Skin and Skin Care
Barrier function in cosmetics: Imokawa has reviewed mechanisms of the skin barrier and its association with cosmetics.1 Barrier function in the stratum corneum plays an important role in protecting the skin from penetration of environmental substances or infection by epidemic bacteria. However, because the phenotype of barrier disruption on the skin is not easily detectable, it remains obscure as to what skin issues can be attributed to a barrier defect.
In this review, an in vivo methodology for evaluating barrier function is described to reveal factors that induce barrier disruption as well as the effects of barrier replenishing substances such as synthetic ceramides. The methods include TEWL, riboflavin technique, nicotinic acid technique and photoacoustic spectrometry (PAS). Recently, several lipids other than free ceramide, a known barrier modulator, have been implicated to serve as barrier modulators and particularly are associated with UVB-induced barrier disruption. These include covalently bound ceramide and glucosylceramide, which are added or reduced based on the down-regulated activity of transglutaminase, or beta-glucocerebrosidase, respectively.
In addition to UVB irradiation, surfactants are potent barrier- and water-disrupting agents in human life activities, and these disrupting effects mainly are evoked by a surfactant’s ceramide-depleting potential rather than its amino acid-releasing ability. The highest frequency of association with barrier function in the cosmetic field occurs in sensitive skin where the barrier function evaluated by TEWL and PAS is slightly but significantly impaired, leading to the lowered current perception threshold (CPT) evaluated by equipmenta that measures the electrodiagnostic sensory nerve conduction threshold (sNCT). The cutaneous features in sensitive skin resemble those of atopic dermatitis with mild severity. It is likely that skin care products appropriate for atopic dermatitis that possess barrier-replenishing potential are also applicable to the sensitive skin. Thus, barrier function has become an essential factor when considering high quality cosmetic preparations.
Microencapsulated thermochromic dyes: Kimberly-Clark disclosed2 the use of microencapsulated thermochromic dye compositions in skin care to indicate where the composition has been applied. After the product is applied to skin, it will quickly turn from colored to colorless as the temperature rises in response to the curing reaction and to heat from the skin.
These dyes are microencapsulated to avoid their migrating into the wound and to protect their functionality. They are selected to have a transition temperature between RT and that of the skin. Thus, 0.1 g of the blue encapsulated thermochromic powderb was added to 10 mL of a one-step skin preparationc. The mixture was stirred for 10 min, applied to the hand of a volunteer and rubbed to disperse the liquid over a 5-cm area. The skin preparation was clearly seen as a blue area that turned colorless very quickly as the alcohol evaporated.
In vivo friction study with moisturizers: Ramalho et al. reported an in vivo friction study of human skin and the influence of moisturizers on different anatomical sites.3 In order to understand the human haptic system, the mechanical characterization of skin must be understood. As the skin constitutes a surface, it is convenient to describe the problem using an analogous contacting surface, especially concerning the friction that occurs when the skin interacts with other surfaces. Several published works have shown that the analysis of the skin’s friction response can provide an indirect way to assess dry skin and other skin conditions.
The present study uses a new approach to evaluate in vivo the human friction measured by direct sliding action with an increase of the normal load. The normal compression and the tangential forces were measured using a three-dimensional force sensor while slipping the skin over a spherical glass surface. Two moisturizer ointments, petrolatum and glycerin, were applied in two anatomical sites on each individual participating this study. In order to evaluate hydration effects, this study also incorporated a direct characterization of the moisture content by measuring the TEWL; the efficacy of the moisturizers as a function of time after the application was studied for the different anatomical sites.
Collagen and fibroblast-promoting composition: Rohto Pharmaceutical Co., Ltd., has received a patent on a composition that promotes intracellular collagen production and/or fibroblast proliferation.4 The invention contains ascorbic acid, its derivatives and/or its salt; and the soybean protein thermolysin hydrolyzate.
Soybean protein powder was treated with Bacillus thermoproteolyticus-derived thermolysind and freeze-dried to obtain a protein hydrolyzate with an average molecular weight of 1500. The effect of combining l-ascorbic acid and the soybean protein hydrolyzate on collagen production in cultured human fibroblast CRL-1836 cells was examined. An example of a skin treatment emulsion is shown in Formula 1.
