Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Cosmetic – antiperspirant – dentifrice
Reexamination Certificate
2000-06-23
2002-11-05
Hartley, Michael G. (Department: 1617)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Cosmetic, antiperspirant, dentifrice
C424S085100, C525S523000, C528S373000
Reexamination Certificate
active
06475495
ABSTRACT:
The present invention relates to novel compounds which can be used in cosmetics or in pharmaceuticals, in particular in dermatology, and which make it possible in particular to obtain thickened compositions, or even gelled compositions.
Hyperbranched polymers and dendrimers are well known in the prior art.
Hyperbranched polymers are molecular constructions having a branched structure, generally around a core. Their structure generally lacks symmetry, the base units or monomers used to construct the hyperbranched polymer can be of diverse nature and their distribution is non-uniform. The branches of the polymer can be of different natures and lengths. The number of base units, or monomers, may be different depending on the different branching. While at the same time being asymmetrical, hyperbranched polymers can have: an extremely branched structure, around a core; successive generations or layers of branching; a layer of end chains.
Hyperbranched polymers are generally derived from the polycondensation of one or more monomers ABx, and B being reactive groups capable of reacting together, x being an integer greater than or equal to 2, but other preparation processes may be envisaged. Hyperbranched polymers are characterized by their degree of polymerization DP=1−b, b being the percentage of non-terminal functionalities in B which have not reacted with a group A. Since the condensation is not systematic, in contrast with the synthesis of dendrimers, the degree of polymerization is less than 100%. An end group T can be reacted with the hyperbranched polymer to obtain a particular functionality on the ends of chains.
Several hyperbranched polymers can be combined together, via a covalent bond or another type of bonding, by means of their end groups. Such polymers, known as bridged polymers, fall within the definition of the hyperbranched polymers according to the present invention.
Dendrimers are highly branched polymers and oligomers having a well-defined chemical structure. As a general rule, dendrimers comprise a core, a given number of generations of branches, or spindles, and end groups. The generations of spindles consist of structural units which are identical for the same generation of spindles and which may be identical or different for different generations of spindles. The generations of spindles extend radially in a geometrical progression from the core. The end groups of a dendrimer from the Nth generation are the end functional groups of the spindles of the Nth generation or end generation.
The definition of dendrimers given above includes molecules containing symmetrical branching; it also includes molecules containing non-symmetrical branching, such as, for example, dendrimers whose spindles are lysine groups, in which the branching of one generation of spindles on the preceding generation takes place on the a and c amines of lysine, which leads to a difference in the lengths of the spindles of different branching.
Dense star polymers, starburst polymers and rod-shaped dendrimers are included in the present definition of dendrimers. The molecules known as arborols and cascade molecules also fall within the definition of dendrimers according to the present invention.
Several dendrimers can be combined together, via a covalent bond or another type of bonding, by means of their end groups to give species known as bridged dendrimers or dendrimer aggregates. Such species are included in the definition of dendrimers according to the present invention.
Dendrimers can be in the form of an assembly of molecules of the same generation, which are referred to as monodisperse assemblies; they can also be in the form of assemblies of different generations, known as polydisperse assemblies. The definition of dendrimers according to the present invention includes both monodisperse and polydisperse assemblies of dendrimers.
French patent application FR 97/04085 in the name of the Applicant in particular discloses novel polymers chosen from hyperbranched polymers and dendrimers, comprising functional groups corresponding to the following formula:
in which
Y represents an oxygen atom or an NH group,
A represents a linear, branched or cyclic, saturated or unsaturated C
1
-C
12
alkanediyl group, this group optionally being interrupted with one or more hetero atoms and/or substituted with a function chosen from amino, acylamino, carboxylic acid and ester.
These polymers find an application in particular in cosmetics and dermatology as antioxidants or reducing agents.
Now, the Applicant has found, surprisingly, that the said polymers can also be used to allow the preparation of compositions, in particular cosmetic or pharmaceutical compositions, which are thickened or even gelled.
Thus, a subject of the present invention is a compound chosen from hyperbranched polymers and dendrimers, characterized in that it comprises at least one group of formula:
in which:
Y represents an oxygen atom or an NH group, and
A represents a linear, branched or cyclic, saturated or unsaturated C
1
-C
12
alkanediyl group, this group optionally being interrupted with one or more hetero atoms and/or substituted with a function chosen from:
amino (—NH
2
)
acylamino (—NH—CO—R) in which R represents a linear, branched or cyclic, saturated or unsaturated C
1
-C
10
alkyl group,
carboxylic acid (—COOH),
ester (—COOR) in which R represents a linear, branched or cyclic, saturated or unsaturated C
1
-C
10
alkyl group.
Another subject of the invention is a process for preparing the above compounds, in which a polymer is oxidized, this polymer being chosen from hyper-branched polymers and dendrimers comprising at least one group of formula (II):
Another subject of the invention is the use of at least one compound as above, as a thickener or gelling agent, in particular in a cosmetic or pharmaceutical composition also comprising a cosmetically or pharmaceutically acceptable medium.
Another subject of the invention is a cosmetic or pharmaceutical composition comprising, in a cosmetically or pharmaceutically acceptable medium, at least one compound as defined above.
Another subject is the use of at least one polymer chosen from hyperbranched polymers and dendrimers comprising at least one group of formula (II), for the preparation of a composition comprising at least one compound as defined above.
The prior art discloses a certain number of common gelling agents or thickeners which can be used to modify the viscosity of compositions, in particular cosmetics. Mention may thus be made of algal extracts such as agar-agar, carrageenans and alginates; gums; seed extracts, plant exudates or microorganism exudates, and cellulose derivatives; fruit extracts such as pectins; gelling agents of animal origin such as gelatin, caseinates or water-soluble gelling synthetic polymers such as crosslinked polyacrylic acids.
However, these gelling agents have certain drawbacks. Specifically, the common gelling agents give gels or thickened media as soon as they are introduced into the said medium. They must thus necessarily be introduced into the medium before it is applied to the intended support.
Now, it has been found that by using the compounds according to the invention or a composition comprising them, it is possible to form the gel when desired, and in particular in situ, i.e. after the composition has been applied to the support.
Thus, it is possible to form the said gel before it has been packaged, and thus to have available a ready-to-apply gelled composition. In this case, the compounds according to the invention are used like common gelling agents.
However, it is also possible to prepare a composition which is not gelled because it is not oxidized, to package it in this form and to carry out the oxidation, and thus the gelation, only when the composition is applied to the support, for example by oxidation in the open air. This may be advantageous in particular in the case of haircare uses, such as styling gels or hair-colouring compositions.
Thus, the invention provides a system for gelling the composition befo
Genard Sylvie
Maignan Jean
Finnegan Henderson Farabow Garrett & Dunner LLP
Hartley Michael G.
L'Oreal (S.A.)
Willis Michael A.
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