Drug – bio-affecting and body treating compositions – Solid synthetic organic polymer as designated organic active... – Aftertreated polymer
Reexamination Certificate
2000-04-05
2004-02-17
Padmanabhan, Sreeni (Department: 1617)
Drug, bio-affecting and body treating compositions
Solid synthetic organic polymer as designated organic active...
Aftertreated polymer
C424S401000, C424S070110, C514S880000, C526S072000, C526S073000, C526S319000, C525S064000, C525S163000, C525S222000, C525S299000, C525S314000
Reexamination Certificate
active
06692733
ABSTRACT:
The present invention relates to a composition, in particular a cosmetic composition, comprising, in a physiologically acceptable medium, at least one polymer with a highly specific ordered structure. These compositions find a specific application in the field of caring for the skin, in particular of the face, and more especially for treating, that is to say decreasing, erasing and/or smoothing out, wrinkles and/or fine lines of the skin of human beings.
During the ageing process, various characteristic signs appear on the skin, such as the appearance of fine lines and/or wrinkles, which increase with age. A disruption of the “grain” of the skin is in particular observed, that is to say that the microrelief is less uniform and exhibits an anisotropic nature.
It is known to treat these signs of ageing by using compositions comprising active principles capable of combating ageing, such as &agr;-hydroxy acids, &bgr;-hydroxy acids and retinoids. These active principles act on the wrinkles by removing dead cells from the skin and by accelerating the process of cell replacement. However, these active principles exhibit the disadvantage of only being effective in the treatment of wrinkles after a certain application time.
In point of fact, attempts are increasingly being made to obtain an immediate effect, resulting rapidly in the smoothing out of the wrinkles and/or fine lines and in the disappearance, even temporary, of the signs of tiredness.
Provision has then in particular been made to use an aqueous dispersion of polymer particles as tightening agent for the skin, resulting in the wrinkles being concealed by smoothing out the skin.
However, these compositions are still provided in the aqueous form, which can result, on the one hand, in bacteriological problems and especially, on the other hand, in excessively easy removal of the make-up in the presence of water. This is because it is impossible, with this solution, to prepare a composition exhibiting good persistence to water.
Applicant has found that, surprisingly and unexpectedly, the use of highly specific polymers exhibiting a specific ordered structure can make it possible to obtain a composition capable of being applied to the skin which can make it possible to improve the “concealing” and/or to soften the wrinkles and/or fine lines already formed.
This is because the polymers employed in the present invention have well determined physical characteristics and constitute particularly effective tightening agents. The term “tightening agent” is understood to mean compounds capable of having a tightening effect, that is to say which can tighten the skin and, by this tightness effect, smooth out the skin and cause the wrinkles and fine lines thereon immediately to decrease, indeed even to disappear.
Furthermore, the compositions thus obtained exhibit a good persistence to water.
Thus, a subject-matter of the present invention is a polymer with a “star” structure represented by the following formula (I):
A—[(M1)
p1
—(M2)
p2
. . . (Mi)
pj
]
n
in which:
A represents a polyfunctional centre, with a functionality of “n”, n being an integer greater than or equal to 2,
[(M1)
p1
—(M2)
p2
. . . (Mi)
pj
] represents a polymer chain, also known as a “branch”, composed of identical or different polymerized monomers Mi having a polymerization index pj, each branch being identical or different and being grafted covalently to the centre A;
i being greater than or equal to 1 and pj being greater than or equal to 2;
the polymer comprising one or more monomers Mi chosen from polymerized monomers Mk, which may be identical or different, wherein a homopolymer formed by the corresponding polymerized monomers Mk has a Tg of greater than or equal to approximately 10° C., preferably of greater than or equal to 15° C and even better still of greater than or equal to 20° C.
In a preferred embodiment, this or these monomers Mk being present, in the final polymer, in a minimum amount of approximately 45% by weight, preferably in an amount of between 55 and 99% by weight and even better still in an amount of 75-90% by weight with respect to the total weight of monomers.
Another subject-matter of the present invention is a polymer as described above further comprising one or more monomers Mj, the corresponding homopolymer of which exhibits a Tg of less than or equal to approximately 10° C., preferably of less than or equal to 5° C. and even better still of less than or equal to 0° C.
In a preferred embodiment, this or these monomers Mj are present in the final polymer in a maximum amount of approximately 55% by weight, preferably in an amount of between 1 and 45% by weight and even better still in an amount of 10-25% by weight with respect to the total weight of monomers.
Another subject-matter of the invention is a composition comprising, in a physiologically acceptable medium, at least one polymer as above.
Another subject-matter of the invention is a process for the cosmetic treatment of the skin of the face, neck, hands and/or body, characterized in that it comprises applying, to the latter, a cosmetic composition as above.
Another subject-matter of the invention is a process for the cosmetic treatment of wrinkled skin which comprises applying, to the latter, a cosmetic composition as above in an amount which is effective in softening the wrinkle or the fine line by a tightening effect.
Another subject-matter of the invention is the use of at least one polymer as above, in a cosmetic composition or for the preparation of a pharmaceutical composition, for decreasing, erasing, concealing and/or softening wrinkles and/or fine lines of the skin.
The compositions according to the invention exhibit a light texture and are very comfortable to wear throughout the day. They make it possible to obtain a film with very good hold which is soft, supple, elastic and flexible on the skin; it follows the movements of the substrate on which it is deposited, without cracking and/or detaching. In particular, it adheres perfectly to the skin of the face.
The compositions according to the invention can be readily applied and spread easily. They make it possible immediately after application to soften the wrinkles and fine lines at the surface of the skin.
The compositions of the invention can be applied in particular to the face and/or to the neck, in particular to the bare neck and shoulders.
The compositions can be easily removed, for example using a conventional make-up remover, in particular one with an oily base.
The composition according to the invention therefore comprises a polymer, the “star” structure of which can be illustrated, in a general way, by the following formula (I):
A—[(M1)
p1
—(M2)
p2
. . . (Mi)
pj
]
n
in which:
A represents a polyfunctional centre, with a functionality of “n”, n being an integer greater than or equal to 2, preferably of between 4 and 10,
[(M1)
p1
—(M2)
p2
. . . (Mi)
pj
] represents a polymeric chain, also known as a “branch”, composed of identical or different polymerized monomers Mi having a polymerization index pj, each branch being identical or different and being grafted covalently to the centre A;
i being greater than or equal to 1, preferably of between 2 and 10;
pj being greater than or equal to 2, preferably of between 10 and 20,000.
The polymer chains are preferably provided in the form of blocks with a molecular mass of greater than or equal to 500 which can range up to 2,000,000.
In a preferred embodiment, the polymer used in the context of the present invention can be obtained by controlled radical polymerization, also known as “living” radical polymerization. This technique makes it possible in particular to overcome the limitations inherent in conventional radical polymerization, that is to say that it makes it possible in particular to control the length of the chains of the polymer which is formed and therefore to obtain block structures.
The controlled radical polymerization makes it possible to reduce the reactions in which the growing radical species is deactivated, in p
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
L'Oreal
Padmanabhan Sreeni
Wells Lauren Q.
LandOfFree
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