Antiaging skin compositions: Access Business Group International LLC disclosed antiaging topical skin compositions, their preparation and their use.5 The topical skin compositions include a complex containing components to provide defense against potentially damaging free radicals, reactive oxygen species (ROS), reactive nitrogen species and other oxidizing species on the human body. The compositions are said to improve barrier function, inhibit elastase and collagenase and/or promote synthesis of collagen and elastin. An example of a topical skin composition providing defense against ROS and that helps to repair damage caused by ROS is shown in Formula 2.
Hair and Hair Care
Removing hair sebum: Pola Chemical Industries Inc. has received a patent for the identification and removal of excess sebum6 that further provides formulations using those substances. The substances are tested for compatibility with solid fatty acids such as palmitic acid, solid cyclic alcohols such as cholesterol, and solid fatty acid triglyceridese at high and low temperatures. The substances are uniformly dispersed in a liquid phase with suitable components to allow shampoos and/or scalp cleansers to remove excess sebum. The preferred substances include polyethylene glycol monostearate and polyoxyethylene fatty acid glyceride.
Hair-styling conditioners: Kao Corp. disclosed nonwash-off hair-styling conditioners containing toluenesulfonic acid, carboxylic acids and organic solvents.7 The hair-styling conditioners contain toluenesulfonic acid or its salts; organic carboxylic acids or their salts; and organic solvents selected from aromatic alcohols N-alkylpyrrolidones, alkylene carbonates, polypropylene glycol, lactones and cyclic ketones. The conditioners may optionally include amphiphilic amide lipids and poly(N-acylalkyleneimine)-modified silicones. An example is shown in Formula 3, where a 20-fold diluted aqueous solution at 25°C is in the range of pH 2–6. The product resulted in hair-smoothing and hair-softening effects on damaged hair.
Hair coloring and bleaching compositions: The Procter & Gamble Co. described cross-linked, amphoteric polymer-thickened hair coloring and bleaching compositions comprising an oxidizing agent; a specified cross-linked, amphoteric, polymeric thickener; and a source of carbonate ion.8 This combination of ingredients surprisingly provided improved hair colorant and bleaching compositions, that deliver improved lift, lightening and color delivery while minimizing damage. The compositions also are easy to manufacture and have long shelf-life stability. An example of a hair dye composition is shown in Formula 4.
Hair treatment for straightening damage: Milbon Co. disclosed a hair processing composition containing disulfides.9 The composition is designed to be applied to hair after a hair has been straightened with an iron. The composition contains at least one reducing agent to optimize hair softness before applying a high-temperature (60–220°C) hair-styling iron. It also contains a disulfide, e.g., dithiodiglycolic acid or its salt, at 5–30%. An example is shown in Formula 5.
Oxidative hair dye: Mandom Corp. describes oxidative hair dye compositions containing polyoxyethylene hydrogenated castor oils, hydrocarbons and quaternary ammonium salts.10 The quaternary ammonium salt is of the form:
where R1CO is a branched fatty acid residue or lanolin fatty acid residue; R2, R3, R4 are C1–3 alkyl; n is 2–3; and X- is a halogen ion, methyl sulfate ion or ethyl sulfate ion. The composition may further contain a fatty acid such as amidoamine and/or an alkyl-quaternary ammonium salt. The invention relates to an oxidative hair dye that is easily applied and provides excellent coloring property, natural gloss and smoothness without causing hair damage. An example of an oxidative hair dye is shown in Formula 6.
Mineral filters in sunscreens: Couteau et al. report on mineral filters in sunscreen products by comparing the efficacy of zinc oxide and titanium dioxide by in vitro method.11 European legislation currently authorizes 26 sun filters among which there is only one mineral filter—titanium dioxide. In the United States, two mineral filters are authorized: titanium dioxide in a maximum dose of 25% and zinc oxide. Zinc oxide is authorized in Europe, but its concentration level is not limited. A large number of commercial products contain one of these mineral filters; however, the difference between these materials lies in the percentage of the active substance, the way they are incorporated into the final product, and the size of the primary particles.
