
aspect is directed to gel consisting of salicylic acid, at least
one thickener, and at least one stabilizer compound selected from
nitrogen compounds. This gel also allows salicylic acid to be
shipped and stored in a safe and stable manner.
[0013] The thickener increases the viscosity of the gel. The
thickened gel allows for use in formulas with higher final
viscosity such as wart, callus, and skin tag removers. These
materials often use higher levels of salicylic acid. Since the gel
is thickened it allows for a thicker final product or less
viscosity adjustments for the manufacturer than if the thinner gel
was used.
[0014] In one aspect, a (concentrated) salicylic acid gel comprises
at least 30 wt % salicylic acid, at least 35 wt %, or at least 40
wt % salicylic acid gel, for example 30 wt % to 60 wt % salicylic
acid, or 35 wt % to 55 wt %, or 40 to 55 wt % salicylic acid each
based on total weight of the gel. Specific amounts may be 30 wt %,
35 wt %, 40 wt %, 50 wt %, and 60 wt % based on total weight of the
gel based on total weight of the gel.
[0015] The concentrated salicylic acid gel comprises the stabilizer
compound in an amount of at least 40 wt %, at least 45 wt %, at
least 60 wt %, and up to 70 wt %, for example 40 to 70 wt %, or 45
to 60 wt %, each based on total weight of the gel which is an
amount effective to provide stability to the salicylic acid in the
gel. Specific amounts may be 40 wt %, 50 wt %, 60 wt %, 65 wt %,
and 70 wt % based on total weight of the gel. The concentrated
salicylic acid gel comprises the thickener compound in an amount of
at least 1 wt %, at least 5 wt %, at least 10 wt %, at least 20 wt
%, at least 30 wt % and up to 50 wt %, for example 1 to 20 wt %, or
5 to 15 wt %, each based on total weight of the gel which is amount
effective to provide thickening of the salicylic acid gel. Specific
amounts may be 1 wt %, 5 wt %, 10 wt %, 15 wt % and 20 wt % based
on the total weight of the gel.
[0016] The ratio of the thickener to salicylic acid and stabilizer
compound depends on the thickener being used. For example, if
cellulose is being used the ratio can be relatively high (47:1)
whereas if a wax is used like stearyl alcohol or PEG-450 the ratio
will be lower (4:1). The amount of thickener may also depend on the
ultimate product. For example, if the ultimate product is a stick,
such as an acne stick, the amount of thickener may be higher than
the amount needed to produce, for example, an acne lotion. For
example, stearyl alcohol at 10% provides a material with a
viscosity greater 100,000 cps, at 20% provides essentially a soft
solid or extremely thick gel. Hydroxypropylcellulose (HPC) at 3%
gives a syrupy gel with a viscosity greater than 100,000 cps.
[0017] In one aspect, the concentrated salicylic acid gel is formed
by mixing salicylic acid with the stabilizer compound until the
salicylic acid is dissolved in the stabilizer compound. The
thickener is than added to increase the viscosity of the gel.
[0018] In a particular aspect, no water or solvent such as ethanol
is included in the gel. In a further particular aspect, no other
active ingredient is present in the gel. In a particular aspect,
there are only three components that form the concentrated gel: the
stabilizer compound (complexing agent), the thickener, and the
salicylic acid. That is the salicylic acid gel consists of
salicylic acid, a thickener, and a stabilizer compound, wherein the
salicylic acid comprises at least 30 wt %, based on total weight of
the gel.
[0019] The mixing of the salicylic acid, the thickener, and the
stabilizer compound may be done at room temperature. Alternatively
the mixing may occur at an elevated temperature such as up to
80.degree. C. After initial heating and blending, the temperature
may be gradually reduced with continued mixing until room
temperatures are reached (20-25.degree. C.). Generally mixing takes
about 30 to 180 minutes.
