Note: Descriptions are shown in the official language in which they were submitted.
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HIGH EFFICIENCY SUNSCREEN COMPOSITION PARTICULARLY USEFUL FOR
WIPES AND SPRAYS
FIELD OF THE INVENTION
[00011 The present invention relates to compositions for sunscreen wipes
and sprays,
which allow an efficient transfer of sunscreen actives to the skin. In the
preferred embodiments,
it relates to high-efficiency (i.e., with enhanced sun protection factor)
sunscreen compositions for
sun protection wipes and sprays, which enable sunscreen actives contained
therein to be
transferred to the skin efficiently, due to having certain desirable
theological properties, and
stability. The preferred composition is in the form of a highly shear-
thinning, stable, oil-in-water
(0-W) emulsion, with at least one water-insoluble, organic sunscreen active
contained in the oil
phase, while the water phase contains i) an SPF (sun protection factor)
booster, comprising a
mixture of particulate materials including smectite clay, and an interfacially-
active phenolic
polymer; and ii) a low molecular weight, non-thickening, water-soluble
polymer, preferably
selected from alkali metal salts of weak acid polymers, wherein the sunscreen
emulsion exhibits
an increased shear-thinning due to having the weak acid polymer as a
component.
BACKGROUND OF THE INVENTION
[0002] It is well recognized that the solar ultraviolet (UV) radiation
poses serious threat
of human skin damage which may range from the short term hazard like erythema,
i.e., sunburn,
to long term hazards like skin cancer and/or premature aging of the skin. The
SPF rating system
has been developed to help consumers select the appropriate sun protection
product for any
given outdoor activity involving exposure to the sun. The SPF number
corresponds to a
multiplying factor by which the duration of protection by a properly applied
sunscreen exceeds
the exposure time that causes the unprotected skin to show darkening. Thus,
with proper
application of an SPF 15 product, a person should be able to remain in the sun
without skin
darkening for fifteen times the usual unprotected duration. In recent years,
due to the increased
public awareness of UV radiation hazards,
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the use of sun protection products has grown considerably. Among these
products, wipes
and sprays are gaining increasing consumer preference because of the
convenience in
product application.
[0003] Most skin care products in the form of creams and lotions are
essentially
emulsions, having either an oil phase emulsified in a water phase (0-W
emulsions) or a
water phase emulsified in an oil phase (W-0 emulsions). Typically, a thickened
continuous phase (e.g., the water phase in O-W emulsions) tends to enhance
emulsion
stability against phase separation induced by flocculation, Ostwald ripening,
sedimentation (creaming) as well as coalescence of emulsion droplets. On the
other hand,
viscous compositions, generally, fall short of being adequately delivered to
the skin from
wipes and sprays. Fulfilling the conflicting demands of having emulsion
compositions
that transfer easily from wipes onto the skin, yet, while remaining stable, is
a challenge
that is met in accordance with the present invention.
[0004] For wipes having a basesheet or fiber-containing substrate impregnated
with an
unstable emulsion, as the emulsion droplets grow bigger in size due to
coalescence, an
effect that eventually leads to the separation of the emulsified phase, the
large droplets
thus formed tend to .deposit onto the wipe substrate due to various phenomena
including
the following: i) increased van der Waals attraction between emulsion droplets
and the
wipe substrate with increasing particle size; and ii) mechanical interception
of large
emulsion droplets by the fibers of the basesheet. Such deposition of emulsion
droplets
onto the basesheet could greatly reduce the skin-delivery of a skin care
active contained
in the emulsion droplets. In O-W sunscreen emulsions, the sunscreen actives
are
generally incorporated into the emulsified oil phase, being oil-soluble or oil-
dispersible.
Clearly, only a small fraction of the sunscreen actives would be delivered to
the skin,
leaving the skin virtually unprotected against LTV radiation, if sunscreen
wipes contained
unstable O-W sunscreen emulsions. It is imperative, therefore, for O-W
emulsion-based
products to be highly stable, in order to ensure an efficient transfer of the
emulsified
sunscreen actives from wipes to any given substrate.
[0005] Most organic sunscreen agents are oil-like and/or oil-soluble materials
that are
often expensive. High levels of these actives in sun care products increase
the cost of the
products, while rendering the products less appealing for their greasy skin
feel and skin
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irritation. One way to address these issues would be to include an ingredient
that
functions as an SPF booster, being capable of increasing the SPF
significantly, despite not
being a strong UV-absorber at its typical use level.
[0006] Polargel UV, a sunscreen additive from AMCOL International
Corporation, is
a proven ingredient for boosting the SPF of sunscreen emulsions that contain
water-
insoluble, organic sunscreen actives (see US 6,500,411 B2 and 6,716,418). It
comprises a
mixture of particulate materials including smectite clay, with an
interfacially-active
phenolic polymer, e.g., lignosulfonate, used as a dispersant or surface-
modifier for the
particulate materials. These particulate materials, with relatively high
specific gravities,
exhibit high settling rates even for particles less than 1 micron in size, in
less viscous
aqueous compositions.
[0007] Polargel UV enables achieving a given SPF for an O-W sunscreen
emulsion,
but with a lower dosage of organic sunscreen actives contained in the
emulsified oil phase
than otherwise. However, its effective use in O-W sunscreen emulsions relies
on having
its particulate constituents remaining suspended in the water phase of the
emulsions, in
turn requiring the emulsions to be viscous under storage conditions. This
requirement is
particularly critical for sunscreen wipes since settling of the particulate
constituents in the
relatively thin emulsion mass impregnating a single wipe basesheet could lead
to a rapid
loss of these SPF-boosting constituents from the skin-contacting surface of
the basesheet.
[0008] The prior art related to sunscreen wipes, for example, published US
patent
applications 2003/0012809 Al and 2004/0228811 Al, describes sunscreen
compositions
with a low-shear-rate viscosity in the range of 0 ¨ 20,000 cps. Nonetheless,
low-shear-
rate viscosities would have to be much greater than 20,000 cps in order to
maintain good
suspension of a particulate-based additive such as Polargel UV, in the water
phase of O-
W emulsions. These prior art sunscreen compositions, therefore, could not
possibly
include a SPF booster comprising of water-dispersible particulate materials,
such as
Polargel UV, while maintaining good suspension of the additive's particulate
constituents in the water phase, a critical requirement for realizing the
efficacy of such an
SPF booster.
