1. Field of the Invention
The present invention relates to a system for cleansing, conditioning, and treating the skin. In particular, the present invention relates to a one-step system that delivers a combination of surfactants, humectants, emollients, antimicrobial agents, and other beneficial ingredients in a no-rinse, self-drying formulation that promotes effective absorption into the surface layers of the skin.
2. Discussion of Background
Many different types of products are used in cleansing and conditioning the skin: solid and liquid soaps, surfactants, humectants, moisturizers, emollients, astringents, deodorants, and antimicrobial agents, and other compositions which provide the desired beneficial effects. The normal method of cleansing the skin with soap and water originated in about 2000 BC with a soap invented by the Mesopotamians. Unfortunately, most soaps are alkali based and rely on consuming the natural skin oils to free up dried or dead skin, dirt, and soil. This strips the skin of natural oils and causes dry skin, flaking and even skin tears, especially in older persons. Liquid cleansers are becoming increasing popular; however, many liquid cleansers do not lather sufficiently well for thorough cleansing. Various cleansing aids such as wash cloths and sponges may impede lathering or even absorb liquid cleansers and moisturizers.
The primary function of human skin is to provide a barrier that contains the other organs of the body. The effectiveness of skin as a barrier depends on its physical integrity, thus, preserving the integrity of healthy skin and restoring the integrity of injured skin are important aspects of maintaining good health. Injuries (burns, cuts, abrasions, incisions) can lead to localized or systemic infection if contaminated; dry skin can lead to pruritis and hasten the formation of skin ulcers (including decubitus ulcers), an especial concern for bedridden patients and the elderly. The normal techniques used in skin cleansingxe2x80x94washing with soap and water, rubbing with sponges and wash clothsxe2x80x94can exacerbate these problems.
The technique of cleansing skin using a basin of water and soap commonly used for bed ridden patients today was popularized by Florence Nightingale over 100 years ago. This technique usually starts with a basin filled with hot water, and involves the use of soap and rough wash cloths to loosen dead skin. Patients are bathed by scrubbing their skin with a well-soaped wash cloth, followed by vigorous towel drying. This technique can easily result in some areas of a patient""s body becoming contaminated by bacteria carried from other parts via the washcloth or towel. Another concern is skin damage (abrasions, tears, etc.) due to friction from washcloths and towels, especially in elderly patients and others with fragile, easily-damaged skin.
Most skin cleansing formulations and techniques were developed primarily to remove dirt, soil, and germs carried on the surface of the skin or in the skin""s oil, and do little or nothing to protect or enhance the skin or its natural functions. In fact, many sacrifice skin health to achieve the primary objective of skin cleansing.
More recently, substrates pre-moistened with various cleansers, moisturizers, and other additives have been used to provide greater convenience and disposable cleansing systems. For example, Elmore (U.S. Pat. No. 4,220,244) describes a soft cloth pad saturated with salt water and enclosed in a moisture proof envelope having a mirrored surface. The pad can be taken out when needed to refresh and clean the user""s face. Toohey (U.S. Pat. No. 4,749,080) teaches a plurality of woven cloths pre-moistened with an aqueous moistening liquid such as pure water, contained in a resealable package. The package is sealed by application of heat and pressure, and sterilized by exposure to gamma radiation. Toohey states that the liquid can contain additives for skin freshening such as alcohol, iodine as an antiseptic, and a skin smoothing agent such as glycerin or lemon oil, altogether not exceeding 10% of the total weight of the aqueous solution.
Some products, such as the delivery system and treatment compositions described by Deckner (U.S. Pat. No. 4,563,346), are designed to air dry after application to the skin. Deckner uses a volatile silicone and a non-ionic lipophilic emulsifier that can be used to deposit a variety of active ingredients on the skin, including oils, humectants, emollients, sunscreens, antiperspirants, and topically active drugs. Other ingredients may include parabens, benzyl alcohol, and imidazolidinyl urea, emollients such as alcohol benzoate, and moisturizers such as panthenol, propylene glycol, or glycerol incorporated into the water phase of the delivery system. The system is said to produce a wash-resistant and sweat-resistant moisturizer film on the skin, which makes it unsuitable for use as a cleanser.
In addition to good cleaning action, cosmetic cleansers should be gentle, causing little or no irritation without drying the skin or leaving it taut. Wivell, et al. (U.S. Pat. No. 5,439,682) provides a personal cleansing and moisturizing composition that includes an anionic surfactant, a long chain C16-22 suspending agent, a dispersed, insoluble oil phase, an additional surfactant, an optional suspending agent, and water. Gordon, et al. (U.S. Pat. No. 5,650,384) combines a hydrophobic, diamond-mesh sponge with a liquid cleansing and moisturizing composition. The composition contains a moisturizing phase and an anionic surfactant in order to clean and moisturize the skin in a single step. Notably, most of the ingredients are rinsed away during use, leaving the relatively heavy, oily moisturizers behind.
