U.S. patent application number 13/860032 was filed with the patent office on 2013-10-17 for skin exfoliation devices and kits.
This patent application is currently assigned to The Procter & Gamble Company. The applicant listed for this patent is THE PROCTER & GAMBLE COMPANY. Invention is credited to Gordon Gerald GUAY, David Edward WILSON.
Application Number | 20130274762 13/860032 |
Document ID | / |
Family ID | 49209520 |
Filed Date | 2013-10-17 |
United States Patent
Application |
20130274762 |
Kind Code |
A1 |
GUAY; Gordon Gerald ; et
al. |
October 17, 2013 |
SKIN EXFOLIATION DEVICES AND KITS
Abstract
A hand held exfoliation device suitable for repeated use on a
facial skin surface is provided. The exfoliation device includes a
body and an exfoliating material attached thereto that is sized for
application to a facial skin surface. The exfoliating material
includes a substrate and an exfoliating surface. The exfoliating
surface is formed from a plurality of particles, wherein the
plurality of particles are attached to the substrate to form peaks
and valleys thereon. The exfoliating material has a surface
roughness S.sub.a from about 2 .mu.m to about 16 .mu.m and the
particles have an average Mohs hardness from about 4 to about
8.
Inventors: |
GUAY; Gordon Gerald;
(Chelmsford, MA) ; WILSON; David Edward;
(Reisterstown, MD) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
THE PROCTER & GAMBLE COMPANY |
Cincinnati |
OH |
US |
|
|
Assignee: |
The Procter & Gamble
Company
Cincinnati
OH
|
Family ID: |
49209520 |
Appl. No.: |
13/860032 |
Filed: |
April 10, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61623466 |
Apr 12, 2012 |
|
|
|
Current U.S.
Class: |
606/131 ;
206/581 |
Current CPC
Class: |
A61H 7/003 20130101;
A61H 2201/1692 20130101; A61H 7/005 20130101; A45D 2200/25
20130101; A45D 34/04 20130101; A45D 2200/1054 20130101; A45D 44/22
20130101; A61H 2201/1688 20130101 |
Class at
Publication: |
606/131 ;
206/581 |
International
Class: |
A45D 44/22 20060101
A45D044/22 |
Claims
1. A hand-held exfoliation device suitable for repeated use on a
facial skin surface, comprising: a. a body; and b. an exfoliating
material attached to the body, the exfoliating material being sized
for application to the facial skin surface and including a
substrate and a plurality of particles attached to the substrate to
form peaks and valleys thereon, wherein the exfoliating material
has an arithmetical mean height over a three dimensional surface
S.sub.a of from about 2 .mu.m to about 16 .mu.m and the particles
have an average Mohs hardness of from about 4 to about 8.
2. The exfoliation device of claim 1, wherein the plurality of
particles have an average size from about 0.25 .mu.m to about 1
.mu.m.
3. The exfoliation device of claim 1, wherein the plurality of
particles are irregularly shaped and randomly dispersed on the
substrate.
4. The exfoliation device of claim 1, wherein some of the plurality
of particles are agglomerated into larger formations.
5. The exfoliation device of claim 1, wherein the exfoliating
material has a root mean square height over a three dimensional
surface S.sub.q of from about 2 .mu.m to about 16 .mu.m.
6. The exfoliation device of claim 1, wherein the plurality of
particles are bonded to the substrate by a bonding means selected
from the group consisting of a binder and an adhesive.
7. The exfoliation device of claim 6, wherein the exfoliation
material comprises an exfoliation surface that includes the
particles and binding means.
8. The exfoliation device of claim 7, wherein the exfoliating
surface is non-porous.
9. The exfoliation device of claim 7, wherein the exfoliating
surface is devoid of fibers.
10. The exfoliation device of claim 1, wherein the plurality of
particles comprise particles selected from the group consisting of
oxides, diamonds, zirconium alumina, silicon carbide, garnet,
emery, cubic boron nitride, nut shells, and combinations
thereof.
11. A skin care kit, comprising an exfoliation device according to
claim 1 and a packaged skin care composition comprising a cosmetic
skin care agent and a dermatologically acceptable carrier.
12. The skin care kit of claim 18, wherein the skin care agent is
selected from the group consisting of skin whitening agents and
skin anti-aging agents.
13. A method of improving penetration of an agent into a facial
skin surface, comprising: a. contacting the facial skin surface
with a hand-held exfoliation device comprising a body and an
exfoliating material attached thereto, the exfoliating material
comprising a plurality of particles attached to a substrate to form
peaks and valleys thereon; and b. applying a cosmetic skin care
composition to the facial skin surface contacted by the hand-held
exfoliation device, wherein the cosmetic skin care composition
comprises a skin care agent and a dermatologically acceptable
carrier.
14. The method of claim 1, wherein contacting the exfoliating
device to the facial skin surface occurs before applying the
cosmetic skin care composition to the facial skin surface.
15. The method of claim 1, wherein the facial skin surface
comprises at least one of a cheek, chin, forehead, and peri-orbital
skin surface.
16. The method of claim 1, wherein the hand-held exfoliating device
is contacted with the facial skin surface by applying a pressure of
from about 20 g/m.sup.2 to about 400 g/m.sup.2 for from 1 to about
10 strokes.
17. The method of claim 4, wherein the hand-held exfoliating device
is contacted with the facial skin for from 3 seconds to about 60
seconds.
18. The method of claim 1, wherein the hand-held exfoliation device
is contacted with the facial skin surface at least once per day for
at least 7 days.
19. The method of claim 1, wherein the exfoliating material has an
arithmetical mean height over a three-dimensional surface S.sub.a
of from about 2 .mu.m to about 16 .mu.m.
20. The method of claim 1, wherein the particles have an average
Mohs hardness of from about 4 to about 8.
Description
TECHNICAL FIELD
[0001] Skin exfoliation devices are provided along with methods and
kits related thereto.
BACKGROUND
[0002] The process of removing dead skin cells, often referred to
as exfoliation, has been practiced for a long time. Exfoliation can
be accomplished by a variety of means. Mechanical exfoliation
typically involves the physical removal of skin cells by an
abrasive. In some instances, abrasive particles may be incorporated
into a composition that is rubbed on the skin. In other instances,
a mechanical device may be used to scrub the skin. Some examples of
various types of exfoliation means are described, for example, in
U.S. Pat. Nos. 7,255,704; 7,297,668; 6,563,012 and 6,391,863 and
U.S. Publication Nos. 2007/0281033 and 2007/0264224.
[0003] Exfoliation is purported to provide a number of benefits
including, removing dull, dry skin cells to reveal smoother and/or
softer skin; simulating cell renewal and turnover rates; and
facilitating hydration and absorption of materials. While one or
more of these benefits may be realized by exfoliation, it is
possible to over exfoliate resulting in skin irritation and/or a
drying of the skin. In addition, facial skin surfaces may be more
susceptible to over exfoliation, as facial skin may be particularly
sensitive compared to some other skin surfaces. A particular
challenge associated with exfoliation is providing a means for
sufficiently exfoliating facial skin surfaces without inducing
irritation whilst providing enough exfoliation to improve the
penetration of cosmetic skin care agents, such as vitamins,
peptides, retinoid compounds, botanicals, etc. in order to deliver
an enhanced skin care benefit. Some examples of cosmetic skin care
benefits include treating fine lines and wrinkles (particularly in
the periorbital area (e.g., to treat crow's feet) and the
forehead), treating age spots and hyper pigmentation, and improving
the hydration status or barrier properties of facial skin.