[0020] The concentrated gel may then be stored for future use. A
benefit of the concentrated gel is that such gel contains very
concentrated amounts of salicylic acid, and less storage space is
required than dilute solutions of salicylic acid. The gel is
storage stable for at least 2 years.
[0021] The thickener may be any suitable nonionic thickener that
increases the viscosity of the salicylic acid gel. The resulting
material can have viscosities from a flowable liquid to a solid bar
or stick. For those materials where it is possible and reasonable
to measure the viscosity, a Brookfield viscometer with a heliopath
can be used. Typically these measurements are made at room
temperature (20.degree. C.-25.degree. C.). Nonionic thickeners
useful to increasing the viscosity of the concentrated salicylic
acid gel include, but are not limited to, agar, align, pectin,
bentonite, chitosan, cellulose, carrageenan, chitin, cassia gum,
cetyl glycol, clay, croscarmellose, dextrin, xanthan gum, gelatin,
hectorite, silica, hydroxyethylcellulose, hydroxypropylcellulose,
methylcellulose, microcrystalline cellulose, pectin, polyester-5,
polyether-1, polyglycerin-20, polyglycerin-40, sclerotium gum,
sodium stearate, stearyl alcohol, starch, beeswax and ceresin.
[0022] The thickener may also be an alcohol such as an alcohol
containing at least 9 carbon atoms, for example, 9-11, 12-13,
12-15, 20-22, 30-50, and 40-60 carbon atoms. Specific alcohols
include cetearyl alcohol, cetyl alcohol, decyl alcohol, lauryl
alcohol, and polyvinyl alcohol.
[0023] The thickener may also be a polyethylene glycol such as
PEG-450, PEG-800, PEG-2M, PEG-5M, PEG-7M, PEG-9M, PEG-14M, PEG-20M,
PEG-23M, PEG-25M, PEG-45M, PEG-65M, PEG-90M, PEG-115M, PEG-160M,
and PEG-180M.
[0024] Mixtures of any of the thickeners may also be used.
Particular thickeners useful in the present invention are PEG-450,
stearyl alcohol, and hydroxypropyl cellulose.
[0025] The stabilizer compound may be any suitable nitrogen
compound that stabilizes the salicylic acid in the concentrated
gel. Nitrogen compounds useful to form the highly concentrated
salicylic gel include, but not limited to, alkoxylated amides,
alkoxylated amines, alkylamido alkylamines, amides, amine oxides,
and amines. Ideally, a clear product should be produced.
[0026] In one aspect, the nitrogen compound is cocamidopropyl
dimethylamine. The cocamidopropyl dimethylamine is particularly
suitable for high concentrations of salicylic acid. When diluted in
water, the resulting solution is stable and clear.
[0027] The concentrated gel can be diluted to any suitable level
for use. Dilution of the salicylic acid gel may occur by the
addition of water. Upon dilution, the salicylic acid forms a clear,
stable solution in the water--that is, the salicylic acid does not
precipitate out.
[0028] In particular the dilute solutions comprise wherein the
concentration of the salicylic acid in the solution is at least 0.5
wt %, at least 1 wt %, at least 5 wt %, at least 10 wt %, at least
15 wt % or at least 20 wt % each based on total weight of the
solution.
[0029] The present invention is further directed to products
prepared with the salicylic acid gel or with dilute solutions of
the gel in solvent wherein the concentration of the salicylic acid
in the product is at least at least 0.5 wt %, at least 1 wt %, at
least 5 wt %, at least 10 wt %, at least 15 wt %, at least 20 wt %,
at least 30 wt %, or at least 40 wt % each based on total weight of
the product.
[0030] Other aspects of the invention are directed to a gel
consisting of salicylic acid, at least one thickener, and at least
one stabilizer compound selected from nitrogen compounds. The gel
allows salicylic acid to be shipped and stored in a safe and stable
manner.
[0031] The salicylic acid gel consists of at least 1 wt %, at least
5 wt %, at least 10 wt %, at least 15 wt %, or at least 20 wt %,
salicylic acid based on total weight of the gel. Specific amounts
may be, but not limited to, 1 wt %, 5 wt % 10 wt %, or 20 wt %.
