Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Cosmetic – antiperspirant – dentifrice
Reexamination Certificate
2001-11-07
2003-05-20
Criares, Theodore J. (Department: 1617)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Cosmetic, antiperspirant, dentifrice
C514S456000, C514S570000
Reexamination Certificate
active
06565864
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to stable skin care compositions containing a retinoid in a first compartment and a phytoestrogen in a second compartment of a dual compartment package.
BACKGROUND OF THE INVENTION
Retinoids (e.g. retinol and retinyl esters) are common ingredients used in cosmetic products. Retinol (vitamin A) is an endogenous compound which occurs naturally in the human body and is essential for normal epithelial cell differentiation. Natural and synthetic vitamin A derivatives have been used extensively in the treatment of a variety of skin disorders and have been used as skin repair or renewal agents. Retinoic acid has been employed to treat a variety of skin conditions, e.g., acne, wrinkles, psoriasis, age spots and discoloration. See e.g. Vahlquist, A. et al.,
J. Invest. Dermatol.,
Vol. 94, Holland D. B. and Cunliffe, W. J. (1990), pp. 496-498; Ellis, C. N. et. Al., “Pharmacology of Retinols in Skin,”
Basel, Karger,
Vol. 3, (1989), pp. 249-252; and PCT Patent Application No. WO 93/19743.
Retinoid metabolism, however may result in conversion of the retinoid to non-beneficial by-products, thus yielding a lesser amount of beneficial retinoic acid to treat skin conditions. Several references, therefore, teach the use of a variety of natural actives for aiding in the treatment of skin conditions such as acne, wrinkles, psoriasis, age spots, and discoloration. For example, phytoestrogens (i.e., natural compounds which have estrogen-like activity and which are found in plants) have been increasingly used for cosmetic and therapeutic purposes. Estrogens and synthetic compounds which act like estrogens are known to increase the thickness of the dermal layer and reduce the wrinkle formation in the aging skin. Changes in the skin such as skin dryness, loss of skin elasticity and plumpness occurring after menopause are attributed to the lack of estrogen production. Estrogen therapy prevents or slows down many of the changes associated with aging skin (Creidi et al., “Effect of a Conjugated Oestrogen Cream (Premarin®) on Aging Facial Skin,”
Maturitas,
19, p. 211-213, 1994).
Several phytoestrogens have been disclosed for cosmetic benefits. For example, U.S. Pat. No. 5,728,726 teaches the use of genistein for thyrosine kinase inhibitory activity. U.S. Pat. Nos. 5,847,003 and 5,834,513, assigned to Avon, disclose the use of oxacids and oxadiacids in combination with retinoids. Both Avon patents disclose the use of antioxidant bioflavonoids, such as genistein and daidzein, as optional ingredients.
It has been discovered, however, that phytoestrogens induce oxidation of retinol, and therefore contribute to retinol degradation. Although multi-compartment systems for delivering compositions have been described, the need to separate phytoestrogens from retinoids has not been disclosed. For example, U.S. Pat. No. 5,914,116, issued to the assignee of the present invention, describes two separate containers for separating two different skin actives to provide dual skin benefits with one compartment containing retinoids and the second compartment containing a second active providing a second and different benefit.
Therefore, there still exists a need for compositions that provide the skin benefits of retinoids with the retinoid enhancing benefits of phytoestrogens.
SUMMARY OF THE INVENTION
A stable skin care product containing:
a first composition comprising about 0.001% to about 10% of a retinoid;
a second composition comprising about 0.001% to about 10% of a phytoestrogen;
a first compartment for storing the first composition; and
a second compartment for storing the second composition, the first and second compartments being joined together.
DETAILED DESCRIPTION
As used herein, the term “comprising” means including, made up of, composed of, consisting and/or consisting essentially of. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts or ratios of materials or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word “about”.
