U.S. patent application number 16/352389 was filed with the patent office on 2019-07-11 for method for evaluating glow of skin, method for examining skin glow improvers, and skin glow improver.
This patent application is currently assigned to Shiseido Company, Ltd.. The applicant listed for this patent is Shiseido Company, Ltd.. Invention is credited to Tomohiro KUWAHARA, Yuji MASUDA, Eiichiro YAGI.
Application Number | 20190212136 16/352389 |
Document ID | / |
Family ID | 55954396 |
Filed Date | 2019-07-11 |
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United States Patent
Application |
20190212136 |
Kind Code |
A1 |
MASUDA; Yuji ; et
al. |
July 11, 2019 |
METHOD FOR EVALUATING GLOW OF SKIN, METHOD FOR EXAMINING SKIN GLOW
IMPROVERS, AND SKIN GLOW IMPROVER
Abstract
Provided are an evaluation method for objectively evaluating the
glow of the skin, a skin glow improver, and a method for examining
skin glow improvers. This method for evaluating the glow of the
skin comprises assessing the specular reflectance and diffuse
reflectance of skin after polarized light is applied to the surface
of the skin, and determining that glow is present in the skin when
prescribed conditions are satisfied. A skin glow improver is
provided by combining an alkali metal salt of alkoxysalicylic acid
and trimethylglycine. This method for examining skin glow improvers
makes it possible, using a significant decrease in surface
roughness as an indicator, to examine samples capable of improving
the specular reflectance of the skin.
Inventors: |
MASUDA; Yuji; (Yokohama-shi,
JP) ; YAGI; Eiichiro; (Yokohama-shi, JP) ;
KUWAHARA; Tomohiro; (Yokohama-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Shiseido Company, Ltd. |
Tokyo |
|
JP |
|
|
Assignee: |
Shiseido Company, Ltd.
Tokyo
JP
|
Family ID: |
55954396 |
Appl. No.: |
16/352389 |
Filed: |
March 13, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15525133 |
May 8, 2017 |
10281267 |
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PCT/JP2015/081615 |
Nov 10, 2015 |
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16352389 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01N 21/57 20130101;
A61B 5/107 20130101; A61B 5/0059 20130101; A61K 8/44 20130101; G01N
21/21 20130101; A61K 8/368 20130101; A61B 5/00 20130101; A61Q 19/00
20130101; G01B 11/30 20130101; A61B 5/441 20130101 |
International
Class: |
G01B 11/30 20060101
G01B011/30; A61B 5/00 20060101 A61B005/00; G01N 21/57 20060101
G01N021/57; G01N 21/21 20060101 G01N021/21; A61K 8/368 20060101
A61K008/368; A61Q 19/00 20060101 A61Q019/00; A61K 8/44 20060101
A61K008/44; A61B 5/107 20060101 A61B005/107 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 10, 2014 |
JP |
2014-228494 |
Claims
1-7. (canceled)
8. A method for improving a glow of a skin comprising applying to a
skin of a subject who desires to improve a skin glow a skin glow
improving amount of alkoxysalicylic acid or an alkaline metal salt
thereof.
9. The method of claim 8, wherein said applying comprises applying
potassium 4-methoxysalicylate to the skin of the subject.
10. The method of claim 8, further comprising applying
trimethylglycine to the skin of the subject.
11. The method of claim 9, further comprising applying
trimethylglycine to the skin of the subject.
12. The method of claim 9, wherein a concentration of potassium
4-methoxysalicylate is 0.5% to 3%.
13. The method of claim 10, wherein a concentration of
trimethylglycine is 2% to 10%.
14. The method of claim 11, wherein a concentration of
trimethylglycine is 2% to 10%.
15. The method of claim 8, wherein the subject further desires to
enhance a specular reflectance.
16. The method of claim 8, wherein the subject has a dull skin.
17. The method of claim 8, wherein the skin of the subject has a
glossy or greasy shine.
18. The method of claim 8, wherein the subject has translucent
skin.
19. A composition, comprising skin glow improving amounts of a)
alkoxysalicylic acid or an alkaline salt thereof and b)
trimethylglycine.
20. The composition of claim 19, wherein the alkoxysalicylic acid
or the alkaline salt thereof is potassium 4-methoxysalicylate.
21. The composition of claim 20, wherein a concentration of
potassium 4-methoxysalicylate is 0.5% to 3%.
22. The composition of claim 19, wherein a concentration of
trimethylglycine is 2% to 10%.
23. The composition of claim 20, wherein a concentration of
trimethylglycine is 2% to 10%.
24. The composition of claim 21, wherein a concentration of
trimethylglycine is 2% to 10%.
Description
TECHNICAL FIELD
[0001] The present invention relates to a method for evaluating the
glow of skin, a method for screening a skin glow improver and a
skin glow improver.
BACKGROUND ART
[0002] Translucency has conventionally been known to serve as an
indicator of the appearance of skin. Translucency has been
determined by sensory evaluations which are conducted by a beauty
technician visually, wherein an external skin preparation is
applied to the skin as necessary.
[0003] However, in addition to requiring many years of experience
in order to evaluate skin translucency accurately, even if skin
translucency was evaluated by a technician having ample experience,
it was difficult to completely eliminate variations between
evaluations.
[0004] For example, a conventional method for evaluating skin
translucency is known that is based on the total reflectance of two
types of reflected light consisting of an S-polarized light
component and a P-polarized light component obtained by irradiating
P-polarized light to the surface of skin and receiving reflected
light in the form of an S-polarized polarized light component, and
irradiating S-polarized light to the surface of skin and receiving
reflected light in the form of a P-polarized light component (see,
for example, PLT 1: Japanese Unexamined Patent Publication No.
2004-215991).
[0005] On the other hand, external skin preparations containing one
or more an alkoxysalicylic acid and/or salt thereof are known as
examples of external skin preparations having a skin whitening
effect (see, for example, PLT 2: Japanese Unexamined Patent
Publication No. H6-40886).
CITATION LIST
Patent Literature
[0006] PLT 1: Japanese Unexamined Patent Publication No.
2004-215991
[0007] PLT 2: Japanese Unexamined Patent Publication No.
H6-40886
[0008] PLT 3: Japanese Unexamined Patent Publication No.
2013-189396
[0009] PLT 4: Japanese Unexamined Patent Publication No.
2013-40114
[0010] PLT 5: Japanese Unexamined Patent Publication No.
2000-63255
[0011] PLT 6: Japanese Unexamined Patent Publication No.
2012-6902
SUMMARY OF INVENTION
Technical Problem
[0012] However, there has been no method available for objectively
evaluating skin glow. Consequently, there is a desire to develop a
method for evaluating skin glow. In addition, there is also a
desire to develop a compound or composition capable of improving
skin glow, namely a skin glow improver, and a method for screening
such skin glow improvers.