[0032] The salicylic acid gel consists of the stabilizer compound
in an amount of at least 30 wt %, at least 80 wt %, at least 90 wt
%, at least 95 wt %, at least 99 wt %, and up to 99 wt %, for
example between 70 wt % and 99 wt %.
[0033] The salicylic acid gel consists of the thickener in an
amount of at least 1 wt %, at least 5 wt %, at least 10 wt %, at
least 20 wt %, at least 30 wt % and up to 50 wt %, for example
between 20 wt % and 50 wt %.
[0034] In one aspect, the salicylic acid gel is formed by mixing
salicylic acid with the stabilizer compound and thickener until the
salicylic acid is dissolved in the stabilizer compound. No water or
solvent such as ethanol is included in the gel.
[0035] The mixing of the salicylic acid and the stabilizer compound
may be done at room temperature. Alternatively the mixing may occur
at an elevated temperature such as up to 80.degree. C. After
initial heating and blending, the temperature may be gradually
reduced
with continued mixing until room temperatures are reached
(20-25.degree. C.). Generally mixing takes about 3 to 180 minutes.
The gel is stable and may be stored.
[0036] The stabilizer compound may be any suitable nitrogen
compound that stabilizes the salicylic acid in the gel as discussed
above and incorporated by reference herein.
[0037] The thickener may by any suitable nonionic thickener that
increase the viscosity of the salicylic acid gel as discussed above
and incorporated by reference herein. It was discovered that a
thickener may be added to the salicylic acid and stabilizing agent
without affecting the stability of the gel.
[0038] As discussed above, the gel can be diluted to any suitable
level for use such as by the addition of water. In particular the
dilute solutions comprise wherein the concentration of the
salicylic acid in the solution is at least 0.5 wt %, at least 1 wt
%, at least 5 wt %, at least 10 wt %, at least 15 wt % or at least
20 wt % each based on total weight of the solution. Upon dilution,
the salicylic acid forms a clear, stable solution in the water.
[0039] The present invention is further directed to products
prepared with the salicylic acid gel or with dilute solutions of
the gel in solvent wherein the concentration of the salicylic acid
in the product is at least at least 0.5 wt %, at least 1 wt %, at
least 5 wt %, at least 10 wt %, at least 15 wt % or at least 20 wt
% each based on total weight of the product.
[0040] For pH evaluation, 94.5 wt % water was added to 5.5 wt % of
the concentrated gel (36 wt % salicylic acid, 10 wt % PEG-450, 54
wt % cocamidopropyl dimethylamine) resulting in a 2 wt % salicylic
acid concentration; the maximum allowed for anti-acne products. The
same evaluation was run using 91.7 wt % water and 8.3 wt % of the
gel (resulting in 3 wt % active salicylic acid; the maximum allowed
for anti-dandruff products) and 33.3 wt % water and 66.7 wt % of
the gel (resulting in 24 wt % active salicylic acid) to evaluate
for the wart remover monograph. All of these studies resulted in
clear, stable solutions with pH levels between 3 and 4.5.
[0041] The pH of the dilute system is generally less than 5, such
as 2 to 5, 2.5 to 4.5, typically 3 to 4.
[0042] For topical purposes, the dilute system must pass the USP
Monograph for a Salicylic Gel which includes an assay for salicylic
acid.
[0043] The diluted product may be combined with other suitable
ingredients to form the final products such as creams, lotions,
make-ups, toners, astringents, skin cleansing compositions,
shampoos, skin tag removers, exfoliants, and conditioners. These
compositions contain about 0.1-40 wt % of salicylic acid. The
amount of salicylic acid in the final product depends on the
intended purpose of the product.
[0044] Creams typically contain about 10-90 wt % water and 10-90 wt
% oil. Creams may also contain humectants, emollients, surfactants,
emulsifiers, preservatives and fragrances. Creams would generally
contain from 0.1 to 10 wt % salicylic acid.
