Note: Descriptions are shown in the official language in which they were submitted.
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1099637
BACKGROUND OF THE INVENTION
The known cosmetic gels are generally pourable gels formed
either by adding an inorganic salt to an alkyl ether sulfate or by the
inclusion in the cosmetic composition of cellulose, an alginate or another
known gum-type thickener.
In the treatment of headlice, bodylice and other parasitic
infestations of the skin and in the treatment of other skin disorders,
it has been found desirable to treat the body or the hair with an active
ingredient which is insoluble in water. Such active ingredients include,
for example, carbaryl, piperonyl butoxide and malathion.
Activeingredientsof this type have been combined in cream- Z
type compositions which have found great acceptablility and use in
temperate climates, but which present considerable problems in more
tropical climates. Thus, in tropical climates the anionic surfactant
generally used, ~or example sodium lauryl sulfate dissolves in the
preparation to form a liquid rather than a cream. On subsequent cooling
of the preparation the surfactant crystallizes out of solution to give
a product containing short needle-like crystals. This is obviously un-
acceptable to the user.
Gel compositions for other purposes than for topical application
cannot be used for topical application purposes because the components
thereof are irritatlng, for example to the skin, causing dermatitis and
~ to the eye, causing conjunctivitis.
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SUM~RY OF THE INVENTION
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Generally speaking, in accordance with this invention a gel
composition for topical application is provided comprising as gel forming
components a mild anionic surfactant, a nonionic surfactant and a polar
solvent such as water. The ingredients are selected and the proportions
of ingredients are selected so that the composition does not irritate
human or animal skin.
It is a primary object of the present invention, therefore, to
provide gel compositions which have a gel structure over whatever temper-
ature range may be encountered by the product, although the composition
may decrease somewhat in viscosity with increasing temperature.
It is another object of the present invention to provide gel
compositions which can be used topically on animal or human skin without
the risk of causing skin or eye irritations.
It is still a further object of the present invention to provide L
gel composittons for topical administration which can be used as a vehicle
for water insoluble active ingredients, such as for the treatment of
parasitic infestat1ons and the like.
Other objects and advantages of the present invention will be
apparent from the further reading of the specification and of the appended
claims.
With the above and other objects in view, the gel compositions
of the present invention mainly comprise a mild anionic surfactant, a
nonionic surfactant and a polar solvent, preferably water.
The anionic surfactants used ~n the gel compositions of this
invention are mild anionic surfactants which do not cause irritations
when applied to animal or human sk~n and thus do not cause complaints
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such as dermatitis and con~unctivitis.
Among the suitable anionic surfactants of this type are straight
chain or branched chain alkyl ether sulfates. These straight chain or
branched chain alkyl ether sulfates are preferably used in the form, for
example of their alkali metal salts, such as sodium or potassium salt, or
their organic amine salts such as the monoethanol amine and the diethanol
amine salts of alkyl ether sulfates containing alkyl groups of 8 to 18
carbon atoms. Sodium salts of straight chain alkyl ether sulfates in
which the alkyl group contains 10-15 carbon atoms are preferred. Most
preferred are sodium lauryl ether sulfate and sodium myristyl ether
sulfate.
Although any nonionic surfactant can be used for the purposes
of the present invention. the preferred nonionic surfactants are of the
polyoxyethylene type, for example polyoxyethylene alkyl ethers containing
alkyl groups of 8-22 carbon atoms and 1-8 oxyethylene units, as well as
polyoxyethylene alkyl phenyl ethers containing alkyl groups of 8-18 car-
bon atoms and 1-8 oxyethylene units. Polyoxyethylene (4-6) nonylphenyl
ethers and polyoxyethylene ~3-5) dodecyl ethers are particularly pre-
ferred. Commercially available nonionic surfactants which can be used
2Q include Antarox* C0630, Fomescol* V27, Texafor* F85 and Volpo* N5.
In addition to the gel forming components of the components
of the composition, namely the mild anionic surfactant, the non~onic
surfactant and the polar solvent such as water, the gel compositions of
this invention can include and carry therein an active ingredient such as
an active ingredient for the treatment o~ parasiticinfestqtionsof the
skin and other disorders, lanolin, a foam synergist, a colorant and a
; perfume.
* Trade Mark
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1099637
The preferred active ingredients for the treatment of body and
headlice are carbaryl, piperonyl butoxide malathion and mixtures thereof. L
The foam synergist which may be incorporated in the composition
is preferably a mono- or diethanolamide, for example lauric diethanolamide
or coconut diethanolamide.
The best gel composition effects are obtained according to the
present invention by maintaining the preferred ratio of the anionic sur-
factant to the nonionic surfactant between about 1:3 and 3:1. The most
preferred ratio is 2:1.
; 10 Furthermore, the comfined percentage of the anionic surfactant
and the nonionic surfactant in the total gel composition is preferably b
maintained between about 20-60% by weight~ .
Since the presence of other formulation excipients in the gel
compositions of the invention may affect the viscosity of the final
composition, adjustment is necessary to determine the optimum percentage
: and ratio of the anionic surfactant and nonionic surfactant in the final
formulation~
Although the invention is not meant to be limited to any theory
as to ho~ the gel composition of suitable properties-is obtained according
to the present invention, the follow~ng theory is given in the hope that
it will aid further investigation in this field. f
It is thought that the combination of the anionic surfactant
w:ith the nonionic surfactant in the water or other polar solvent creates
a co~micelle phase within the solvent which leads to gel formation by an
increase in the bulk volume of the co-micelle phase. Thus, the bulk
volume of tKe two surfactants or combined percentage of the two surfactants f
determines~the gelling point of tKe composition, and it is for this reason
that the preferred combined percentage of the anionic surfactant and the
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nonionic surfactant in the gel composition ranges between 20-60% by weight.