[0013] Taking into consideration the problem which the prior art
may cause, one aspect of the present invention is directed to
evaluating the glow of skin, a skin glow improver, and a method for
examining skin glow improvers.
Solution to Problem
[0014] One aspect of the present invention is a method for
evaluating the glow of skin, comprising: a step for measuring a
first reflectance by irradiating polarized light to the surface of
skin followed by receiving reflected light polarized in a direction
parallel to the direction of polarization of the irradiated
polarized light, a step for measuring a second reflectance by
applying the polarized light to the surface of the skin followed by
receiving reflected light in a direction perpendicular to the
direction of polarization of the irradiated polarized light, and a
step for determining diffuse reflectance and specular reflectance
from the first reflectance and the second reflectance; wherein, the
skin is determined to have glow in the case the diffuse reflectance
and the specular reflectance satisfy prescribed conditions.
[0015] One aspect of the present invention is a method for
screening a skin glow improver, comprising: a step for measuring
surface roughness of horny layer cells, a step for applying a test
sample to the horny layer cells, and a step for measuring surface
roughness of the horny layer cells to which the test sample has
been applied; wherein, the test sample is judged to be able to
improve specular reflectance of the skin in the case surface
roughness of the horny layer cells to which the test sample has
been applied decreases significantly in comparison with surface
roughness of the horny layer cells to which the test sample has not
been applied.
[0016] One aspect of the present invention is a skin glow improver,
comprising one or more medicinal agents selected from the group
consisting of an alkaline metal salt of salicylic acid, an alkaline
metal salt of an alkoxysalicylic acid and glycolic acid.
[0017] More specifically, the present invention relates to that
indicated below.
[0018] [1] A skin glow improver, comprising an alkaline metal salt
of an alkoxysalicylic acid and trimethylglycine.
[0019] [2] The skin glow improver described in [1], wherein the
alkaline metal salt of an alkoxysalicylic acid is potassium
4-methoxysalicylate.
[0020] [3] The skin glow improver described in [2], comprising 0.5%
to 3% of potassium 4-methoxysalicylate.
[0021] [4] The skin glow improver described in any of [1] to [3],
comprising 2% to 10% of trimethylglycine.
[0022] [5] A method for screening a skin glow improver,
comprising:
[0023] measuring surface roughness of horny layer cells,
[0024] applying a test sample to the horny layer cells, and
[0025] measuring surface roughness of the horny layer cells to
which the test sample has been applied;
wherein the sample is determined to be able to improve specular
reflectance of skin in the case surface roughness of the horny
layer cells to which the test sample has been applied decreases
significantly in comparison with surface roughness of the horny
layer cells to which the test sample has not been applied.
[0026] [6] A method for evaluating the glow of skin,
comprising:
[0027] measuring a first reflectance by irradiating polarized light
to the surface of skin followed by receiving reflected light
polarized in a direction parallel to the direction of polarization
of the irradiated polarized light,
[0028] measuring a second reflectance by irradiating polarized
light to the surface of the skin followed by receiving reflected
light in a direction perpendicular to the direction of polarization
of the irradiated polarized light, and
[0029] determining diffuse reflectance and specular reflectance
from the first reflectance and the second reflectance;
wherein the skin is determined to have glow in the case the diffuse
reflectance and the specular reflectance satisfy prescribed
conditions.
[0030] [7] The method for evaluating skin glow described in [6],
further comprising a step for applying a sample to skin before
measuring the first reflectance and the second reflectance.
[0031] [8] Use of an alkaline metal salt of an alkoxysalicylic acid
and trimethylglycine for the production of a skin glow improver and
specular reflectance enhancer.
[0032] [9] The use described in [8], wherein the alkaline metal
salt of an alkoxysalicylic acid is potassium
4-methoxysalicylate.
[0033] [10] The use described in [9], wherein 0.5% to 3% of
potassium 4-methoxysalicylate is used.
[0034] [11] The use described in any of [8] to [10], wherein 2% to
10% of trimethylglycine is used.
[0035] [12] A method for improving skin glow, a method for
enhancing specular reflectance or a cosmetic method, comprising the
application of an alkaline metal salt of an alkoxysalicylic acid
and trimethylglycine.
[0036] [13] The method described in [12], wherein the alkaline
metal salt of an alkoxysalicylic acid is potassium
4-methoxysalicylate.
[0037] [14] The method described in [13], wherein 0.5% to 3% of
potassium 4-methoxysalicylate is used.
[0038] [15] The method described in any of [8] to [10], wherein 2%
to 10% of trimethylglycine is used.
Advantageous Effects of Invention
[0039] According to one aspect of the present invention, a method
for evaluating the glow of skin, a skin glow improver and a method
for screening a skin glow improver can be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] FIG. 1 is a flow chart indicating an example of the method
for evaluating the glow of skin in the present embodiment.
[0041] FIG. 2 is a flow chart indicating an example of the method
for screening a skin specular reflectance improver in the present
embodiment.
[0042] FIG. 3 is a map indicating the relationship of specular
reflectance versus diffuse reflectance in Example 1.
[0043] FIG. 4 is a map indicating the relationship of specular
reflectance versus diffuse reflectance in Example 2.
[0044] FIG. 5 is a map indicating the relationship of specular
reflectance versus diffuse reflectance before and after applying a
skin lotion and milky lotion in Example 3.
[0045] FIG. 6 is a graph indicating specular reflectance before and
after applying a skin lotion and milky lotion in Example 3.
[0046] FIG. 7 is a map indicating the relationship of specular
reflectance versus arithmetic average roughness (Sa) of horny layer
cells in Example 4.
[0047] FIG. 8 indicates the rate of change of arithmetic average
roughness (Sa) of horny layer cells after having added potassium
4-methoxysalicylate (4-MSK) while changing the concentration
thereof.
[0048] FIG. 9 indicates the rate of change of arithmetic average
roughness (Sa) of horny layer cells after having added
trimethylglycine (TMG) while changing the concentration
thereof.
[0049] FIG. 10 indicates the rate of change of arithmetic average
roughness (Sa) of horny layer cells after having added potassium
4-methoxysalicylate (4MSK) alone and combining potassium
4-methoxysalicylate (4-MSK) and trimethylglycine (TMG) while
changing the concentrations thereof.
[0050] FIG. 11 is a graph indicating arithmetic average roughness
(Sa) of horny layer cells before and after applying Sample 1-1 and
water.
[0051] FIG. 12 is a graph indicating the rate of decrease of
arithmetic average roughness (Sa) of horny layer cells before and
after applying Sample 1-1 and water.
[0052] FIG. 13 is a graph indicating the rate of decrease of
arithmetic average roughness (Sa) of horny layer cells before and
after applying Sample 1-1 and Sample 1-2.
