The formation mechanism of multilamellar emulsions of artificial stratum corneum lipids containing synthetic pseudo-ceramide and their physiological effects on dry and scaly skin, lacking the function of stratum corneum lipids, have been investigated. A pseudo-ceramide being the analogous molecular structure to the natural occurring ceramide was synthesized according to the molecular design. The highly selective reaction of the synthesis enabled the industrial production of this synthetic ceramide. Then the artificial stratum corneum lipids, possessing self-organizing lamellar structure, were prepared by using the synthetic pseudo-ceramide in combination with amphiphilic molecules. It was confirmed that these amphiphilic molecules stabilized the lamellar association structure by intermolecular interactions thus enhancing the bound water content. Using these artificial stratum corneum lipids as the oil phase, we obtained multilamellar emulsion in which each emulsion droplet possesses a concentric lamellar structure. The multilamellar emulsion recovered the water-retaining ability of stratum corneum, which was not recovered solely by the treatment of an ordinary emulsion, and improved the scaling to restore the fine texture of the skin. It is concluded that we could succeed in developing a highly functional skin protection cosmetic, a multilamellar emulsion, which recovers water-retaining ability and adhesion of corneocytes in the identical mechanism with intercellular stratum corneum lipids.

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Lecithin is a safe and effective ingredient for skin care cosmetics but can not solely stabilize emulsions. Liposomal suspensions attractive for skin treatment, have limited physical stability when formulated into cosmetic products. Acrylates/C10-30 Alkyl Acrylate Crosspolymer (Acrylate Crosspolymer) at very low concentrations are highly effective at stabilizing lecithin emulsified Mineral oil of Glyceryl trioctanoate O/W emulsions. The Acrylate Crosspolymer was most effective at stabilizing liposomal suspensions compared to other water soluble polymers.
The oxidative and particle size stability of Vitamin A ester (Retinol Palmitate) in a O/W emulsion was greater for lecithin vs POE (5.5) Cetylether when stabilized with Acrylate Cross-polymer.
The improvement in waterproof character/wearing time of Octyl Dimethyl PABA was higher in lecithin vs POE (5.5) Cetylether sunscreen formulation when stabilized with Acrylate Cross-polymer.
Formulations of various skin care cosmetics were also developed to study the effects of Acrylates/C10-30 Alkyl Acrylate Crosspolymer on Lecithin and Liposomal emulsions.

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The long-term stability of liposomes prepared from hydrogenated phosphatidylcholine was investigated in order to utilize liposomes in cosmetics.
When incompletely hydrogenated soya phosphatidylcholine (IH-Soya PC) liposomes were stored at 40°C, pH decrease and corresponding change of liposomal appearance were observed. It was found that pH decrease was induced by the peroxidation of the residual unsaturated fatty acyl chains in IH-Soya PC. The liposomes composed of completely hydrogenated soya phosphatidylcholine (CH-Soya PC), whose appearance, pH and particle size did not change at wide-range thermal conditions, could maintain the trapped, water-soluble materials inside themselves for a long time. Furthermore, we examined the decomposition of PC during storage and observed that PC was drastically hydrolyzed by incorporating dicetylphosphate, a negatively charged lipid, into liposomes.
On the basis of all the results, we finally succeeded in developing a stable liposomal formula.
To investigate the potential of these liposomes as a delivery system in topical formulations, the percutaneous absorption of liposomes with radioactively labelled mannitol was studied in comparison with percutaneous absorption without liposomes. The [³H]-mannitol disposition studies indicated that the liposomal form produced significantly higher [³H]-mannitol accumulation in the skin. It was confirmed that the liposomal encapsulation favorably altered drug disposition when topically applied on the skin, a finding which led to the development of cosmetics with a long-lasting topical effect on the skin.

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In order to discover the antimicrobial activity against skin resident microorganisms responsible for axillary odor, the minimum inhibitory concentrations (MICs) of common fragrance materials were determined by agar plate dilution method.
In this assay, Corynebacterium minutissimum (CM), Arthrobacter sp., (LT), Staphylococcus aureus (SA), Staphylococcus epidermidis var. (SE) and Escherichia coli (EC) were tested.
Twelve musk chemicals were active against LT. Particularly, the MICs of ethylene brassylate and 5-α-androst-16-en-3-ol were both 12.5ppm. Also, nine sandal chemicals were active against CM, LT, and SA. Among them, the MICs of derivatives of camphorenic aldehyde were 50, 25 and 50ppm against CM, LT and SA respectively. But the MIC of its derivative against SE which dose not generate axillary odor was 2000ppm. Considering the fact that the MICs of fragrance materials ranged from 1000 to 2000ppm against common bacteria, musk and sandal chemicals are by far more effective against aerobic diphtheroids responsible for axillary odor.

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To observe the growth activity of bacteria and molds in cosmesics and toiletries, we attempted to create a device to measure the metabolic heat associated with growth nondestructively and continuously. However, in cosmetic products inoculated with microbes the growth rate is too slow to make an accurate measurement of the metabolic heat, even in a system without preservatives. we then found that the growth rate of microbes is elevated when they are adhered to material with a large specific surface area. Therefore, we examined the utility of various supports. As a result, the metabolic heat generated by the growth of the microbes became measurable by saturating a porous urethane foam with the products. This process elevated the growth activity about ten-fold.
The growth of microbes observed using this method exhibited different characteristics depending on the types and amounts of preservatives contained in the product, or on the type of microbes. The procedure employed here was found to be very useful in analyzing the preservative characteristics of the cosmetic products. It is suggested that this method can be used to evaluate quantitatively the preservative properties of cosmetics and toiletries.