The gel compositions of the invention are prepared by heating
the anionic surfactant paste (in the form of a concentrate in water, for
example a 70~ concentrate) with the nonionic surfactant (in pure liquid
form), adding water (or other polar solvent) and mixing to form a clear
solution. On cooling a product is formed which, depending on the proportions
of the two surfactants, may range from a viscous liquid to a hard gel. If
an active ingredient is present, this .is dissolved in the nonionic sur-
factant before the nonionic surfactant is heated with the anionic surfactant.
Similarly, the other optional ingredients are dissolved in
whichever phase (surfactant or aqueous) they are most soluble. Any perfume
which is added as a final ingredient is added at as low a temperature as
possible.
DESCRIPTION OF PREPERRED EMBODIMENTS
The following examples are given to further illustrate the
invention. The scope of the invention is not, however, meant to be limited
to the specific details of the examples.
; EXAMPLE 1
; Ingredients Weight in grams
20 Carbaryl 1.0
`~ Nonylphenoxypoly(ethyleneoxy)ethanol 12.5
Sodium lauryl ether sulfate (70%) 25.0
Coconut Diethanolamide 1.0
Ethoxylated Lanolin 1. 5 r
Colorant - F.D. and C Yellow No 5 0.01
Perfume - Glarland Flora 0.2
Water To lOO gm.
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The sodium laurylethersulfate, coconut diethanolamide and
ethoxylated lanolin are mixed together at a temperature of 70 to 80 C.
The carbaryl is dissolved in the nonylphenoxypoly(ethyleneoxy) ethanol
by warming to a temperature of 40 to 50 C. The mixture is stirred to form
a clear solution. The resulting solution is added to the mixture of
sodium lauryl ether sulfate, coconut diethanolamide and ethoxylated
lanoline and stirred to produce a homogeneous solution.
The colorant is completely dissolved in the calculated amount
of water and the resulting solution is heated to a temperature just below
boiling point and then slowly added to the above-prepared homogeneous
solution. The resulting mixture is maintained at a high temperature to
allow air to escape. The mixture is then cooled to 55 to 60 C and the
perfume slowly stirred into it. On cooling to room temperature a gel is
formed which retains its gel form and shape for at least two years when
stored at room temperature or 30 C.
EXAMPLE 2
Ingredients Weight in grams
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Malathion 1.10
Nonylphenoxypoly(ethyleneoxy~ ethanol 20.00
~20 Sodium lauryl ether sulfate (70%~ 25.00
Coconut Diethanolamide 2.50
Ethoxylated lanolin 1.25
Colorant - F.D. and C Yellow No 5 0.01
Perfume - May & Baker No 1658 0,2
Dilute Hydrochloric acidQ.S. (to pH 5.2)
Water To 100 gm.
The sodium lauryl ether sulfate, coconut diethanolamide and L
ethoxylated lanolin are mixed together at a temperature of 70 to 80 C.
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The nonylphenoxypoly(ethyleneoxy) ethanol is then added to the mixture
which is stirred to produce a homogeneous solution. The colorant is
completely dissolved in the calculated amount of water and the resulting
solution heated to a temperature just below boiling point and then slowly
added to the above-prepared homogeneous solution.
The resulting mixture is maintained at a high temperature to
allow air to escape. The mixture is then cooled to 55 to 60 C and ad-
justed to pH 5.2 with dilute hydrochloric acid. The malathion and
perfume are then slowly stirred into the mixture. On cooling to room
temperature a gel is formed which retains its gel form and shape when
heated to a temperature of at least 30 C.
EXAMPLE 3
Ingredients Weight in grams
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Carbaryl 1.00
Piperonyl Butoxide 5.00
Alkyl Phenol Polyoxyethylene Ether 12.50
Sodium Lauryl Ether Sulfate 30.00
, Isopropyl myristate 3,00
Coconut Diethanolamide 1.00
20 Ethoxylated Lanolin 2.00
Colorant F.D. and C Yellow No 5 0.0025
F.D. and C Blue No l 0.0025
Perfume - Freska 0.4
Water To 100 gm.
The sodium lauryl ether sulfate, coconut diethanolamide and
ethoxylated lanolin are mixed together at a temperature of 70 to 80 C.
The carbaryl, piperonyl botoxide and isopropyl myristate are dissolved
in the nonylphenoxypoly(ethyleneoxy)ethanol by warming to a temperature
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of 40 to 50 C. The mixture is stirred to form a clear solution.
The resulting solution is added to the mixture of sodium L
lauryl ether sulfate, coconut diethanolamide and ethoxylated lanolin and
stirred to produce a homogeneous solution. The colorant is completely
dissolved in the calculated amount of water and the resulting solution
heated to a temperature just below boiling point and then slowly added
to the above-prepared homogeneous solutton. The resulting mixture is
maintained at a high temperature to allow air to escape. The mixture is
then cooled to 55 to 60 C and the perfume slowly stirred into it.
On cooling to room temperature a gel is formed which retains
its gel form and shape when heated to a temperature of at least 30 C.
While the invention has been ~llustrated with respect to
particular compositions it i5 apparent that variations and modifications
thereof can be made.
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