Blieszner, et al. (U.S. Pat. No. 5,648,083) teach the addition of a cleansing composition to pre-moistened disposable wipes for personal cleansing of the perineal area. The composition includes water, a protective barrier agent that contains silicone oil, and an emulsifier; it may also include additional components such as pH-adjusting agents, antimicrobial agents, chelating agents, fragrances, skin soothing aids, moisteners, humectants, emollients, and powders. The composition is formulated for use in the normally moist perineal area; thus, repeated use in other, normally-drier areas would cause problems.
Additional compositions and methods are disclosed by Martin, et al. (U.S. Pat. No. 5,702,992), who add an anti-microbial agent to a patient care kit that includes a plurality of cleanser-impregnated cloths packaged in a sealed polyethylene bag. The cleanser is a nonionic, non-rinsing mixture of surfactants, emollients or humectants, vitamin E and deionized water. Williams, et al. (U.S. Pat. No. 4,761,402) describes a soluble, phophorylated glucan composition for treatment of viral and fungal infections; additional ingredients may include antimicrobial agents such as aminoglycoside and gentamicin. The composition is administered in vivo through injection, orally, topically, or by inhalation. Buchalter (U.S. Pat. No. 3,896,807) impregnates an article such as a glove with a therapeutic substance (a non-oily solid which is activated to form a cream upon addition of water or moisture). Murphy""s cosmetic product (U.S. Pat. No. 5,653,967) also includes beta glucan as a suspension agent. The beta glucan is non-toxic and non-irritating, but was not noted to demonstrate any stimulation of macrophages or curative effects.
Many of the substrates used with cleansing compositions are unsuitable for long-term use. For example, paper substrates are biodegradable but abrasive to the skin, and, like dense woven or nonwoven substrates, are ineffective at trapping and carrying away dirt. Unfortunately, most nonwoven substrates that are available to consumers are selected for softness and reduced friction without regard for their ability to trap and carry away dirt or soil.
Most known skin cleansing systems contain ingredients that are aimed at producing specific outcomes, but that may also have detrimental side effects. For example, alcohol is fast-drying and kills many varieties of microorganism, but also dries the skin. Iodine, widely used in antiseptic compositions such as Betadine(copyright), is harsh and discolors the skin. Propylene glycol (the main ingredient in antifreeze) is used as a soap, emollient, or preservative, but repeated use and exposure have been found to contribute to contact dermatitis, liver abnormalities, and kidney damage. Mineral oil and other oils may suffocate the skin by forming an oil film; any excess oily residue on the skin surface (including vitamin E) promotes excess sweating which can be detrimental to skin health and maintenance. Sodium lauryl sulfate (SLS) and sodium alureth sulfate (SLES) may cause formation of potentially carcinogenic nitrates and dioxins by reacting with commonly used ingredients found in many products. Glycerin and some other humectants attract and draw in moisture to keep the dead surface skin moist, but when used in quantity can dry out and damage the subsurface, living skin. Other humectants that trap water in solution can damage the skin by over-hydration.
Alcohol, glycerin, and other common ingredients used in cosmetics and skin cleansers are relatively inexpensive at least partly because they have been used in volume in so many different applications for many years. To reduce costs, these ingredients are normally a first choice for new product formulations. Many common ingredients, including propylene glycol and glycerin, are included to impart an impression of silkiness, slipperiness, and other tactile sensations deemed to be desirable to consumers. This poses no significant skin problems for normal usage, or when the product is rinsed off after use. However, many of these popular ingredients are simply inappropriate for repeated use in no-rinse, fast-drying cleansing and moisturizing systems.
Many cosmetic and skin cleansing compositions include antimicrobial agents and preservatives that extend the shelf life of the product (these constituents restrict the growth of microorganisms in the substrate, solution, and container). These constituents are typically selected for their effectiveness in protecting the product rather than their compatibility with human skin or even their effectiveness against microorganisms found on the skin. These constituents are selected for their ability to act relatively slowly during product storage; they are not designed to kill large amounts of microorganisms quickly during skin cleansing, nor are they suitable for leaving on the skin for extended periods of time: an agent that helps prevent the growth of undesired microorganisms during product storage cannot be assumed to be equally effective against bacteria in vivo.
An additional problem is that of cross reactions, which can result in the breakdown of various product constituents and the formation of new compounds that may be harmful to the skin. Many common preservatives are subject to cross reactions, for example, Diazolidinylurea (marketed, inter alia, under the trademarks Germall II or Germaben II) is a broad-spectrum preservative used in cosmetics and pharmaceutical preparations. Diazolidinylurea, which has become a popular constituent of cosmetics, creams and lotions since the early 1980s, is now known to change into formaldehyde if activated to kill microorganisms. When radiated at normal sterilization levels, cross-reactions may change diazolidinylurea into offensive-smelling ammonia or formaldehyde.