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[0009] A common method for thickening the water phase of O-W emulsion-based
personal care and cosmetic compositions is to use water-soluble, polymeric
thickeners
and/or particulate material-based thickeners, such as smectite clay and fumed
inorganic
oxides (e.g., silica). The most widely used polymeric thickeners include
crosslinked
acrylic acid polymers, xanthan gum, and cellulosic polymers. It is known in
the art that
combining any of these polymers with smectite clay results in synergy in
thickening.
Accordingly, with any of these polymers used as the primary thickener for an O-
W
emulsion, the emulsion viscosity would be considerably higher if the emulsion
contains a
smectite clay-laden additive such as Polargee) UV. The increased viscosity is
expected to
have a positive impact on emulsion stability, but it would render the emulsion
unsuitable
for wipe and spray products, as there would be a less efficient transfer of
the emulsion
onto the skin from these products, if the emulsion is more viscous but while
not highly
shear-thinning.
[00101 in the light of all of the above, and in particular the benefits of
including a
water-borne SPF booster such as Polargel UV in a sunscreen formulation, it is
an object
of the present invention to produce sunscreen wipe and spray compositions
comprising a
highly stable, O-W emulsion-based sunscreen formulation that contains, in the
water
phase, a phenolic polymer, a smectite clay particulate together with one or
more
additional particulate materials having a primary particle size of less than 1
micron, and a
low molecular weight, weak-acid polymer having a weight average molecular
weight in
the range of 1,000 - 100,000 Dalton, with the weak acid polymer enabling the
sunscreen
composition to exhibit certain desirable viscosity properties, specific to
sunscreen wipes
and spray compositions, while maintaining good suspension of the particulate
constituents in the water phase of the emulsion.
SUMMARY
[0011] Described herein are sunscreen compositions in the form of wipes and
sprays,
comprising an oil-in-water (0-W) sunscreen emulsion that meets certain
specifications
related to sun protection factor (SPF), viscosity, shear-thinning, and
stability, wherein the
wipes comprise a wipe substrate impregnated with the said sunscreen emulsion.
More
particularly, the O-W sunscreen emulsion contains, in the water phase, a water-
borne SPF
booster, and a low molecular weight, weak-acid polymer, while in the oil
phase, at least
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one water-insoluble organic sunscreen active. The SPF booster additive
comprises a
phenolic polymer, and a mixture of water-dispersible particulate materials,
one of which
is smectite clay, wherein at least one of the particulate components has a
primary particle
size of less than 1 micron. The phenolic polymer serves as a dispersant or
surface-
modifier for the particulate components of the additive, and is further
capable of
functioning as an emulsifier for O-W emulsions.
[0012] In order to ensure that the particulate components of the SPF booster
can remain
suspended in the water phase of the sunscreen emulsion compositions described
herein
over extended storage durations, the emulsion's water phase is thickened with
a
thickening agent. The thickening agent is preferably selected from high
molecular
weight, water-soluble or water-dispersible polymers known in the art as
thickening
agents, and particulate-based thickening agents such as smectite clay and
fumed inorganic
oxide (e.g., silica). The thickening agents may further include the liquid-
crystalline
structure forming materials such as fatty acids, fatty esters, and fatty
alcohols.
[0013] For the O-W sunscreen emulsions of the present invention, the ratio of
the SPF
to the total amount, expressed as % by weight of the sunscreen emulsion, of
organic
sunscreen active(s) contained in the emulsion is at least 1.8. In other words,
the SPF of
the sunscreen emulsion described herein is at least 18, if the organic
sunscreen content is
10% by weight of the emulsion.
[0014] These sunscreen emulsions should have low-shear-rate viscosities of
at least =
50,000 cps at 0.5 rpm and 35,000 cps at 1 rpm, while the high-shear-rate
viscosities are
10,000 - 30,000 cps at 5 rpm and 2,500 ¨ 10,000 cps at 20 rpm, as measured on
a
Brookfield RVT viscometer, at 25 C, using spindle # 7. As a critical
requirement for the
sunscreen compositions described herein, the sunscreen emulsions contain a
shear-
thinning-boosting ingredient that is capable of increasing the shear-thinning
index of the
compositions by at least 5% over the shear-thinning index of the compositions
without
the shear-thinning-boosting ingredient (when the ingredient is replaced by the
same
weight of water), where shear-thinning index is a term used herein for
quantifying the
level of shear-thinning. As defined herein, shear-thinning index is the ratio
of emulsion
viscosities at 0.5 rpm and 20 rpm, with the viscosities measured on a
Brookfield RVT
viscometer, at 25 C, using spindle # 7. Unexpectedly, the inclusion of a low
molecular
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weight weak acid polymer as a water-phase component for the 0-W sunscreen
emulsions
described herein, enables achieving a 5% or greater increase in the shear-
thinning index.
100151 Furthermore, to achieve the full advantage of the sunscreen emulsions
described
herein, the emulsion has no visible separation of the oil phase or the
particulate
components of the water phase, when centrifuged at 3,000 rpm for 30 minutes
after being
heated to 60 C. In a preferred embodiment, the sunscreen emulsions also show
good
stability against any separation of the oil phase and the particulate
components of the
water phase, when subjected to freeze-thaw stability testing involving the
following: i)
freezing the emulsion sample at -10 C for a period of 24 hours, followed by
thawing the
emulsion sample at room temperature; ii) repeating these steps at least three
times on the
same emulsion sample; and iii) repeating (i) and (ii) with sunscreen wipes
made after
impregnating a wipe-substrate with the said emulsion.
DETAILED DESCRIPTION
[00161 Described herein are compositions for sunscreen wipes and sprays,
comprising a
sunscreen emulsion that meets certain specifications related to sun protection
factor
(SPF), viscosity, shear-thinning, and stability properties. In one embodiment,
the
sunscreen emulsion impregnates a water-insoluble wipe substrate or basesheet.
By
"water-insoluble" is meant the wipe substrate does not dissolve in or
disintegrate upon
immersion in water. Nonlimiting examples of such substrates include both
nonwoven
substrates and woven substrates known in the art, made from polymeric and/or
natural
fibers. The amount of the sunscreen emulsion relative to the weight of the
wipe substrate
may range from about 20: Ito about 1:1, more preferably from about 15:1 to
about 10:1,
and most preferably from about 6:1 to about 2:1.
[00171 The preferred sunscreen emulsion composition is produced in the form of
an oil-
in-water (0-W) emulsion, wherein the oil phase, as is typical in prior art
sunscreen
compositions, contains at least about 2% by weight of a (any) water-insoluble,
organic
sunscreen active, based on the weight of the emulsion.
