This month’s survey of recent patent and research literature describes moneymaking ideas for personal care product development including the chitosan-coated liposome delivery of tamarind, luminescent pigments, microemulsions and laudanosine for antiaging, among others.
Skin and Skin Care
Skin moisturization: Tomaru has published a review on moisturizing products for the skin.1 Moisturization is an important claim for skin care products. The stratum corneum (SC) has its own water-holding mechanisms but they are not always enough. Successful ways to moisturize skin include humectants and emollients that are adapted to the skin’s condition and the natural water-holding mechanisms.
Formulators can improve upon the water-holding ability of humectants by adjusting the microstructure of the ingredients; for example, with liposomes and other lamellar structures. Furthermore, improvement of total skin condition can be achieved by applying ingredients that promote the production of a moisturizing factor. An example of such an ingredient is an extract of rice in combination with water,a which has been shown to increase the amount of ceramides, the main components of intercellular lipids.
W/O emulsion to prevent TEWL: L’Oréal discloses a skin care w/o emulsion for topical application comprising at least one emulsifying silicone elastomer and at least one semi-crystalline polymer.2 The invention relates to the use of the composition or skin care, in particular for nourishing the skin, preventing transepidermal water loss and protecting the skin. The disclosed composition for a w/o moisturizing day cream is shown in Formula 1.
Liquid crystal composition: Bioentech Co., Ltd., discloses a liquid crystal composition, its manufacturing method and the cosmetic composition containing it.13 The liquid crystal composition contains saturated lecithin, cetyl alcohol, stearyl alcohol and glyceryl stearate. According to the inventors, based on the lamella-forming capability of lecithin, other components and an additional coating process are not necessary. The liquid crystal composition exhibits improved stability and moisturizing effects and reportedly bears a likeness to skin. The composition is capable of reducing water loss and can be widely used in cleansers. The invention also relates to a method for manufacturing the liquid crystal composition.
Laudanosine for antiaging: Sederma discloses antiaging cosmetics containing laudanosine.3 The cosmetic use of laudanosine, one of its analogs, or a vegetable extract containing laudanosine is described for improving the general state of skin. An example of an antiaging cosmetic is shown in Formula 2.
Three-part cosmetic kit for skin: Beiersdorf AG discloses a cosmetic combination product for improving the external appearance of skin.4 The invention concerns a cosmetic kit that contains at least two components from: one or more dietary supplements, one or more topically applicable cosmetic preparations, and one or more self-adhesive skin masks. A typical self-adhesive gel mask is shown in Formula 3.
Hair and Hair Care
Long-lasting hair gel: Beiersdorf AG discloses a long-lasting hair styling gel.5 The described cosmetic preparation contains at least one: anionic, film-forming polymer; hydrophobically modified acrylate thickener; and one block polymer that in turn comprises at least one: polyethylene glycol block, polypropylene glycol block, and an optional silicone copolyol. An example is shown in Formula 4.
Nonsticky, oily lip cosmetic: Mandom Corp. launched oily solid cosmetics containing dimer acid esters, waxes (solid at RT) and C5-10 1,2-alkanediols that impart a nonsticky, moist feel to lips.6 The lip cosmetics additionally contain optional N-acylglutamic acid diesters. An example of an oily, non-sticky lipstick is shown in Formula 5. The product reportedly showed good spreadability on skin and gloss, provided a moist and nonsticky feel, and was stable in appearance after storage for four weeks at 40°C.
Light-stimulated pigments: Henkel AG & Co. introduced coloring agents containing luminescent pigments that are stimulated by visible light.7 The resulting colors are said to give a gloss effect. The coloring agents are described for use in textile dyes and color cosmetics for materials containing keratin, such as skin, hair and fingernails.
