Drug – bio-affecting and body treating compositions – Topical body preparation containing solid synthetic organic...
Reexamination Certificate
1999-07-20
2002-12-17
Hartley, Michael G. (Department: 1616)
Drug, bio-affecting and body treating compositions
Topical body preparation containing solid synthetic organic...
C514S844000, C514S847000
Reexamination Certificate
active
06495126
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to a treatment method and composition for improving the skin's visual appearance, function, and clinical/biophysical properties which have been changed by factors such as chronological age, chronic sun exposure, adverse environmental pollutants, household chemicals, disease pathologies, smoking, and malnutrition. In particular, the present invention relates to a method of treating skin by increasing the skin's stratum corneum turnover rate through corneum protease activation. More particularly, the invention relates to the use of a combination of a cationic surfactant such as N,N,-dimethyldodecyl amine oxide (DMDAO), an anionic surfactant such as sodium dodecyl sulfate (SDS), and a chelating agent such as ethylene diamine tetraacetate (EDTA) as additives to topically-applied cosmetic skincare products to treat and reduce the clinical and functional signs of aging and environmental damage in skin. The invention provides for an effective alternative to the use of hydroxy acids and retinoid compounds to treat aged and environmentally-damaged skin.
BACKGROUND OF THE INVENTION
With chronological age and chronic exposure to adverse environmental factors, the visual appearance, physical properties, and physiological functions of skin change in ways that are considered cosmetically undesirable. The most notable and obvious changes include the development of fine lines and wrinkles, loss of elasticity, increased sagging, loss of firmness, loss of color evenness (tone), coarse surface texture, and mottled pigmentation. Less obvious, but measurable changes which occur as skin ages or endures chronic environmental insult include a general reduction in cellular and tissue vitality, reduction in cell replication rates, reduced cutaneous blood flow, reduced moisture content, accumulated errors in structure and function, and a reduction in the skin's ability to remodel and repair itself. Many of the above alterations in appearance and function are caused by changes in the outer epidermal layer of the skin, while others are caused by changes in the lower dermis. Regardless of the stimulus for skin damage, when damage occurs, numerous natural and complex biochemical mechanisms are set into motion in attempts to repair the damage.
When the epidermis is injured, the epidermal basal cells respond to the injury by dividing at a more frequent rate. This increase in replication rate results in a more rapid replacement of the damaged epidermis with a new epidermis and stratum corneum, a process referred to as “epidermal cell renewal.” Common examples of injuries which can increase epidermal cell renewal rates include abrasion, chemical damage, pH extremes, excessive sun exposure, or allergic or non-allergic contact irritation. If the injury is too severe, the increased replication will result in a “hyperplastic” epidermis and a thickened, poorly-functioning stratum corneum which is manifested as dry, rough scales. Other common stimuli which induce epidermal cell renewal include physical removal of the stratum corneum (i.e., an example of which is tape stripping, a process where tape is applied to the skin and pulled off, removing the top layer of the stratum corneum with it) and friction (i.e., on the soles and heels of the feet), all processes which result in epidermal hyperplasia. Hydroxy acids and retinoids also induce epidermal hyperplasia at appropriate concentrations, although the mechanisms appear to be different. It is believed by many that hydroxy acids exert their effects by inducing physical exfoliation of the corneum, whereas the retinoids more likely work by interacting with cytoplasmic and nuclear binding receptors to alter gene expression. Schiltz, J. et al. “Retinoic acid induces cyclic changes in epidermal thickness and dermal collagen and glycosaminoglycan biosynthesis rates,” J. Invest. Dermatol. 87:663-667 (1986), describe various effects of retinoic acid on epidermal and dermal biology including cyclical epidermal thickening and hyperplasia, and dermal changes in the rates of biosynthesis of collagen and glycosaminoglycans.
With chronological age and chronic environmental exposure (notably UVA, UVB, and IR radiation), the dermis undergoes changes in structure and function which result in many of the characteristics of aged skin, including loss of elasticity, formation of wrinkles, loss of water-holding capacity, sagging, and poor microcirculation. At the molecular level, these changes have been correlated with biochemical changes in the content and structure of the extracellular matrix to which the major cells of the dermis (i.e., the fibroblasts) reside. Collagen becomes highly cross-linked and inelastic, elastin is reduced in amounts and is incorrectly distributed, and the glycosaminoglycans become reduced in amounts, which results in reduced intercellular water.
As a result of this changed architecture, the normal amounts and distribution of trace metal ions, growth factors, hormones, and cytokines becomes altered which causes the fibroblasts to become metabolically less active or quiescent. Although these cells have natural mechanisms to repair themselves and the matrix in which they reside, with age and too much damage, they are less able to repair the damage, and the condition continues to deteriorate. If the quiescent fibroblasts can be metabolically activated and stimulated to divide, they will synthesize new extracellular matrix and the old, damaged matrix will be enzymatically degraded and replaced. This process of balanced synthesis and degradation is referred to as “dermal remodeling.” The activation process can be accomplished in many different ways, including chemical stimulation by selected hormones, growth factors, cytokines, vitamins, botanical extracts and retinoids, or by increasing the nutrient supply (i.e., blood flow) to the tissue.
Although the mechanisms are not completely understood, it appears that physical or chemical changes to the intact stratum corneum of the skin will result in epidermal basal cell replication and subsequent increases in epidermal cell renewal. If the injury stimulus is too great, the skin will be unable to correct the damage or will “over-respond” in such a way as to cause extensive epidermal hyperplasia and dry, flaky, poorly-differentiated stratum corneum. If the damage stimulus is less and is well controlled, the process of epidermal replacement should result in a healthier, better-functioning epidermis and in a stratum corneum which looks and feels better, has greater capacity to hold moisture, and has fewer surface fine lines.
It is known that damage to the stratum corneum not only sets into motion natural biochemical mechanisms to repair and replace the epidermis, but disturbances in the corneum also stimulate repair and remodeling of the dermis. U.S. Pat. No. 5,720,963 to Smith (“the '963 patent”) teaches that chronic and significant disruption of the skin's water barrier using a combination of cerebrosides, hydroxy acids, and retinoids causes chronic injury to the corneum and results in epidermal and dermal repair of the structurally-deteriorated skin if the disruption is maintained for a sufficient period of time. The mechanisms by which the combination of materials used in the '963 patent cause increased epidermal cell renewal and chronic skin repair are entirely different from those which are involved in the current invention. Although the end benefits to the skin are similar, the '963 patent teaches that water barrier disruption agents such as cerebrosides or organic solvents or detergents, in combination with retinoids or hydroxy acids will disrupt the corneum water barrier and stimulate basal cell replication rates. The Applicant has discovered that chronic stimulation of the normal process of desquamation by activation of at least one endogenous corneum protease will result in increased epidermal turnover and epidermal and dermal remodeling. This is not a chronic injury; instead, it is an increase in the rates of corneum
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Hartley Michael G.
Mary Kay Inc.
LandOfFree
Treatment and composition for achieving skin anti-aging... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Treatment and composition for achieving skin anti-aging..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Treatment and composition for achieving skin anti-aging... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2980796