[0004] While various skin exfoliation means and benefits are known,
there is a continuing desire to provide improved exfoliation
devices, methods and kits relating thereto that are suitable for
use on facial skin surfaces. There is also a continuing desire to
provide improved exfoliation devices and methods relating thereto
which are relatively simple to manufacture and can provide
effective exfoliation without inducing substantial redness or
irritation, particularly on sensitive facial skin. Further, there
is a continuing desire to provide improved exfoliation devices,
methods and kits relating thereto that, additionally, enhance the
penetration of cosmetic skin care agents into skin surfaces. Still
further, there is a continuing desire to provide improved
exfoliation devices, methods and kits relating thereto that are
effective and may be used across a range of consumer habits and
practices (e.g., applied pressure and/or number of strokes).
SUMMARY
[0005] In order to provide a solution to the problems above, a
hand-held exfoliation device is provided. The exfoliation device
comprises a body and an exfoliating material attached thereto that
is sized for application to a facial skin surface. The exfoliating
material comprises a substrate and an exfoliating surface. The
exfoliating surface is formed from a plurality of particles,
wherein the plurality of particles are attached to the substrate to
form peaks and valleys thereon. The exfoliating material has a
surface roughness S.sub.a from about 2 .mu.m to about 16 .mu.m and
the particles have an average Mohs hardness from about 4 to about
8.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] While the specification concludes with claims, it is
believed that the same will be better understood from the following
description taken in conjunction with the accompanying drawings in
which:
[0007] FIG. 1A is a photograph of an abrasive material;
[0008] FIG. 1B is an Optical Coherence Tomography image of the
abrasive material of FIG. 1A;
[0009] FIG. 1C is an Scanning Electron Microscopy (SEM) image of
the abrasive material of FIG. 1A at 130.times. magnification;
[0010] FIG. 2A is a photograph of an abrasive material;
[0011] FIG. 2B is an SEM image of the abrasive material of FIG. 2A
at 130.times. magnification;
[0012] FIG. 2C is an OCT image of the abrasive material of FIG.
2A;
[0013] FIG. 3A is a photograph of an abrasive material;
[0014] FIG. 3B is an SEM image of the abrasive material of FIG. 3A
at 100.times. magnification;
[0015] FIG. 3C is an OCT image of the abrasive material of FIG.
3A;
[0016] FIG. 4A is a photograph of an abrasive material;
[0017] FIG. 4B is a OCT image of the abrasive material of FIG.
4A;
[0018] FIG. 5 is a SEM image of a portion of the surface of the
abrasive material of FIG. 4A at 50.times. magnification;
[0019] FIG. 6 is an SEM image of a formation of particles of the
material shown in FIG. 5 at a 500.times. magnification;
[0020] FIG. 7 is a SEM image of the formation of particles shown in
FIG. 6 at 800.times. magnification;
[0021] FIG. 8 is a SEM image of a random distribution of particles
shown in FIG. 4A at 10,000.times. magnification;
[0022] FIG. 9 is perspective view of an exfoliation device;
[0023] FIG. 10 is a cross-sectional side view of the exfoliation
device of FIG. 9, taken along line A-A thereof;
[0024] FIG. 11 is a perspective view of an embodiment of an
exfoliation device comprising a rounded exfoliating surface;
[0025] FIG. 12 is a perspective view of an embodiment of an
exfoliation device comprising a strap for attaching the exfoliation
device to a finger; and
[0026] FIG. 13 is a perspective view of an embodiment of an
exfoliation device comprising a hollow cylinder into which one or
more fingers may be inserted.
DETAILED DESCRIPTION
[0027] "Cosmetic skin care composition" means a composition
suitable for topical application to mammalian skin, which is
intended to improve the condition and/or appearance of the skin or
otherwise provide a skin care benefit. Some non-limiting examples
of skin care benefits include improving skin appearance and/or feel
by providing a smoother, more even appearance and/or feel;
increasing the thickness of one or more layers of the skin;
improving the elasticity or resiliency of the skin; improving the
firmness of the skin; reducing the oily, shiny, and/or dull
appearance of skin, improving the hydration status or
moisturization of the skin, improving the appearance of fine lines
and/or wrinkles, improving skin texture or smoothness, improving
skin exfoliation or desquamation, plumping the skin, improving skin
barrier properties, improving skin tone, and/or improving the
brightness, radiancy, or translucency of skin. Some non-limiting
examples of cosmetic skin care compositions include skin creams,
moisturizers, lotions, and products that leave color on the face,
such as foundations and concealers.
[0028] "Dermatologically acceptable carrier" means any carrier that
may be applied topically to skin tissue. The dermatologically
acceptable carrier may be provided by a wide variety of materials
and/or in a wide variety of forms including, but not limited to,
simple solutions (e.g., water-based or oil-based), solid forms
(e.g., gels or sticks) and emulsions (e.g., water-in-oil or
oil-in-water).
[0029] "Non-porous" means a material, substrate or surface that: i)
lacks passageways that permit a liquid from passing from one side
of the material to the other side of the material, and/or ii) does
not absorb an appreciable amount of water over a one hour period of
time at standard ambient temperature and pressure. In some
embodiments, an appreciable amount of water is an amount greater
than 5% by weight of the material, substrate, or surface.
[0030] "Surface roughness" refers to the 3D areal roughness of a
surface and may be quantified by the parameters S.sub.a, S.sub.q,
S.sub.t, S.sub.tm, etc., which are known in the art and defined in
ISO 25178, the substance of which is incorporated herein by
reference in its entirety. For example, S.sub.a refers to the
arithmetical mean height over a 3D surface. S.sub.q refers to the
RMS height over a 3D surface. S.sub.t refers to maximum height
difference between the highest and the lowest points on the
profile, and S.sub.tm refers to average of the S.sub.t values
(maximum height differences between the highest and lowest
heights).
[0031] "Topical" and variations thereof refer to compositions that
are intended to be applied directly to the outer surface of skin
tissue.
[0032] Described hereafter are various embodiments of exfoliation
devices and cosmetic skin care compositions suitable for use on
facial skin. In some embodiments, the exfoliation device can
provide a sufficient level of exfoliation adequate to enhance
penetration of a cosmetic skin care agent of the skin care
composition while still providing an aesthetically pleasing feel.
Preferably, the exfoliation devices can provide these benefits even
when used daily.
I. Surface Characteristics of some Abrasive Materials
[0033] A wide variety of abrasive materials are known in the art.