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Lauroyl beta-alanine (LBA) is a unique amino acid derivative-surfactant which has recently been found to have very low potential of inducing a specific inflammationrelated receptor on epidemal cells, intercellular adhesion molecule-1 (ICAM-1) when incubated with human keratinocytes. This led us to assume that this surfactant possesses very low cutaneous inflammatory properties as opposed to ordinary commercially available anionic surfactants. Thus, we have assessed the biologic effects of LBA on several cellular derangements in the stratum comeum, cytotoxicity against human keratinocytes and an influence on arachidonic metabolism in skin tissue in comparison with those by other ordinary anionic surfactants such as potassium myristate (SOAP), sodium dodecyl sulfate (SDS), sodium cocoyl isethionate (SCI), acylmethyl taurine (AMT) and monoalkyl phosphate (MAP).
Permeability experiments using hairless pig skin indicated that LBA is 10 and 3 times as lower permeable as SOAP and MAP, respectively. In in vitro study on human keratinocytes, of all anionic surfactants used, LBA showed the lowest inhibitory effect on cell growth which was accompanied by a lower level of the release of arachidonic metabolite such as prostaglandin E₂ (PGE₂) from human keratinocytes. This mild cellular effect was also corroborated by the previous observations that LBA elicits on substantial expression of ICAM-1 which has recently been identified on surface of epidermal cells in inflammatory dermatosis typified by T cell infiltration, in contrast to a marked expression by some of other anionic surfactants.
In order to clarify in vivo cutaneous effect, cumulative cup shaking test was carried out on the inner surface of human forearm skin by applying surfactant aqueous solutions twice a day for four days. Whereas almost all anionic surfactants induced severe scaling and erythematous reactions during repeated treatments, LBA was the only surfactant which did not elicit any roughness and inflammatory reaction. This non-inflammatory property was also corroborated by an additional study on damaged skin that roughened forearm skin after acetone/ether treatment can be slightly restored even by successive applications of LBA, but not other anionic surfactants used. These findings indicate that LBA has biologically low active properties to both stratum coreum and epidermal cells which may lead to the development of a unique surfactant applicable to damaged skins.

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The foaming property of alkylsaccharide surfactants and their effects on protein, skin and scalp were examined, in consideration of their application to personal care products especially detergents. The alkylsaccharides showed a highly stable foaming property as compared with nonionic surfactants containing polyoxyethylene-added type nonionic surfactants. Judging from the results of the measurments of surface pressure, apparent molar volume of hydrophilic group and mobility oh hydrophilic group, we considered that the highly stable foaming property is due to the strong cohesive force at the air-liquid interface of the hydrophilic group of the alkylsaccharide molecules which consisted of a compact sugar structure having low mobility.
The effects of alkylsaccharides on proteins, skin and scalp were next examined. Alkylsaccharides had lower denaturating effect on myoglobin than anionic surfactants, and prevented the denaturation by heat and urea more than noionic surfactants with polyoxyethylene added. Measurements of the loss of amino acids and lipids from the skin during washing showed that less were lost when alkylsaccharides were used than when anionic surfactants were used. Production of dandruff by shampoo containg lauryl surfate triethanolamine salt was less than that produced by shampoo containing alkylsaccharide. These results suggested the high possibility of applying alkylsaccharide to low irritant detergent products (shampoo, body shampoo).

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The major role of cosmetic in the 21st century wil be in anti-aging. Many mechanisums of aging have been reported. The effect of the active oxygens in aging have been noted. The active oxygens generated by UV irradiation and other stimulations in the body, attack various organs and components. If the active oxygens attack the DNA directly, the DNA is injured, and an error in gene transmission arises. When active oxygens attack the cell membrane, lipids in the membrane are peroxidated. Peroxidation of the membrane is resposible for errors in the various membranes mediating biological reactions. Consequently, it may be presumed that aging is thus caused. Therefore, strong active oxygen scavengers are required for anti-aging. The active oxygen source in a body is superoxide anion. We researched the anti-aging ingredient in plants by using the superoxiae disumutase-like activity (SOD-like activity) as an indicator. It was found that Hamamelitannin in Hamamelis virginiana L. had just such an effect. The effect of Hamamelitannin as the ingredient for anti-aging was evaluated by using in vitro and in vivo methods.

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The effect of protease as a cleansing agent and the improvement of protease stability by chemical modification with polyethylene glycol derivatives were studied. The proteolytic actions of Bioprase and papain on keratins and sweat proteins, which are major proteinic impurities on the skin, were compared. Bioprase degraded both more effectively than papain. Although Bioprase possesses potential usefulness as a cosmetic material, it has a defect: low staility in a system containing water. This defect prevents the application of Bioprase to various preparations except for powder-type preparations. To improve the stability of the native Bioprase, it was chemically modified with copolymers of α-allyl-ω-methoxy polyoxyethylene and maleic anhydride. The stability of Bioprase was extremely improved by the modification. The modified Bioprase was further stabilized by adding such polyols as 1, 3-butylene glycol, glycerin, and propylene glycol. Some nonionic surfactants did not decrease the stability of the modified Bioprase. This method for stabilization allows the application of enzyme to various preparations. By continual use of a cleansing preparation containing the modified Bioprase, skin conditions improved.

