Note: Descriptions are shown in the official language in which they were submitted.
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NAIL COSMETIC COMPOSITIONS
TECHNICAL FIELD
The present invention relates to improvements in the field of
nail care products. In particular, this invention relates to cosmetic
compositions for improving the structure of nails.
BACKGROUND ART
The nails of mammals, particularly the fingernails and
toenails of humans, are composed of epidermis transparent cells called
corneocyte cells, which are produced at the root of the nail. These cells
join together to form a solid and continuous surface on the back of the
terminal phalanges.
Each nail adheres intimately to the underlying support that
forms the bed of the nail. The visible part of the nail is called the body of
the nail. The hidden part is called the root.
The propagation of the corneocyte cells in the root ensures
nail growth. The new cells go through a transformation in the solid layers
and dry until they form a solid plate. The nail permanently receives
continuous additions of cells at the level of its bed, which push the bed
beyond the extremity of the phalange.
Keratin fibrils present inside the corneocyte cells, as well as
the intercellular cements present, bring rigidity and flexibility to the
nails.
Unfortunately, the fragility and vulnerability of the nails are
observed in presence of mechanical, thermal and/or chemical attacks.
For example, nails which are brittle and friable eventually break, split or
crack due to mechanical shocks. The nails may also be degraded in the
presence of aggressive chemical agents, particularly those present in
household products. Nails degradation may also be a secondary effect of
the ageing process. Degradation of nails can be very painful, unpleasant
and unsightly, and permit to foreign bodies to cause infection to the nails.
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Numerous approaches have been investigated in order to
improve the resistance of the nails to different aggressions of mechanical,
thermal, chemical or temporal nature by hardening or strengthening them.
Various compositions based on chemical products such as synthetic gums
of an acrylic polymer film, varnishes based on nitrocellulose combined
with inert glass fibers and other hardening agents have been proposed
respectively in U.S. patents Nos. 5,508,027, 4,873,077, 4,482,538 and
5,785,959. Although these compositions may have an hardening or
strengthening action on the nails, they do not allow one to improve the
structure of the nails. If any one of these compositions is applied to fragile
or soft nails, harder nails may be obtained, but the latter will still have a
tendency to crack and break.
Several approaches have also been investigated in order to
improve the flexibility and resistance of the nails by nourishing and
moisturizing them. Many attempts have been made to prevent the nails
from dehydrating and to protect them against various types of
aggressions. Compositions comprising synthetic active agents such as
moisturizing, antimicrobial or antifungal agents have been extensively
proposed.
U.S. patent No. 6,517,863 discloses compositions and
methods for improving durability and hardness of the nail body. The
compositions increase the durability of the nails by forming a protective
layer of hydroxyapatite or other calcium phosphate mineral on the nail.
Such compositions includes synthetic and inorganic bioactive glasses as
active agents. These inorganic glass materials are bound to the nails and
comprise a plurality of synthetic chemicals products.
U.S. patent No. 5,645,823 discloses an aqueous solution for
restoring and maintaining the compositional balance of normal, healthy
keratinous tissue and their adjacent structures. The latter composition
comprises a plurality of synthetic compounds used as antimicrobial or
active agents
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U.S. patent No. 4,919,920 discloses compositions and
methods for reinforcing and hardening mammals keratinized appendages,
wherein fluoride ions in an aqueous cosmetic carrier are topically applied.
The utilization of fluoride ions increases both the hardness and the
resistance of the nail. However, this method presents the drawback of
generating in situ acidity. U.S. patent No. 5,478,551 also discloses the
use of fluoride ions for strengthening nails. A non-aqueous organic
composition containing ammonium hexafluorophosphate is used to
provide an effective amount of fluoride ions to the nail body. In the latter
two cases, harmful acidic by-products can potentially be formed.
Although the above-mentioned compositions may prevent
brittleness of the nails, they all comprise synthetic chemicals as main
active agents, in respect of which long term and/or secondary effects are
still not completely known.
During the last decade, in the field of pharmaceutical
products, nutrition and cosmetic cares, the attitude of our society in
respect of synthetic products has considerably changed. The trend has
been to avoid synthetic products as much as possible and replace them
by natural or organic products. The emergence of functional food,
neutraceuticals and natural cosmetic products represents a good example
of this trend. People are now more aware of the fact that frequent or long
term consumption or utilization of certain chemicals may have negative
and side effects on human health. Since many of these chemicals are
quite recent, the long term effects are often unknown. Thus, natural or
organic products have been extensively used as active agents in
pharmaceutical or cosmetic products. For example, U.S. patent No.