[0045] Lotions typically contain 20-80 wt % oil and 10-80 wt %
water in an emulsion form. In addition, lotions may contain
humectants, emollients, surfactants, fragrances, preservatives and
so forth. Creams would generally contain from 0.2 to 10 wt %
salicylic acid.
[0046] Make-ups typically contain about 5-70 wt % oil, 10-95 wt %
water, and about 5-40 wt % pigment. In addition, the makeup may
contain surfactants, silicones as part of the oil phase,
humectants, emollients, preservatives, fragrances, etc. Make-up
would generally contain from 0.1 to 3 wt % salicylic acid.
[0047] Anti-dandruff shampoos typically contain 1-40 wt % of a
cleansing surfactant and 10-90 wt % water. The shampoo may also
contain any one of ingredients such as surfactants, colorants,
preservatives, fragrance, emulsifiers, viscosity adjusters, and
conditioning agents. Anti-dandruff shampoos would generally contain
from 0.18 to 3 wt % salicylic acid.
[0048] Hair conditioners typically contain include 10-95 wt %
water, 0.5-30 wt % conditioning ingredients such as quaternary
ammonium compounds or amphoteric polymers, proteins, etc., and
1-40% surfactants. Hair conditioners may also contain volatile or
nonvolatile silicones. Hair conditioners would generally contain
from 0.1 to 4 wt % salicylic acid.
[0049] Toners typically contain about 0-85 wt % alcohol, 0.01-5 wt
% surfactant, and 0.1-5 wt % humectants, 0.1-85% water.
[0050] The salicylic acid may also be used in ointments, gels, or
solutions. Suitable ointments are hydrophilic ointments (USP) or
petroleum.
[0051] The amount of salicylic acid present in the final product
depends on the product. For example, skin exfoliation products can
use as high as 10% salicylic acid, acne treatment products
generally contain 0.5 to 2 wt % salicylic acid, dandruff and
seborrheic dermatitis, and psoriasis treatment products generally
contain 3 wt % salicylic acid, and wart treatments and skin tag
removers generally contain up to 40 wt % salicylic acid, typically
5 wt % to 40 wt % or 17 wt % to 25 wt %.
Example 1
[0052] A 36% salicylic acid was blended with 54% cocamidopropyl
dimethylamine and 10% PEG-450. The resulting concentrated gel was a
yellow opaque semi-solid gel.
[0053] The concentrated gel was diluted to 2 wt % active salicylic
acid in water and separately in ethanol. The resulting solutions
were clear and colorless. No precipitate was formed either in water
or in ethanol. The pH of the water solution was approximately
3.2.
[0054] Stability tests were then performed on the water solution.
The concentrated gel and the diluted 2 wt % active salicylic acid
solution were prepared and subjected to accelerated stability
protocol which consisted of five freeze/thaw cycles and two weeks
in a 50.degree. C. oven. Under both of these conditions there were
no significant changes to either sample. The samples that were
frozen were obviously solid when removed from the freezer and the
50.degree. C. samples were less viscous. In both cases, when the
samples returned to room temperature, they were essentially
identical to the control samples. There was no color or viscosity
change and no precipitate was formed.
[0055] The gel was also diluted to 25 wt % active salicylic acid in
water. The resulting solution was a slightly viscous, yellow, clear
solution. No precipitate was formed. A physical accelerated
stability test was run on this prototype consisting of samples be
held at 50.degree. C. for two weeks and another sample run through
five freeze/thaw cycles. Under both of these conditions there were
no physical changes to the product include pH, viscosity, color and
appearance.
Example 2
[0056] A lotion was prepared with 5.5% of the gel of example 1 in
90.5% water with 4% Egel 305 [Polyacrylamide (&) C12-13
isoparaffin (&) Laureth-7]. The result was a white lotion that
would be applicable for an anti-acne product. The lotion underwent
the same accelerated stability testing as mentioned in example 1
(50.degree. C. for 2 weeks and 5 freeze/thaw cycles); there were no
significant physical changes to the product during the stability
testing.
