Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Liposomes
Reexamination Certificate
2001-08-23
2003-05-06
Kishore, Gollamudi S. (Department: 1615)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Liposomes
C424S401000, C424S047000, C424S070100, C424S070200, C424S070110, C424S070210, C424S070220, C424S073000, C514S880000, C514S881000, C514S937000
Reexamination Certificate
active
06558697
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to compositions and delivery systems based on a combination of organic phospholipids capable of forming bilayers in aqueous solution; amphoteric surfactants; and nonionic surfactants, wherein the combination of these ingredients allows water-insoluble ingredients, particularly waxes or water-insoluble polymers, resins, or latexes, to be incorporated into aqueous solutions.
BACKGROUND OF THE INVENTION
Organic phospholipids play an important role in the cosmetics and pharmaceutical industries because of their outstanding physiological properties, such as, for example, emulsifying, softening, and anti-oxidant effects. When hydrolyzed, organic phospholipids yield phosphoric acid, an alcohol, a fatty acid, and a nitrogenous base. Most phospholipids are amphipathic, i.e., have polar “heads” and non-polar “tails.” As a result, most phospholipids tend to arrange spontaneously into a bilayer when suspended in an aqueous environment, with the polar heads contacting the water and the non-polar tails contacting each other. Most naturally occurring phospholipids prefer to form vesicular bilayers in water solutions. In such a bilayer vesicle, no non-polar part of the phospholipid has any contact with the water solution.
Because of their non-polar portions, phospholipids typically are water-insoluble and incompatible with many water soluble anionic compounds, such as anionic surfactants. While they can be solubilized in water at low levels by a range of surfactants, this is often not easily accomplished.
Instead, solubilization has been accomplished conventionally using specific solubilizing agents in aqueous alcoholic solutions. For example, U.S. Pat. No. 4,874,553 to Hager et al. discusses methods of rendering phospholipid mixtures water-soluble or water-dispersible by using certain amine compounds as solubilizing agents. U.S. Pat. No. 4,174,296 to Kass describes a method of improving the solubility of phospholipid compounds in water, in particular lecithin compounds, by mixing lecithin with specific single solubilizing agents, including amphoteric and anionic surfactants. These methods require alcohol for cosolubilization. Alcohol solutions have the drawback of disrupting any bilayer formation by altering the solution such that the alcohol functions as a secondary solvent.
Lecithins and other phospholipids have been used in the pharmaceutical industry to formulate carriers for water-insoluble drugs. For instance, in U.S. Pat. No. 5,173,303 to Lau et al., water-insoluble material is encapsulated by vesicles composed of phospholipids such as lecithin. I. Ribosa et al., in “Physico-chemical modifications of liposome structures through interaction with surfactants,” Int'l Journal of Cosmetic Science 14:131-149 (1992), also discuss solubilization of phospholipids via the interaction of liposomes with surfactants. Lau and Ribosa, however, investigated only dilute solutions of pure liposomes.
Despite difficulties in solubilization, certain organic phospholipids, such as lecithin, can advantageously give hair and skin a soft, moisturized feel because they have a strong affinity for the hydrophobic surface of the hair and skin. In addition, these phospholipids are toxicologically safe. It would thus be desirable for cosmetic and pharmaceutical applications to provide delivery systems that include such organic phospholipids as a carrier for other lipophilic ingredients, without the need for alcohols and other similar solvents.
In addition to solubilizing lipophilic ingredients such as oils, vitamins, and ceramides in aqueous systems, it would be desirable to solubilize other water-insoluble ingredients, such as waxes or unneutralized or partially neutralized polymers, resins, or latexes, in aqueous delivery systems. U.S. Pat. No. 5,391,368 to Gerstein teaches solubilization of a hair-styling polymer in a composition comprising an anionic surfactant and an amphoteric surfactant. According to Gerstein, it is the amphoteric surfactant which dissolves the water-insoluble styling polymer because the polymer is not soluble in the anionic surfactant alone.
Gerstein presents some problems, however. Many hair care and hair setting products are formulated at acidic pH because of a desire for such products to be compatible with the pH of the scalp and hair surface. Gerstein does not disclose a pH at which its system is formulated, but if the Gerstein system is acidified, the polymer will precipitate out of solution. In addition, the Gerstein system does not carry and there is no suggestion that it could carry any additional lipophilic ingredients in its mixture of anionic surfactant, amphoteric surfactant, and styling polymer. Further, Gerstein does not describe the incorporation of its styling polymer into any products other than the disclosed styling shampoo, nor does Gerstein suggest that such incorporation would be possible.
Thus, there remains a need for an aqueous delivery system that can solubilize water-insoluble materials in such a manner that they will not precipitate out of solution upon acidification and where the system could carry other ingredients in addition to the water-insoluble ingredient. There is additionally a need for hair styling products which contain reduced VOC (volatile organic content). Laws in several states have already set a ceiling for the acceptable percentage of VOC in consumer products. When, in an effort to lower VOC's, some of the alcohol used in such products is lowered and replaced with water, the product is unable to form a good film, is sticky and thick, and is generally an ineffective hair styling aid, resulting, for example, in unacceptable curls. Attempts to remedy the problems encountered when alcohol is replaced with water in these formulations have not resulted in satisfactory products either. In particular, although the amount of water-insoluble styling polymer or resin can be increased to improve the curl or styling capability of the hair product, the outcome is a tacky formulation which flakes easily on the hair. Alcohol can also be replaced with acetone instead of water, but, as is commonly known in the art, acetone is flammable and is also an undesirable ingredient in hair products because it is such a strong solvent and can, for example, dissolve many varnishes or finishes. For instance, if a user is spraying the product on the hair while wearing nail polish, the acetone content of the hair spray could cause the nail polish to dissolve and run from the hands into the hair.
Accordingly, there is a need for hair styling compositions with little or no volatile organic content which still effectively solubilize styling ingredients and hold the hair while still allowing the hair to be shiny, flexible, and washable.
SUMMARY OF THE INVENTION
In order to achieve these and other advantages, the present invention is drawn to a composition made up of at least one organic phospholipid capable of forming bilayers in aqueous solution; at least one amphoteric surfactant; and at least one nonionic surfactant. The nonionic surfactant is present in an amount by weight equal to or greater than the amount of the organic phospholipid. The phospholipid, amphoteric surfactant, and nonionic surfactant are present in a combined amount sufficient to allow at least one water-insoluble ingredient, selected from waxes and unneutralized and partially neutralized water-insoluble polymers, resins, and latexes, to be incorporated into an aqueous solution.
In another embodiment, the present invention relates to an aqueous delivery system for water-insoluble materials. As defined herein, “water-insoluble” means a material which is insoluble in water but which can be solubilized in accordance with the present invention. The delivery (or “carrier”) system includes at least one organic phospholipid capable of forming bilayers in aqueous solution, at least one amphoteric surfactant, at least one nonionic surfactant, at least one water-insoluble ingredient selected from waxes and unneutralized and partially neutralized water-insolub
Cannell David W.
Espino Cynthia
Mathur Hitrendra
Nguyen Nghi
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Kishore Gollamudi S.
L'Oreal
LandOfFree
Compositions and methods for treating hair and skin using... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Compositions and methods for treating hair and skin using..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Compositions and methods for treating hair and skin using... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3069983