[0053] FIG. 14 is a graph indicating arithmetic average roughness
(Sa) of horny layer cells before and after applying Sample 2.
[0054] FIG. 15 is a graph indicating the rate of decrease of
arithmetic average roughness (Sa) of horny layer cells before and
after applying Sample 2 and water.
[0055] FIG. 16 is a graph indicating arithmetic average roughness
(Sa) of horny layer cells before and after applying Sample 3.
[0056] FIG. 17 is a graph indicating the rate of decrease of
arithmetic average roughness (Sa) of horny layer cells before and
after applying Sample 3 and water.
[0057] FIG. 18 is a graph indicating arithmetic average roughness
(Sa) of horny layer cells before and after applying Sample 4-1.
[0058] FIG. 19 is a graph indicating the rate of decrease of
arithmetic average roughness (Sa) of horny layer cells before and
after applying Sample 4-1 and water.
[0059] FIG. 20 is a graph indicating arithmetic average roughness
(Sa) of horny layer cells before and after applying Sample 4-1 and
Sample 4-2.
[0060] FIG. 21 is a graph indicating arithmetic average roughness
(Sa) of horny layer cells before and after applying Sample 5.
[0061] FIG. 22 is a graph indicating the rate of decrease of
arithmetic average roughness (Sa) of horny layer cells before and
after applying Sample 5 and water.
[0062] FIG. 23 indicates the results of a questionnaire given after
continuous use of candidate skin lotiones.
[0063] FIG. 24 indicates the rate of decrease of arithmetic average
roughness (Sa) of horny layer cells in the third month of
continuous use of candidate skin lotiones.
[0064] FIG. 25 indicates changes in the number of texture pixels in
the third month of continuous use of candidate skin lotiones.
[0065] FIG. 26 indicates changes specular reflectance and diffuse
reflectance in the third month of continuous use of candidate skin
lotiones.
DESCRIPTION OF EMBODIMENTS
[0066] The following provides an explanation of embodiments for
carrying out the invention along with drawings.
[0067] Skin glow is one of the properties of skin that makes skin
appear beautiful. Examples of properties of the skin surface that
make skin appear beautiful include translucence and glow.
Translucence is thought to have an effect on the color of skin.
Diffuse reflectance of light by the skin is thought to contribute
to translucence (Measurement of Skin Translucence and Evaluation of
the Usefulness of Applicable Cosmetics, J. Soc. Cosmet. Chem.
Japan, 2005, 39: 201-208), and translucence can be increased by
increasing diffuse reflectance of light by the skin as a result of
whitening. In addition to whitening, moisture retention and
promotion of blood circulation also contribute to increased
translucence. Although glow refers to the luster of skin, the
aesthetically undesirable property of glossy or greasy shine is
also related to luster, and since this makes it difficult to
distinguish between them when evaluating skin, skin glow has yet to
be evaluated properly. According to research conducted by the
inventors of the present invention, it was found that skin glow can
be realized by additionally increasing specular reflectance in skin
having translucence resulting from an increase in diffuse
reflectance (FIG. 3), and skin glow is therefore thought to involve
both diffuse reflectance and spectral reflectance. The glow of skin
can be represented by several parameters, and can be referred to as
glow, luminous sheen, luster or sheen. Thus, the skin glow improver
of the present invention can be said to be a luminous sheen or
luster improver.
[0068] Light that is radiated onto skin is partially reflected
resulting in reflected light. This reflected light can be broadly
categorized as specular reflection and diffuse reflection. Specular
reflection refers to light from one direction being reflected in
another direction, and specular reflection in the skin refers to
reflection generated mainly on the skin surface. Although specular
reflection in the skin is thought to contribute to skin luster,
properties of the skin relating to skin luster not only include
glow, but also include a glossy or greasy shine. Although glow is a
property that makes the skin appear beautiful, since a glossy or
greasy shine is produced by secretion of large amounts of sebaceous
matter, it is considered to be a property of skin that is
aesthetically undesirable. Diffuse reflection refers to incoming
light being reflected in various directions, and refers to
reflection occurring within the skin. Diffuse reflection in the
skin contributes to skin translucence, and skin having a low level
of diffuse reflection gives a dull impression.
[0069] According to research conducted by the inventors of the
present invention, while enhancement of only specular reflection
results in a glossy or greasy shine, it was clearly determined that
enhancement of specular reflection in translucent skin having a
high degree of diffuse reflection could result in glow skin (FIG.
3). On the basis of these findings, the present invention relates
to a method for evaluating the glow of skin using reflected light
polarized in a direction parallel to the polarized direction of
irradiated polarized light and reflected light polarized in a
direction perpendicular to the polarized direction of irradiated
polarized light as an indicator, when polarized light is irradiated
onto the skin surface, as will be subsequently described.
<Method for Evaluating Glow of Skin>
[0070] The method for evaluating the glow of skin of the present
invention comprises:
[0071] a step for irradiating polarized light to the surface of
skin,
[0072] a step for measuring reflected light polarized in a
direction parallel to the direction of polarization of the
irradiated polarized light (parallel reflected light) and reflected
light polarized in a direction perpendicular to the direction of
polarization (perpendicular reflected light),
[0073] a step for calculating reflectance of the parallel reflected
light and the perpendicular reflected light, and
[0074] a step for determining the glow of skin based on parallel
reflectance and perpendicular reflectance.
[0075] In the step for determining the glow of skin based on
parallel reflectance and perpendicular reflectance, the glow of the
skin can be determined based on a graph indicating the relationship
between skin glow and the preliminarily determined parallel
reflectance and perpendicular reflectance, or can be determined
based on a predetermined threshold value. In still another aspect,
the step for determining the glow of skin based on parallel
reflectance and perpendicular reflectance may also include a step
for calculating specular reflectance and diffuse reflectance from
parallel reflectance and perpendicular reflectance. In this case,
the glow of skin can be determined based on a graph indicating the
relationship between skin glow and predetermined specular
reflectance and diffuse reflectance, or can be determined based on
a predetermined threshold value.
[0076] According to the present invention, the glow of skin, which
conventionally was only able to be evaluated by a sensory
evaluation relying on a visual evaluation by a beauty technician,
can be evaluated objectively.
[0077] An explanation of the method for evaluating the glow of skin
in a specific embodiment of the present invention is provided using
FIG. 1.
[0078] First, after having irradiated polarized light to the skin
surface, a first reflectance (parallel reflectance) is measured by
receiving reflected light polarized in a direction parallel to the
direction of polarization of the irradiated polarized light
(S01).
[0079] In this connection, the direction parallel to the direction
of polarization of the irradiated polarized light refers to the
direction parallel to the direction of polarization in the case of
the irradiated polarized light having been reflected on the surface
of the skin without undergoing a change in the direction of
polarization.