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Wheat gluten was hydrolyzed enzymatically to produce wheat polypeptides (W. P.) having designed main molecular weight range 5000-10000. This fraction has been found to have excellent functional properties as compared with that of animal-derived collagen in the treatment and protection of hair. Experimental evidence indicates that W. P. has several advantages: 1) low average coefficient of friction which gives excellent lubricity as indicated by an atomic force microscope (AFM); the cuticle of the hair possesses remarkable smoothness, 2) enhances hair wettability, 3) imparts good foaming ability, rinseability, combability and suaveness in shampoos, and 4) excellent emulsifying ability which also forms a stable emulsion. Having these functional properties, W. P. would find widespread application in hair-care and moisturecontrol products.

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We developed polyether modified silicones as a nonionic w/o type emulsifier for dimethylpolisiloxane. However, the silicone emulsion prepared with the polyether silicone gave an unpleasant odor after a few days, making it difficult to apply to cosmetics. We found that the smell is caused by a very smal amount of propionaldehyde and that the mechanism forming the propionaldehyde is as follows.
In the process of producing polyether modified silicone, the terminal allyl group of polyether which is used as a starting material is partially isomerized to iso-propenyl group in the presence of the platinum catalyst. Isopropenyl group does not react with the hydrogen siloxane and remains as an impurity in the polyether modified silicone produced by the main reaction. Then, it is gradually hydrolyzed to produce produce propionaldehyde and polyethyleneglycol with the passage of time. And the hydrolysis of the isopropenyl group is accelerated by acid.
We developed refined and cosmetically applicable silicones by treating polyether modified silicones containing the iso-propenyl impurities with a dilute hydrochloric acid to give rise to propionaldehyde, followed by elimination of it.

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Black iron oxides are used to prepare make-up products having blackish color tone.
The color of black iron oxides on the market shows yellowish and reddish black color tone. Black iron oxide is formed by the oxidation of Fe(OH)₂ obtained by mixing NaOH soln. and FeSO₄ soln.
The mechanistic study is investigated from Ferrous-Ferric Mixture by Prof. Machvec, Tamaura and Kiyama, et. al. In the wet method, several kinds of iron compounds are formed such as Fe(OH)₂, Green Rust, Fe₃O₄, FeOOH, FeOOH and Polynuclear complex containing [Fe₂(OH)₃]³⁺ and Fe₂(OH)₂O²⁺. It is difficult to produce black iron oxide consisting uniform particle because the particle size and the particle shape are different by the reaction condition such as concentration of alkaline solution and iron salts solution, oxidation condition of green rust containing Fe(OH)₂, kinds of iron salts and reaction temperature.
Therefore, black iron oxide having high chroma can not be produced by heterogenious precipitation method.
The chemical structure of black iron oxide is written as (FeO)x(Fe₂O₃)y. In black iron oxide (Fe₃O₄), the theoritical FeO content is 23.8%. The black iron oxide containing below 10% FeO, the color is brown. We have developed thin filler pigment coated with uniform black iron oxides in the crystal shape. The uniform black iron oxide were precipitated on the thin filler pigment by homogeneous precipitation using iron salts and urea. The particle size of black iron oxides on thin filler pigment depended on kinds of iron salts as raw materials. The pigment having 0.3um of black iron oxide in mean particle size was very stable in thermal stability and very much higher in chroma. Black iron oxide coated mica having interference color were formed from hydrolysis of Iron salts using urea.
We studied to confirm the ratio of Fe(III)/Fe(II) of the formed black iron oxide by ion chromatography in comparison with the color tone of produced pigment. And the crystal structure could be analyzed by mössbauer spectrum. The black iron oxide in interference colored pigments consisted of γ-Fe₂O₃ and Fe₃O₄.

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Although a conventional make-up foundation looks natural indoors, it seems too white and unnatural under the direct sunlight. It was found out that a make-up foundation of one rank darker looked more natural outdoors.
In order to solve the problem of a conventional make-up foundation, we have attempted to develop a new foundation which has an unique property capable of changing its color corresponding with the strength of lighting conditions.
Accordingly it was necessary to develop a photochromic materials which is sensitive to UV-ray, but still have other excellent properties including safety.
Thus 1% of iron oxide was added to anatase titanium dioxide and heated at 800°C to thereby synthesize photochromic titanium dioxide. This photochromic titanium dioxide decreased in lightness by UV-A and the saturation value depended on the UV intensity. It was excellent in returning and durability and, therefore, highly useful as a cosmetic material.
A photochromic make-up foundation obtained by substituting a conventional titanium dioxide with the photochromic titanium dioxide showed a decrease in lightness due to outdoor UV-ray. Thus it looked not too white, not too thick and more natural under the sunlight. We have successfully developed a make-up foundation which looks natural under any lighting conditions.