100181 In accordance with the 0-W sunscreen-emulsion compositions described
herein,
it has been found that by incorporating, into the water phase, a water-borne
SPF booster
comprising a water-soluble or water-dispersible phenolic polymer and a
combination of
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water-dispersible particulate materials, one of which is smectite clay, the
ratio of the SPF
(in-vivo SPF measured as per the standard protocols known in the art,
preferably under
the very water-resistant SPF testing conditions) of the sunscreen emulsion to
the total
amount (expressed as % by weight of the emulsion) of the sunscreen actives
contained
therein, can be at least as high as 1.8, provided that one of the particulate
components of
the SPF booster has a primary particle size of less than 1 micron. One
particularly
effective SPF booster is Polargel UV containing about 0.5% to about 40% by
weight of
smectite clay, together with about 0.5% to about 40% of another particulate
material, and
about 0.5% to about 20% of a phenolic polymer. A low molecular weight weak-
acid
polymer is included in the water phase of the sunscreen emulsion to provide
unexpected
viscosity characteristics for the emulsion, that enable maintaining
sedimentation-stability
of the SPF-boosting particulate components contained in the emulsion's water
phase,
while ensuring that the emulsion can be transferred adequately to the skin
from wipe and
spray form.
[0019] The water phase of the sunscreen emulsions described herein should
contain
smectite clay in an amount of about 0.1% to about 5% by weight, preferably
about 0.5%
to about 2% by weight, and more preferably about 1% to about 1.5% by weight.
The
amount of phenolic polymer contained (dissolved or dispersed) in the water
phase should
be in the range of about 0.025% to about 2.5%, preferably about 0.05% to about
1% by
weight, and more preferably about 0.1% to about 0.5% by weight. The additional
particulate material, (in addition to the smectite clay) should be included in
the water
phase in an amount of about 0.1% to about 20%, preferably about 0.3% to about
5% by
weight, and more preferably about 0.5% to about 3% by weight. When the SPF
booster is
supplied from Polargel UV, the dosage of Polargel UV may range from about
0.5% to
about 35%, more preferably from about 1% to about 20%, and most preferably
from
about 2% to about 15%, based on the weight of the water phase of the sunscreen
emulsion
in order to achieve the final water phase composition of the sunscreen
emulsion, detailed
above.
[0020] The preferred SPF booster comprises a mixture of water-dispersible
particulate
materials at least one of which is smectite clay, and a phenolic polymer,
serving as
dispersant/surface-modifier for the particulate materials. The particulate
component that
is combined with the smectite clay can be any particulate material selected
from inorganic
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oxides, water-insoluble inorganic salts, silicate minerals, and water-
insoluble organic
particulate materials, whose surface can be modified by the adsorption of the
phenolic
polymer on the particle surface. Preferred examples of these particulate
materials for
combination with the smectite clay include titanium dioxide, zinc oxide,
alumina, silica,
talc, and latex polymers. The essential smectite clay particulate component of
the SPF
booster is selected from bentonite, rnontmorillonite, saponite, hectorite,
bidelite, and/or
stevensite. The ratio of the amount of smectite clay to the amount of the non-
smectite
clay particulate component(s) of the SPF booster is in the range of 1:1 ¨
1:30. To achieve
the full advantage of the sunscreen emulsions descried herein, at least one
particulate
component of the SPF booster should have a primary particle size of less than
1 micron,
preferably less than 0.5 micron, and most preferably less than 0.25 micron. In
a preferred
embodiment, the SPF booster is preferably an aqueous dispersion of the
foregoing
particulate components, wherein the smectite clay remains in a highly
exfoliated form
(i.e., wherein the clay platelets are delaminated or separated from one
another across their
face surfaces).
10021] The dispersant/surface modifier for the particulate materials is either
a phenolic
polymer, or a mixture of a phenolic polymer and an alkali metal salt of an
acrylic acid
polymer. Non-limiting examples of the phenolic polymer include lignosulfonate,
lignin,
oxylignin, and humate.
[0022] The water phase of the sunscreen emulsion compositions described
herein is
thickened using a thickening agent known in the art, in order to ensure good
suspension
of the particulate materials of the SPF booster, e.g., Polargele UV. The
thickening agent
is selected preferably from high molecular weight (with a weight average
molecular
weight of > 500,000 Dalton) polymeric thickeners, particulate-based thickeners
such as
smectite clays, and mixtures thereof. The polymeric thickener is preferably an
anionic
polymer, and most preferably a crosslinked acrylic acid polymer, non-limiting
examples
of which include the following polymers listed by their respective
International
Nomenclature Cosmetic Ingredient name: A cryl ates/C10-30 Alkyl Acrylates
Crosspolymer and Carbomer. The amount of the high molecular weight polymeric
thickener in the water phase of the sunscreen emulsions described herein is in
the range of
from about 0.05% to about 5%, preferably in the range of from about 0.1% to
about 1%,
and most preferably in the range of from about 0.15% to about 0.5%, based on
the weight
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of the emulsion. The most preferred smectite clay-based thickener is sodium
bentonite,
comprising about 0.1 ¨ 5%, preferably 0.25% - 2%, and most preferably 0.5 ¨ 1%
by
weight of the water phase of the sunscreen emulsion. With the use of the
foregoing
thickening agents, the sunscreen emulsions are required to have low-shear-rate
viscosities
of at least 50,000 cps at 0.5 rpm and 30,000 cps at 1 rpm, while the high-
shear-rate
viscosities are 10,000 - 35,000 cps at 5 rpm and 2,500 ¨ 10,000 cps at 20 rpm,
as
measured on a Brookfield RVT viscometer, at 25 C, using spindle # 7.
[0023] The water phase of the sunscreen emulsion of the present invention
further
contains a water-soluble or water-dispersible shear-thinning-boosting
ingredient selected,
preferably, from alkali metal salts of weak acid polymers and copolymers
having a weight
averaged molecular weight of 1,000 ¨ 100,000 Dalton and an anionic charge
density of no
less than 1.5 milliequivalents per gram of the polymer. Non-limiting examples
of such
preferred shear-thinning aids include polyacrylate, polyphosphate,
polyphosphonate,
polyphenolate, and mixtures thereof. The polymer is necessarily such that,
when used at
or above a certain threshold dosage that may vary from one polymer to another,
the ratio
of emulsion-viscosities (measured on a Brookfield RVT viscometer, using
spindle # 7) at
0.5 rpm and 20 rpm is at least 5% greater as compared to when the emulsion
does not
contain the polymer, i.e., when the polymer is replaced by an equivalent
amount of water.
