USOO6692728B2 (12) United States Patent (10) Patent No.: US 6,692,728 B2 Weipert et al. (45) Date of Patent: Feb. 17, 2004 (54) POLYESTERS BASED ON HYDROXY FATTY (52) U.S. Cl. ......................... 424/59; 424/497; 424/489; ACDS AND LOWER HYDROXY ALKYL 424/70.11; 424/78.37; 424/78.08; 514/785; ACDS AND USES THEREOF 560/171; 560/172; 560/176; 560/183; 525/400 (58) Field of Search .......................... 424/59, 497, 489, (75) Inventors: Paul David Weipert, High Point, NC 424/70.11, 78.37; 514/785; 560/172,176, (US); Bharat B. Desai, Spartanburg, 183; 525/400 SC (US) (73) Assignee: Ethox Chemicals LLC, Greenville, SC ") References Cited (US) U.S. PATENT DOCUMENTS ( c: ) Notice: Subject to any disclaimer, the term of this 5,502,116 A 3/1996 Noda ......................... 525/415 patent is extended or adjusted under 35 5,614,576 A * 3/1997 Rutherford et al. ......... 524/270 U.S.C. 154(b) by 0 days. 5,851,937 A * 12/1998 Wu et al. ................... 442/394 * cited by examiner (21) Appl. No.: 10/388,426 (22) Filed: Mar 17, 2003 Primary Examiner Sabiha Qazi 9 (74) Attorney, Agent, or Firm-Isaac A. Angres (65) Prior Publication Data (57) ABSTRACT US 2003/0175222 A1 Sep. 18, 2003 The present invention provides biodegradable polyesters Related U.S. Application Data based on lower hydroxy acids and hydroxy fatty acids. The resulting polyesters are useful as cosmetic vehicles for (62) Division of application No. 09/805,894, filed on Mar. 15, Sunscreens, skin lotions and by themselves are also useful as 2001, now Pat. No. 6,540,987. milder skin exfoliants. (51) Int. Cl." ....................... C07C 229/00; CO7C 69/66; CO7C 69/73; A61K 7/06; A61K 3/765 3 Claims, No Drawings US 6,692,728 B2 1 2 POLYESTERS BASED ON HYDROXY FATTY pliancy, drug or nutrient delivery, texturizing, environmental ACIDS AND LOWER HYDROXY ALKYL protection, and coloration. Some of these objectives inher ACDS AND USES THEREOF ently require Substances which are water compatible Such as humectants, and others require lipid compatible Substances This application is a divisional application of pending Such as emollients. The largest class of cosmetic mixtures application Ser. No. 09/805,894 filed Mar. 15, 2001 now are emulsions of oil and water based fractions, and may be U.S. Pat. No. 6,540,987. either oil in water (O/W) or water in oil (W/O), or both. For a review of the various physical forms and processes of FIELD OF INVENTION making mixtures Such as true emulsions, microemulsions, This invention relates to new biodegradable polymers and gels, and liposomes, See Fox, C., “Cosmetic Vehicles., their use in the cosmetic field. The instant invention is also Advances in Cosmetic Science and Technology, part 4,” directed to biodegradable polyester polymers. This inven Cosmetics and Toiletries, 110:59 (1995). tion also relates to new biodegradable polyester polymers These emulsions have both occlusivity and humectancy. derived from hydroxy fatty acids and lower alkyl hydroxy In occlusivity, a non-irritating moisture barrier is established acids or alkyl polyhydroxy diacids. The invention is further 15 on the Surface of the skin, to prevent loss of moisture. directed to cosmetic compositions containing biodegradable Typical materials are petroleum jelly, mineral or vegetable polyester. This invention further relates to biofriendly poly oils, Silicones, waxes, fatty acids, and esters. Typical ester polymers and copolymers derived from lactic acid, humectants, which attract water and help bind water to the other hydroxy acids, ricinoleic acid and other hydroxy fatty skin, include glycerin, Sorbitol, Sodium lactate, and Sodium acids. The present invention also relates to polyhydroxy pyrrollidone carboxylate, are beneficial in hydrating the polyalkanoates and their use as a vehicle for cosmetic Stratum corneum and improving its Viscoeleastic behavior products. (See Williams and Schmitt, eds., Chemistry and Technology The present invention also relates to biodegradable poly of the Cosmetics and Toiletries Industry, 2nd ed., Blackie ester polymeric compositions especially poly(lactic acid)- Academic and Professional, London: 1996). co-(ricinoleic acid) and their use in cosmetic applications. 