5,667,768 discloses nail care compositions comprising an organic solution
or dispersion of at least one natural active agent. However, the use of
such compositions is tedious since they must be applied 2 to 3 times per
week for at least 8 weeks in order to provide encouraging results.
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DISCLOSURE OF THE INVENTION
It is therefore an object of the present invention to overcome
the above-mentioned drawbacks and to provide compositions for
improving the structure of nails, which comprise as main active ingredient
a natural active agent.
According to one aspect of the invention, there is provided a
nail cosmetic composition comprising a source of calcium in powder form
and a cosmetically acceptable carrier therefor, the source of calcium being
selected from the group consisting of pearl, ivory, seashell and mixtures
thereof.
According to another aspect of the invention, there is
provided in a nail cosmetic composition comprising an active agent and a
cosmetically acceptable carrier therefor, the improvement wherein the
active agent is selected from the group consisting of pearl powder, ivory
powder, seashell powder and mixtures thereof.
According to still another aspect of the invention, there is
provided a nail enamel composition comprising:
- a film former;
- an organic solvent; and
- a source of calcium in powder form, the source of calcium
being selected from the group consisting of pearl, ivory, seashell and
mixtures thereof.
According to yet another aspect of the invention, there is
provided in a nail enamel composition comprising an active agent, a film
former and an organic solvent, the improvement wherein the active agent
is selected from the group consisting of pearl powder, ivory powder,
seashell powder and mixtures thereof.
According to a further aspect of the invention, there is
provided a method of treating nails, comprising the step of applying to the
nails a nail cosmetic composition or a nail enamel composition according
to the invention.
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According to still a further aspect of the invention, there is
provided a method of treating nails, comprising the step of applying to the
nails at least one layer of a nail cosmetic composition or a nail enamel
composition according to the invention.
According to yet a further aspect of the invention, there is
provided an active agent for improving structure of nails, comprising a
source of calcium in powder form, the source of calcium being selected
from the group consisting of pearl, ivory, seashell and mixtures thereof.
Applicant has found quite surprisingly that by applying to the
nails a nail cosmetic composition or a nail enamel composition as defined
above, the treated nails have an improved structure. Nails treated with the
compositions of the present invention are strengthened, and the risks of
breaking, splitting and cracking are thus considerably reduced. Moreover,
the treated nails have a healthy appearance and their growth rate is
increased.
Even if the compositions of the invention can potentially
contain few synthetic products, the main active agents used, such as pearl
powder, ivory powder or seashell powder, are natural and mild, and are
thus not detrimental to the user's health.
The expression "a source of calcium" as used herein refers
to pearl, ivory and seashell. Pearl and seashell comprise calcium
carbonate and ivory comprises calcium phosphate.
The term "ivory" as used herein refers to ivory of an animal
source. The animal can be an elephant, a mammoth, a walrus, a warthog,
a hippo, a sperm whale or a narwhale. Preferably, the animal is a
mammoth or an elephant and, more preferably, the animal is a mammoth.
The expression "pearl powder" as used herein refers to a
natural pearl powder which is a source of calcium and more particularly
calcium carbonate. The pearl powder is obtained by grinding a pearl
originally contained inside the shell of a mollusk.
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The expression "seashell powder" as used herein refers to a
powder obtained by grinding the shell of mollusks. Such a powder
preferably comprises nacre, which is also referred to as mother of pearl,
amber poria pearl, conchs margarita, marine calcium, or conchs
margaritaferae. Nacre, a highly ordered microlaminate composite of
crystals and biopolymers, is found in the iridescent inner layer of mollusk
shells. Its biomaterials comprise calcium carbonate in a matrix of proteins
and glycoproteins.
The expression "suspending agent" as used herein refers to
a thixotropic agent or a rheological agent.
The terms "1/4 sec" and "1/2 sec" as used herein in respect
of nitrocellulose viscosity refers to the necessary time for a ball to fall to
a
given depth in nitrocellulose. The percentage of nitrocellulose optionally
present in the compositions of the invention is given on a dry basis.
MODES FOR CARRYING OUT THE INVENTION
The source of calcium in powder form used in the
compositions of the invention can be present in an amount of at least
0.5 % by weight, based on the total weight of the composition. Preferably,
the amount of calcium source is comprised between 1.0 and 30.0 % by
weight, and more preferably between 2.0 and 10.0 % by weight. Use is
preferably made of pearl powder.