Treating nails with chitosan: Polichem S.A. discloses the use of chitosan to increase nail growth rate and to treat nail disorders.8 The described invention uses chitosan, a chitosan derivative or a physiologically acceptable salt thereof. The invention is further indicated for use in accelerating nail growth during treatment of nail diseases, nail dystrophy or other nail conditions to considerably shorten the specific treatments of the nail inflictions. The composition shown in Formula 6 had a clear, homogeneous appearance even after prolonged storage. Moreover, when applied on the nails, the liquid formed a nonsticky, elastic film that could strongly adhere to the nail surface.
Nail lacquer additive: Evonik Degussa GmbH discloses a shiny and scratch-proof nail varnish obtained via the addition of silanes to nail lacquer.9 The additives contain at least one silane and one solvent; water; and a catalyst selected from: hydrochloric, nitric, phosphoric, sulfuric, formic, propionic, acetic or citric acid or their mixture. The additive is mixed with conventional or unconventional nail lacquers and prepared from: 10% w/w orthosilicate (and) tetraethoxysilane; 50% methyltriethoxysilaneb; 12 % nitric acid (1%); 12% propanol and 16% butyl acetate. The additive was mixed at 10% with 90% available nail lacquer.
Scratch-proof silane nail varnish: Evonik Degussa GmbH also discloses the formation of a shiny and scratch-proof nail varnish through addition of silanes to nail lacquer.10 The additives contain at least one silane and one solvent and are mixed with conventional or unconventional nail lacquers. Thus, an additive was composed from 30 g tetraethyl orthosilicate (and) tetraethoxysilaneb and 30 g butyl acetate in an impeller blade mixer. The additive was mixed at 5% with 95% available nail lacquer.
Spectrophotometric SPF evaluation: Bleasel et al. have published on the in vitro evaluation of sun protection factors (SPFs) of sunscreen agents using a novel UV spectrophotometric technique.11 The method described determines the low and high value SPF of sunscreens using artificial substrates and a novel pseudo-double-beam (PDB) mode of operation of a standard double beam UV spectrophotometer. This technique allows transmittance to be calculated from detector responses of reference and sample beams measured at different gain levels. The method facilitates the accurate quantification of low levels of electromagnetic radiation transmitted through highly absorbing samples.
The standard double beam UV spectrophotometer was modified to hold quartz diffusing plates onto which a substrate—Transpore adhesive tape or human SC obtained from a skin surface biopsy (SSB)—and the sunscreens to be tested were applied. The PDB mode of operation increased the effective linear range of the detector response of the spectrophotometer by approximately 20,000-fold, enabling the in vitro SPF determination technique to be applied to both high and low SPF value sunscreens. Eight commercial sunscreens with known SPF values of 4–77, previously determined by in vivo methods, were tested using both test substrates and correlations between the in vivo and in vitro values. The SPF values measured using the described in vitro method correlated well with the known in vivo results—Transpore tape, R2 = 0.611 : SSB, R2 = 0.7928). However, the in vitro SPF obtained for one of the tested products differed substantially from the cited in vivo SPF value. The independent in vitro and in vivo re-evaluation of the SPF of this product matched the value predicted by the present method much more closely than the originally cited in vivo value. All determined SPF values were ordered correctly in comparison with their in vivo ranking, and the technique appeared to correctly identify a sunscreen that had a labeled SPF value that was significantly higher than its true SPF.
Water-soluble UV filter: Beiersdorf AG discloses cosmetic preparations with water-soluble UV filters and a vinylpyrrolidone/acrylic acid copolymer.12 The cosmetic preparations contain one or more water-soluble UV photoprotective filters selected from 2-phenylbenzimidazole-5-sulfonic acid and the sodium, potassium and triethanol ammonium salts thereof, as well as phenylene-1,4-bis-(2-benzimidazyl)-3,3’-5,5’-tetrasulfonic acid and the sodium, potassium and triethanolammonium salts thereof; and a copolymer of vinylpyrrolidone and acrylic acid. An example is shown in Formula 7.