However, much is still not understood regarding the surface
characteristics affecting both the aesthetics and the level of
exfoliation provided by a material, particularly when utilized
according to typical consumer practices. Four materials were
investigated, including two materials formed from a plurality of
fibers and two materials comprising abrasive particles bonded to a
substrate. Referring to FIGS. 1, 2, 3 and 4, photographic images of
the four tested materials are shown along with images generated by
Optical Coherence Tomography (OCT) of the material surfaces.
Material #1 (FIGS. 1A, 1B, and 1C) is a porous, nylon woven mesh
formed by a plurality of fibers. The individual fibers appear to
range in thickness from about 0.05 mm to about 0.08 mm. Material #2
(FIGS. 2A, 2B, and 2C) is a non-porous, sandpaper-like material
comprising abrasive particles formed from diamond embedded in a
binder on a thin polyethylene terepthalate (PET) film. Material #3
(FIGS. 3A, 3B and 3C) is a non-woven, porous cloth available under
the tradename Exfolia from Beauty Cloth, Inc. Material #4 (FIGS. 4A
and 4B) is a non-porous, film substrate to which are bonded cerium
oxide particles. The cerium oxide particles have an average size of
from about 0.25 microns to about 1 micron.
[0034] Example 1, which is described in more detail below, sets
forth a methodology suitable for measuring surface roughness of a
material. Surface roughness of a material may be characterized
using an interferometric measurement device that utilizes light to
measure a variety of surface area roughness parameters such as
S.sub.a, S.sub.t, and S.sub.tm. One such device is the
DermaTop-Blue device available from Breuckmann GmbH (Germany),
which utilizes a narrow-band, blue light source. Other test methods
and devices may also be employed, as known in the art, to measure
surface roughness parameters according to ISO 25178. Table 1 sets
forth a summary of the average surface roughness values (in
microns) measured for Materials #1 to #4.
TABLE-US-00001 TABLE 1 Material S.sub.a S.sub.q S.sub.t S.sub.tm #1
187 253 3918 1491 #2 19 23 167 130 #3 19 24 178 113 #4 10 11 60
48
[0035] As illustrated in Table 1, Material #1 had the highest
surface roughness values, while Material #4 had the lowest
values.
II. In Vivo Testing
[0036] Referring to Example 2 below, Materials #1 to #4 were tested
in vivo and the amount of protein removed by use of the materials
was measured using a protein quantification assay. Protein removal
is believed to be a proxy for measuring the amount of exfoliation
achieved by a material. Protein quantification assays utilize a
fluorogenic reaction between proteins and a reducing reagent to
quantify the amount of proteins in the sample. The users applied
small samples of the abrasive materials to dry forearm skin (e.g.,
without prior application of a skin care composition, which can act
as a lubricant) by applying five strokes of the material over a two
inch area of the forearm skin, after which the residual skin on the
material surface was harvested and quantified using the protein
quantification assay. In addition, comments were collected from the
users about the skin feel of the abrasive materials.
[0037] The results from the in vivo testing of the four materials,
including both the protein quantification values and an example of
the user comments are summarized in Table 2 below.
TABLE-US-00002 TABLE 2 Protein Removed Material (.mu.g/ml) Some
User Comments Material #1 247 Very rough Material #2 120 Scratchy
Material #3 129 Very soft Material #4 256 Excellent feel, abrasive
yet soft
[0038] Surprisingly, while Materials #2 and #4 were both formed
from abrasive particles bonded to a substrate, the user perception
of the materials was quite different. While not intending to be
bound by theory, the difference in user perception could be due to
the higher surface roughness of Material #2 (see, e.g., Table 1)
and/or a difference in the hardness and/or shape of the abrasive
particles. Material #2 contained amorphous diamond particles, which
have a Mohs hardness of 10, in contrast to Material #4 which
contained cerium oxide particles, which have a Mohs hardness of 6.
The lower surface roughness values and/or particle hardness of
Material #4 appear to produce a more pleasing aesthetic benefit
when rubbed against skin. Without intending to be bound by any
theory, the disparate protein removal results between Material #2
and #4 might be explained by potential user self regulation, which
may occur in instances where a user adjusts the amount of force
applied to the exfoliating material to account for differences in
material feel. Notably, Material #4 also had the greatest amount of
protein removal, followed closely by Material #1, despite the
observed differences in surface roughness. Interestingly, the
amount of protein removal by Material #4 was more than double that
of Material #2 and almost double that of Material #3 despite
Materials #2 and #3 having higher surface roughness values. With
regard to Material #3, while it also had higher surface roughness
values than Material #4, the higher surface roughness was
apparently not sufficient to overcome the inherent flexibility
provided by the fiber construction and this might have contributed
to the lower protein removal value compared to Material #4.
III. In Vitro Penetration of Skin Care Agents
[0039] While Materials #1 and #4 may provide superior protein
removal compared to Materials #2 and #3, this does not necessarily
quantify the impact that this level of exfoliation may have on skin
penetration of cosmetics agents. For example, the depth of
localized protein removal and/or the amount of surface area removed
can impact the amount of skin penetration of a cosmetic agent even
though the total removed protein is about the same. Referring to
Example 3, which is described in more detail below, samples of
Materials #1 and #4 were also tested in vitro using human cadaver
skin to assess the penetration of radio-labeled niacinamide into
the skin following application of the abrasive materials.
Penetration of the radio labeled niacinamide into the cadaver skin
was assessed using a Franz diffusion cell system, which is a well
known device in the art for measuring skin penetration of
compounds. The abrasive materials were applied to the cadaver skin
for 10 strokes (5 strokes in one direction and 5 strokes in
reverse) using 50, 100, and 200 grams of force, which is within the
range believed to be customary for consumer habits and practices,
as discussed in Example 4 below. Table 3 summarizes the total
percentage dose of niacinamide recovered from the epidermis,
dermis, and the Franz cell receptor, twenty-four hours after
application of Material #1 to six cadaver skin replicates, and the
total percentage dose recovered for an untreated (i.e., not
abraded) control tissue sample.
TABLE-US-00003 TABLE 3 Material #1 Control 50 grams 100 grams 200
grams Sample #1 70.31 73.87 99.42 98.65 Sample #2 45.79 92.72 85.32
92.88 Sample #3 71.50 65.56 82.75 95.98 Sample #4 78.66 99.52 96.62
98.57 Sample #5 74.62 91.19 96.71 Sample #6 74.19 54.95 88.59 Avg
66.57 80.08 85.04 95.23 Stdv 14.33 13.05 16.06 3.88 p-value 0.160
0.100 0.0013
[0040] Table 4 summarizes the total percentage dose of niacinamide
recovered from the epidermis, dermis, and the Franz cell receptor,
twenty-four hours after application of Material #4 to six cadaver
skin replicates, and the total percentage dose recovered for an
untreated (i.e., not abraded) control tissue sample. While Material
#4 did not perform quite as well as Material #1, it provided a more
consistent level of skin penetration enhancement across the applied
forces while importantly providing a more aesthestically pleasing
skin feel in vivo than Material #1.