In the nail cosmetic compositions of the invention, the
cosmetically acceptable carrier can be present in an amount of 20 to 97
by weight, based on the total weight of the composition. Preferably, the
amount of cosmetically acceptable carrier is comprised between 75 and
95 % by weight. The cosmetically acceptable carrier can be selected from
the group consisting of a cream, a foam, a gel, a solution, a nail varnish
composition, a nail enamel composition, a nail glue, a nail resin and a
spray. Preferably, the cosmetically acceptable carrier is a cream, a gel or
a solution. The cosmetically acceptable carrier can also be selected from
the group consisting of a nail enamel composition, a nail glue, a nail
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varnish composition and a nail resin. The source of calcium in powder
form is preferably suspended in the cosmetically acceptable carrier.
In the nail enamel compositions of the invention, the film
former can be present in an amount of 10 to 60 % by weight, based on the
total weight of the composition. Preferably, the amount of film former is
comprised between 15 and 40 % by weight, and more preferably between
20 and 30 % by weight. Examples of film formers include but are not
limited to acrylate esters, acrylate polymers, acrylate copolymers, acrylate
terpolymers, cellulose acetates, cellulose acetate butyrate, cellulose
acetate propionate, ethyl cellulose, methacrylate esters, methacrylate
polymers, methacrylate copolymers, methacrylate terpolymers,
nitrocellulose, polycarbonates, polyester resins, polyurethanes,
polyvinylbutyral, polyvinyl acetates, polyvinyl acetate phthalates, a
tosylamide epoxy resin, a tosylamide formaldehyde resin and mixtures
thereof. Preferably, the film former is selected from the group consisting of
nitrocellulose, a tosylamide epoxy resin, a tosylamide formaldehyde resin
and mixtures thereof.
Alternatively, the film former preferably comprises a primary
film former and a secondary resin. The primary film former can be
selected from the group consisting of acrylate esters, acrylate polymers,
acrylate copolymers, acrylate terpolymers, cellulose acetates, cellulose
acetate butyrate, cellulose acetate propionate, ethyl cellulose,
methacrylate esters, methacrylate polymers, methacrylate copolymers,
methacrylate terpolymers, nitrocellulose and mixtures thereof. Preferably,
the primary film former is nitrocellulose. The secondary resin can be
selected from the group consisting of polyester resins, polyvinylbutyral,
polyvinyl acetates, polyvinyl acetate phthalates, a tosylamide epoxy resin,
a tosylamide formaldehyde resin and mixtures thereof. Preferably, the
secondary resin is selected from the group consisting of a tosylamide
epoxy resin, a tosylamide formaldehyde resin and a mixture thereof.
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In the nail enamel compositions of the invention, the organic
solvent can be present in an amount of 30 to 90 % by weight, preferably
45 to 80 % by weight and more preferably 50 to 75 % by weight, based on
the total weight of the composition. Examples of organic solvents include
but are not limited to abietyl alcohol, acetone, benzyl alcohol, butanol,
t-butanol, butoxyethanol, butoxypropanol, n-butyl acetate, sec-butyl
acetate, 1,4-butylene, butylene glycol, cyclopentane, cyclohexane,
diethylene glycol, diethylene glycol monomethyl ether, diethyl ketone,
dihydroxyacetone, ethanol, ethyl acetate, glycol, heptane, hexane, isobutyl
acetate, isopropyl acetate, methanol, methoxy ethoxy ethanol, methyl
ethyl ketone, methyl acetate, methyl isobutyl ketone, propan-1-ol, propan-
2-0l, n-propyl acetate, pentane, propylene glycol, propylene glycol
monomethyl ether, toluene and mixtures thereof. Preferably, the organic
solvent is n-butyl acetate, ethyl acetate or a mixture thereof.
In the nail enamel compositions of the invention, the source
of calcium in powder form can be suspended in a mixture of the film
former and the organic solvent.
The nail enamel compositions of the invention can further
comprise a plasticizer. The plasticizer can be present in an amount of 1 to
25 % by weight, based on the total weight of the composition. Preferably,
the amount of plasticizer is comprised between 2 and 20 % by weight,
and more preferably between 5 and 15 % by weight. Examples of
plasticizers include but are not limited to benzyl benzoate, butyl
acetylricinoleate, butyl glycolate, butyl stearate, camphor, citrate esters,
diamyl phthalate, dibutyl phthalate, dibutyl tartrate, dioctyl phthalate, di-2-
ethylhexyl phthalate, diisononyl phthalate, di-2-ethylhexyl adipate,
diisononyl adipate, dimethoxyethyl phthalate, glycerol triacetate, glyceryl
acetylricinoleate, methoxypolyethylene glycol, octyl palmitate,
polyethylene glycol, propylene carbonate, propylene glycol, tributoxyethyl
phosphate, tributyl phosphate, tricresyl phosphate, trioctyl trimellitate,
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triphenyl phosphate and mixtures thereof. Preferably, the plasticizer is
dibutyl phtalate.
