Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Cosmetic – antiperspirant – dentifrice
Reexamination Certificate
1996-09-06
2001-01-23
Venkat, Jyothsna (Department: 1627)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Cosmetic, antiperspirant, dentifrice
C514S562000, C514S568000, C514S844000, C514S845000, C514S847000
Reexamination Certificate
active
06177089
ABSTRACT:
The present invention is directed to the use of specific sulphonic acids in or for the preparation of a cosmetic and/or dermatological composition for such purposes as promoting desquamation of the skin and/or for combatting intrinsic and extrinsic aging of the skin, as well as treating various skin conditions. The present invention is also directed to a process for the non-therapeutic treatment of the skin for purposes such as desquamating the skin and treating the skin for cutaneous aging and various skin conditions.
Cutaneous aging resulting from the effects on the skin of intrinsic or extrinsic factors is reflected, for example, by the appearance of wrinkles and fine lines, by the yellowing of the skin, which develops a wizened appearance, by the appearance of pigmentary blemishes, by disorganization of the elastin and collagen fibres, which results in a loss of elasticity, suppleness and firmness, and by the appearance of telangiectasias.
Some of these signs of aging are more particularly related to intrinsic or physiological aging, that is to say, to the “normal” effects of age, whereas others are more specific to extrinsic aging, that is to say, aging generally caused by the environment, more particularly photoaging due to exposure to the sun, to light or to any other radiation. The present invention is concerned with both intrinsic or physiological aging and with extrinsic aging of the skin.
The changes in the skin due to intrinsic aging are the consequence of a genetically programmed senescence involving endogenous factors. This intrinsic aging causes, in particular, a slowing down in the renewal of the cells of the skin, which is essentially reflected by the appearance of undesirable clinical changes, such as the reduction in the subcutaneous adipose tissue and the appearance of fine lines or wrinkles, and by histopathological changes, such as an increase in the number and thickness of the elastic fibres, the loss of vertical fibres in the membrane of the elastic tissue and the presence of large irregular fibroblasts in the cells of this elastic tissue.
In contrast, extrinsic aging results in undesirable clinical changes, such as thick wrinkles and the formation of a flabby and tanned skin, and in histopathological changes, such as excessive accumulation of elastic matter in the upper dermis and degeneration of the collagen fibres.
Various agents intended for combatting cutaneous aging are known in the prior art. In this regard, U.S. Pat. No. 4,603,146 describes the use of retinoic acid and its derivatives in cosmetic compositions for the purpose of controlling cutaneous aging.
Further, many patents and publications, for example, European Patent application EP-A-413,528, and many commercial cosmetic compositions teach the use of &agr;-hydroxy acids, such as lactic acid, glycolic acid or citric acid, for treating cutaneous aging.
Finally, &bgr;-hydroxy acids, and more particularly salicylic acid and its derivatives, are known for their desquamating properties, see, for example, International patent application WO-A-93/10756 and U.S. Pat. No. 4,767,750.
All these compounds have an action against aging of the skin which includes a desquamation, that is to say the removal of the “dead” cells situated at the surface of the stratum corneum. This desquamating property is also known, often wrongly, as a keratolytic property. However, these compounds also exhibit side effects, which consist of stinging, tightness, overheating and redness, which the user often finds unpleasant.
It can thus be seen that there is still a need for anti-aging agents which act on the skin, at least as effectively as that of the compounds of the prior art, but which do not exhibit their disadvantages.
The Inventor has unexpectedly discovered that the topical application of cysteic or homocysteic acid or of one of their derivatives makes it possible to desquamate the skin as well as to stimulate epidermal cell renewal and epidermal repair.
Cysteic and homocysteic acids are certainly already known in the pharmaceutical field for the treatment of dry skin, warts, actinic or non-actinic keratoses, acne, ichthyoses and palmar and plantar hyperkeratoses, see, for example, U.S. Pat. No. 4,224,339. However, no one, until now, has envisaged or suggested the use of these acids for desquamation of the skin, stimulation of epidermal renewal, epidermal repair and/or the treatment of cutaneous aging.
A subject of the present invention is consequently the use of at least one sulphonic acid or a hydrate thereof, in the free state or at least partially neutralized, in or for the preparation of a cosmetic or dermatological composition for promoting desquamation of the skin and/or for stimulating epidermal renewal and/or epidermal repair. This at least one sulphonic acid has the formula (I):
wherein p is 1 or 2 and R
1
represents a hydrogen atom or an acyl residue having the structure —COR
2
wherein R
2
is a linear or branched C
1
-C
19
alkyl or alkenyl group. which is unsubstituted or substituted by at least one hydroxyl functional group.
Desquamation of the skin is associated with a clinical improvement in the quality of the skin which becomes more radiant, less wrinkled and generally younger in appearance. Moreover, the above sulphonic acids or hydrates thereof can be used to treat imperfections of the skin, such as blemishes, cutaneous dyschromias, dermatites, actinic lentigines, scars and cicatricial pigmentations.
A further subject of the invention is consequently the use of at least one sulphonic acid or hydrate thereof, in the free state or at least partially neutralized, for the preparation of a cosmetic or dermatological composition useful as an anti-aging agent, in particular for combatting at least one condition selected from wrinkles, fine lines, actinic blemishes, cutaneous dyschromias, dermatites, and scars.
The Inventor has, in particular, observed, without a full explanation for this being available, that these compounds can have an anti-aging action which is at least as effective as the compounds of the prior art which are all carboxylic acids. It has also been observed that, compared to compounds of the prior art, this action can also be milder, insofar as little or no irritation is experienced and little or no redness is observed, when a cosmetic or dermatological composition containing them is applied to the skin.
In particular, the acids of the invention include cysteic and homocysteic acids. These two acids have the advantage of being commercially available. The other acids of the invention can be prepared according to known methods. For example, the products of formula (I), wherein R
1
represents H, can be reacted with an activated form of an acid having the formula R
2
—COOH, with R
2
being defined as indicated above, which can be an anhydrous product, a mixed anhydride (obtained from a chloroformate) or an acid chloride (CICOR
2
), the pH being maintained at a value within the range from 7 to 9 (i.e., a Schotten-Baumann reaction). At the end of the reaction, the product obtained is precipitated at an acidic pH (pH=1) or extracted according to conventional techniques.
All or part of the acids of the invention can be neutralized to form a salt, in particular by sodium hydroxide, potassium hydroxide, ammonia, monoethanolamine, triethanolamine and isopropanolamine.
In the compositions according to the invention, the sulphonic acid or the mixture of sulphonic acids, including the hydrates thereof, are used in an amount effective to achieve the purpose desired, and are preferably used in an amount ranging from 0.2 to 20% by weight with respect to the total weight of the composition, more preferably in an amount ranging from 0.5 to 10% and, most preferably, in an amount ranging from 0.5 to 5% by weight with respect to the total weight of the composition.
The acids of the invention can be combined with other active agents known for their desquamating properties, such as hydroxy acids, &agr;- or &bgr;-keto acids or retinoids. Such a combination makes it possible to decrease the active c
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
L'Or{acute over (e)}al
Ponnaluri P.
Venkat Jyothsna
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