[0080] Next, after having irradiated polarized light to the skin
surface, a second reflectance (perpendicular reflectance) is
measured by receiving reflected light in a direction perpendicular
to the direction of polarization of the irradiated polarized light
(S02). Here, the surface of the skin to which the polarized light
was irradiated and the polarized light applied to the surface of
the skin are the same as in S01.
[0081] In this connection, the direction perpendicular to the
direction of polarization of the irradiated polarized light refers
to the direction perpendicular to the direction of polarization in
the case of the irradiated polarized light having been reflected on
the surface of the skin without undergoing a change in the
direction of polarization.
[0082] At this time, there are no particular limitations on the
order of S01 and S02.
[0083] Moreover, diffuse reflectance and specular reflectance are
determined form the first reflectance and the second reflectance
(S03).
[0084] Next, a map is prepared that indicates the relationship of
the specular reflectance versus the diffuse reflectance determined
in S03 (S04). Here, skin is determined to have glow in the case
diffuse reflectance and specular reflectance satisfy prescribed
conditions. At this time, evaluation criteria can be determined by
determining the diffuse reflectance and specular reflectance of a
plurality of preliminary subjects and evaluating the skin glow of
the plurality of preliminary subjects by visual sensory evaluations
performed by a beauty technician.
[0085] As an example thereof, skin is judged to have glow in the
case diffuse reflectance is equal or greater than a prescribed
value and specular reflectance is equal to or greater than a
prescribed value. In this case, diffuse reflectance at which skin
is judged to have glow is normally 25% or more and preferably 27%
or more. In addition, specular reflectance at which skin is judged
to have glow is normally 10% or more and preferably 12% or
more.
[0086] Although there are no particular limitations on the site of
the skin where total reflectance, first reflectance and second
reflectance are measured, an example thereof is the cheeks (and
particularly the area of the upper cheek directly below the corner
of the eye (cheekbone)).
[0087] Furthermore, the first reflectance and the second
reflectance can be measured using a known method (see, for example,
PTL 1: Japanese Unexamined Patent Publication No. 2004-215991).
[0088] The method for evaluating the glow of skin in the present
embodiment may also further comprise a step for applying a sample
to the skin prior to measuring the first reflectance and the second
reflectance. In this case, skin glow improvers can be screened by
determining diffuse reflectance and spectral reflectance before and
after applying the sample to the skin.
[0089] <Method for Calculating Diffuse Reflectance and Specular
Reflectance>
[0090] Diffuse reflectance can be calculated from formula (1) and
specular reflectance can be calculated from formula (2) by defining
first reflectance (parallel reflectance) and second reflectance
(perpendicular reflectance) as x.sub.1 (%) and x.sub.2 (%),
respectively.
2x.sub.2 (1)
x.sub.1-x.sub.2 (2)
[0091] Next, an explanation is provided of the method for screening
a skin glow improver. Here, an explanation is provided of a method
for screening a skin glow improver that is simpler than methods for
screening skin glow improvers by using the method for evaluating
the glow of skin of FIG. 1.
<Method for Screening a Skin Glow Improver>
[0092] As was previously described, in order to improve the glow of
skin, it is necessary to enhance the diffuse reflectance and
specular reflectance of skin. Here, skin diffuse reflectance is
typically known to be high in skin having a smooth texture, low
levels of melanin and hemoglobin, and high horny layer moisture
content. In addition, application of cosmetics incorporating a
whitening agent (such as albumin or ethyl vitamin C), circulation
promoter (such as vitamin E acetate) or moisturizer (such as
glycerin) are known to increase the diffuse reflectance of skin
(see, for example, J. Soc. Cosmet. Chem. Jpn., 39(3), 201-208
(2005)).
[0093] However, with respect to specular reflectance, it has not
yet known as to what types of properties of the skin are associated
with this parameter, and it has not yet known as to a method for
improving specular reflectance of the skin.
[0094] Therefore, in order to screen a skin glow improver, it is
necessary to screen compounds or compositions that improve specular
reflectance of skin, namely a skin specular reflectance
improver.
[0095] According to research conducted by the inventors of the
present invention, decreasing the surface roughness of skin was
found to be effective for enhancing specular reflection (FIG. 7).
The surface roughness of skin as referred to in the present
description does not refer to surface irregularities represented by
skin depressions or protrusions, but rather refers to surface
irregularities of horny layer cells present on smaller skin
protrusions. Without intending to be limited by a particular
theory, specular reflectance is thought to increase by a reduction
in diffuse reflection of incoming light due to smoothening of
surface irregularities of protruding portions of the skin. Thus,
the action of smoothing the horny layer can be also said to be an
action that increases specular reflectance, and horny layer
smoothing agents can also be said to be specular reflectance
enhancers.
[0096] The surface roughness of skin can be determined by measuring
the surface of horny layer cells sampled with a strip of adhesive
tape and the like using a microscope such as an atomic force
microscope. Surface roughness can be calculated in terms of
arithmetic average roughness (Sa) as defined in ISO25178 by
acquiring 3D-scanned images captured using an atomic force
microscope, correcting the inclination of the 3D shape by
subtracting those images applicable to a Gaussian filter having a
half width of 2 .mu.m, displaying the images, and calculating the
average of absolute values of the Z axis for each XY
coordinate.
[0097] The following provides an explanation of the method for
screening a skin specular reflectance improver of the present
embodiment using FIG. 2.
[0098] First, the arithmetic average roughness (Sa) of horny layer
cells is measured (S11). Next, a sample is applied to the horny
layer cells (S12). Then, the arithmetic average roughness (Sa) of
the horny layer cells to which the sample has been applied is
measured (S13). Next, the rate of decrease of the arithmetic
average roughness (Sa) of the horny layer cells to which the sample
was applied is determined relative to the arithmetic average
roughness of the horny layer cells to which the sample was not
applied (S14). Here, the sample is judged to be able to improve the
specular reflectance of skin in the case the arithmetic average
roughness (Sa) of the horny layer cells to which the sample was
applied significantly decreases relative to the arithmetic average
roughness (Sa) of the horny layer cells to which the sample was not
applied.
[0099] Furthermore, although arithmetic average roughness (Sa) of
horny layer cells was used as an indicator for screening a skin
specular reflectance improver in the present embodiment, there are
no particular limitations thereon, as long as surface roughness of
horny layer cells is used for the indicator. As a result of
carrying out screening using the method for screening a skin
specular reflectance improver of the present invention, the
medicinal agent indicated below could be selected as a medicinal
agent capable of improving specular reflectance. The action of
improving glow can be demonstrated in the case of using a specular
reflectance improver together with a medicinal agent having an
action that improves translucence, in the case the specular
reflectance improver per se has the effect of improving
translucence, or in the case of using on a subject already having
sufficiently translucent skin. Thus, a specular reflectance
improver can also be referred to as a skin glow improver.