When the nail enamel composition of the present invention
comprises a plasticizer, the source of calcium in powder form can be
suspended in a mixture of the film former, the organic solvent and the
plasticizer.
The nail enamel compositions of the invention can further
comprise a suspending agent. The suspending agent can be present in an
amount of 0.10 to 15.00 % by weight, based on the total weight of the
composition. Preferably, the amount of the suspending agent is comprised
between 0.25 and 10.00 % by weight, and more preferably between 0.50
and 5.00 % by weight. The suspending agent can be selected from the
group consisting of attapulgite, bentonite, hectorite and mixtures thereof.
Preferably, the suspending agent is bentonite and more preferably
stearalkonium bentonite.
The compositions of the invention can also comprise an
additive such antibacterial agents, antifungal agents, botanical extracts,
fragrances, moisturizers, preservatives, UV filters, proteins, stabilizers,
vitamins or mixtures thereof.
The active agents and compositions according to the
invention can be used for preventing friability of nails, improving the
structure of nails, providing an increased growth rate of nails and/or
increasing the thickness of nails.
The compositions of the invention are preferably capable of
protecting, hardening and/or embellishing the nails.
In the method for treating nails using a nail cosmetic
composition according to the invention, the composition can be applied to
the nails at least once a week for a period of at least 2 weeks. Preferably,
the composition is applied to the nails at least once a week for a period of
at least 3 weeks and more preferably for a period of at least 5 weeks.
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In the method for treating nails which consist of applying at
least one layer of a nail enamel composition according to the invention,
the composition can be applied to the nails at least once a week for a
period of at least 2 weeks. Preferably, the composition is applied to the
nails at least once a week for a period of at least 3 weeks and more
preferably for a period of at least 5 weeks. Preferably, prior to apply a new
layer of the nail enamel composition, the previously applied layer is
removed by applying to the nails a nail polish remover.
The nail cosmetic compositions and nail enamel
compositions of the present invention can be prepared by simply mixing
together the cosmetic ingredients described hereinabove by stirring. The
cosmetic ingredients are added one by one to form the composition and,
after each addition, the mixture is stirred so as to be homogenized.
Examples of satisfactory equipment and how to use it are readily apparent
to one of ordinary skill in the art of nail care products.
The present invention will be more readily understood with
reference to the following non-limiting examples.
EXAMPLE 1
Cosmetic ingredients Wt
1/4 sec. nitrocellulose8.5
1/2 sec. nitrocellulose8.5
tosylamide / epoxy resin4.7
tosylamide / formaldehyde4.7
dibutyl phtalate 7.6
n-butyl acetate 33.3
ethyl acetate 25.7
stearalkonium bentonite1.0
methanol 95 % 1.0
pearl powder 5.0
TOTAL 100
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wnnnoi c ~
Cosmetic ingredients Wt
1/4 sec. nitrocellulose8.7
1/2 sec. nitrocellulose8.7
tosylamide / epoxy resin4.8
tosylamide / formaldehyde4.8
dibutyl phtalate 7.7
n-butyl acetate 34.0
ethyl acetate 26.2
pearl powder 5.1
TOTAL 100
The nail enamel compositions of Examples 1 and 2 were
tested so as to determine their efficacy for improving the structure of nails.
In order to perform such a test, four female test subjects were selected.
Firstly, the quality of the nails of the test subjects was quantified by using
the 1 to 10 evaluation scale defined as follows:
- grades 1 to 3 correspond to nails which are extremely thin
and peeling; such nails are usually filed using a 400 or 600 grit file and are
considered extremely weak nails;
- grades 4 to 6 correspond to nails of weak to medium quality,
which are regularly broken; such nails are usually filed using a 300 grit file
and are considered weak to average nails;
- grades 7 and 8 correspond to nails of good quality, which
are rarely broken; such nails are usually filed using a 200 grit file and are
considered good nails; and
- grades 9 and 10 correspond to very thick and strong nails;
such nails are usually filed using a 120 grit file and are considered
excellent nails.