[0024] The water phase of the sunscreen emulsion of the present invention may
also
contain a polymeric emulsifier for stably dispersing the oil phase within the
water phase
of the emulsion. This is to minimize the use of detersive surfactants as an
emulsifier,
since these surfactants tend to mar the water resistance property of the
sunscreen
emulsion, especially when used at relatively high dosages. The polymeric
emulsifier is
selected from water-soluble or water-dispersible amphiphilic copolymers,
polyalkyl
glucoside with an alkyl chain length of C8 ¨ C30, and hydrophobically-
modified, water-
soluble or water-dispersible polymers.
[0025] The sunscreen emulsions described herein may further contain, in either
the oil
phase or the water phase, emulsifiers, emollients, fatty acids, alcohols and
esters, oil-
phase thickening agents such as oragnoclays, waxes, and polymeric thickeners,
hydrophilic liquids such as glycols and glycerin, chelating agents,
waterproofing agents,
Film-forming agents, moisturizing agents and humectants, sensory property
boosting
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agents, antioxidants, vitamins, preservatives, fragrances, coloring pigments
and dyes, water-
insoluble particulate material-based SPF boosters of inorganic and/or organic
origin (for example,
SunSpheresTM from Rohm and Haas Company), and surface-modified particulate
materials,
known in the art.
10026] The following examples will more fully illustrate the preferred
embodiments
within the scope of the present invention. The scope of the claims should not
be limited by the
preferred embodiments set forth in the examples, but should be given the
broadest interpretation
consistent with the description as a whole.
EXAMPLE I
[0027] This example demonstrates the benefit of incorporating an SPF booster,
Polargel UV 1116, from AMCOL International Corporation, in the O-W emulsion-
based
sunscreen compositions described herein, inasmuch as the present composition
required
considerably lower amounts of sunscreen actives as compared to O-W emulsion-
based sunscreen
compositions in the prior art, for attaining comparable SPF values. Table I
shows the sunscreen
active contents of the various formulations along with their respective SPF
values, while Table IT
shows the sunscreen composition of the present invention.
TABLE I
Formulation Sunscreen Actives SPF
Sunscreen Composition of 5% Octyl Methoxycinnamate, 3% Octyl 32
the Present Invention Salicylate, 3% Oxybenzone, 2% Avobenzone
Neutrogena Active 7.5% Octinoxate, 5% Octyl
Salicylate, 3% 30
Breathable Sunblock Oxybenzone, 2% Avobenzone, 7% Homosalate
Banana Boat , Kids, Quik 7.5% Octyl Methoxycinnamate, 5% Octyl 35
Blok, Spray Lotion Salicylate, 6% Oxybenzone, 2.5% Octocrylene,
3% Avobenzone
Fruit of the Earth - Block 7.5% Octyl Methoxycinnamate, 5% Octyl 30
Up with Aloe Vera Salicylate, 5% Oxybenzone, 2% Avobenzone,
TABLE II
SUNSCREEN COMPOSITION OF THE PRESENT INVENTION
Ingredient
Tradename/Description/Function Weight %
Water Phase
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SUNSCREEN COMPOSITION OF THE PRESENT INVENTION
Ingredient Tradename/Descri p tion/Functi on Weight %
Water 68.970
Propylene Glycol Moisturizer 1.000
Acrylates/C10-30 alkyl acrylates Penntlen TR2, Emulsifier ¨ 0.220
crosspolymer thickener (Noveon)
Sodium Polyacrylate Solcalan
PA 30 CL (45% active), 0.470
Low molecular weight weak acid
polymer (BASF)
Phenoxyethanol; Methylparaben, Phenonip0, Preservative mixture 1.000
Butylparab en, Ethyl p araben , (C lari ant)
Propylparaben
Sodium Hydroxide (50% active) pH adjustment reagent 0.200
Aloe Extract (50% active) Skin feel enhancer 0.150
Water, Sodium bentonite (26.7% of Po1arget9 UV 1116, SPF booster 3.750
the dispersion), Titanium Dioxide (AMCOL)
(20% of the dispersion),
Lignosulfonate (5.75% of the
dispersion)
Tetrasodium ethylene diamine Chelating agent 0.050
tetracetate
Phenoxyethanol, Chlorphenesin, Germazicle MPB, Preservative 1.330
Glycerin, Methylparaben, Benzoic (Englehard)
Acid
Oil Phase
Octyl Methoxycinnamate Sunscreen active 5.000
Octyl S ali cylate Sunscreen active 3.000
Oxybenzone Sunscreen active 3.000
Avobenzone Sunscreen active 2.000
Isopropyl Myristate Emollient 7.000
Cetearyl Polyglucoside Tego
Care() CG 90, Polymeric 0.250
emulsifier (Degussa)
Tocopheryl Acetate Vitamin E 0.100
Retinyl Palmitate Vitamin A 0.010
Polyethylene
Polyethylene AC 1700, Water 2.500
resistance promoter (Honeywell)
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Manufacturing Procedure
= Heat the water phase to 85-90 C, under mixing in a rotor-stator
homogenizer (Si Iverson laboratory homogenizer).
= Heat the oil phase to 85-90 C under gentle agitation.
= Add slowly the heated oil phase to the heated water phase, while the
batch
remains under homogenizer mixing at 5,000¨ 10,000 rpm of homogenizer
speed.
= Continue homogenizing until the batch appears uniformly mixed.
Sun Protection Factor (SPF)
[0028] The SPF value, 32, for the above sunscreen composition was determined
based
on 20-subject in-vivo SPF testing as per the very water resistant SPF testing
protocol
mandated by the US Federal Drug Administration.
Stability Properties
[0029] The sunscreen formulation did not show visible separation of any
component,
when subjected to stability tests such as the following:
i) heating the emulsion to 60 C, followed by centrifuging the heated
emulsion at 3,000 rpm for 30 minutes
ii) storing the emulsion in a 45 C-oven for 3 months
[0030] The levels of sunscreen actives contained in the sunscreen emulsion did
not vary
much between before and after the emulsion was placed in a 45 C-oven,
indicating good
stability of the sunscreen actives during storage at 45 C.
Sunscreen Wipes
[0031] Sunscreen wipes manufactured using the sunscreen emulsion of Table II
were
shown to provide adequate protection of the skin from UV damage when used by
panelists during outdoor activities lasting from about 2 to about 8 hours
under direct
sunlight in summer months. The basesheet for these sunscreen wipes comprised a
non-
woven fabric made from a spunlace, rayon-polyester blend material. The loading
level of
the sunscreen emulsion was about 400%, based on the weight of wipe basesheet.