Lipid microemulsions: Cargill Inc. has been issued a patent on lipid microemulsions.14 The described microemulsions include an aqueous component, a lipid (e.g., sterol esters or omega-3 fatty acids), a saccharide, an alcohol, and an emulsifier. The microemulsion is produced by first adding the saccharide to the aqueous liquid to form a mixture, then adding an alcohol and emulsifier to the mixture and finally adding a lipid to the mixture to form a microemulsion. An example is shown in Formula 8. Food or beverage products including a microemulsion are also disclosed in the patent.
Catechin and surfactant antibacterial detergents: Kao Corp. introduced antibacterial detergent compositions containing catechins and surfactants, and a method for imparting antibacterial activity on various compositions.15 The compositions contain 0.0005–5% catechins and 0.00001–80% cationic, amphoteric and/or nonionic surfactants. The method involves adding the above compositions to cosmetics, quasi drugs, pharmaceuticals, and household products. Thus, a combined use of catechinc and a surfactant chosen from lauramine oxide, alkylbenzyl dimethyl ammonium chlorided and glyceryl lauratee showed synergistic antibacterial activityc.
Rheology in stable, tactile cosmetics: Akatsuka has reviewed the application of rheology properties for developing highly stable and tactile cosmetics.16 The rheological properties of ternary systems containing single-chain cationic surfactants, long-chain alcohols and water were studied to enhance their long-term stability and usability. The basic ternary systems behave as solids at low stress, due to the formation of alpha-gels. Adding a double-chain cationic surfactant to a ternary system causes the rupture of the alpha-gels, transforming them to vesicles. Thus, the viscosity of the system as well as its stability was lowered significantly.
The effect of polyols on the rheological properties of ternary systems also was studied to improve their usability against shear forces. External shear to ternary systems causes the rupture of gel structures and the systems are converted from solid-like bodies to viscoelastic liquids. The mechanism resulting in the rheological changes is the release of bound water in lamella liquid crystals without rupture of lipophilic layers.
When a trivalent alcohol like glycerin is added, the quaternary systems show plastic responses even after violent shear. The phase transition behavior implies that the glycerin molecules are hardly incorporated into the lamella layers of lipophilic groups but remain in the water layers to increase their strength. This was confirmed through differential scanning calorimetry and small angle x-ray scattering.
Interesting Raw Materials
Delivery of tamarind with chitosan: Phetdee et al. have published on the development of chitosan-coated liposomes for sustained delivery of tamarind fruit pulp extract to the skin.17 In this study, chitosan-coated liposomes were developed. To entrap lyophilized tamarind extract containing alpha hydroxy acids (AHAs) with tartaric acid, reverse phase evaporation was used to obtain well-formed liposomes loaded with the extract. The highest entrapment efficiency of 68.3 ± 3.0% into the liposomes was obtained with liposomes consisting of phosphatidylcholine and cholesterol in a molar ratio of 2:1 after the extrusion process. The average particle size of the prepared liposomes was 158 ± 26 nm showing a negative zeta potential of -6 mV. For the preparation of the chitosan-coated liposomes, two selected independent parameters were varied—chitosan concentrations of 0.1, 0.5 and 1.0% w/v and volumes of the chitosan solutions of 1.2 mL and 3 mL—to study the effects of such parameters on the entrapment efficiency of the extract-loaded liposomes.
Variation in the volumes of the chitosan solution did not affect the entrapment efficiency of the liposomes. However, the entrapment efficiency of the AHAs in the chitosan-coated liposomes significantly increased with increasing chitosan concentration. The size of the chitosan-coated liposomes was in the range of 200–300 nm with a positive zeta potential in the range of 6–29 mV. An in vitro release study using a dialysis technique was performed to evaluate the release profile of the tartaric acid from the chitosan-coated liposomes. The results showed the effect of the chitosan-coated liposomes on the lower release rate and on the amount of tartaric acid in comparison with that of the uncoated liposomes. The study in an in vitro skin cell model indicated the developed system could enhance the potential of tamarind AHAs on the stimulation of human keratinocyte proliferation twice as much as the solution of the tamarind extract.