<Skin Glow Improver>
[0100] The skin glow improver comprises, for example, one or more
types of medicinal agents selected from the group consisting of an
alkaline metal salt of salicylic acid, an alkaline metal salt of an
alkoxysalicylic acid and glycolic acid. Examples of alkaline metal
salts include sodium salt, potassium salt and lithium salt.
[0101] The alkaline metal salt of salicylic acid includes, but is
not limited to, sodium salicylate (sodium 2-hydroxybenzoate).
[0102] The alkaline metal salt of an alkoxysalicylic acid includes,
but is not limited to, potassium 4-methoxysalicylate
(2-hydroxy-4-methoxybenzoate). 4-methoxysalicylate is a cosmetic
component known to demonstrate cuticle exfoliating action, melanin
formation preventing action and turnover normalizing action, and is
incorporated in cosmetics claiming primarily whitening action (PTL
3: Japanese Unexamined Patent Publication No. 2013-189396 and PTL
4: Japanese Unexamined Patent Publication No. 2013-40114). Although
whitening action contributes to improvement of skin translucence by
enhancing diffuse reflection, the specular reflectance improving
action and glow improving action of potassium 4-methoxysalicylate
were previously not known.
[0103] Although the incorporated amount of an alkaline metal salt
of alkoxysalicylic acid can be selected arbitrarily, it can be
incorporated in a cosmetic, for example, at a concentration of 0.5%
by weight to 5% by weight. It is preferably incorporated at 1% by
weight or more from the viewpoint of demonstrating glow improving
action. On the other hand, since it is an effective medicinal
agent, the incorporated amount thereof is preferably reduced
provided the glow improving action thereof is demonstrated, and is
preferably incorporated at 3% by weight or less. From the viewpoint
of reducing the incorporated amount while demonstrating a glow
improving action, the alkaline metal salt of an alkoxysalicylic
acid is preferably incorporated at 1% by weight to 3% by weight,
and for example, at 1% by weight, 1.5% by weight, 2% by weight,
2.5% by weight or 3% by weight.
[0104] The skin glow improver may also further contain trimethyl
glycine. As a result, the glow of skin can be further improved.
Trimethylglycine is frequently incorporated in cosmetics as a
moisturizer (PTL 5: Japanese Unexamined Patent Publication No.
2000-63255 and PTL 6: Japanese Unexamined Patent Publication No.
2012-6902). On the other hand, according to tests conducted by the
inventors of the present invention, trimethylglycine does not have
the effect of smoothing the horny layer or improving skin glow
(FIG. 9). When the inventors of the present invention incorporated
an alkaline metal salt of an alkoxysalicylic acid in the form of
potassium 4-methoxysalicylate with trimethylglycine, synergistic
effects were surprisingly observed with respect to horny layer
smoothing effects (FIG. 10). Since potassium 4-methoxysalicylate is
an expensive agent, it is imperative to reduce the amount used
while maintaining glow improving action.
[0105] The incorporated amount of trimethylglycine can be
arbitrarily selected provided synergistic action is demonstrated
with respect to the glow improving action of an alkaline metal salt
of an alkoxysalicylic acid, and can be incorporated in a cosmetic,
for example, at a concentration of 1% by weight to 10% by weight.
From the viewpoint of demonstrating a synergistic effect with the
alkaline metal salt of an alkoxysalicylic acid with respect to the
glow improving action thereof, trimethylglycine is preferably
incorporated at 2% by weight or more, more preferably at 2.5% by
weight or more, even more preferably at 3% by weight or more, and
still more preferably at 5% by weight or more. Trimethylglycine is
preferably incorporated at 8% by weight or less and more preferably
at 6% by weight or less from the viewpoints of stability and
usability.
[0106] The present invention also relates to use of one or more of
agents selected from the group consisting of an alkaline metal salt
of salicylic acid, an alkaline metal salt of an alkoxysalicylic
acid and glycolic acid for the production of a skin glow improver
or specular reflectance enhancer. In another aspect thereof, the
present invention relates to use of one or more agents selected
from the group consisting of an alkaline metal salt of salicylic
acid, an alkaline metal salt of an alkoxysalicylic acid and
glycolic acid, and trimethylglycine for the production of a skin
glow improver or specular reflectance enhancer. The specific agents
used and the concentrations thereof are as previously
described.
[0107] In one aspect of the present invention, the present
invention relates to a method for improving the glow of skin or
enhancing the specular reflectance thereof, comprising application
of one or more agents selected from the group consisting of an
alkaline metal salt of salicylic acid, an alkaline metal salt of an
alkoxysalicylic acid and glycolic acid. This method may further
comprise the application of trimethylglycine. Subjects to which
this method is applied may be arbitrary subjects such as subjects
desiring to improve skin glow or enhance specular reflectance, and
applicable subjects include subjects having skin problems such as
dull skin or a glossy or greasy shine and subjects having
translucent skin. The specific agents used and the concentrations
thereof are as previously described. Although these agents can be
applied using an arbitrary method and can be applied
percutaneously, orally or enterally, percutaneous application by
application to the skin is particularly preferable.
[0108] In another mode of the present invention, the present
invention relates to a cosmetic method comprising the application
of one or more agents selected from the group consisting of an
alkaline metal salt of salicylic acid, an alkaline metal salt of an
alkoxysalicylic acid and glycolic acid. This method may further
comprise the application of trimethylglycine. Subjects to which
this method is applied may be arbitrary subjects such as subjects
desiring to improve skin glow or enhance specular reflectance, and
applicable subjects include subjects having skin problems such as
dull skin or a glossy or greasy shine and subjects having
translucent skin. The specific agents used and the concentrations
thereof are as previously described.
[0109] The skin glow improver includes, but is not limited to, skin
lotions, milky lotions, beauty essences and creams, and the skin
glow improver may be incorporated in these cosmetics. In addition,
the skin glow improver can also be incorporated in pharmaceuticals
or quasi-drugs, and can be incorporated in external skin
preparations in particular. Medicinal agents commonly added to
these cosmetics can also be contained, examples of which include
moisturizers, whitening agents, antioxidants, oily components,
ultraviolet absorbers, surfactants, thickeners, alcohols,
colorants, fragrances, water, solvents, antiseptics, preservatives,
pH adjusters, gelling agents and other active ingredients.
[0110] All documents mentioned in the present description are
incorporated in the present description in their entirety by
reference.
[0111] Examples of the present invention indicated below are
provided for exemplary purposes only, and do not limit the
technical scope of the present invention. The technical scope of
the present invention is only limited by the description of the
claims. The present invention can be modified, such as by adding,
deleting or substituting constituents of the present invention, on
the condition that such modification does not deviate from the gist
of the present invention.