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Commercial makeups for covering spots, freckles and birthmarks generally contain large amounts of high-refractive index materials such as titanium dioxide. Since covering power is proportional to the amount of titanium dioxide in the film, a thick makeup films is needed to cover serious imperfections. A thick makeup film looks artificial, unattractive and is easily rubbed off. Sometimes, even a thick makeup cannot adequately hide deep-colored birthmarks such as nevus of Ota which are not rare amoung Asian women.
In searching for new materials for a better makeup for women with deep-colored facial marks, we discovered that certain metal powders could be effectively used to replace titanium dioxide for enhanced covering. One metal powder found to be very effective for this purpose consists of aluminum platelets 5 to 30 microns in size with an aspect ratio greater than 10. However, the metal platelets must be properly oriented on the skin surface to achieve maximum optical-shielding.
To obtain proper platelet orientation and adehesion onto the skin, we further discovered that a copolymer of isobutyl acrylate, ethyl acrylate and acrylic acid having a molecular weight in the 10, 000-1, 000, 000 range could be used as a base coat. The polymer, having an adehesive strength of 500-2000g/25mm, was found to be ideal as it also offers flexibility, wear-resistant, water/oil-resistant properties.
By applying the acrylic base film to the subject's skin and sandwitching a layer of orderly arranged metal platelets between the base and a pigment surface, a novel makeup with superior covering power was obtained. Since this tri-layered makeup film is thiner and more flexible than films formed by conventional makeups, it does not flake or rub off easily. It looks natural and effectively covers deep-colored nevus.
Experimental results indicated that our tri-layered makeup, applied on a group of female subjects, lasted more than 12 hours. When applied on subjects with dark nevus, our new makeup showed ΔE, a color differential between the nevus area and the surrounding area, of less than 1.5. It was not possible to reduce ΔE to less than 2.8 when conventional makeups were used. The low ΔE value for our makeup demonstrated the superior covering effect of the film.
There is no question that the new principle of multiple-layered films resulting from this research will find many applications in designing natural-looking makeups requiring super-covering and high-wear-resistant properties.

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In order to develop an excellent lipstick without darkened color or difference between the product colors and the applied ones, mainly due to aggregation of pigments, we have developed a novel “Ultra-thin silicone coating” technology utilizing a catalytic activity of the pigment surface, and furthermore, a modification technology of this film by introducing functional molecules with an additional reaction.
The treated pigments with this novel coating and modification techologies maintained the original fine particle size and showed an excellent dispersibility in oils. By formulating these pigments into lipsticks, they provided various superiorities to the conventional lipstick as follows.
(1) Show bright, vivid, and glossy color.
(2) Not recognize the difference between the product colors and the applied ones.
(3) Long-lasting effect on the lips when applied.
(4) No sweating in a long period.
Moreover, we could develop a new emulsion type lipstick, since the pigments did not aggregate under the presence of water because of the provided hydrophobicity. The emulsion lipstick has two excellent properties in addition to (1)-(4).
(5) Soft usability like cream.
(6) Protects lips better than conventional lipstick because of moist effect.

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The essential role of water in elasticity of the stratum corneum (SC) has been well acknowledged, while water-holding property of the SC is mainly associated with natural moisturizing factors (NMF) and intercellular lipids. Because available evidence indicates that water itself has no substantial capacity of increasing elasticity in the SC depleted of NMF, it has been speculated that a specific intermolecular interaction between keratin fibers and NMF is required for the complete achievement of elasticity due to association with water molecules. In order to elucidate precise molecular mechanisms underlying SC elasticity, we have measured the molecular dynamics of chemical residues within keratin fibers of human plantar SC under various conditions by cross polarization/magic angle spinning (CP/MAS) ¹³C-NMR technique in which the elasticity of keratin fibers can be evaluated by comparing the intensities of their NMR spectra.
The intensities of NMR spectra responsible for amide bond-carbonyl, Cα methine and sidechain aliphatic carbons in the intact SC were found to decrease markedly with increasing water content up to 30% of dry SC and then to reach a constant value over 30%. Lipid extraction of intact SC with acetone/ether (1/1) did not induce any significant change in the NMR spectrum, whereas an additional treatment with water that releases NMF consisting mainly of amino acids, caused the SC to lose elasticity as revealed by significantly increased intensity of the spectrum even in the presence of excess water. The observed decrease in elasticity of the SC was found to recover after treatment with basic and neutral amino acids, but not with acidic amino acid. Parallel studies for complex modulus on elasticity of SC sheet by the rheovibron also demonstrated that removal of NMF reduces elasticity of the SC whose effect is reversible with the application of basic and neutral amino acids. These findings suggest that structural proteins mainly consisting of keratin acquire their elasticities by reducing intermolecular forces between keratin fibers with the help of hydrated NMF.

