Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Cosmetic – antiperspirant – dentifrice
Reexamination Certificate
1998-11-23
2002-05-14
Bawa, Raj (Department: 1616)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Cosmetic, antiperspirant, dentifrice
C424S725000, C424S747000, C424S729000, C424S764000, C514S063000, C514S844000, C514S938000
Reexamination Certificate
active
06387382
ABSTRACT:
BACKGROUND
The present invention relates to multipurpose skin preparations in the form of oil-in-water emulsions. More particularly, the present invention relates to oil-in-water emulsions containing a combination of silicones. Such oil-in-water emulsions, when blended in accordance with the teaching of the present invention, provide excellent water-proof, cross-linked, respirable, and protective barriers on the skin, provide superior tactile properties, and effectively deliver and maintain moisturizing and therapeutic agents on the skin. It is believed that the skin preparations of the present invention also effectively deliver and maintain moisturizing and therapeutic agents useful for the treatment of pathologies of the skin.
The skin has a naturally produced sebum layer which acts as a barrier to protect the skin from external factors and prevent the escape of moisture from the skin. This natural sebum layer barrier dissipates with age. Low humidity, harsh soaps and chemicals, and excessive bathing and washing further accelerate the removal of the sebum layer from the skin. With the loss of this barrier, the skin loses its ability to retain water, is left unprotected from external factors, and, consequently, pathologies of the skin often result.
It is known that certain professions require constant washing of the hands and/or constant exposure of the skin to detergents, harsh chemicals, and water-borne irritants. For instance, physicians are required to thoroughly wash their hands both prior to and after seeing a patient or performing a surgical procedure. Therefore, physicians may wash their hands repeatedly throughout the day. These repeated washings may dry, damage and otherwise harm the skin. Furthermore, the hands of hair stylists and beauty salon employees may be continually exposed to detergents, chemicals, and water-borne irritants when performing hair care, nail care, and other personal care services for clients. These repeated exposures to such irritants may likewise dry, damage and otherwise harm the skin.
Such professionals, as well as people in the medical industry, cosmetic industry, consumers, and people with skin disorders, typically use known oil-in-water emulsions, such as lotions and creams, to alleviate dryness and chapping that may be caused by repeated washings of the skin. In general, such oil-in-water emulsions contain water and known ingredients such as emollients, emulsifiers, antioxidants, skin conditioners, preservatives, humectants, thickeners, cleansers, colorants, fragrances, and other ingredients generally used in the cosmetic art. However, many such known preparations lack good tactile properties and may create a sticky, oily, greasy, or waxy feel when applied to the skin. In addition, many such known preparations do not stay on the skin after a single washing with soap and water and must be reapplied after each washing. This decreases the effectiveness of the preparations and increases the costs to businesses such as hospitals and salons which require a constant supply of such lotions and creams for use by employees. In addition, many such known preparations contain undesirable ingredients such as perfumes and colorants which may cause allergic reactions when applied to the skin.
Moreover, the use of silicones in oil-in-water emulsions is also known. Silicones are found in a number of personal care products and are especially desirable for their water repellency, superior emolliency and lubricity, and for facilitating the formation of thin coatings on the skin that do not impart a greasy or sticky feeling. However, such known skin preparations or compositions containing silicones may require use of a large amount of silicones, i.e., greater than 20% by weight of the total composition, in order to sufficiently impart the beneficial properties of such silicones. Because silicones are generally expensive, use of such large amounts of silicones in skin preparations can increase manufacturing costs. In addition, since silicones have limited solubility in water, use of large amounts of silicones can limit the ability to form effective oil-in-water emulsions. Moreover, applicants are unaware of any known skin preparations containing silicones that stay on the skin and provide a protective barrier for up to 3 to 6, or more, washings of the skin surface, where each washing is made with soap and water for an average of 15-20 seconds long.
Thus, a need exists for skin preparations that provide superior tactile properties; that impart a silky, smooth and non-greasy feel when applied to the skin; that provide water-proof, cross-linked, respirable barriers on the skin; that protect the skin from water-borne irritants, deleterious chemicals, and other external factors; that provide resistance to repeated exposures to water and detergents; that prevent moisture from escaping from the skin and seal in moisture for up to hours; that act like the skin's naturally produced protective barrier (sebum layer), while also acting as a medium for the introduction of therapeutic agents to the skin, such that the efficacy of these therapeutic agents is amplified by the barrier function of the skin preparations since the therapeutic agents remain on the skin for long periods of time; that facilitate the healing of damaged skin as a result of cuts, scratches, burns, and other abuses of the skin; that substantially remain on the skin after multiple washings, that is, that maintain and provide a protective barrier on the skin for up to 3 to 6, or more, washings of the skin surface, where each washing is made with soap and water for an average of 15-20 seconds long; that contain sufficiently low, less costly amounts of silicones yet maintain all of the beneficial properties of known preparations containing higher, more costly amounts of silicones; that it is believed when combined with select therapeutic agents, biological agents, pharmaceutical agents, and/or steroids, facilitate the healing of a variety of skin pathologies; that form oil-in-water emulsions having good viscosity, stability, and proccessability; and that are easy and cost efficient to manufacture.
Although attempts have been made to produce such skin preparations, to date, applicants are unaware of such multipurpose skin preparations that provide all of the advantages of the present invention. For the foregoing reasons, there is a need for multipurpose skin preparations that provide all of these advantages.
SUMMARY
The present invention is directed to multipurpose skin preparations that satisfy these needs. A first version of a skin preparation having features of the present invention is prepared by combining an oil phase and an aqueous phase. The oil phase is prepared by combining by total weight of the skin preparation the following: (i) at least 2% by weight of a siloxane polymer; (ii) at least 1% by weight of a cyclic silicone, and wherein the siloxane polymer and cyclic silicone are present in a respective weight ratio in the range of from about 2:1 to about 7:1; (iii) at least 1.5% by weight of at least one emulsifier; (iv) at least 0.1% by weight of at least one antioxidant; and, (v) at least 2% by weight of at least one emollient. The aqueous phase is prepared by combining by total weight of the skin preparation the following: (i) at least 0.1% by weight of at least one humectant; (ii) at least 0.1% by weight of at least one rheology modifier; (iii) at least 0.1% by weight of at least one thickener; and, (iv) water. The silxoane polymer may comprise dimethicone, trimethylsiloxysilicate, or mixtures thereof The siloxane polymer and cyclic silicone are preferably in sufficient amounts such that after the skin preparation is applied to the skin and a cross-linked protective coating is formed on the skin, when the skin is washed up to 3 to 4 times with soap and water for an average of 15-20 seconds each wash, the skin preparation maintains a protective barrier on the skin, wherein a protective barrier is one that is water-proof and prevents moisture from escaping from the skin and wherein at leas
Leahy Kimberly A
Saleh Michael
Axiom Laboratories, Inc.
Bawa Raj
McCuse Lawrence J.
Paterka Karin E.
Townsley Norton R.
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