Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Wearing apparel – fabric – or cloth
Reexamination Certificate
2000-04-26
2001-08-07
Page, Thurman K. (Department: 1615)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Wearing apparel, fabric, or cloth
C424S400000, C424S443000, C424S010100, C424S010300, C424S445000, C424S447000, C424S077000
Reexamination Certificate
active
06270783
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns cosmetic dermal strips or patches which provide consumers with a color change indicator as a sensorial signal.
2. The Related Art
Cosmetics are often provided with consumer perceivable sensorial signals. Most common of these signals are fragrances. Pleasing odor is often the single most important attribute inducing re-purchase by a consumer. Other sensorial attributes are also significant in cosmetic chemistry. Skinfeel of a product is highly important. Creams, lotions, gels and pastes often are judged for their efficacy by the tacticity of their feel. Silky, non-residue leaving cosmetics are much preferred over tacky ones, and the consumer may relate those aesthetics to actual pharmacological performance.
Sometimes the sensorial attribute is that of temperature. Coolness is imparted to toothpastes and aftershave lotions through the presence of camphor, menthol or menthol derivatives such as menthol lactate. Some formulations signal efficacy through a temperature increase. Inclusion of capsaicin, an alkaloid extracted from capsicum, gives a brief temperature rise sensation to the human neural system.
Dermal patches or strips have recently become popular as delivery vehicle systems for cosmetic compositions. For instance, WO 98/42303 (Crotty et al.) describes a dry-to-the-touch keratotic plug remover strip. Upon wetting, the strip turns tacky and mobile. This product is placed on the bridge of the nose or other areas of the face requiring keratotic plug removal. Within a short time period, water evaporates from the wetted adhesive forming a dry film. The consumer must then peel the film from the face along with unwanted plugs bonded thereto. Amounts of water applied by the consumer may vary. Drying times are therefore also variable. A sensorial signal would be helpful for the consumer to know when to begin the peel removal.
Exothermic and endothermic reactions are other sources of temperature signaling. U.S. Pat. No. 5,861,440 (Gohla et al.) reports use of sugars, especially xylitol, for inducing a cooling sensation when contacted with water. Generation of exothermic heat is reported in U.S. Pat. No. 4,379,143 (Sherry et al.), U.S. Pat. No. 4,626,550 (Hertzenberg), U.S. Pat. No. 4,362,715 (Strianse et al.) and U.S. Pat. No. 3,250,680 (Menkart et al.). Each of these patents employ an aluminosilicate interacting with water to release momentary heat.
Other types of sensorial signals have been sought for incorporation into cosmetics. The signals should either provide an independently new effect or complement those which have traditionally been employed.
Accordingly, it is an object of the present invention to provide cosmetic products, especially dermal strips or patches with a new sensorial signal.
Still another object of the present invention is to provide cosmetic products, especially dermal strips or patches with a sensorial signal which may augment other sensory or emotive aesthetics of such products.
Yet another object of the present invention is to provide cosmetic products, especially dermal strips or patches which include a timing mechanism for application, rub-in or removal of the product from a consumer's skin.
These and other objects of the present invention will become more readily apparent from consideration of the following summary and detailed discussion.
SUMMARY OF THE INVENTION
An adhesive cosmetic strip is provided for placement on skin which includes:
(i) a flexible water-insoluble substrate;
(ii) an adhesive composition deposited onto the substrate;
(iii) an agent interactive with water present in a sufficient quantity to induce a change of temperature in the strip of at least 2° C.; and
(iv) a liquid crystal thermochromic substance incorporated into at least one of the substrate or adhesive composition, the thermochromic substance changing color in response to the change of temperature.
DETAILED DESCRIPTION OF THE INVENTION
Now a visual sensorial signal has been found for use with dermal strips or patches. The invention is based upon the use of liquid crystal thermochromic substances whose color changes in response to a change in temperature. The substances may either be incorporated into the flexible substrate structurally supporting the strip or patch or may be formulated with the adhesive.
Liquid crystal thermochromic substances ordinarily are colorless (essentially transparent) except when in a specific temperature range, at which time they become visible. Often mixtures of these substances are employed to change different colors responsive to changes in temperature. They may be cholesteric or chiral nematic liquid crystals. Commercially the substances are available from Hallcrest of Glenview, Ill. Hallcrest has developed a silk-screenable liquid crystal material which is called a microencapsulated chiral nematic with vivid colors. Since the liquid crystal scatters light, it thus requires a generally dark background to be most visible. It changes through its liquid crystal visible color spectrum of clear to red to green to blue to purple to clear (as heated) or the reverse color sequence (when cooled). Temperature below its design temperature range, the liquid crystal substance is essentially transparent. Similarly, the temperature above its design temperature range, the liquid crystal material is also essentially transparent. Therefore, the liquid crystal material is only visible when at a temperature within the desired temperature range. Typical liquid crystals are cholesteryl ester carbonates or chiral nematic (non-sterol) aryl compounds. Particularly useful are (2-methylbutyl)phenol 4-alkyl(oxy)benzoates. Hallcrest provides microencapsulated thermochromic liquid crystals in sheet form with an adhesive backing under stock items R20C5W, R25C5W, R29C5W, R30C5W, R35C5W, R40C5W and R35C1W. Other types of liquid crystals which may be useful for the present invention are mentioned in WO 91/09106 (El-Nokaly et al.), U.S. Pat. No. 5,705,093 (Coates et al.) and U.S. Pat. No. 5,690,857 (Osterried et al.). Amounts of the liquid crystal in strips of the present invention may range from about 0.00001 to about 20%, preferably from about 0.01 to about 10%, optimally about 0.5 to about 5% by weight of the strip.
Liquid crystal thermochromic substances of the present invention will be capable of operating across many temperature change windows. Some windows may be as small as 0.5° C. while others may range as high as 20° C.
Flexible water-insoluble substrates are another essential element of the present invention. By “water insoluble” is meant that the substrate does not dissolve in or readily break apart upon immersion in water. A wide variety of materials can be used as the substrate.
Nonlimiting examples of suitable substrates include nonwoven substrates, woven substrates, hydroentangled substrates, air entangled substrates and the like. Preferred embodiments employ nonwoven substrates since they are economical and readily available in a variety of materials. By nonwoven is meant that the layer is comprised of fibers which are not woven into a fabric but rather are formed into a sheet, particularly a tissue. The fibers can either be random (i.e., randomly aligned) or they can be carded (i.e. combed to be oriented in primarily one direction). Furthermore, the nonwoven substrate can be composed of a combination of layers of random and carded fibers.
Nonwoven substrates may be comprised of a variety of materials both natural and synthetic. By natural is meant that the materials are derived from plants, animals, insects or byproducts. By synthetic is meant that the materials are obtained primarily from various man-made materials or from material that is usually a fibrous web comprising any of the common synthetic or natural textile-length fibers, or mixtures thereof.
Nonlimiting examples of natural materials useful in the present invention are silk fibers, keratin fibers and cellulosic fibers. Nonlimiting examples of keratin fibers include those selected from the group consisting of wool f
Crotty Brian Andrew
Indursky Michael
Slavtcheff Craig Stephen
Znaiden Alexander Paul
Evans Charesse L.
Honig Milton L.
Page Thurman K.
Unilever Home & Personal Care USA , division of Conopco, Inc.
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