EXAMPLE II
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100321 This example demonstrates that the viscosity of an O-W sunscreen
emulsion
having a crosslinked polyacrylate used as a thickener for the water-phase of
the emulsion,
would be considerably higher if the emulsion further contained an SPF booster
such as
Polargel UV 1116 (Table III). It further demonstrates that the sunscreen
emulsion with
Polargel UV 1116 contained therein, would exhibit an increased level of shear-
thinning
rheology (now-property), if it contained a low molecular weight sodium
polyacrylate
(Sokalan PA 30CL, Table II) in the water phase of the emulsion.
10033.1 . A series of sunscreen emulsions were produced as per the
formulations
presented in Table III. The method used in manufacturing these emulsions is
nearly
similar to the procedure described in EXAMPLE I, except that Polargel UV 1116
was
added to certain emulsion batches as a post-emulsification-addition ingredient
after
cooling the emulsions to room temperature. Emulsion 1 did not contain either
Polargel
UV 1116 or Sokalan PA 30CL. Emulsion 2 contained 3.75% by weight of Polargel
UV 1116, but no Sokalan PA 30CL. Emulsions 3, 4, and 5 contained the same
amount
of Polargel LTV 1116 as in Emulsion 2, and varying amounts of Sokalan PA
30CL. For
these emulsions, Polargel UV 1116 and Sokalan PA 30CL were mixed together in
a
Silverson-homogenizer operated at a speed of 6,000 ¨ 8,000 rpm, prior to
addition to an
emulsion batch. In mixing Polargel UV 1116 and Sokalan PA 30CL, the former
ingredient was first diluted with deionized water in 1:1 proportion under
vigorous
agitation. Sokalan PA 30CL was subsequently added to the diluted batch of
Polargel
UV 1116 for mixing in a Silverson homogenizer.
[0034] The room-temperature viscosities of these emulsions were measured at
various
shear rates, using a Brookfield RVT viscometer, wherein the speed of the
viscometer
spindle was varied in order to vary the shear rate. For each emulsion, the
viscosity
measurement was carried out after the emulsion had been stored at room
temperature for
a period of at least 16 hours after it was manufactured. Spindle 7 was used
for all
viscosity measurements. In measuring the viscosity, first, the spindle was
inserted gently
into an emulsion sample with minimal disturbance of the emulsion, after which
a period
of 1 minute was allowed to pass before initiating the viscometer run.
Subsequently, the
viscometer was turned on and the spindle was allowed to rotate for a given
length of time,
depending on the speed of spindle rotation, prior to recording the viscosity
reading. The
spindle rotation time allowed for the different spindle speeds are as follows:
2 minutes for
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0.5 rpm, 1 minute for 1 rpm, 30 seconds for 2.5 rpm, and 15 seconds for each
of 5 rpm,
rpm, and 20 rpm. The results of these viscosity measurements are given in
Table IV.
In Table IV, the column-label "shear-thinning index" denotes the ratio of 0.5
rpm to 20
rpm viscosities, signifying the level of shear-thinning - the higher the
ratio, the greater
the level of shear-thinning.
TABLE III
Ingredients Emulsion Emulsion Emulsion Emulsion Emulsion
1 2 3 4 5
Water Phase
Water 73.180 69.430 69.150 68.990 68.700
Propylene Glycol 1.000 1.000 1.000 1.000 1.000
_
Pemulen TR2 0.230 0.230 0.230 0.230 0.230
Tego Care CG 90 0.250 0.250 0.250 0.250 0.250
Phenonip 1.000 1.000 1.000 1.000 1.000
,
50% Sodium Hydroxide 0.200 0.200 0.200 0.200 0.200
50% Aloe Extract 0.150 0.150 0.150 0.150 0.150
Tetrasodium ethylene 0.050 0.050 0.050 0.050 0.050
diamine tetracetate
Germazide MPB 1.330 1.330 1.330 1.330 1.330
Oil Phase
Octyl 5.000 5.000 5.000 5.000 5.000
Methoxycinnamate
Octyl Salicylate 3.000 3.000 3.000 3.000 3.000
Oxybenzone 3.000 3.000 3.000 3.000 3.000
Avobenzone 2.000 2.000 2.000 2.000 2.000
_
Isopropyl Myristate 7.000 7.000 7.000 7.000 7.000
Tocopheryl Acetate 0.100 0.100 0.100 0.100 0.100
Retinyl Palmitate 0.010 0.010 0.010 0.010 0.010
Polyethylene 2.500 2.500 2.500 2.500 2.500
Post-Add Phase
Polargel UV 1116 0 3.75 3.75 3.75 3.75
Sokalan PA 30 CL 0 0 0.28 0.44 0.73
TABLE IV
Emulsion Brookfield Viscosity, cps Shear-
#
thinning
0.5 rpm 1 rpm 2.5 rpm 5 rpm 10 rpm 20 rpm
Index
1 90,000 68,000 44,400 25,800 12,200 6,700 13.43
2 200,000 128,000 74,400 48,600 28,400 15,100 13.25 _
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WO 2008/097223 PCT/US2007/003372
3 160,000 91,000 51,600 32,600 19,000 9,100 17.58
4 124,000 68,000 40,000 25,800 _ 15,300 7,400
16.76
83,200 52,000 30,800 19,000 10,700 5,750 14.47
[0035] The effects of sodium polyacrylate on the rheological properties of the
sunscreen
compositions described herein are demonstrated further through the
formulations
presented in Table V, which contain a crosslinked polyacrylate-based
thickening agent,
Ultrez 21 (Noveon). The Brookfield viscosities of these formulations at
various spindle
speeds, as measured using spindle 7 at 20 ¨ 25 C, are given in Table VI.