Depending on the ingredient used, there is a large variation in efficacy. The efficacy of the products tested was determined by an in vitro method using a spectrophotometer equipped with an integration sphere. Titanium dioxide was seen to be much more effective than zinc oxide. No commercial form of zinc oxide tested can give an SPF level higher than 10 at its maximum usage dose, whereas titanium dioxide coated with alumina, stearic acid, etc., has an SPF of 38.
This study has also allowed the authors to dispel the theory that talc, a raw material used for years for photoprotective effects in foundation, has an effect against sun rays. When talc was formulated at a level of 25%, it only produced a totally negligible SPF of one unit, proving it ineffective.
Eye makeup composition: Mandom Corp. discloses a color cosmetic composition containing dyes, 1,2-octanediol, a clay mineral, and/or a water-soluble polysaccharide.12 The cosmetic composition has good dispersibility of dye with storage stability and provides a soft, long-lasting cosmetic film. The composition may further contain a film-forming polymer. An example of an eyeliner is shown in Formula 7.
Glycerin esters for skin moisturization: Shiseido Co., Ltd., disclosed stable, w/o emulsions containing glycerin esters with a skin care effect.13. The emulsions contain 0.1–10% w/w glycerin monooleate, glycerin monoisostearate and/or polyoxyethylene glyceryl monoisostearate; 70–98% w/w aqueous ingredients; and oily ingredients containing 3–70% w/w oily solids. The disclosed emulsion, shown in Formula 8, exhibited stability and moisturizing effects.
Microparticle drug delivery system: Amcol International Corp. disclosed a polymeric microparticle drug delivery system and a method of manufacturing the system.14 The system for an active compound includes an active compound loaded onto polymeric microparticles, wherein the loaded microparticles are encased by a matrix material comprising about 68–99% w/w of the microparticle delivery system. A dihydroxyacetone (DHA) o/w lotion was used as the base into which 5% DHA was added from a 50% aqueous solution; this was followed with the addition of a loaded microparticle/matrix delivery system containing either an allyl methacrylate crosspolymerf or a lauryl methacrylate/dimethacrylate crosspolymerg. The base formulation is shown in Formula 9.
Alcohol-free cosmetic or pharmaceutical foam carrier: Foamix Ltd. discloses an alcohol-free cosmetic and pharmaceutical foam carrier comprising water (aqua); a hydrophobic solvent such as mineral/silicone/vegetable oil, triglycerides, isopropyl myristate or octyl dodecanol; a foam adjuvant agent, a surfactant, and a water-gelling agent as a flame retardant or flame resistant foam.15 The cosmetic or pharmaceutical foam carrier does not contain aliphatic alcohols, making it nonirritating and nondrying. The alcohol-free foam carrier is suitable for including both water-soluble and oil-soluble pharmaceutical and cosmetic agents. The composition of an antifungal foam formulation is shown in Formula 10.
Dry personal cleansing products: The Procter & Gamble Co. discloses dry, disposable personal cleansing articles for skin or hair comprising nonfibrous polymeric material, a lathering surfactant and a conditioning component.16 These articles are wetted with water by the consumer and then rubbed against the skin or hair.
The articles are made up of a water-insoluble substrates having nonfibrous polymeric raised areas on at least one surface. The raised areas are formed of a polymeric material having a specified hardness (i.e., no more than approximately 80 on the Shore A hardness scale) and a lathering surfactant releas-ably associated with the substrate. Preferably, the articles of the invention further comprise a conditioning component.
An example is shown in Formula 11.
Polyglycerin ester emulsified composition: Sakamoto Yakuhin Kogyo Co., Ltd., discloses emulsified cosmetic compositions containing polyglycerin esters.17 The disclosed compositions provide minimized oily feeling and stickiness with usage. The essential components are polyglycerin condensed ricinoleate ester, polyglycerin myristate ester and polyglycerin stearate ester. The essential components represent 1–10% of the composition, and the content of polyglycerin condensed ricinoleate ester among the three components is 1–20%. For example, an emulsified cosmetic composition was prepared with 0.2% w/w polyglycerin condensed ricinoleate, 0.5% decaglyceryl monomyristate, 0.3% decaglyceryl monostearate, and the following ingredients: 10% squalane; 5% trioctanoin; 3% behenyl alcohol; 4% 1,3-butylene glycol; 0.1% sodium hyaluronate; and a water balance to 100%.