EXAMPLES
[Example 1] Evaluation of Skin Glow
[0112] The diffuse reflectance and specular reflectance of the
cheeks of 28 subjects to which nothing had been applied were
determined for cheeks presenting with glow, glossy or greasy shine,
translucence and dullness using a skin gloss measuring device
(Samba Face, Bossa Nova Technologies LLC). At this time, a
polarizing filter was respectively installed on the front of the
irradiation light source and the front of the light receiving
camera. Here, parallel polarization images and perpendicular
polarization images were acquired by making the direction of
polarization of the polarizing filter on the front of the light
receiving camera to be parallel or perpendicular to the direction
of polarization of the polarizing filter on the irradiation light
source, and diffuse reflectance and specular reflectance were
determined from formulas (1) and (2). In addition, classification
of glow, glossy or greasy shine, translucence and dullness was
determined by sensory evaluation based on visual evaluations
performed by multiple beauty technicians.
[0113] Furthermore, the direction parallel (or perpendicular) to
the direction of polarization of the polarizing filters refers to
the direction parallel (or perpendicular) to the direction of
polarization in the case polarized light that has passed through a
polarizing filter is reflected by the surface of the skin without
undergoing a change in the direction of polarization.
[0114] FIG. 3 indicates a plot of specular reflectance versus
diffuse reflectance, and is shown together with the results of
sensory evaluations performed on the subjects.
[0115] It can be understood from FIG. 3 that those cheeks having
glow demonstrated diffuse reflectance of 30% or more and specular
reflectance of 12% or more.
[Example 2] Evaluation of Skin Glow in Subjects According to
Age
[0116] The diffuse reflectance and specular reflectance of the
cheeks of 20 subjects each in their twenties, thirties, forties,
fifties, sixties and seventies to which nothing had been applied
were determined using a skin gloss measuring device (Samba Face,
Bossa Nova Technologies LLC) in the same manner as Example 1.
[0117] FIG. 4 indicates a plot of specular reflectance versus
diffuse reflectance along with the ages of the subjects.
[Example 3] Change in Skin Glow Attributable to Application of
Cosmetics
[0118] [Preparation of Skin Lotion]
[0119] water (balance), Ethanol (5% by weight), glycerin (10% by
weight), dipropylene glycol (10% by weight), polyoxyethylene (10)
methyl glucoside (1% by weight), erythritol (1% by weight),
trehalose (1% by weight), sodium hyaluronate (0.1% by weight),
polyoxyethylene (14) polyoxypropylene (7) dimethyl ether (1% by
weight), carboxyvinyl polymer (0.1% by weight), sodium hydroxide
(as suitable), polyoxyethylene (60) hydrogenated castor oil (0.2%
by weight), polyglyceryl diisostearate (0.1% by weight),
diphenylsiloxy phenyl trimethicone (0.2% by weight), isostearyl
alcohol (0.1% by weight), isostearic acid (0.1% by weight),
trisodium edetate (as suitable), phenoxyethanol (as suitable), and
fragrance (as suitable) were mixed to obtain a skin lotion.
[Preparation of Milky Lotion]
[0120] Water (balance) and ethanol (5% by weight), glycerin (4% by
weight), dipropylene glycol (5% by weight), sodium hyaluronate
(0.1% by weight), carboxyvinyl polymer (0.1% by weight), xanthan
gum (0.1% by weight), sodium hydroxide (as suitable), isostearic
acid (0.5% by weight), stearic acid (0.5% by weight), behenic acid
(0.5% by weight), self-emulsifying glyceryl monostearate (1% by
weight), polyoxyethylene-glycerin monostearate (1% by weight),
behenyl alcohol (1% by weight), Vaseline (3% by weight),
pentaerythritol tetra(2-ethylhexanoate) (5% by weight), olefin
oligomer (3% by weight), diphenylsiloxy phenyl trimethicone (2% by
weight), trisodium edetate (as suitable), sodium metaphosphate (as
suitable), phenoxyethanol (as suitable), and fragrance (as
suitable) were mixed to obtain a milky lotion.
[0121] Application of the skin lotion and milky lotion to the
cheeks of the subjects appeared to further enhance glow due to the
physicochemical action thereof.
[0122] The diffuse reflectance and specular reflectance of the
cheeks of 10 subjects to which nothing had been applied were
determined using a skin gloss measuring device (Samba Face, Bossa
Nova Technologies LLC) in the same manner as Example 1. Next, after
applying the skin lotion and milky lotion to the cheeks of the
subjects, diffuse reflectance and specular reflectance of the
cheeks were determined in the same manner as described above. The
relationship of specular reflectance versus diffuse reflectance
before and after applying the skin lotion and milky lotion is
indicated in FIG. 5. In addition, changes in specular reflectance
before and after applying the skin lotion and milky lotions are
indicated in FIG. 6.
[0123] It can be understood from FIG. 6 that application of the
skin lotion and milky lotion enhanced specular reflectance of the
cheeks. Although changes in diffuse reflectance before and after
application of the skin lotion and milky lotion were small,
specular reflectance tended to increase following application. As a
result of the skin lotion and milky lotion imparting moisture to
the skin, surface irregularities in the surface of the horny layer
were thought to have been temporarily smoothened, thereby resulting
in an increase in specular reflectance. On the other hand, a study
was conducted as indicated below on indicators that make it
possible to screen medicinal agents capable of increasing specular
reflectance in a state in which cosmetics such as skin lotion or
milky lotion have not been applied.
[Example 4] Examination of Indicator Correlating with Skin Specular
Reflectance
[0124] The diffuse reflectance and specular reflectance of the
cheeks of 20 subjects each in their twenties, thirties, forties,
fifties, sixties and seventies to which an external skin
preparation has not been applied were determined using a skin gloss
measuring device (Samba Face, Bossa Nova Technologies LLC).
[0125] On the other hand, horny layer cells were exfoliated from
the cheeks of the subjects using adhesive strips (Post-It.RTM., 3M
Corp.). Next, double-sided adhesive tape was adhered to a slide
glass and the exfoliated horny layer cells were transferred to the
slide glass. Moreover, the arithmetic average roughness (Sa) of
five horny layer cells was measured using an AFM attached to the
Optelics H1200A 3CCD real color confocal microscope (Lasertec
Corp.) followed by determination of the average value thereof.
[0126] FIG. 7 indicates the relationship of specular reflectance
versus arithmetic average roughness (Sa) of the horny layer
cells.
[0127] It can be understood from FIG. 7 that the correlation
coefficient between arithmetic average roughness (Sa) of the horny
layer cells and specular reflectance was observed to be -0.222,
thus demonstrating a negative correlation. Namely, specular
reflectance was determined to improve as a result of a decrease in
the arithmetic average roughness (Sa) of horny layer cells.
Therefore, skin specular reflectance improvers were screened using
the arithmetic average roughness (Sa) of horny layer cells as an
indicator.