TABLE V
Ingredients Emulsion 1 Emulsion 2
Water Phase
Water 68.250 67.500
Glycerin 1.000 1.000
Ultrez 21 0.200 0.200
Phenonip 1.000 1.000
50% Sodium Hydroxide 0.200 0.200
Tetrasodium ethylene 0.100 0.100
diamine tetracetate
Oil Phase
Octocrylene 5.000 5.000
Octyl Salicylate 5.000 5.000
Oxybenzone 2.000 2.000
Avobenzone 3.000 3.000
Homosalate 6.000 6.000
Stearic Acid 1.000 1.000
Cetyl Phosphate 1.000 1.000
Polyethylene 2.500 2.500
Post-Add Phase
Polargel UV 1116 3.750 3.750
Sokalan PA 30 CL 0.000 0.750
TABLE VI
Emulsion Brookfield Viscosity, cps Shear-
thinning
0.5 rpm 1 rpm 2.5 rpm 5 rpm 10 rpm 20 rpm
Index
1 96,000 48,000 32,000 -21,600 16,000 11,000 8.73
2 80,000 34,000 24,000 16,000 11,600 7,800
10.26
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EXAMPLE III
100361 This example demonstrates that a sunscreen composition, containing a
SPF
booster such as Polargel UV 1116, may not be stable against the separation of
the
particulate components of the SPF booster, if the low-shear-rate viscosities
of the
composition, as measured on a Brookfield RVT viscometer using spindle 7 at 25
C, are
not? 50,000 cps and 30,000 cps, respectively, at 0.5 rpm and 1 rpm of spindle
speeds,
wherein the viscosity is measured after at least about 24 hours of room-
temperature
storage from the time of manufacturing of the composition.
[0037] Table VII presents sunscreen emulsion formulations that are identical,
except for
the dosages of the thickening agent, Pemulene TR2, and its neutralizing
agent, sodium
hydroxide. The respective Brookfield viscosities of the emulsions at various
spindle
speeds, as measured using spindle # 7 at 25 C, are also shown in Table V.
Following
overnight storage at room temperature post manufacturing, emulsion 1 showed
separation
of the particulate components of Polargel UV 1116, when centrifuged at 3,000
rpm for
30 minutes, after being heated to 60 C, albeit there was no separation of the
oil phase.
This would suggest that while a stable emulsion could be made using the
emulsion 1
formulation presented in Table V, the emulsion, however, would not allow an
effective
use of Polargel UV 1116 and therefore would not perform well as a high-
efficiency
sunscreen emulsion. On the other hand, emulsion 2 did not show any separation
of the
particulate components of Polargel UV 1116, when centrifuged at 3,000 rpm for
30
minutes, after being heated to 60 C. Viscosity measurements of the sunscreen
compositions were carried out following the procedure summarized in EXAMPLE
II.
TABLE VII
Ingredients Emulsion 1 Emulsion 2
Water Phase
Water 66.950 66.845
Propylene Glycol 1.000 1.000
Pemulen TR2 0.100 0.145
Phenonipe 1.000 1.000
50% Sodium Hydroxide 0.350 0.410
Tetrasodium ethylene 0.100 0.100
diamine tetracetate
Oil Phase
Octyl Methoxy Cinnamate 7.500 7.500
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CA 02677793 2011-10-18
Ingredients Emulsion 1 Emulsion 2
Octyl Salicylate 5.000 5.000
Oxybenzone 4.000 4.000
Avobenzone 2.000 2.000
Isopropyl Myristate 3.000 3.000
Stearic Acid 1.000 1.000
Cetyl Phosphate 1.000 1.000
Polyethylene 2.500 2.500
Post-Add Phase
Polargel UV 1116 3.750 3.750
Sokalan PA 30 CL 0.75 0.750
Brookfield RVT Viscosity, cps
0.5 rpm 32,000 96,000
1 rpm 20,000 48,000
2.5 rpm 9,600 28,800
rpm 5,200 19,200
rpm 3,200 11,000
rpm 2,200 6,000
EXAMPLE IV
[0038] This example presents the composition for a sunscreen emulsion of
the present
invention, which passed the 3-cycle freeze-thaw test noted in a previous
section. The emulsion
remained intact, showing no visible separation of any materials, after it was
subjected to the
freeze-thaw test (with -10 C as the freezing temperature). The SPF of the
emulsion was 75.8 and
the very water resistant SPF was 60, wherein the SPF values were determined
based on 3-
subject, in-vivo SPF testing in accordance with the US FDA SPF testing
protocols. Sunscreen
wipes made with the foregoing emulsion showed good freeze-thaw stability.
TABLE VIII
SUNSCREEN COMPOSITION OF THE PRESENT INVENTION
Ingredient Tradename/Description/Function Weight %
Water Phase
Water 47.318
Propylene Glycol Humectant 5.000
Urea Humectant 6.000
Acrylates/C10-30 alkyl Pemulen TR2, Emulsifier ¨ 0.175
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SUNSCREEN COMPOSITION OF THE PRESENT INVENTION
Ingredient Tradename/Description/Function Weight %
acrylates crosspolymer thickener (Noveon)
Sodium Polyacrylate Sokalan PA 30 CL (45% active), Low 0.320
molecular weight weak acid polymer
(BASF)
Phenoxyethanol, Ewcyl PE 9010, Preservative 1.000
Ethylhexylglycerin mixture
(Schulke & Mayr)
Sodium Hydroxide (50% pH adjustment reagent 0.127
active)
Aloe Extract (50% active) Skin feel enhancer 0.150
Water, Sodium bentonite, Polargel UV SPF booster (AMCOL). 8.000
Titanium Dioxide, Kaolin, (0.373%
Lignosulfonate, Sodium Sodium
Polyacrylate (Sokalang PA Polyacrylate
3 OCL) Solution)
Oil Phase
Octyl Salicylate Sunscreen active 5.000
Oxybenzone Sunscreen active 6.000
Avobenzone Sunscreen active 3.000
Homosalate Sunscreen Active 15.000
Methyl Glucose Tego Care PS, Emulsifier 0.800
Sesquistearate (Degussa)
Tocopheryl Acetate Vitamin E 0.100
Retinyl Paimitate Vitamin A 0.010
Vinylpyrrolidone/Eicosene Ganex0 V-220F, Water resistance 2.000
Copolymer promoter (International Specialty
Products)
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WO 2008/097223 PCT/US2007/003372
Manufacturing Procedure
= Combine the oil phase and heat the mixture to 60-65 C, under agitation
until the solids dissolve completely.
= Cool the heated oil phase to the ambient temperature.
= Combine the water phase ingredients under mixing in a rotor-stator
homogenizer (SiIverson laboratory homogenizer). Continue mixing until
the composition looks uniform or lump-free.
= Add slowly the oil phase to the water phase, while the batch remains
under
homogenizer mixing at 5,000¨ 10,000 rpm of homogenizer speed.
= Continue homogenizing until the batch appears uniformly mixed.
The Brookfield viscosities of the above emulsion, measured at various spindle
speeds,
using spindle # 7 are presented in Table IX.