25 Most emulsions require one or more Stabilizers to main The instant invention also relates to novel polyester tain the microdispersion, and to prevent collapse and Sepa polymers, polymer compositions and methods for using ration of the blend. A widely used stabilizer system utilizes Such polymers and compositions in personal care applica Stearic acid in the oil phase, and tri-, di-, or monoethanola tions. In general terms, the polyester polymers and polymer mine in the aqueous phase. The resulting ethanolamine compositions of the present invention are believed to be Stearate is an excellent Stabilizer. Combinations of interme useful in the cosmetic treatment of keratin-containing Sub diate chain length (C-C) aliphatic alcohols, esters, and Strates. Keratin Substrates include, but are not limited to, carboxylic acids may act as Stabilizers. Cetyl alcohol (C) animal and human hair, skin and nails. is commonly used in conjunction with triethanolamine to More particularly, the instant invention relates to polyes impart both soft “feel” and stabilization of the emulsion. ter polymer compositions and methods for treating keratin in 35 Cetyl palmitate, isolated from natural Sources, is a preferred which a cosmetically acceptable formulation is made with Stabilizer and carrier for other ingredients. the instant polyesters as a cosmetic vehicle. Preferably, the Many cosmetic preparations require thickeners to provide cosmetically acceptable medium is a hair care product Such the desired Viscosity. These thickeners are often used when as a shampoo, conditioner, Styling product or rinse, or a skin the lubricity of the oil fraction is heightened by a high care product Such as a cleaner, lotion or cream. 40 unsaturated oil composition of the cosmetic. Typical thick The invention further relates to improved waterproof eners include coconut diethanolamide, cellulose and certain Sunscreen compositions containing the polyesters of the ether derivatives such as hydroxyethylcellulose or instant invention. hydroxypropylcellulose, carrageenan, which is a linear Sul The invention also relates to waterproof, high-SPF Sun 45 fated polysaccharide of D-galactose and D-anhydro-D- Screen compositions comprising an emollient/Solvent Sys galactose. For a good discussion of the role of thickeners in tem and Sunscreen agent(s) in a polyester vehicle Suitable for cosmetic preparation, See Knowlton, et al., eds., Handbook topical administration. of Cosmetic Science and Technology, 1st ed., Elsevier, The invention is also concerned with waterproof Sun Oxford: 1993). Screen formulations and methods of protecting human skin 50 Since the advent of polymer Surfactant chemistry, a large from the effects of harmful ultraViolet radiation, e.g., and varied number of Surface active compounds have been erythema and burning, using effective amounts of the same. available for incorporation into cosmetics. Because Surfac tants tend to mobilize natural lipid, there is a pronounced BACKGROUND OF THE INVENTION tightening effect on the skin associated with their use, Even though cosmetic preparations have been a Staple of 55 presumably by their residues binding to keratin. This effect commerce for centuries, there continues to be a continual is most Severe using Sodium lauryl Sulfate, and is much expansion of cosmetic markets, and proliferation of new diminished in the use of potassium myristate. The use of products. The field of Skin care products has grown tremen Surfactants, of course, has an important cleaning function, So dously as new naturally occurring and Synthetic polymeric that they are common ingredients in cleansing creams. Since materials have been identified. Processing equipment and 60 these creams are first spread onto the skin and then removed techniques have also become more Sophisticated, So that almost immediately by tissue wiping, Surface contact is many of the current cosmetic products available over the minimized. counter, have a high level of uniformity and wholesomeness, There have been many studies of cosmetic additives but also impart Substantive pharmacologic and nutritive which enhance the penetration of the beneficial ingredients properties not realized in older preparations. 65 into the lower strata of the epidermis. Similarly there have The goal of modern cosmetics is to achieve multiple been many Studies of the physiology, histology, and bio effects simultaneously, Such as moisturizing, increased chemistry of the epidermis and dermis and their relation to US 6,692,728 B2 3 4 absorption. Among those compounds Studied, the following In a low oil formulation, the oil content may be only a few have been identified as promoting adsorption and penetra percent, and the texture of the preparation will rely upon tion (also termed “flux”) of chemicals through the lipid thickeners and emulsion StabilizerS Such as triethanolamine dominated interstices between cells of the lamellar layer: in combination with Stearic acid. propylene glycol either alone or in combination with unsat There have been many variations of cosmetic preparations urated fatty acids, and propylene glycol diesters of caprylic incorporating skin active agents in delivery Systems of and capric acids. Solvents such as DMSO, ethanol, varying efficiency. U.S. Pat. No. 5,618,850 discloses a tetrahydrofuran, and isopropanol are known to deplete