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The four test subjects selected were between the ages of 20
and 50 and had different grades of nails. The nails of test subjects 1, 2
and 3 were treated with the nail enamel composition of Example 1 and the
nails of test subject 4 were treated with the nail enamel composition of
Example 2.
Test Subject 1
Test subject 1 had extremely thin and brittle nails prior to
treatment with the nail enamel composition of Example 1. In particular,
the nails were of grade 1 and had first been filed with a 600 grit file. At
the
beginning of the treatment, the subject's nails were cleansed using a nail
polish remover and then, two layers of the nail enamel composition were
applied to the nails. During the next four weeks, two new layers of the
composition were applied each week. Prior to applying a new layer, the
nails were filed and the previously-applied layer was removed using a nail
remover. During the third week, considerable improvements of the nails
were noticed. The nails were of grade 2, thicker and peeling was no
longer observed. After five weeks of treatment, the nails improved from
grade 1 to grade 3 and a 400 grit file was necessary to file the nails.
Test Subject 2
Test subject 2 had good quality nails, but the nails of both
hands were of a different quality i.e. the nails of the right hand were of
grade 7 and the nails of the left hand were of grade 6. The nails of both
hands of test subject 2 were filed with a 200 grit file. The same procedure
as described for test subject 1 was applied to the nails of test subject 2,
with the exception that each week, only one layer of the nail enamel
composition of Example 1 was applied instead of two, in view of the
quality of the nails. During the second week, substantial improvements of
the nails were noticed. The right hand nails were of grade 8 and the left
hand nails were of grade 7. After five weeks of treatment, the nails of both
hands were longer and of the same quality, and an increased growth rate
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was observed. The nails of both hands became nails of grade 9 and a
120 grit file was now more appropriate to file the nails.
Test Subject 3
Test subject 3 had weak and short nails of grade 2, which
were very brittle and of uneven length. Prior to applying the nail enamel
composition of Example 1, the nails were filed with a 400 grit file. The
nails of test subject 3 were treated according to the same procedure as
described for test subject 1. During the third week, the nails were of grade
3; they were longer and of similar length. After five weeks, the quality of
the nails increased to grade 4 for certain nails and to grade 5 for other
nails, and they all needed to be filed with a coarser grit such as a 300 grit
file.
Test Subject 4
Test subject 4 had grade 5 nails of average thickness prior
to treatment with the nail enamel composition of Example 2. The nails
were first filed with a 300 grit file prior to applying the composition. The
same procedure as described for test subject 2 was applied to the nails of
test subject 4, with the exception that nail enamel composition of Example
2 was applied instead of the nail enamel composition of Example 1.
During the second week, the quality of the nails increased to grade 6 and,
after five weeks, outstanding improvement in nail quality was observed. In
particular, the nails were longer and their growth rate was greater. During
the five-week treatment, the quality of the nails increased from grade 5 to
grade 8 and, at the end, a 200 grit file was thus more appropriate to file
them.
In view of the above-mentioned results for test subjects 1 to
4, it is apparent that the nail enamel compositions of Examples 1 and 2
improve the structure of the nails. For all the above-mentioned subjects,
the treated nails appeared to be stronger and thicker, and they all
demonstrated an increased growth rate. It has been demonstrated that
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when the nails have a quality of grade 5 and higher, only one layer of the
composition is necessary to improve the structure of these nails.
Thus, by using the above-mentioned nail enamel
compositions, improvement of the structure of the nails is rapidly
observed. For nails of grades 1 to 3, improvement was noticed after three
weeks of treatment and, for nails of grade 4 and higher, improvement was
noticed after only two weeks of treatment.
It should be understood from the experiments carried out on
the above-mentioned test subjects, that the treatment using the
compositions of the invention can be advantageously continued for more
than five weeks and that by doing so, a user will still improve the quality of
the nails. It should also be understood that by applying the compositions
of the invention more than once or twice a week, the improvement in the
quality of the nails can be obtained more rapidly. For example, the
treatment of test subject 1 was extended to seven weeks. In the sixth
week, two new layers were applied and few days later, an additional layer
was applied without removing the two layers previously applied. In the
seventh week, the quality of the nails reached grade 4. The compositions
of the invention can be applied to the nails by a professional nail
technician or by the customer.
While the invention has been described in connection with
specific embodiments thereof, it will be understood that it is capable of
further modifications. This application is intended to cover any variations,
uses or adaptations of the invention following, in general, the principles of
the invention and including such departures from the present disclosure as
come within known or customary practice within the art to which the
invention pertains and which may be applied to the essential features
hereinbefore set forth, and as follows in the scope of the appended claims.
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