Table IX
Brookfield Viscosity
Spindle Speed, Viscosity, CPS
Rpm
0.5 112,000
1 60,000
2.5 33,600
18,400
8,400
4,800
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CA 02677793 2013-08-16
[0039] In accordance with a first aspect, the present disclosure provides
a sunscreen wipe
comprising a water-insoluble wipe substrate comprising synthetic and/or
natural fibers,
impregnated with an oil-in-water sunscreen composition having an oil phase and
a water phase
and having low-shear-rate viscosities of at least 50,000 cps at 0.5 rpm and
35,000 cps at 1 rpm,
while the high-shear-rate viscosities are 10,000 - 30,000 cps at 5 rpm and
2,500 ¨ 10,000 cps at
20 rpm, as measured on a Brookfield RVT viscometer, at 25 C, using spindle #
7, the
composition containing (i) a water-insoluble organic sunscreen active, (ii) a
particulate-based
additive comprising a smectite clay and one or more additional particulate
materials wherein at
least one of the particulate materials has an average particle size of less
than 1 micron, (iii) a
shear-thinning index-boosting weak acid polymer, having an average molecular
weight in the
range of 1,000 to 100,000 Dalton, and (iv) a sun protection factor (SPF)-
boosting phenolic
polymer additive that is soluble in the sunscreen composition, the sunscreen
composition
meeting the following specifications: a) for a dosage of 1.5% by weight of
component (ii), the
in-vivo SPF of the sunscreen composition is? 1.8 times the weight percent of
the sunscreen
active contained therein, based on the weight of the sunscreen composition; b)
without any
sunscreen active contained therein, the composition containing 1.5% by weight
of component (ii)
yields an SPF of < 2; and c) the shear-thinning index of the sunscreen
composition is greater by a
factor of at least 1.05 with the component (iii) contained therein than
without the component
(iii), the shear-thinning index being defined as the ratio of viscosities of
the sunscreen
composition at 0.5 rpm and 20 rpm, measured on a Brookfield RVT viscometer at
25 C, using
spindle 7, after cooling the composition to room temperature and storing it at
that temperature for
about 24 hours.
100401 In some embodiments, the ratio of the weight of the sunscreen
composition
impregnated into the wipe substrate to the weight of the wipe substrate is
20:1 ¨ 1:1.
[0041] In some embodiments, the ratio of the weight of the sunscreen
composition
impregnated into the wipe substrate to the weight of the wipe substrate is
10:1 ¨ 2:1.
[00421 In some embodiments, the ratio of the weight of the sunscreen
composition
impregnated into the wipe substrate to the weight of the wipe substrate is 6:1
¨ 3:1.
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CA 02677793 2013-08-16
[0043] In some embodiments, the sunscreen active is an organic UV-
absorbing material
selected from the group consisting of octyl methoxycinamate, homosalate,
octocrylene, octyl
salate, methylbenzylidene camphor, phenylbenzimidazole sulfonic acid,
ethylhexyl triazone,
oxybenzone, methyl anthranilate, avobenzone, 3-benzylidene camphor, 4-
methylbenzylidene
camphor, benzylidene camphor sulfonic acid, camphor benzalkonium methosulfate,
isoamyl-p-
methoxycinnamate, isopropylbenzyl salicylate, and mixtures thereof.
[0044] In some embodiments, the amount of the sunscreen active is no less
than 2%,
based on the weight of the sunscreen composition impregnating the wipe.
[0045] In some embodiments, component (ii) comprises 0.1 ¨ 25% by weight
of the
sunscreen composition impregnating the wipe.
[0046] In some embodiments, component (ii) comprises 0.25 ¨ 10% by weight
of the
sunscreen composition impregnating the wipe.
[0047] In some embodiments, component (ii) comprises 0.5 ¨ 2% by weight
of the
sunscreen composition impregnating the wipe.
[0048] In some embodiments, component (iv) comprises 0.025 ¨ 2.5% by
weight of the
water phase of the sunscreen composition impregnating the wipe.
[0049] In some embodiments, component (iv) comprises 0.1 ¨ 2% by weight
of the water
phase of the sunscreen composition impregnating the wipe.
[0050] In some embodiments, component (iv) comprises 0.5 ¨ 1% by weight
of the water
phase of the sunscreen composition impregnating the wipe.
[0051] In accordance with a second aspect, the present disclosure
provides a use of the
sunscreen wipe described above for the protection of human skin from UV
radiation.
[0052] In accordance with a third aspect, the present disclosure provides
an oil-in-water
sunscreen composition, either impregnating a wipe substrate or in the form of
a sunscreen spray,
wherein the composition has low-shear-rate viscosities of at least 50,000 cps
at 0.5 rpm and
30,000 cps at 1 rpm, and high-shear-rate viscosities of 10,000 - 30,000 cps at
5 rpm and 2,500 ¨
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CA 02677793 2013-08-16
10,000 cps at 20 rpm, as measured on a Brookfield RVT viscometer, at 25 C,
using spindle # 7,
the composition comprising an oil phase containing a UV-absorbing organic
sunscreen active,
the oil phase dispersed as a stable emulsion in a water phase that contains i)
a booster for the
SPF, comprising a combination of water-dispersible particulate materials
comprising (a) a
smectite clay and (b) one or more additional particulate materials wherein at
least one of the
particulate materials has an average particle size of less than 1 micron, and
(c) a water-soluble or
water-dispersible phenolic polymer; and ii) a water-soluble or water-
dispersible polymer having
a weak acid group as a shear-thinning index-boosting additive, the polymer
having a weight
average molecular weight of 1,000 ¨ 100,000 Dalton, and an anionic charge
density of no less
than 1.5 milliequivalents per gram of the polymer.
[0053] In some embodiments, the organic sunscreen active is selected from
the group
consisting of octyl methoxycinamate, homosalate, octocrylene, octyl salate,
methylbenzylidene
camphor, phenylbenzimidazole sulfonic acid, ethylhexyl triazone, oxybenzone,
methyl
anthranilate, avobenzone, 3-benzylidene camphor, 4-methylbenzylidene camphor,
benzylidene
camphor sulfonic acid, camphor benzalkonium methosulfate, isoamyl-p-
methoxycinnamate,
isopropylbenzyl salicylate, and mixtures thereof.
[0054] In some embodiments, the amount of the organic sunscreen active is
no less than
2%, based on the weight of the composition.
[0055] In some embodiments, one of the particulate materials of the SPF
booster is
smectite clay and the other particulate material is selected from the group
consisting of inorganic
oxides, water-insoluble inorganic salts, silicate minerals, and latex
polymers.