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We measured changes in facial wrinkles and skin texture by aging, sunlight exposure and applicaion of cosmetics.
With a replica photographing system and image analysis, we measured wrinkles for parameters of depth and the ratio of wrinkled area (RWA: showing amount of wrinkles). As for skin texture, we measured depth and distance of furrows, ratio of furrow depth (RFD: showing amount of skin texture) and anisotropy.
As a result of measuring changes in wrinkles due to aging, it was found that the process of wrinkle formation was classified roughly into 2 stages. In the initial stage of wrinkles, RWA incseased greatly in the 30s, due to many fine wrinkles 0.15mm or less in depth. Then, the second stage showed the acceleration in the increase of wrinkle depth which seemed to be caused by a vicious circle in solar elastosis. It was also observed that, compared to the office workers, the outdoor workers showed higher values of RWA in the initial stage and of wrinkle depth in the second stage.
The result of measuring changes of textures revealed that the amount of furrows decreased with aging and morphology after 60s differed from that of natural furrows and resembled to the morphology observed in the initial stage of wrinkles. As for the influence of sunlight exposure, the furrows in the outdoor workers of 30s and 40s became more indistinct in comparison to those of the office workers.
Then, as a result of examining changes in wrinkles by the continuous application of moisturizing lotion and eye cream, relatively small wrinkles below 0.15mm depth decreased in both cases probably due to increase in hydration in the stratum corneum. We thought this effect reduced the degree of vicious circle in solor elastosis and delayed the appearances of deep wrinkles. From these results, it was thought that skin care around the age of 30s, when small wrinkles started to increase, was extremely important to control wrinkle appeararances.

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We describe a light scattering methodology that could facilitate a non-invasive, in vivo measurement of the thickness of stratum corneum in skin, as well as other physical observables. Namely, the in vivo method could well be based on the detailed observations of the scattered photons emitted at the surface of skin, as a laser beam focused on the surface propagates within. Preliminary in vitro investigations using this methodology on pig skin indicate that it is possible to distinguish the boundary between the stratum corneum (SC) and the Malphigian layer (ML), via the measured intensity of photons emitted at the surface but along the expected trajectory of the laser beam within the skin. The thickness of the SC could then be calculated from the measured distance between the skin surface and the SC/ML boundary, if also the angle of trajectory of the transmitted light is known (Snell's law). Since this angle is dependent on the unknown refractive index of SC, further measurements at different incident angles were necessary to determine the SC thickness and refractive index. Based on the results of our preliminary studies, it is reasonable to predict that light scattering methodologies could be useful for cosmetic industry.

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To study the basic mechanism of dry skin formation and its relationship with the state of stratum corneum, the rate of stratum corneum turnover and the time required for completing the turnover were measured. This was accomplished by observing the process of declining intensity of fluorescence by dansyl chloride dyed on skin surface.
The investigaion revealed a positive correlation between dry skin condition and the distribution of turnover speeds for corneocytes in the stratum corneum. When the skin was dry and scaly, the turnover speeds tended to show a wide distribution. For a healthy, smooth skin, the turnover speeds always showed narrower distribution, indicating that all corneocytes were being renewed at a nearly constant rate. When the dry skin condition improved after a treatment, the distribution also became narrower. Contrary to common belief, the time required for stratum corneum turnover was found to have little relationship with the condition of dry skin.
Extensive screening of many active substances resulted in a discovery of a phytosterol glycoside, which was found effective in regulating and normalizing turnover speeds and improving dry skin. Clinical tests using an O/W cream containing this substance proved its effectiveness in treating dry skin.

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This work was initiated to determine the quantity of dandruff scales by measuring total nitrogen content which can be recalculated based on the amount of proteins. And the method involved the collection of dandruff with a newly designed system and rinsing the dandruff from the scalp. Using this method, we investigated the seasonal variations in dandruff during a 13 month period on 160 subjects under strict control. We also studied the turnover time of the stratum corneum of the scalp and found that it averaged 15.3 days for the dandruff subjects but 17.1 days for non-dandruff subjects.
The newly synthesized vitamin E derivative, L-ascorbic acid dl-α-tocopherol phosphoric acid ester potassium salt (EPC) was proven to have moisturizing effects, free fatty acid formation-inhibiting activity, and an antioxidant property but no bactericidal activity. In addition, EPC normalized the turnover time of the scalp in 16 subjects who used the hairtonic containing EPC. We conducted a double-masked application study of our new antidandruff hair tonic containing EPC. The antidandruff effects of our product were statistically significant when compared with a placebo. Its antidandruff effect was superior to that of zinc pyrithione shampoo.

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The inhibitory effects of magnesium ascorbyl phosphate (VC-PMG) on melanogenesis were investigated in vitro using purified tyrosinase, B16F10 murine melanoma cell extract, and KHm-1/4 human melanoma cells. VC-PMG inhibited tyrosinase activity at a concentration of more than 0.001% for the purified tyrosinase, at a concentration of more than 0.01% for the B16F10 murine melanoma cells extract, and at a concentration of 0.1% for the KHm-1/4 human melanoma cells.
Percutaneous absorption of ¹⁴C-labeled VC-PMG was examined by applying creams containing 3% VC-PMG onto dermatomed human cadaver skin. After 48 hours, VC-PMG was retained in the skin at levels of less than 2% of the applied dose.
The lightening effects of VC-PMG on hyperpigmentation disorders, such as ephelides, chloasma, and senile freckle, in human skin in vivo were also studied. Cream containing 10% VC-PMG was applied to the pigmented area of 34 patients' faces twice a day for three months. Measurement by a color difference meter showed that the color of those pigmentations for 26 patients was lightened due to the topical application of VC-PMG cream. VC-PMG cream was also applied to non-pigmented area of 27 out of 34 patients. VC-PMG cream was also effective in lightening on 11 out of 27 healthy skin.
These results suggested that VC-PMG was absorbed by topical application, and stayed in the skin, and inhibited tyrosinase activity of melanocytes. In vivo results clearly showed that topical application of VC-PMG can be effective in lightening human skin pigmentations.