TABLE-US-00004 TABLE 4 Material #4 Control 50 grams 100 grams 200
grams Sample #1 70.31 89.00 73.81 67.51 Sample #2 45.79 83.95 76.91
85.23 Sample #3 71.50 82.22 65.07 71.73 Sample #4 78.66 52.17 94.36
71.46 Sample #5 48.24 91.05 94.21 Sample #6 91.87 69.23 90.40 Avg
66.57 74.58 78.40 80.09 Stdv 14.33 19.23 11.83 11.27 p-value 0.499
0.190 0.132
[0041] Abrasion of the cadaver skin samples by Materials #1 and #4
increased the total average percentage dose of niacinamide
recovered across applied forces compared to the untreated control.
Skin samples abraded by Material #1 exhibited more niacinamide
penetration than observed for skin samples abraded by Material
#4.
[0042] The amount of protein removed by the abrasive materials from
the cadaver skin samples was also quantified for three of the
replicates using a protein quantification assay. Tables 5 and 6 set
forth the quantity of protein measured.
TABLE-US-00005 TABLE 5 Protein Protein Protein removed removed
removed Material #1 (mg/ml) (mg/ml) (mg/ml) Samples 50 grams 100
grams 200 grams 1 171 217 243 2 176 209 245 3 172 207 234 Avg 173
211 241 Stdv 3.0 5.0 6.0
TABLE-US-00006 TABLE 6 Protein Protein Protein removed removed
removed Material #4 (mg/ml) (mg/ml) (mg/ml) Samples 50 grams 100
grams 200 grams 1 140 176 153 2 141 174 148 3 142 180 149 Avg 141
177 150 Stdv 1.0 3.0 2.0
[0043] The niacinamide recovery data of Tables 3 and 4 appear
consistent with protein recovery data of Tables 5 and 6, wherein
both the average niacinamide and protein recoveries for skin
samples abraded by Material #4 showed a less pronounced increase
with increasing force compared to skin samples abraded by Material
#1.
IV. Exfoliating Materials
[0044] From a review of the data in Tables 1 and 2, it appears
there is a co-dependent interplay between material feel, material
properties, and the amount of exfoliation produced in vivo. First
with respect to fiberous Materials #1 and #3, Material #1 provided
the best protein removal but had a negative aesthetic feel compared
to Material #3. While Material #3 had a pleasing aesthetic feel, it
did not provide the best protein removal in vivo. Thus, while these
materials might be used for facial skin exfoliation, they did not
provide the best combination of attributes. Comparing Materials #2
and #4, Material #2 provided neither the best protein removal nor
the best aesthetic skin feel. As between all the tested materials,
Material #4 provided the best combination of aesthetic skin feel
and in vivo protein removal.
[0045] Comparing Tables 1 and 2, it appears that surface roughness
alone does not characterize the exfoliation capability of Materials
#2 and #4, as Material #2, which had the higher surface roughness
values, provided a lower protein removal value in vivo compared to
Material #4, contrary to what might have been intuitively expected
beforehand. In contrast, Material #4, which had the lowest lower
surface roughness values of all four materials generated the
greatest amount of protein removal in vivo (Table 3). It is
believed that, in instances where an exfoliating material comprises
particles on a substrate, particle/material hardness in combination
with surface roughness may be co-dependent properties affecting
aesthetic feel and the level of skin exfoliation. As described
above, Material #2 is formed from amorphous diamond particles (Mohs
hardness=10) compared to Material #4 which is formed from cerium
oxide particles (Mohs hardness=6). It is believed that the harder
particles of Material #2 contributed to, at least in part, user
self regulation that effectively limited the amount of exfoliation
provided by Material #2 in vivo.
[0046] In order to provide exfoliation that quantitatively enhances
penetration of a skin care agent while providing a pleasing
aesthetic feel, it is believed that exfoliating materials
comprising a substrate and particles having certain properties may
be particularly useful in some instances. In some embodiments,
these exfoliating materials have one or more of an arithmetical
mean height of the surface (S.sub.a) greater than 2, 4, 6, 8, 10
.mu.m and/or less than 16, 14, 12, or 10 .mu.m; and/or a root mean
square height of the surface (Sq) greater than 2, 4, 6, 8, 10 .mu.m
and/or less than 16, 14, 12, or 10 .mu.m; and/or a maximum height
difference between the highest and the lowest points on the profile
(S.sub.t) greater than 20, 40, 60 .mu.m and/or less than 140, 120,
100, or 80 .mu.m; and/or an S.sub.tm value greater than 20, 40, or
60 .mu.m and/or less than 100, 80, or 60 .mu.m.
[0047] In some embodiments, the particles have an average Mohs
hardness greater than 4, 5, 6, or 7 and/or less than 8, 7, or 6.
Mohs harness is an ordinal scale (1 to 10) that measures mineral
hardness based on the ability of one mineral to scratch another.
Talc is an example of a mineral with the lowest Mohs hardness
(designated as 1), and a diamond has a Mohs hardness of 10 since it
is one of the hardest minerals. The exfoliating material may also
contain a mixture of a plurality of different particles (e.g.,
cerium oxide and diamond) having different Mohs hardness values.
Some of the particles may have Mohs hardness values above and/or
below what is described herein. If a mixture of particles is used,
the average Mohs hardness of the combination of particles may be
approximated by a weighted average based on the particle
concentrations attached to or deposited on the substrate.
[0048] In some embodiments, the exfoliating material is non-porous
(meaning both the exfoliating surface and the substrate are
non-porous). In some embodiments, only the surface of the
exfoliating material that is used to exfoliate the skin is
non-porous, but the substrate may be porous. For example, the
substrate may be provided as a porous woven or non-woven while the
exfoliating surface formed by the binder and plurality of particles
is non-porous and/or a solid surface. In some embodiments, the
exfoliating surface is porous and the substrate is non-porous. In
some embodiments, the exfoliating surface and/or substrate and/or
the exfoliating material are devoid of fibers. In some embodiments,
the exfoliating material, exfoliating surface, and/or substrate are
provided in a flexible form to facilitate attachment to complex
geometries of an exfoliation device.
[0049] A wide variety of rough materials comprising particles are
suitable for use with the exfoliating devices described herein.
While Material #4 is described herein as one example, it will be
appreciated that other materials are equally suitable and are
described herein. Referring to FIGS. 5 to 8, scanning electron
microscopy images from a sample of Material #4 are shown at various
magnifications. FIG. 5 shows a portion of the material at 50.times.
magnification, while FIG. 6 shows a portion of the surface at
500.times. magnification. FIG. 7 is an 800.times. magnification of
an agglomeration of particles on the material surface. FIG. 8 is a
10,000.times. magnification of a portion of the material surface.
The material comprises irregularly shaped cerium oxide particles
bonded to a substrate by an epoxy resin. Some of the particles are
agglomerated into larger formations, one of which is shown in FIG.
7. The larger formations may have a size greater than 75 microns or
from about 75 microns to about 150 microns. In some embodiments,
there may be from about 1000 to about 50,000 agglomerated
formations per 1 mm.sup.2 of material surface area. Some of the
particles may range in size from 0.25 microns to about 1 micron. In
some embodiments, a majority of the particles may range in size
from 0.25 microns to about 1 micron.