[0056] In some embodiments, at least one of the particulate materials has
an average
particle size of less than 0.5 micron.
[0057] In some embodiments, at least one of the particulate materials has
an average
particle size of less than 0.25 micron.
[0058] In some embodiments, the particulate materials of the SPF booster
comprise 0.1 ¨
25% by weight of the composition.
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CA 02677793 2013-08-16
[0059] In some embodiments, the particulate materials of the SPF booster
comprise 0.25
¨ 10% by weight of the composition.
[0060] In some embodiments, the particulate materials of the SPF booster
comprise 0.5
2% by weight of the composition.
[0061] In some embodiments, the phenolic polymer is selected from the
group consisting
of lignosulfonate, lignin, oxylignin, humate, and mixtures thereof
[0062] In some embodiments, the phenolic polymer comprises 0.05 ¨2% by
weight of
the composition.
[0063] In some embodiments, the phenolic polymer comprises 0.1 ¨ 1% by
weight of the
composition.
[0064] In some embodiments, the phenolic polymer comprises 0.2 ¨ 0.5% by
weight of
the composition.
[0065] In some embodiments, the weak acid group is selected from the
group consisting
of carboxylate, phosphate, phosphonate, phenolate, and mixtures thereof.
[0066] In some embodiments, the weak acid polymer is sodium polyacrylate.
[0067] In some embodiments, the weak acid polymer comprises 0.025 ¨ 5% by
weight of
the composition.
[0068] In some embodiments, the sunscreen composition meets the following
specifications: (a) the in-vivo sun protection factor (SPF) is? 1.8 times the
weight percent of the
sunscreen active(s) contained therein, based on the weight of the sunscreen
composition; and (b)
the shear-thinning index of the composition is greater by a factor of at least
1.05 with the weak
acid polymer contained therein than without the polymer, the shear-thinning
index being defined
as the ratio of viscosities of the sunscreen composition at 0.5 rpm and 20
rpm, measured on a
Brookfield RVT viscometer at 25 C, using spindle 7, after cooling the
composition to room
temperature and storing it at that temperature for about 24 hours.
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CA 02677793 2013-08-16
[0069] In some embodiments, the low-shear-rate viscosities are at least
50,000 cps at 0.5
rpm and 35,000 cps at 1 rpm, while the high-shear-rate viscosities are 10,000 -
30,000 cps at 5
rpm and 2,500 ¨ 10,000 cps at 20 rpm, as measured on a Brookfield RVT
viscometer, at 25 C,
using spindle # 7 at room temperature and storing it at that temperature for
about 24 hours.
[0070] In some embodiments, the composition does not show any separation
of either the
oil phase or the particulate components of the water phase, when centrifuged
at 3,000 rpm for 30
minutes at 60 C.
[0071] In some embodiments, the composition does not show any visible
separation of
either the oil phase or the particulate components of the water phase, after
three freeze-thaw
cycles wherein during each cycle, the sunscreen composition is stored in a
freezer at -10 C for a
period of 24 hours, followed by thawing the composition to room temperature.
[0072] In some embodiments, the organic UV-absorbing sunscreen active is
selected
from the group consisting of octyl methoxycinamate, homosalate, octocrylene,
octyl salate,
methylbenzylidene camphor, phenylbenzimidazole sulfonic acid, ethylhexyl
triazone,
oxybenzone, methyl anthranilate, avobenzone, 3-benzylidene camphor, 4-
methylbenzylidene
camphor, benzylidene camphor sulfonic acid, camphor benzalkonium methosulfate,
isoamyl-p-
methoxycinnamate, isopropylbenzyl salicylate, and mixtures thereof.
[0073] In some embodiments, the amount of the organic sunscreen active is
no less than
2%, based on the weight of the composition.
[0074] In some embodiments, one of the particulate materials of the SPF
booster is
smectite clay and the other particulate material is selected from the group
consisting of inorganic
oxides, water-insoluble inorganic salts, silicate minerals, and latex
polymers.
[0075] In some embodiments, at least one of the particulate materials has
an average
particle size of less than 0.5 micron.
[0076] In some embodiments, at least one of the particulate materials has
an average
particle size of less than 0.25 micron.
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CA 02677793 2013-08-16
[0077] In some embodiments, the particulate materials of the SPF booster,
comprise 0.1
¨25% by weight of the composition.
[0078] In some embodiments, the particulate materials of the SPF booster,
comprise 0.25
¨ 10% by weight of the composition.
[0079] In some embodiments, the particulate materials of the SPF booster,
comprise 0.5
¨2% by weight of the composition.
[0080] In some embodiments, the phenolic polymer is selected from the
group consisting
of lignosulfonate, lignin, oxylignin, humate, and mixtures thereof.
[0081] In some embodiments, the phenolic polymer comprises 0.05 ¨ 2% by
weight of
the composition.
[0082] In some embodiments, wherein the phenolic polymer comprises 0.1 ¨
1% by
weight of the composition.
[0083] In some embodiments, the phenolic polymer comprises 0.2 ¨ 0.5% by
weight of
the composition.
[0084] In some embodiments, the weak acid group is selected from the
group consisting
of carboxylate, phosphate, phosphonate, phenolate, and mixtures thereof.
[0085] In some embodiments, the weak acid polymer is sodium polyacrylate.
[0086] In some embodiments, the weak acid polymer comprises 0.025 ¨ 5% by
weight of
the composition.
[0087] In some embodiments, the weak acid polymer comprises 0.1 ¨ 2% by
weight of
the composition.
[0088] In some embodiments, the weak acid polymer comprises 0.5 ¨ 1% by
weight of
the composition.
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CA 02677793 2013-08-16
. ,
[0089] In accordance with a fourth aspect, the present disclosure
provides a sunscreen
wipe, comprising: a water-insoluble wipe substrate comprising synthetic and/or
natural fibers
impregnated with the sunscreen composition described above.
[0090] In some embodiments, the ratio of the weight of the
sunscreen composition
impregnated into the wipe substrate to the weight of the wipe substrate is
20:1 ¨ 1:1.
[0091] In some embodiments, the ratio of the weight of the
sunscreen composition
impregnated into the wipe substrate to the weight of the wipe substrate is
10:1 ¨ 2:1.
[0092] In some embodiments, the ratio of the weight of the
sunscreen composition
impregnated into the wipe substrate to the weight of the wipe substrate is 6:1
¨ 3:1.
[0093] In accordance with a fifth aspect, the present disclosure
provides a use of the
sunscreen wipe described above for the protection of human skin from UV
radiation.
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