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Linoleic acid has an inhibitory effect on melanogenesis in B16 mouse melanoma cells. Linoleic acid did not affect the expression level of tyrosinase mRNA and the pattern of tyrosinase glycosylation. The production of premelanosomes and the transfer of tyrosinase into them were also not affected by linoleic acid. The decrease of tyrosinase activity in golgi apparatus and the inhibition of melanin polymer formation within premelanosomes were found in linoleic acid-treated B16 cells.
Using cultured normal human melanocytes, it was shown that linoleic acid inhibited melanogenesis as well as using B16 cells.
We also report here the evidence that linoleic acid can diminish UVB-induced pigmentation. Linoleic acid was topically applied daily for one month after UVB-induced pigmentation was fully developed on the back of brownish guinea pigs, and resulted to marked depigmentation.

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The effects of UV radiation on human hair were examined concerning physical properties and fine structure of internal protein. The breaking strength of sample hair decreased from 152g to 138g, depending on UV irradiation period for 0 to 55 hours. Water content decreased from 10 to 7% at first 10hrs exposure and became almost constant after that. The significant damage brought by UV exposure was observed on the cuticle surface and the internal section of sample hair by SEM. M. W. and amino acid composition of extracts eluted by two kinds of solvent were examined. With the increase of UV irradiation period, M. W. seemed to decrease and cysteinic acid increased significantly. X-Ray diffraction analysis suggested that UV irradiation and elution process brought on sample hair affect not only hair surface but also the structure of internal keratinous protein. It may be concluded that the effects on physical properties of hair by UV irradiation are attributed to both the damage of cuticle and the degradation of internal prorein.

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Recently a great deal of attention has been paid to the prevention of photo-aging, many kinds of UVA, UVB-absorbents and micro fine powders have been developed as new cosmetic raw materials. We have recently developed a new type of melanin, “BIO-MELANIN” which is produced by microorganism Streptomyces sp.
(1) BIO-MELANIN is obtained at high purity without protein contamination after simple purification techniques.
(2) BIO-MELANIN has been shown to be very safe in the following tests; acute lethal toxicity test, photocontact sensitivity test and human closed patch test.
(3) BIO-MELANIN showed protective effects on cultured mouse fibroblast cells (L929) against UVB irradiation.
(4) BIO-MELANIN is alkaline soluble natural UV-absorber and is suited for use in new cosmetic powders and BIO-MELANIN-coated powders (TiO₂, sericite, mica etc.).
(5) This type of cosmetic powder (BIO-MELANIN-coated powder) has dual function and reflection and can be used in the production of FOUNDATION, LIPCREAM, EYE LINER and SKIN CARE PRODUCTS.
(6) We found the sun cut cream containing BIO-MELANIN-coated powder had a high SPF value.

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Recent studies on the influence of ultraviolet light (UV) on the skin have clarified that UV not only causes sunburn and pigmentation in the skin but also induces photosensitive dermatitis and promotes photoaging. Current popular sunscreen agent protecting the skin from these disorders include UV absorbent or titanium oxide. These however carry problems in thier safety or feeling in use. The present authors, taking into consideration the stability, safety, and characteristics in use. focused special attention on pigment materials especially those consisting of organic polymors. which have led to the development of UV absorbing hollow organic microspheres. These microspheres are synthesized by multilayer emulsion polymerization and have external diameters ranging from 0.2 to 0.4μm and a shere exhibits photoabsorption at appropriate wavelengths, which, coupled with the UV diffusion occurring within the sphere, obstruct the penetration of UV. The microspheres are stable to light and show a high level of safety. Additionally, since these microspheres are submicron in size, their adhesion to the skin is satisfactory. Although these UV absorbent hollow organic microspheres exhibit an inferior UV obstracting capacity when incorporated in a cosmetic product, compared with of titanium oxide microparticle, the hollow microspheres applied to the skin can give a natural finished appearance in contrast to the somewhat bluishwhite hue of the skin finished with titanium oxide microparticles.

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Effects of hygroscopic moisturizers are evaluated by means of dynamic hygroscopicity and unfrozen water (UFW) value measured by DSC.
The Natural Moiturizing Factors (NMF) evaluated are Na PCA, L-Proline, Na lactate, Glycerin, Na hyaluronate, partially hydrolyzed chitin and Na polyglutamate. NMF moisturizers are classified into four types of groups by their hygroscopic profiles and water holding capacities. L-Proline showed desirable features as a moisturizer which has relatively consistent water retention with the excellent water holding capacity regardless of humidity change.
UFW are measured by DSC and showed good correlation to the hygroscopicity of NMF moisturizers.
UFW measurement can be done within one hour, while it will take several weeks to finish conventinal hygroscopicity measurement.
Thus UFW measurement by DSC is found to be useful method to predict potential hygroscopicity.