[0050] While Material #4 comprises cerium oxide particles, other
abrasive particles such as other oxides, diamonds, zirconium
alumina, silicon carbide, garnet, emery, cubic boron nitride, nut
shells, and combinations thereof may be substituted in whole or
part. In addition, the particles may be solid, hollow, irregularly
shaped or have a more defined geometrical shape (e.g., trapezoidal,
spherical, etc.) than shown in the FIGS. 5 to 8. The abrasive
particles may be randomly distributed or provided in a
regular/repeating pattern. The abrasive particles may or may not be
agglomerated into larger formations as shown by way of example in
FIG. 7. In addition, at least some of the abrasive particles may
have a particle size smaller than 0.25 or greater than 1
micron.
[0051] The abrasive particles may be cast, molded or otherwise
attached to a substrate using a binder or adherent, as known in the
art, thereby forming an exfoliating surface comprising peaks and
valleys. Some methods which may be suitable for forming the
exfoliating materials herein are described, for example, in U.S.
Pat. Nos. 8,038,751; 7,947,097; 7,993,420; 7,811,342; 8,062,394;
and U.S. Publication No. 2011/0162287. Some examples of binders
which may be suitable for use include epoxy resins, polyester
resins, acrylonitile, cyanoacylate, resorcinol, polysulfides,
polypropylene, silicone, polyvinyl pyrrolindone, and polystyrene
cement/butanone. Binders may be heat curing (e.g., epoxies,
urethanes and polyimides), moisture curing (e.g., cyanoacylate,
urethanes) or thermosetting (e.g., epoxy, urethanes, cyanoacylates
and acrylic polymers). In some embodiments, the substrate may be a
film formed from a polymer or mixture of polymers, paper, fabric,
nonwovens, and combinations thereof. Some polymers suitable for
forming a film include polyester or polypropylene. In some
embodiments, the substrate may have a thickness greater than 0.02,
0.04, or 0.06 mm and/or less than about 0.5, 0.4, 0.3, 0.2, or 0.1
mm. In some embodiments, the exfoliating material is thin, for
example having an overall thickness from about 0.01 mm to about 0.1
mm or from about 0.02 mm to about 0.05 mm.
V. Exfoliating Devices
[0052] Referring to FIGS. 9 and 10, one embodiment of an
exfoliation device will now be described. The exfoliation device 10
comprises a body 12 and a facial skin contacting surface 14 formed
at least partially from an exfoliating material 16. The exfoliating
material 16 may be attached to a portion of the body 12 by any
suitable means known in the art, including by use of an adhesive. A
portion of the body 12 can be provided in the form of a disc,
although it will be appreciated that a wide variety of shapes and
sizes for the body 12 may be provided. The body 12 may further
comprise an elongate handle 18, which in one embodiment may be
directed upwardly away from the disc shaped portion of the body 12.
The handle 18 may be sized to be comfortably grasped by a hand so
that the exfoliating device 10 may be hand held during use. The
exfoliating material 16 may be provided in the form of a
substantially flat, thin sheet. In some embodiments, the
exfoliating material 16 has a surface area from about 5 mm.sup.2 to
about 100 mm.sup.2 or from about 10 mm.sup.2 to about 50 mm.sup.2,
so as to provide a surface suitable for engaging a variety of
facial skin surfaces. The exfoliating material 16 may be provided
in a wide variety of shapes, circular being shown as one example in
FIGS. 9 and 10.
[0053] Referring to FIG. 11, another embodiment of an exfoliating
device is shown. The exfoliating device 100 comprises a body 120
and a three dimensional facial skin contacting surface 140 (as
opposed to the substantially flat or planar contacting surface 14
illustrated in FIGS. 9 and 10). The facial skin contacting surface
140 may be provided in a partially rounded, cylindrical, or
hemispherical shape. At least a portion of the facial skin
contacting surface 140 has a plurality of abrasive particles 144
attached thereto to form peaks and valleys. In some embodiments,
the facial skin contacting surface 140 comprises a flexible and/or
resilient material such as, for example, a foam material. The
abrasive particles 144 may be applied to at least a portion of the
facial skin contacting surface 140 using a variety of processes. In
one method, an adhesive, such as a cyanoacylate glue, may be
applied to the substrate and the abrasive particles 144 may be
electrostatically deposited onto the surface. The exfoliating
material properties may be varied by controlling the abrasive
particles 144 sizes (e.g., via sieving), the electrostatic charge
and/or the deposition time. In some embodiments, the abrasive
particles 144 may be cerium oxide. In other embodiments, a 3D
exfoliating surface may be provided by adhering a flexible
exfoliating material to a 3D surface, such as the surface 140 shown
in FIG. 11.
[0054] Referring to FIG. 12, yet another embodiment of an
exfoliating device 200 is shown. The exfoliating device 200
comprises a body 220 and a facial skin contacting surface 240. The
exfoliating device 200 is the same as the exfoliating device 10
shown in FIGS. 9 and 10, except that the handle 18 is replaced by
one or more flexible straps 218 thru which a user may insert one or
more fingers to retain the exfoliating device 200 about the
finger(s) during use.
[0055] In yet another embodiment, the exfoliating device 300 may be
provided in the form of a hollow cylinder or tube (FIG. 13) into
which at least one finger may be inserted. The hollow cylinder may
be closed at one end 310 and have an opening 312 at the opposite
end. An exfoliating material 314 may be attached to or otherwise
formed adjacent the end 310.
[0056] The exfoliating devices may be formed from a wide variety of
materials according to any appropriate forming process, as known in
the art. For example, in some embodiments, all or a portion of the
exfoliating device may be formed from a polymeric material by
injection molding. The exfoliating devices may or may not include
an electrical power source (such as a battery) and/or an electric
motor for moving the exfoliating material. In some embodiments,
however, the exfoliating material may provide sufficient
exfoliation without the need for an electric motor, for example,
through manual movement by a user. While exfoliating devices 10,
100, 200 and 300 have been described as some examples suitable for
use with the exfoliating materials and surfaces described herein,
it will be appreciated that other exfoliating devices may be
equally well suited for use with these materials and surfaces.
VI. Cosmetic Skin Care Compositions
[0057] The exfoliating devices described herein may be used in
combination with one or more cosmetic skin care compositions
suitable for topical application to a facial skin surface. The
cosmetic skin care composition may comprise one or more cosmetics
agents and a dermatologically acceptable carrier.
[0058] The cosmetic skin agents may be any agent that provides an
efficacious and/or consumer desirable skin benefit. A wide variety
of cosmetic agents may be included in the cosmetic skin care
compositions, as known in the art. Some suitable agents may
include, but are not limited to, sugar amines, vitamins, oil
control agents, moisturizers, photosterols, hexamidine compounds,
skin tightening agents, anti-wrinkle agents, flavonoids, hydroxyl
acids, N-acyl amino acid compounds, retinoids, peptides,
anti-cellulite agents, desquamation agents, anti-acne agents,
anti-oxidants, radical scavengers, anti-inflammatory agents, skin
lightening agents, botanical extracts, antimicrobials, antifungal
agents, antibacterial agents, and combinations thereof. Examples of
these materials are provided in U.S. Patent Publication Nos.