Anhydrous film for improved dissolution: L’Oréal received a patent on a film with improved dissolution and a cosmetic product containing that film.18 The described water-soluble anhydrous film comprises at least one water-soluble or hydrodispersible film-forming polymer, at least one polysaccharide thickening agent and a water-soluble or hydrodispersible oxyalkylenepolydimethylsiloxane. The invention also refers to a cosmetic kit containing a film with an aqueous composition. An example from the patent is shown in Formula 12.
1. G Imokawa, Barrier mechanisms and its association with cosmetics, Nippon Koshohin Gakkaishi 31(2) 85–91 (2007) (in Japanese)
2. WO 2008 12,709, Microencapsulated thermochromic dye compositions for skin application, Kimberly-Clark Worldwide Inc, USA (Jan 31, 2008)
3. A Ramalho et al, In vivo friction study of human skin: Influence of moisturizers on different anatomical sites, Wear 263(Pt 2) 1044–1049 (2007) (in English)
4. JP 2008 24,703, Composition having collagen production-promoting effect and/or fibroblast proliferation-promoting effect, Rohto Pharmaceutical Co, Ltd, Japan (Feb 7, 2008)
5. WO 2008 16,838, Topical skin antiaging compositions, their preparation and their use, Access Business Group International LLC, USA (Feb 7, 2008)
6. JP 2008 24,663, Cosmetics for excess sebum removal, Pola Chemical Industries Inc, Japan (Feb 7, 2008)
7. JP 2008 24,609, Non-wash-off type hair-styling conditioners containing toluenesulfonic acid, carboxylic acids, and organic solvents, Kao Corp, Japan (Feb 7, 2008)
8. WO 2008 15,646, Cross-linked amphoteric polymer thickened hair coloring and bleaching compositions comprising oxidizing agent and a source of carbonate ion, The Procter & Gamble Co, USA, (Feb 7, 2008)
9. JP 2008 31,052, Hair processing compositions containing disulfides, Milbon Co, Ltd, Japan (Feb 14, 2008)
10. JP 2008 31,056, Oxidative hair dye compositions containing polyoxyethylene hydrogenated castor oils, hydrocarbons and quaternary ammonium salts, Mandom Corp, Japan (Feb 14, 2008)
11. C Couteau et al, Mineral filters in sunscreen products: Comparison of the efficacy of zinc oxide and titanium dioxide by in vitro method, Pharmazie 63(1) 58–60 (2008) (in English)
12. JP 2008 31,057, Makeup cosmetics containing dyes, 1,2-octanediol, clay minerals and/or water-soluble polysaccharides, Mandom Corp, Japan (Feb 14, 2008)
13. JP 2008 24,630, Storage-stable water-in-oil emulsions containing glycerin esters with skin care effect, Shiseido Co Ltd, Japan (Feb 7, 2008)
14. WO 2008 13,757, Polymeric microparticle drug delivery system and method of manufacturing the same, Amcol International Corp, USA (Jan 31, 2008)
15. US 2008 31,907, Alcohol-free cosmetic and pharmaceutical foam carrier comprising hydrophobic solvent such as mineral/silicone/vegetable oil, triglycerides, isopropyl myristate, octyl dodecanol, foam adjuvant agent, surfactant and gelling agent, Foamix Ltd, Israel (Feb 7, 2008)
16. WO 2008 15,641, Disposable personal cleansing articles for skin or hair comprising nonfibrous polymeric material, lathering surfactant, and conditioning component, The Procter & Gamble Co, USA(Feb 7, 2008)
17. JP 2008 31,051, Emulsified cosmetic compositions containing polyglycerin esters, Sakamoto Yakuhin Kogyo Co, Ltd, Japan (Feb 14, 2008)
18. FR 2,904,765, Film with improved dissolution and a cosmetic product containing it, L’Oréal, France (Feb 15, 2008)