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The purpose of the present study is to get an accurate grasp of female's self assessments, examine which skin problems have good/bad correlations with objective evaluations and analyze the reasons for the ones that do not match.
In this study, we collected 174 healthy Japanese female's evaluations on their own facial skin through the face to face interviews and questionnaires. Then the results were compared with physiological evaluations, which include clinical observations and measurements for the water content, skin surface lipids, skin elasticity, skin microstructure, etc.
Oiliness and age related condition (pigmentation, wrincles, sagging) show relatively good correlation while dryness does not. This incongruity between the subjective evaluation and the actual skin codition often leads to an inadequate selection of cosmetics and improper skin care which may induce skin troubles.

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The technique in which oligopeptide is sorbed on damaged hair is widely utilized to repair the damage caused by several external sources such as shampooing, permanentwaving, brushing, hair drying, exposure under ultraviolet ray and so on.
There are few studies on the desorption of oligopeptide from hair which has been once adsorbed by treatment with oligopeptide alone or mixture with other ingredients, although we can find some reports about the elution of protein from hair which also induces hair damage.
It is our pleasure to report our newly developed study on the behavior of oligopeptide on hair using a ‘Column Circulation Method’, through that interesting results about substantivity of it has been found.
In addition, we would like to refer to the achievements of study on sorption and desorption of newly developed oligopeptide derivatives on hair as some noticeable results have obtained.

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Emolliency effects and characteristic features including surface active effects of N-Acyl glutamic acid cholesteryl ester (AGCE) are presented. Among the series of AGCE, descrived here is the properties of AGCE-301 (N-Lauroyl glutamic acid cholesterol-containing alcohol ester). This highly substantive emollient has excellent emolliency (water holding capacity, moisture permeability, moisture absorbing and retaining ability) and characteristic features (emulsifying effects, pigment dispersion capacity, melting point at the body temperature). AGCE-301 is superior as an emollient than lanolin and other cholesteryl derivatives in tackness, emolliency and substantive effects.

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Cross-linked silicone polymer is effective as a thickening agent of dimethylpolysiloxane. This agent was composed of methylhydrogenpolysiloxane, methylvinylpolysiloxane and dimethylpolysiloxane with platinum catalyst. This agent has some interesting properties as follows.
(1) Low cross-linked density is necessary to get high thickness.
(2) Effect of thickness is depending on the content of dimethylpolysiloxane.
(3) This agent is more effective to low viscosity dimethylpolysiloxane.
The uniform pasty silicone compound can be easily obtained by enoughly mixing this agent and another dimethylpolysiloxane as a main component with higher shearing force by the use of three-roll mixing mill. Silicone paste using this agent gives excellent properties as follows.
(1) High transparency.
(2) Excellent feeling and extendibility to skin without stickiness.
(3) Long storage stability without oil separation.
(4) Stable W/O emulsion can be easily obtained by using polyoxyalkylene-modified silicone fluid.

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Emulsifing ability of Polyoxyethylenemodified-polydimethylsiloxane (POES) in Silicone-Water system was investigated.
9 kinds of POES were synthesized by addition reaction of SiH and CH₂=CH-in the presence of Platinum catalyst. These were devided into 3 type by molecule structure, Polyoxyethylene (A)-Polydimethylsiloxane (B) linear block copolymer, A-B-A linear block copolymer and branched copolymer with side chain of A. Emulsifing ability of these POES was evaluated by observing the physical appearance of the mixture of each Silicone and Water with 4% of POES.
Some of A-B and A-B-A linear copolymer showed higher emulsifing ability than branched copolymer. These copolymers are considered as promising emulsifier for silicone.

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Cosmetic-grade polymetylsilsesquioxanes with chemical formula (CH₃ SiO_1⋅5) n have been developed. Owing to their unique structure and shape, they have excellent lubricity, water repellency, flowability, resistance to heat and solvent, and low toxicity.
Our tests have shown that these powders, when used in make-up, skin care products and antiperspirants, give smoother application to the skin, lips and hair. Furthermore these products prevent agglomerization of pigments and powders to improve flowability.
The shape of these powders remains unchanged when exposed to heat during the manufacturing process, and when added to cyclomethicone, and other solvents.
The use of spherical polymethylsilsesquioxane powders are recognized as effective additives for use in many cosmetic products.

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A high performance liquid chromatography (HPLC) for cationics and carboxybetaine amphoterics in cosmetic products was developed with a cation-exchanger as a stationary phase. An aqueous methanol solution containing glycine-perchloric acid salt was used as a mobile phase.
Cationics were retained in the whole range of the mobile phase pH, whereas amphoterics were retained only below pH 4. The order of elution in homologous species was related to its organic moiety and the elution time decreased with increasing carbon numbers of the solute. The ion-exchange mechanism was confirmed to be operative in this separation.
As this chromatography retained only cationic or carboxy betaine amphoteric species, it would be suitable for a quality control of cosmetic products containing them.