[Example 5] Screening of Specular Reflectance Improvers
[0128] Horny layer cells were exfoliated from the cheeks of
subjects using adhesive strips (Post-It.RTM., 3M Corp.).
[0129] Next, double-sided adhesive tape was adhered to a slide
glass and the exfoliated horny layer cells were transferred to the
slide glass. Moreover, the arithmetic average roughness (Sa) of
five horny layer cells was measured using an AFM attached to the
Optelics H1200A 3CCD real color confocal microscope (Lasertec
Corp.) followed by determination of the average value thereof.
Next, 100 .mu.l of a candidate sample were dropped onto the horny
layer cells followed by incubating for 30 minutes at 37.degree. C.
Moreover, arithmetic average roughness (Sa) of the aforementioned
five horny layer cells was then measured in the same manner
followed by determination of the average value thereof. The
aforementioned sample was judged to be able to improve the specular
reflectance of skin in the case the surface roughness of horny
layer cells to which the aforementioned sample had been applied
decreases significantly in comparison with the surface roughness of
horny layer cells to which the candidate sample had not been
applied.
[0130] As a result of screening candidate samples for nine types of
cosmetic ingredients, potassium 4-methoxysalicylate (4-MSK), sodium
salicylate and glycolic acid were determined to be specular
reflectance improvers. Candidate samples obtained as a result of
screening were further analyzed in the following formulations.
[0131] [Sample Preparation 1]
[0132] Candidate samples of potassium 4-methoxysalicylate (4-MSK)
were prepared at concentrations of 0% by weight, 0.1% by weight,
1.0% by weight, 3.0% by weight and 10.0% by weight.
[0133] The rates of change of arithmetic average roughness (Sa) of
horny layer cells before and after addition of the candidate
samples are indicated in FIG. 8. Potassium 4-methoxysalicylate
induced a dose-dependent increase in the rate of decrease of
arithmetic average roughness (Sa) up to 3.0% by weight, thereby
indicating smoothening of the surface of the horny layer cells. As
a result, specular reflectance can be expected to improve.
Furthermore, since potassium 4-methoxysalicylate is a compound
having whitening effects, it is able to act as a skin glow improver
by increasing both translucence and specular reflectance.
[0134] [Sample Preparation 2]
[0135] Candidate samples of trimethylglycine (TMG) were prepared at
concentrations of 0% by weight, 5% by weight and 10% by weight.
[0136] The rates of change of arithmetic average roughness (Sa) of
horny layer cells before and after addition of the candidate
samples are indicated in FIG. 9. There were no differences in the
rates of decrease of arithmetic average roughness (Sa) at any of
the concentrations of trimethylglycine.
[0137] [Sample Preparation 3]
[0138] Candidate samples containing potassium 4-methoxysalicylate
at a concentration of 1.0% by weight and trimethylglycine (TMG) at
a concentration of 1% by weight, potassium 4-methoxysalicylate at a
concentration of 1.0% by weight and trimethylglycine (TMG) at a
concentration of 3% by weight, and potassium 4-methoxysalicylate at
a concentration of 1.0% by weight and trimethylglycine (TMG) at a
concentration of 5% by weight were prepared in addition to the
candidate samples described in the aforementioned Sample
Preparation 1.
[0139] The rates of change of arithmetic average roughness (Sa) of
horny layer cells before and after addition of the candidate
samples are indicated in FIG. 10. In the case of having further
added TMG, the rate of decrease of Sa increased dose-dependently in
comparison with the case of potassium 4-methoxysalicylate at a
concentration of 10% by weight. Although trimethylglycine alone did
not have an effect on the rate of decrease of Sa, when combined
with potassium 4-methoxysalicylate, the rate of decrease of Sa
increased significantly, and this can be said to be the result of a
synergistic effect.
[0140] [Preparation of Sample 1-1]
[0141] Potassium 4-methoxysalicylate at 3% by weight and water at
97% by weight were mixed to obtain Sample 1-1.
[0142] [Preparation of Sample 1-2]
[0143] Potassium 4-methoxysalicylate at 10% by weight and water at
90% by weight were mixed to obtain Sample 1-2.
[0144] FIG. 11 indicates arithmetic average roughness (Sa) of horny
layer cells before and after application of Sample 1-1. FIG. 11
also indicates the arithmetic average roughness (Sa) of horny layer
cells before and after application of water.
[0145] FIG. 12 indicates the rate of decrease of arithmetic average
roughness (Sa) of horny layer cells before and after application of
Sample 1-1. Here, FIG. 12 also indicates the rate of decrease of
arithmetic average roughness (Sa) of horny layer cells before and
after application of water.
[0146] Based on FIG. 12, Sample 1-1 causes a significant decrease
in the arithmetic average roughness (Sa) of horny layer cells in
comparison with water, and is able to improve the specular
reflectance of skin as a result thereof.
[0147] FIG. 13 indicates the rate of decrease of arithmetic average
roughness (Sa) of horny layer cells before and after application of
Samples 1-1 and 1-2. Here, FIG. 13 also indicates the rate of
decrease of arithmetic average roughness (Sa) of horny layer cells
before and after application of water.
[0148] It can be understood from FIG. 13 that the arithmetic
average roughness (Sa) of horny layer cells decreases significantly
if the concentration of potassium 4-methoxysalicylate in a sample
is 3% by weight to 10% by weight.
[0149] [Preparation of Sample 2]
[0150] Potassium 4-methoxysalicylate at 1% by weight,
trimethylglycine at 5% by weight and water at 94% by weight were
mixed to obtain Sample 2.
[0151] FIG. 14 indicates the arithmetic average roughness (Sa) of
horny layer cells before and after application of Sample 2. Here,
FIG. 14 also indicates the arithmetic average roughness (Sa) of
horny layer cells before and after application of water.
[0152] FIG. 15 indicates the rate of decrease of arithmetic average
roughness (Sa) of horny layer cells before and after application of
Sample 2. Here, FIG. 15 also indicates the rate of decrease of
arithmetic average roughness (Sa) of horny layer cells before and
after application of water.
[0153] Based on FIG. 15, Sample 2 is able to significantly decrease
the arithmetic average roughness (Sa) of horny layer cells in
comparison with water, and is able to improve the specular
reflectance of skin as a result thereof. Furthermore, specular
reflectance of the skin was confirmed to not be improved by
trimethylglycine alone.
[0154] [Preparation of Sample 3]
[0155] Sodium salicylate at 3% by weight and water at 97% by weight
were mixed to obtain Sample 3.
[0156] FIG. 16 indicates the arithmetic average roughness (Sa) of
horny layer cells before and after application of Sample 3. Here,
FIG. 16 also indicates the arithmetic average roughness (Sa) of
horny layer cells before and after application of water.