Very few products are sterilized as part of, or after the manufacturing process. Instead, manufacturers rely on less costly preservatives matched to known microbial loads on the product to restrict microbial growth during storage. Sterilization is desirable for all skin cleansing products, but especially so for products used in hospitals, nursing homes, extended care facilities, and the like. Contrary to many statements in the prior art literature, presently-available pre-moistened substrates used for skin cleansing typically cannot be adequately sterilized by ultraviolet light, and cannot be ETO-sterilized due to the resulting unallowable levels of ethylene glycol. Gamma or E-beam sterilization is usually unacceptable due to the difficulty in matching multiple ingredients with desired functions that are not significantly altered during required radiation levels. If sterilized by gamma radiation, diazolidinylurea and many other commonly-used ingredients deteriorate, resulting in foul odors or new compounds.
Known skin care compositions rely on pre-cleansing, rinsing, and manually drying the skin, or are intended for temporary skin coatings such as sunscreens and supplemental creams. These compositions are not effective as a one-step, no-rinse cleansing system; their effectiveness is hampered by the problems created during normal pre-cleansing. Furthermore, many presently-available compositions contain ingredients that have harmful side effects. Thus, known skin cleansing systems and compositions rely on a very careful selection of sometimes-incompatible ingredients to prevent unwanted interactions, during storage, during sterilization, and during use. This problem is so common that manyxe2x80x94perhaps mostxe2x80x94formulations include additional ingredients specifically to help offset the side effects caused by the other ingredients.
Despite the variety of skin cleansing and conditioning systems available to consumers, there is still a need for a practical, cost-effective system based on skin-friendly ingredients. An ideal system would include a non-irritating, lint-free substrate impregnated with a composition that simultaneously cleanses, detoxifies, restructures, and revitalizes the skin, and that air-dries rapidly, leaving a protective film on the skin surface.
According to its major aspects and broadly stated, the present invention consists of a skin care system that cleanses, therapeutically conditions, and provides additional beneficial treatment to the skin in a simple, one-step application that air dries quickly. (For purposes of this specification, the terms xe2x80x9cair dries quicklyxe2x80x9d and xe2x80x9cair dries rapidlyxe2x80x9d refer to a composition that air dries within approximately two minutes following application to the skin.) The system is implemented as a skin care kit: a container having a plurality of articles therein, each article consisting of a pre-moistened soft cloth. The cloths are impregnated with a treatment composition that contains ingredients selected from the following groups: (a) surfactants, (b) anti-inflammatory agents, (c) non-foaming agents, (d) cell-growth-promoting agents, (e) immune system-enhancing agents, (f) fast-acting antimicrobial agents, (g) absorption facilitating agents or ingredients, (h) humectants and emollients, (i) free radical-scavenging agents, and (j) healing promoting agents. (The terms xe2x80x9cagent,xe2x80x9d xe2x80x9cingredient,xe2x80x9d and xe2x80x9cconstituentxe2x80x9d are used interchangeably.) The ingredients are further selected to form a stable composition, that is, neither the ingredients nor the composition as a whole deteriorates or undergoes cross reactions when the composition is sterilized by gamma or electron-beam radiation.
In use, the cloths gently cleanse the skin, trap and carry away dirt and soil, and deposit a film of beneficial ingredients that coat and are absorbed into the skin. The system is portable, disposable, easily stored, and can be partially used and resealed for further use. Thus, it is both useful and convenient for medical-related and non-medical skin cleansing.
An important feature of the present invention is the synergistic effect of the selected ingredients. When combined according to the invention, surprisingly low concentrations of these ingredients are needed to provide effective cleansing and moisturizing of the skin, together with delivery of antimicrobial agents that act against local bacteria, viruses, fungi, etc. to help promote healthy skin. The combination of surfactants, humectants, emollients, and other ingredients promotes deeper and more effective absorption of multiple ingredients into the layers of the skin, in a disposable, one-step cleansing and moisturizing system that quickly air dries so that towel drying is not needed.
Another important feature of the present invention is the combination of ingredients used in formulating the composition. In a preferred embodiment, the composition is an aqueous solution that contains approximately 70-90 wt. % water and at least four additional ingredients: at least one ingredient selected from each of groups (a)-(c), and at least one ingredient selected from one of groups (d)-(j). More preferably, the composition contains at least five ingredients in addition to water: at least one ingredient from each of groups (a)-(c), and at least two different ingredients from one of groups (d)-(j). Most preferably, the composition contains at least two different ingredients from each of two different groups (d)-(j) in addition to the ingredients from groups (a)-(c). Additional ingredients such as preservatives and fragrances may be added if desired. The ingredients are selected so as to be compatible with each other, to be radiation-sterilizable, and to provide the desired beneficial treatment.
Another feature of the present invention is the cloths that carry the composition. The cloths are made of a soft, pliable fabric, preferably a fabric that contains at least 50% rayon or other suitable fibers. The structure of the fabric is sufficiently porous (i.e., with a sufficient number of air spaces) that it retains the composition therein during manufacture and storage, but easily releases the composition when wiped gently across the area of skin to be cleansed. The fabric also picks up and carries away dirt, dead skin flakes, and excess skin oils, while depositing a thin layer of the composition on the skin surface.
Other features and advantages of the present invention will be apparent to those skilled in the art from a careful reading of the Detailed Description of Preferred Embodiments presented below and accompanied by the drawings.