2007/0185038; 2006/0275237; 2004/0175347; and 2006/0263309. The
cosmetic skin care composition may comprise from about 0.0001%,
0.001%, 0.01%, 0.05%, 0.1%, 0.5%, 1%, 2%, or 3% to about 30%, 25%,
20%, 15%, 10%, 7%, 5%, 3%, 2%, or 1%, by weight based on the weight
of the composition, of one or more skin care agents.
[0059] Examples of sugar amines that are useful herein include
glucosamine, N-acetyl glucosamine, mannosamine, N-acetyl
mannosamine, galactosamine, N-acetyl galactosamine, their isomers
(e.g., stereoisomers), and their salts (e.g., HCl salt).
[0060] "Vitamins" means vitamins, pro-vitamins, and their salts,
isomers and derivatives. Non-limiting examples of suitable vitamins
include: vitamin B compounds (including B1 compounds, B2 compounds,
B3 compound, B5 compounds, such as panthenol or "pro-B5",
pantothenic acid, pantothenyl; B6 compounds, such as pyroxidine,
pyridoxal, pyridoxamine; carnitine, thiamine, riboflavin); vitamin
A compounds, and all natural and/or synthetic analogs of Vitamin A,
including retinoids, retinol, retinyl acetate, retinyl palmitate,
retinoic acid, retinaldehyde, retinyl propionate, carotenoids
(pro-vitamin A), and other compounds which possess the biological
activity of Vitamin A; vitamin D compounds; vitamin K compounds;
vitamin E compounds, or tocopherol, including tocopherol sorbate,
tocopherol acetate, tocopherol succinate, other esters of
tocopherol and tocopheryl compounds; vitamin C compounds, including
ascorbate, ascorbyl esters of fatty acids, and ascorbic acid
derivatives, for example, ascorbyl phosphates such as magnesium
ascorbyl phosphate and sodium ascorbyl phosphate, ascorbyl
glucoside, and ascorbyl sorbate; and vitamin F compounds, such as
saturated and/or unsaturated fatty acids.
[0061] In certain embodiments, the cosmetic skin care compositions
may comprise a vitamin B3 compound. As used herein, "vitamin B3
compound" means a compound having the formula:
##STR00001##
wherein R is --CONH.sub.2 (i.e., niacinamide), --COOH (i.e.,
nicotinic acid) or --CH2OH (i.e., nicotinyl alcohol); derivatives
thereof; and salts of any of the foregoing.
[0062] As used herein, "peptide" refers to peptides containing ten
or fewer amino acids and their derivatives, isomers, and complexes
with other species such as metal ions (e.g., copper, zinc,
manganese, magnesium, and the like). Peptide refers to both
naturally occurring and synthesized peptides. Also useful herein
are naturally occurring and commercially available compositions
that contain peptides. The peptides may contain at least one basic
amino acid (e.g., histidine, lysine, arginine). Peptide derivatives
useful herein include lipophilic derivatives such as palmitoyl
derivatives. In one embodiment, the peptide is selected from
palmitoyl-lys-thr-thr-lys-ser, palmitoyl-gly-his-lys, their
derivatives, and combinations thereof.
[0063] Polyphenolic compounds include flavonoids such as those
broadly disclosed in U.S. Pat. No. 5,686,082. Exemplary flavonoids
include one or more flavones, one or more isoflavones, one or more
coumarins, one or more chromones, one or more dicoumarols, one or
more chromanones, one or more chromanols, isomers (e.g., cis/trans
isomers) thereof, and mixtures thereof.
[0064] In certain embodiments, the cosmetic compositions herein may
include one or more suitable dermatologically acceptable carriers.
The carriers may be provided in a wide variety of forms. In some
embodiments, the carrier comprises water and/or water miscible
solvents. The carrier may be present at an amount of from 1% to 95%
by weight, based on the weight of the composition (e.g., from 1%,
3%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%,
70%, 75%, 80%, or 85% to 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%,
50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, or 5%). Suitable water
miscible solvents include monohydric alcohols, dihydric alcohols,
polyhydric alcohols, glycerol, glycols, polyalkylene glycols such
as polyethylene glycol, and mixtures thereof. When the cosmetic
composition is in the form of an emulsion, the water and/or water
miscible solvents are typically associated with the aqueous phase
of the emulsion.
[0065] The dermatologically acceptable carrier may also comprise
one or more suitable oils. The oils may be volatile or nonvolatile
oils. Volatile oils suitable for use herein may have a viscosity
ranging from 0.5 to 5 centistokes (cSt) at 25.degree. C. Volatile
oils may be used to promote more rapid drying of the skin care
composition after it is applied to skin. Nonvolatile oils may be
included to provide emolliency and protective benefits to the skin.
In certain embodiments, the cosmetic compositions may include one
or more suitable silicone oils such as, for example, one or more
polysiloxanes. Other silicone oils that may be suitable for use in
the cosmetic compositions herein include cyclic silicones. In
certain embodiments, hydrocarbon oils (e.g., straight, branched, or
cyclic alkanes and alkenes) may be included in the present cosmetic
compositions. Other suitable oils include amides (e.g., compounds
having an amide functional group while being liquid at 25.degree.
C. and insoluble in water) and ethers.
[0066] The dermatologically acceptable carrier may also comprise an
emulsifier. An emulsifier may be desirable when the composition is
provided in the form of an emulsion or if immiscible materials are
being combined. The cosmetic compositions herein may include from
0.05%, 0.1%, 0.2%, 0.3%, 0.5%, or 1% to 20%, 10%, 5%, 3%, 2%, or 1%
emulsifier. Emulsifiers may be nonionic, anionic or cationic.
Linear or branched type silicone emulsifiers may also be used.
Emulsifiers also include emulsifying silicone elastomers. Suitable
silicone elastomers may be in the powder form, or dispersed or
solubilized in solvents such as volatile or nonvolatile silicones,
or silicone compatible vehicles such as paraffinic hydrocarbons or
esters. Silicone gums are another oil phase structuring agent.
Another type of oily phase structuring agent includes silicone
waxes. Silicone waxes may be referred to as alkyl silicone waxes
and are semi-solids or solids at room temperature.
[0067] Optionally, the cosmetic skin care composition may further
comprise a sunscreen active. Sunscreen actives include both
sunscreen agents and physical sunblocks. Sunscreen actives may be
organic or inorganic. A wide variety of conventional sunscreen
actives may be used. Sagarin, et al., at Chapter VIII, pages 189 et
seq., of Cosmetics Science and Technology (1972), discloses
numerous suitable actives. The sunscreen active may be present at
an amount of from 1% to 20%, or from 2% to 10% by weight based on
the weight of the composition. Exact amounts may vary depending
upon the sunscreen chosen and the desired Sun Protection Factor
(SPF).
[0068] The skin care compositions may be generally prepared by
conventional methods such as known in the art of making
compositions and topical compositions. Such methods typically
involve mixing of ingredients in or more steps to a relatively
uniform state, with or without heating, cooling, application of
vacuum, and the like. Typically, emulsions are prepared by first
mixing the aqueous phase materials separately from the fatty phase
materials and then combining the two phases as appropriate to yield
the desired continuous phase.