Oil gelling agent for cosmetics: Yoshida describes the characteristics of a new oil gelling agent for cosmetics and its application.18 An oligomeric polyamide gelation agent, distearylamine-terminated dilinoleic acid-ethylenediamine copolymerf was examined using diisostearyl malate as the solvent. The characteristics of the gelling agent were: safety, confirmed by a closed patch test for 48 hr and a test stimulating the mucous membrane for 24 hr; miscibility, with oil agents in a use range of 40–50%; transparency, evaluated at a range of 400–800 nm; and hardnessg. Oil agents with an ester group and/or a hydroxyl group were superior in the transparency and hardness, as compared with oil agents without these groups. Proposed formulas for a transparent lipstick and a hair styling treatment product are shown in Formulas 9 and 10.
The quality of the formulated products was assessed for styling power and found to be as effective as commercial products without the need for natural wax. High humidity was found to affect product performance much less in products incorporating the oil gelling agents than in commercial products without them.
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1. J Tomaru, Moisturizing products for skin, Frag J 36(7) 43–48 (2008) (in Japanese)
2. US 2008 199,421, Skin care w/o emulsion for topical application comprising emulsifying silicone elastomer and semi-crystalline polymer, L’Oréal, France (Aug 21, 2008)
3. FR 2,912,653, Antiaging cosmetics containing laudanosine, Sederma, France (Aug 22, 2008)
4. EP 1,961,408, Cosmetic combination product for improving the external appearance, Beiersdorf Aktiengesellschaft, Germany (Aug 27, 2008)
5. DE 102,007,008,089, Hair styling gel having a long-lasting effect, Beiersdorf AG, Germany (Aug 14, 2008)
6. JP 2008 189,618, Oily solid cosmetics containing dimer acid esters, waxes and 1,2-alkanediols with nonsticky, moist feel for lips, Mandom Corp., Japan (Aug 21, 2008)
7. WO 2008 92,522, Colouring agents containing luminescent pigments that can be stimulated by visible light, Henkel AG & Co. KGaA, Germany (Aug 7, 2008)
8. WO 2008 98,869, Use of chitosan to increase nail growth rate and to treat nail disorders, Polichem S.A., Luxembourg (Aug 21, 2008)
9. EP 1,961,449, Shiny and scratch-proof nail varnish through addition of sol gel systems, Evonik Degussa GmbH, Germany (Aug 27, 2008)
10. EP 1,961,448, Shiny and scratch-proof nail varnish through addition of silanes, Evonik Degussa GmbH, Germany (Aug 27, 2008) 11. MD Bleasel and S Aldous, In vitro evaluation of sun protection factors of sunscreen agents using a novel UV spectrophotometric technique, Intl J Cosm Sci 30(4): 259–270 (2008) (in English)
12. EP 1,958,609, Cosmetic preparation with water-soluble UV filter and vinylpyrrolidone/acrylic acid copolymer, Beiersdorf A.G., Germany (Aug 20, 2008)
13. KR 830,153, Liquid crystal composition, its manufacturing method, and cosmetic composition containing the liquid crystal composition, Bioentech Co., Ltd., S. Korea (May 20, 2008)
14. US 2008 199,589, Lipid microemulsions, Cargill, Inc., USA (Aug 21, 2008) 15. JP 2008 195,917, Antibacterial detergent compositions containing catechins and surfactants, and method for imparting antibacterial activity on various compositions, Kao Corp., Japan (Aug 28, 2008)
16. H Akatsuka, Application of rheology properties for developing highly stable and tactile cosmetics, Frag Jrnl 36(7) 36–42 (2008) (in Japanese)
17. M Phetdee et al, Development of chitosan-coated liposomes for sustained delivery of tamarind fruit pulp’s extract to the skin, Intl J Cosm Sci 30(4): 285–295 (2008) (in English)
18. M Yoshida, Characteristics of a new oil gelling agent for cosmetics and its application, Frag J 35(11) 72–76 (2007) (in Japanese)