[0157] FIG. 17 indicates the rate of decrease of arithmetic average
roughness (Sa) of horny layer cells before and after application of
Sample 3. Here, FIG. 17 also indicates the rate of decrease of
arithmetic average roughness (Sa) of horny layer cells before and
after application of water.
[0158] Based on FIG. 17, Sample 3 is able to significantly decrease
the arithmetic average roughness (Sa) of horny layer cells in
comparison with water, and is able to improve the specular
reflectance of skin as a result thereof.
[0159] [Preparation of Sample 4-1]
[0160] Glycolic acid at 4% by weight and water at 96% by weight
were mixed to obtain Sample 4-1.
[0161] [Preparation of Sample 4-2]
[0162] Glycolic acid at 40% by weight and water at 60% by weight
were mixed to obtain Sample 4-2.
[0163] FIG. 18 indicates the arithmetic average roughness (Sa) of
horny layer cells before and after application of Sample 4-1. Here,
FIG. 18 also indicates the arithmetic average roughness (Sa) of
horny layer cells before and after application of water.
[0164] FIG. 19 indicates the rate of decrease of arithmetic average
roughness (Sa) of horny layer cells before and after application of
Sample 4-1. Here, FIG. 19 also indicates the rate of decrease of
arithmetic average roughness (Sa) of horny layer cells before and
after application of water.
[0165] Based on FIG. 19, Sample 4-1 is able to significantly
decrease the arithmetic average roughness (Sa) of horny layer cells
in comparison with water, and is able to improve the specular
reflectance of skin as a result thereof.
[0166] FIG. 20 indicates the rate of decrease of arithmetic average
roughness (Sa) of horny layer cells before and after application of
Samples 4-1 and 4-2. Here, FIG. 20 also indicates the rate of
decrease of arithmetic average roughness (Sa) of horny layer cells
before and after application of water.
[0167] It can be understood from FIG. 20 that the arithmetic
average roughness (Sa) of horny layer cells decreases significantly
if the concentration of glycolic acid in an external skin
preparation is 4% by weight to 40% by weight.
[0168] [Preparation of Sample 5]
[0169] Glycolic acid at 2% by weight, trimethylglycine at 5% by
weight and water at 93% by weight were mixed to obtain Sample
5.
[0170] FIG. 21 indicates the arithmetic average roughness (Sa) of
horny layer cells before and after application of Sample 5. Here,
FIG. 21 also indicates the arithmetic average roughness (Sa) of
horny layer cells before and after application of water.
[0171] FIG. 22 indicates the rate of decrease of arithmetic average
roughness (Sa) of horny layer cells before and after application of
Sample 5. Here, FIG. 22 also indicates the rate of decrease of
arithmetic average roughness (Sa) of horny layer cells before and
after application of water.
[0172] Based on FIG. 22, Sample 5 is able to significantly decrease
the arithmetic average roughness (Sa) of horny layer cells in
comparison with water, and is able to improve the specular
reflectance of skin as a result thereof.
[Example 6] Skin Application Test
[0173] Female subjects aged 31 to 59 years were divided into three
groups and candidate skin lotiones were applied to their cheeks for
3 months once a day after bathing. The subjects were given
questionnaires at one month, two months and three months after the
start of application. In addition, horny layer samples were
simultaneously acquired from the subjects and used to measure skin
grain and horny layer roughness. Specular reflectance and diffuse
reflectance were measured using Samba Face to evaluate skin
glow.
[0174] [Candidate Skin Lotiones] [0175] The skin lotiones indicated
below were used in testing. [0176] A: Milky skin lotion not
incorporating medicinal agent (control group) [0177] B: Milky skin
lotion incorporating 1% potassium 4-methoxysalicylate and [0178] 5%
trimethylglycine (1% 4-MSK+5% TMG group) [0179] C: Milky skin
lotion incorporating 3% potassium 4-methoxysalicylate (3% 4-MSK
group) [0180] The skin lotion indicated below was used for the
milky skin lotion.
TABLE-US-00001 [0180] (Incorporated Components) (wt %) Ethanol 5%
Glycerin 2% Dipropylene glycol 4% 1,3-butylene glycol 2% Xanthan
gum 0.1%.sup. Polyoxyethylene glyceryl isostearate 1% Lipophilic
glyceryl monostearate 2% Batyl alcohol 1% Behenyl alcohol 2.5%.sup.
Methyl polysiloxane 5% Hydrogenated oil 2.5%.sup. Jojoba oil 3%
Cetyl ethylhexanoate 3% Citric acid As suitable Sodium citrate As
suitable EDTA-3Na As suitable Methyl p-hydroxybenzoate As suitable
Water Balance 100%
[0181] [Questionnaire]
[0182] The contents of the questionnaire consisted of ranking
improvement of skin glow by assigning a value of 5 points for
improved, 4 points for somewhat improved, 3 points for no change, 2
points for somewhat worsened and 1 point for worsened followed by
calculating the average scores. The results obtained in the 1st
month, 2nd month and 3rd month are shown in FIG. 23.
[0183] [Measurement of Horny Layer Roughness]
[0184] Samples of the corny layer were exfoliated from the surface
of subjects' skin using adhesive strips (Post-It.RTM., 3M Corp.).
Arithmetic average roughness (Sa) was measured in accordance with
the method described in Example 4 followed by determination of the
average value thereof, and results for the rate of decrease in
comparison with arithmetic average roughness (Sa) prior to
application are shown in FIG. 24.
[0185] [Measurement of Skin Texture]
[0186] Samples of the corny layer were exfoliated from the surface
of subjects' skin using adhesive strips (Post-It.RTM., 3M Corp.).
The exfoliated horny layer cells were transferred to carbon
conductive adhesive tape adhered to the stand of a scanning
electron microscope (SEM) followed by observation of the cells by
SEM. The number of texture pixels was measured using image
processing (see Skin Res. Technol., 2014, 20: 299-306). The results
are shown in FIG. 25.
[0187] [Evaluation of Glow]
[0188] Specular reflectance and diffuse reflectance of subjects
were measured using the method described in Example 1. The results
for specular reflectance and diffuse reflectance three months later
versus specular reflectance and diffuse reflectance prior to
application are shown in FIG. 26.
[0189] Improvement of skin glow was observed in both the 1%
4-MSK+5% TMG group and 3% 4-MSK group for both the results of the
questionnaire and the glow evaluation results, and the degree of
improvement was indicated to be superior in the 1% 4-MSK+5% TMG
group. In addition, a similar trend was observed in the evaluation
of glow based on horny layer roughness. Moreover, results
indicating that skin texture was finer were obtained in both the 1%
4-MSK+5% TMG group and 3% 4-MSK group based on the results of
measuring skin texture. Although specular reflectance is known to
increase as skin texture becomes coarser, the 1% 4-MSK+5% TMG and
3% 4-MSK groups each indicated that specular reflectance can be
increased without making skin texture coarser.
* * * * *