The term “conditioning” as used herein means prevention and treatment of dry skin, acne, photodamaged skin, appearance of wrinkles, age spots, aged skin, increasing stratum corneum flexibility, lightening skin color, controlling sebum excretion and generally increasing the quality of skin. The composition may be used to improve skin desquamation and epidermal differentiation.
The inventive compositions contain, as a preferred ingredient, a retinoid, which is selected from retinyl esters, retinol, retinal and retinoic acid, preferably retinol or retinyl ester. The term “retinol” includes the following isomers of retinol: all-trans-retinol, 13-cis-retinol, 11-cis-retinol, 9-cis-retinol, 3,4-didehydro-retinol, 3,4-didehydro-13-cis-retinol; 3,4-didehydro-11-cis-retinol; 3,4-didehydro-9-cis-retinol. Preferred isomers are all-trans-retinol, 13-cis-retinol, 3,4-didehydro-retinol, 9-cis-retinol. Most preferred is all-trans-retinol, due to its wide commercial availability.
Retinyl ester is an ester of retinol. The term “retinol” has been defined above. Retinyl esters suitable for use in the present invention are C
1
-C
30
esters of retinol, preferably C
2
-C
20
esters, and most preferably C
2
, C
3
, and C
16
esters because they are more commonly available. Examples of retinyl esters include but are not limited to: retinyl palmitate, retinyl formate, retinyl acetate, retinyl propionate, retinyl butyrate, retinyl valerate, retinyl isovalerate, retinyl hexanoate, retinyl heptanoate, retinyl octanoate, retinyl nonanoate, retinyl decanoate, retinyl undecanoate, retinyl laurate, retinyl tridecanoate, retinyl myristate, retinyl pentadecanoate, retinyl heptadeconoate, retinyl stearate, retinyl isostearate, retinyl nonadecanoate, retinyl arachidonate, retinyl behenate, retinyl linoleate, retinyl oleate.
The preferred ester for use in the present invention is selected from retinyl palmitate, retinyl acetate and retinyl propionate, because these are the most commercially available and therefore the cheapest. Retinyl linoleate and retinyl oleate are also preferred due to their efficacy.
Retinol or retinyl ester is employed in the inventive composition in an amount of about 0.001% to about 10%, preferably in an amount of about 0.01% to about 1%, most preferably in an amount of about 0.01% to about 0.5%.
Phytoestrogens
As part of the present invention, it has been surprisingly found that phytoestrogens synergistically improve the skin benefits of retinoids. Essentially, phytoestrogens increase the sensitivity of the skin to retinoids.
Therefore, the present invention contains about 0.001% to about 10% of at least one phytoestrogen in the second composition.
Phytoestrogens include flavonoids such as estrogenic flavonoids, genistein, daidzein, glycitin, biochanin A, formononetin and equol and mixtures thereof, acetyl and malonyl esters of genistein and daidzein, and glucosides of genistein and daidzein. It should be noted that the aforementioned list is not exclusive, and may include other phytoestrogens known to persons of ordinary skill in the art.
Dual Compartment Package
Compositions which include retinoids are generally unstable and may undergo chemical degradation. As a further retinoid enhancing benefit, phytoestrogens are an essential component of the present invention. Phytoestrogens such as genistein and daidzein synergistically interact with retinoids to deliver skin benefits. However, phytoestrogens contribute to the oxidation, and thus the degradation of retinoids. The phytoestrogen induced retinol destabilization dramatically reduces the overall efficacy of the boosted retinoid composition when both ingredients are contained in a single formula. Therefore, in order to protect against retinoid breakdown while still providing the synergistically beneficial effects of phytoestrogens, the present invention provides a dual compartment package that contains a first composition containing retinoids in a firs
Granger Stewart Paton
Pillai Sreekumar
Pocalyko David Joseph
Scott Ian Richard
Criares Theodore J.
Kim Jennifer
Plotkin Ellen
Unilever Home & Personal Care USA a division of Conopco, Inc.
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