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Acylglutamate is an anionic surfactant synthesized from two natural occuring moieties, glutamic acid and fatty acid. The pH of its aqueous solution is around 5.5 which is nearly equal to that of normal human skin. Acylglutamate has been used as a primary surfactant for various types of cleansing products which offer mildness as main concept.
Extreme mildness of acylglutamate for skin and eye has been proven through laboratory and clinical test. Consumers experience for the products of acylglutamate has proven this feature.
In this paper, we will present the overviews for mildness of acylglutamate by several methodologies and new features of acylglutamate as an anti-irritanting agent.
Mildness is evaluated by growth of human keratinocytes by MTT assay and Neutral Red assay (KURABO's NR Bioassay Kit), by SIRC Cell Toxicity Assay, and by SKINTEX^TM, and EYTEX^TM system which had been developed by Ropak Laboratotories.
Acylglutamate showed the lowest irritation scores by all the test mentioned above in comparison with other mild surfactants such as sodium monolaurylphosphate, sodium acylmethyltaurate, sodium acylisethionate, sodium lauryl POE (3) sulfate and so on.
Additionally acylglutamate reduces irritation score of other surfactants, by adding more than 50%.

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This study was aimed at examining the mechanism of anti-inflammatory actions of placenta extract. Placenta extract suppressed carrageenin edema. Carrageenin edema is a model of acute inflammation.
Carrageenin edema is mediated by serotonin, histamine, bradykinin, arachidonic acid prostaglandin E₁ and prostglandin E₂. We investigated the effect of placenta extract on rat hind paw edema induced by carrageenin edemas chemical mediators.
Placenta extract suppressed serotonin edema and histamine edema. Serotonin and histamine are regarded as allergy inducing factors. Moreover placenta extract had inhibitory effect on prostaglandins. Namely, placenta extract suppressed arachidonic acid-mediated edema and prostaglandin E₂-mediated edema.
Arachidonic acid is a precursor of prostaglandin E₂.
Arachidonic acid and prostaglandin E₂ are regarded as edema enhancing factors. From these results, placenta extract had inhibitory effect on arachidonic acid and prostaglandin E₂. Aspirin is a non-steroid anti-inflammtory drug. Non-steroid anti-inflammtory drugs have inhibitory effect of synthetic process from arachidonic acid to prostaglandin E₂.
Differently from the mechanism of non-steroid anti-inflammatory drugs, placenta extract might have direct suppressive actions on prostaglandin E₂. On the other hand, inflammatory exudates are an important response in inflammation. The post-treatment of placenta extract for 7 days showed anti-exudative actions. This experiment is a model of subacute inflammation. The above results suggested that anti-inflammatory actions of placenta extract are very particular.

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In a previous report, a robot-type device with a tactile function was developed from a video taped study of human finger movements-the softness was evaluated, softness of human skin was measured and the softening effect of a facial treatment was confirmed. In this second report, an evaluation model of elasticity was extracted from a movement analysis of human touch, and the method of measuring elasticity was established by this robot-type device. This method was applied to the measurement of the dynamic properties of human skin.
In observation practical manipulation of elasticity of pliant objects such as the human cheek, a forefinger was used and an object was pushed against it, applying a small amount of pressure, then released. In order to measure the stroke and speed of forefinger movements, a luminous element diode was attached to the forefinger and its movement was measured by an infrared position-sensing system. The evaluation model of elasticity was described as the input of a stroke to the object and the response detected as a stress change.
The robot-type device consisted of a robot arm controlled by a microcomputer system and probe with a mounted mechanical strain gauge. With regards to measurement, the stroke and speed were controlled under conditions derived from the analysis of forefinger movements.
With the aim of extracting physical parameters that can explain elasticity, two types of pliant polymers differing in elasticity, were utilized. The rate of reaction force change in relation to the maximum value during the holding time was extracted as a parameter in order to distinguish elasticity from a qualitative comparison of two reaction force curves when objects were depressed and held in position.
In subsequent experiments, this method of measurement was used for measuring the dynamic properties of human skin. After experimental conditions such as the fixation of panelists' faces were established, correlation were obtained between parameters from the measurement by the robot type device and the elasticity evaluated by experts. As an example of an application of this device, the relationship between dynamic properties and human age were discussed.
These experiments suggest the probability of extension of palpation items with this device as well as its application in measuring other dynamic elements in the cosmetic field through an ergonomic approach to human tactility.

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Seven different synthetic detergents, i.e., four for kitchen use and two for household use obtained from domestic market and one imported from U.S.A., were assessed for their safety to use by bacterial growth inhibition, fish toxicity and human skin irritation tests. The results are as follows:
1) The imported synthetic detergent and both synthetic detergents for household use inhibited bacterial growth at lower concentrations than the synthetic detergents for kitchen use.
2) When the detergents were assessed by the fish toxicity test, the two detergents for kitchen use containing straight chain of alkylbenzene sodium sulfonate, as a main ingredient were most toxic. Sequential toxic manifestations eventuating in death of fish were common with all synthetic detergents tested, being diminished power of swimming, swarming up to the surface of water, difficult to keep equilibrium and incapable of swimming.
3) The intensity of skin irritation varied with chemical characteristics of synthetic detergents. The four products for kitchen use (containing straight chain of alkylbenzene sodium sulfonate, as a main ingredient) were more potent than the imported product in eliciting a irritant skin response, which might be responsible for hand eczema.

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