Example 3
[0057] An anti-dandruff shampoo was prepared containing 3 wt %
salicylic acid.
TABLE-US-00001 An anti-dandruff Percent Water 35.67 Active
ingredient Cocamidopropyl 8.33 Dimethylamine (&) Salicylic Acid
Surfactant blend PEG-80 Sorbitan Laurate (&) 50.00
Cocamidopropyl Betaine (&) Sodium Trideceth Sulfate (&)
Glycerin (&) Disodium Lauroamphodiacetate (&) PEG-150
Distearate (&) Sodium Laureth-13 Carboxylate Thickener PEG-120
Methyl Glucose 5.00 Trioleate (&) Propylene Glycol (&)
Water (Glucamate .TM. LT) Preservative Propylene Glycol (&)
Diazolidinyl 1.00 Urea (&) Methylparaben (&) Propylparaben
(Nipaguard PDU) Citric Acid qs to pH 4 100.00%
[0058] In an appropriate container, water, and salicylic acid gel
were mixed until uniform. Sulfochem B-NBB, Glucamate LT and
Nipaguard PDU were added and mixed until homogenous. Then citric
acid was added, with continued mixing, until the batch reached pH
of approximately 4.0. Viscosity: >1300cp. Stability: Passed 2
weeks 50.degree. C.; 5 Freeze/Thaw cycles.
Example 4
[0059] A wart remover was prepared containing 17% salicylic
acid.
TABLE-US-00002 Percent Water 41.8 Active Ingredient Cocamidopropyl
Dimethylamine (&) 47.2 Salicylic Acid Propanediol 5.0
(Zemea.sup.()) Hydrogenated Methyl Abeitate 1.0 (Meristant .RTM.
101L) Alcohol 4.0 Preservative Blend Phenoxyethanol (&)
Methylparaben 1.0 (&) Ethylparaben (&) Butylparaben
Propylparaben (&) Isobutylparaben Citric Acid Qs 100.0%
[0060] In an appropriate container, water and salicylic acid gel
were blended until homogenous. In a separate container, alcohol and
Meristant.RTM. 101 L were mixed until homogenous and then added to
and mixed with the salicylic acid gel/Water blend. Zemea.RTM. and
Phenonip were then added to the blend and mixed until clear. The pH
was adjusted with citric acid to 4-4.5 as necessary.
Example 5
[0061] A 40% salicylic acid was blended with 60% cocamidopropyl
dimethylamine and then combined in a 4:1 weight ratio with stearyl
alcohol. The resulting blend was mixed and heated to 65-70.degree.
C. Mixing and heating were maintained until all of the stearyl
alcohol had melted and the blend was clear. The heat was then
turned off with continued mixing. The blend was mixed until the
batch cooled to 20-25.degree. C. The batch was then allowed to sit
for a 3-4 hours. The resulting material was a solid. Viscosity
measurements were difficult but all results were above 100,000 cps
at 25.degree. C.
Example 6
[0062] A 40% salicylic acid was blended with 60% cocamidopropyl
dimethylamine and then combined in a 47:1 weight ratio of a high
molecular weight hydroxypropyl cellulose (HPC). The resulting blend
was then heated to 70-75.degree. C. and mixed until the HPC has
dispersed as evenly as possible. The mix time was between 2-3
hours. The heat was then removed from the blend which was mixed
continuously until the blend reached room temperature. The
resulting blend was a syrupy liquid with a viscosity greater than
100,000 cps at 25.degree. C.
[0063] While the invention has been described with respect to
specific examples including presently preferred modes of carrying
out the invention, those skilled in the art will appreciate that
there are numerous variations and permutations of the above
described systems and techniques that fall within the spirit and
scope of the invention as set forth in the appended claims.
* * * * *