[0069] The cosmetic skin care composition may be provided in a
package sized to store a sufficient amount of the composition for a
treatment period. The size, shape, and design of the package may
vary widely. Certain package examples are described in U.S. Pat.
Nos. D570,707; D391,162; D516,436; D535,191; D542,660; D547,193;
D547,661; D558,591; D563,221; 2009/0017080; 2007/0205226; and
2007/0040306. In addition or alternatively, the exfoliating devices
described herein may be packaged as a kit with one or more cosmetic
skin care compositions suitable for use on a facial skin surface
with the exfoliating device.
VII. Methods of Use
[0070] The exfoliating devices disclosed herein may be applied to
one or more facial skin surfaces as part of a user's routine
involving the application of one or more cosmetic skin care
compositions thereto. Additionally or alternatively, the
exfoliating devices and cosmetic skin care compositions herein may
be used on an "as needed" basis. In some embodiments, the
exfoliating device may be applied to the facial skin surface before
application of one or more cosmetic skin care compositions. In
other embodiments, the cosmetic skin care composition may be
applied to the facial skin surface using the exfoliating device.
For example, the cosmetic skin care composition might be applied to
the exfoliating material and then the exfoliating material and the
cosmetic skin care composition might be simultaneously applied to
the facial skin surface. In still other embodiments, the cosmetic
skin care composition may be dispensed by the exfoliating device
onto the facial skin surface during use. In some embodiments,
particular areas of the facial skin may be identified as being in
need of a skin care benefit that can be provided by topical
application of a cosmetic skin care composition, and it is then
desirable to apply an exfoliating device to the skin area in need
of treatment in order to enhance penetration of a cosmetic agent in
the cosmetic skin care composition.
[0071] In some embodiments, the exfoliating device may be applied
to the facial skin surface at least once per day, twice per day, or
three times per day for a period of 7, 14, 21, or 28 days or more.
During each use, one or more facial skin surfaces may be exfoliated
using the device, wherein the facial skin surface is subjected to a
plurality of repetitive motions of the exfoliating device across
the facial skin surface. In certain embodiments, the exfoliating
device may be applied to the facial skin surface between 2 and
about 10 strokes during each use.
VIII. Examples and Test Methods
[0072] The following are non-limiting examples and/or test methods
relating to various aspects of the methods, devices, and kits
described herein. The examples are given solely for the purpose of
illustration and are not to be construed as limiting the invention,
as many variations thereof are possible.
EXAMPLE 1
Surface Roughness Measurements
[0073] This Example describes a method for measuring the surface
roughness of a material. Other suitable methods and devices may be
employed, as known in the art. In this example, a DermaTop-Blue
device, available from Breuckmann GmbH (Germany), was utilized for
measuring the surface roughness of Materials #1 to #4 described
above. The DermaTop-Blue device has a measurement field of 40
mm.times.30 mm, a depth of measuring volume of 20 mm, a resolution
of 1280.times.1024 pixels, a depth resolution of 4 .mu.m, a lateral
resolution of 15 .mu.m, and a measurement points distance of 30
.mu.m. The software version was DermaTop Ver. 3.1.09. The following
parameters were selected for the measurements.
[Application]
[0074] TYPE=Wrinkles [0075] LPC=NO [0076] Align_TASK=Global [0077]
check_Expression=Yes [0078] Enhance=NO [0079] Sorting_Mode=SOI
[0080] Par_Rotation_Side_link=YES
[Acquisition]
[0080] [0081] ZOOM=1 [0082] AUTOEXPOSURE=Yes [0083] AOI-MASK=Square
[0084] Visualization-3D=2 [0085] REPLICA-MAS K=None [0086]
Sensor-Volume=No [0087] Help_PopUp=Yes
[Processing]
[0087] [0088] PROCESS_FILTER=Hair [0089] Filter_Weight=Medium
[0090] Levelling=POLYNOM 3.ORDER [0091] Extract-Eyebag=No [0092]
SOLINVERT=NO [0093] SOI_XSIZE=10 [0094] SOI_YSIZE=10 [0095]
XOffset=0 [0096] YOffset=0 [0097] Rotation=0 [0098]
Rotation_link=NO [0099] SnapShot_SOI=Single [0100] Save_Texture=NO
[0101] SOI_ASCII-EXPORT=NO
[Evaluation]
[0101] [0102] SOI-Filter=Low [0103] CUTOFF-FILTER=Gauss [0104]
CUTOFF=2.5 [0105] Save-Cutoff-SOI=NO [0106] ROUGHNESS-2D=YES [0107]
TARGET-2D=Original [0108] PROFILE-TYPE=PARALLEL [0109]
Profile-Dir=Auto [0110] NB-PROFILES=50 [0111] ROUGHNESS-3D=YES
[0112] TARGET-3D=Original
[0113] A 10 mm.times.10 mm square area of each of Materials 1 to 4
was measured for the surface profile. Average values for S.sub.a,
S.sub.q, S.sub.t, and S.sub.tm were calculated by the software for
the sampled areas of each Material. The average values (in microns)
are summarized in Table 1 above.
EXAMPLE 2
In Vivo Testing of Four Materials
[0114] In this Example, samples of Materials #1 to #4 were tested
by six test subjects. Each test subject treated a small forearm
area (dry, without the addition of a topical composition) with
approximately a 12 mm diameter sample of the abrasive material for
5 strokes using a device similar to that shown in FIGS. 9 and 10
along a 152 mm.times.25 mm area of the forearm. The skin exfoliated
by the material was harvested and the amount of protein quantitated
using a protein assay. Table 2 above sets forth the results of the
protein assay.
[0115] The following protein assay procedure was used to generate
the results set forth in Table 2. First, the exfoliated skin was
harvested from the surface of the abrasive material by placing the
abrasive surface in a 1.5 mL Eppendorf tube containing 1.5 mL of
saline. The samples were vortexed for 3 minutes. The harvested
samples were placed in a 16 mL centrifuge tube with saline added.
The sample was agitated with a Vortex mixer and centrifuged at
20,000 RPM for 30 minutes. The supernatant was then removed and
discarded leaving the bottom 2 ml in the tube along with the skin
sample. The skin sample was then washed with 50/50 MeOH/H2O by
adding 4 mL of 50/50 MeOH/H2O, vortexing to mix and then adding
another 8 mL to fill tube. The skin sample was then centrifuged for
another 30 minutes at 20,000 RPM. This process was repeated 3
times. The sample was then transferred to a 2 mL centrifuge vial
and centrifuged for 30 minutes at 13,000 RPM. The supernatant was
then removed and discarded leaving the bottom 0.5 mL in the tube
along with the sample. This process was repeated until the original
centrifuge tube was clean of all samples. The sample was then dried
in an oven set at 60.degree. C. overnight. When dry, 1 mL of 0.1N
NaOH was added to each sample vial and digested at 95.degree. C.
overnight. The sample was centrifuged at 13,000 RPM for 30 minutes
and 25 .mu.l of the sample pipetted in triplicate to 96-well plate
for the protein assay.
[0116] The protein assay can be performed using any suitable
quantitation kit, as known in the art. One example is the AnaLyte
OPA Protein Quantitation Kit (Catalog #71015) available from
AnaSpec, Inc. of San Jose, Calif., USA. This kit is designed to
detect protein concentration using o-pthaladehye (OPA) as a
sensitive fluorimetric indicator. OPA in the presence of a reducing
agent reacts with an .alpha.-amino acid to form an intense blue
fluorescent product, which can be read by fluorescence microplate
reader or fluorometer (e.g., SpectraMax Plus 384 available from
Molecular Devices, LLC of CA, USA) capable of detecting emission at
440-480 nm with an excitation at 335-345 nm. The quantity of
protein in the assay solution may be determined from the
fluorescence, as known in the art.
EXAMPLE 3
In Vitro Measurement of Niacinamide Penetration
[0117] This Example describes the measurement of niacinamide
penetration thru human cadaver skin using a Franz diffusion cell
assay following abrading of six replicate skin samples by Material
#1 and six replicate skin samples by Material #4. Split-thickness
human cadaver skin (Allosource, Englewood, Colo.) was thawed at
ambient conditions, cut into appropriately sized sections resulting
in six test samples plus six control samples. A 20 to 25 cm.sup.2
cadaver skin sample was fixed at each end and each abrasive surface
(31.75 mm diameter circle) was placed against the skin with a 50,
100 or 200 gm weight. The weighted abrasive surface was dragged
across the cadaver skin for five strokes in one direction and then
five strokes in the perpendicular direction. This was repeated for
six skin samples, one for each of the six samples of Material #1
and the six samples of Material #4. 1 cm.sup.2 cadaver skin plugs
were cored out of the treated skin samples and mounted in standard
Franz-type diffusion cells (0.79 cm.sup.2 surface area) maintained
at about 37.degree. C. The receptor compartments were filled with 5
mL phosphate buffered saline (PBS--pH 7.4) that included 1%
polysorbate-20 and 0.02% sodium azide, and the skin was allowed to
equilibrate for two hours. The cells were randomized to treatment
group based upon .sup.3H.sub.2O flux through the mounted skin (150
.mu.L of .sup.3H.sub.20 applied for five minutes, removed and
followed by collection of receptor fluid after 60 minutes).
Diffusion cells were randomized by ranking each cell according to
water flux and distributing cells across treatment legs such that
each group included cells across the range of observed water flux.
Each treatment group typically had 6 replicates.
[0118] Aliquots of the test products/formulations were spiked with
.sup.14C-niacinamide with approximately 3 .mu.Ci per 300 mg product
aliquot, mixed and assayed for total radioactivity in triplicate
using Ultima Gold (available from Perkin-Elmer) liquid
scintillation cocktail (LSC) and liquid scintillation counting
(Tri-Carb 2500 TR Liquid Scintillation Analyzer, PerkinElmer,
Boston, Mass.). The skin samples were topically dosed with 5 .mu.L
of the radio labeled niacinamide product using a positive
displacement pipette. The product was gently spread over the
surface of the skin samples (0.79 cm.sup.2) using the pipet tip.
The receptor solution was collected and replaced at various time
points following application every 6 hrs with a final collection at
24 hours. After the final receptor collection, each skin sample was
wiped two times with Whatman filter paper soaked with PBS/Tween 20
and once with 70%/30% ethanol/water to remove unabsorbed (residual)
product. The epidermis was separated from the residual dermis by
dissection. The skin sections were dissolved in 0.50-1.25 mL
Soluene-350 (Perkin Elmer, Boston, Mass.) at 60.degree. C.
overnight, and all receptor collections, filter paper wipes, and
solubilized tissue sections were counted using liquid scintillation
counting. Disintegrations-per-minute (dpm) for each compartment of
each cell were blank corrected and summed to obtain a total
recovered radiolabel value for a given cell. The dpm of each
compartment were then normalized to the total recovered radiolabel
value to obtain a "percent recovered radiolabel" parameter for each
compartment (individual receptor collections, epidermis, dermis,
and wipes for mass balance). Cumulative receptor values for each
collection time point were calculated as the sum of the individual
collections to that time point, with the total receptor value as
the sum of all individual collections. The total skin value was the
sum of the epidermis (including stratum corneum) and dermis values,
and the total permeated value the sum of total skin and cumulative
receptor values. Tables 4 and 5 summarize the niacinamide recovery
results. In addition to niacinamide recovery, protein recovery from
three samples of Material #1 and Material #4 was also measured
using generally the same procedure described in Example 2. A
summary of the protein recovery data is provided in Tables 5 and
6.
EXAMPLE 4
Consumer Practices
[0119] This Example describes the investigation of consumer habits
and practices for applying cosmetic skin care compositions. In
order to identify exfoliating materials that are suitable for
frequent use while still providing a sufficient level of
exfoliation to enhance penetration of skin care agents, it is
useful to understand consumer habits and practices with regard to
the application of skin care products. Understanding how skin care
products are applied in daily practice informs how (e.g., number of
strokes, pressure, etc.) an exfoliating device might be used by a
typical user, which is useful, in turn, for assessing the in vitro
effects of various abrasive materials. Seven female test subjects
were monitored while applying a skin care composition to their
faces using four different application methods. The methods
included applying the composition using their fingers, applying the
composition using a cotton surface, applying the composition using
a hand held applicator, and applying the composition using a
powered applicator. The number of strokes used during each
application method, and the number of strokes used in various
regions of the face (e.g., cheeks, forehead, and chin) were
observed. The amount of pressure applied by the user was also
measured using a pressure sensitive glove. From this study, it was
found that consumer's typically utilize from 2 to 10 strokes at a
pressure from 50 g/cm.sup.2 to 400 g/cm.sup.2 when applying a skin
care composition to facial skin surfaces. In some instances, the
number of strokes is from 7 to 10 and the pressure is from 100
g/cm.sup.2 to 300 g/cm.sup.2.
[0120] The dimensions and values disclosed herein are not to be
understood as being strictly limited to the exact numerical values
recited. Instead, unless otherwise specified, each such dimension
is intended to mean both the recited value and a functionally
equivalent range surrounding that value. For example, a dimension
disclosed as "40 mm" is intended to mean "about 40 mm."
[0121] Every document cited herein is hereby incorporated herein by
reference in its entirety unless expressly excluded or otherwise
limited. In addition, U.S. Provisional App. No. 61/623,466 is
incorporated by reference herein in its entirety. The citation of
any document is not an admission that it is prior art with respect
to any invention disclosed or claimed herein or that it alone, or
in any combination with any other reference or references, teaches,
suggests or discloses any such invention. Further, to the extent
that any meaning or definition of a term in this document conflicts
with any meaning or definition of the same term in a document
incorporated by reference, the meaning or definition assigned to
that term in this document shall govern.
[0122] While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention. It is therefore intended to cover in the appended claims
all such changes and modifications that are within the scope of
this invention.
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