The effects of cosmetic treatments and procedures, such as cold-waving, bleaching, brushing, combing, etc., on the damage of the hair were studied under practical conditions. The hair samples of known history were provided from 107 women aged between 15 and 59. The degree of damage of the hair was evaluated by observing cuticle scales with a scanning electron microscope (SEM). The fine structure of cold-waved and bleached hair was also examined in comparison with that of untreated, virgin hair with a transmission electron microscope (TEM). In addition, the alkali solubility test and tensile test were carried out in order to understand the changes of chemical and physical properties by varying the degree of cuticle damage. The results obtained are as follows: (1) With increasing the degree of cuticle damage, the alkali solubility was increased and the breaking stress was decreased. This shows that the hair cuticle cells play an important role in determining chemical and physical properties of the hair. (2) Bleaching, hair-dyeing, cold-waving and brushing were found to have a great effect on the increase of the degree of cuticle damage. Bleaching among chemical treatments was found fo have the greatest influence on the cuticle damage. (3) The bleached and cold-waved hair was found to show the destruction of the inner layer of cuticle cell, i.e., the endo-cuticlar layer, which leads to lifting and stripping away cuticle cells. (4) The cuticle cells were considerably stripped off by bleaching followed by brushing or combing, but the loss of cuticle scales did not generally occur without brushing or combing. From the above results, it is clear that the mechanical factors are of primary importance and they are the direct cause for stripping away of the hair cuticle. Thus, investigation on a suitable procedure of brushing and a desirable brush is important to decrease the damage of the hair by daily brushing or combing.
To study light fastness of dyestuffs contained in cosmetic liquid, trichromatic coefficients of aqueous or alcoholic solutions containing dyestuff (s) popularly used for cosmetic ingredients were tested by their exposure to sun light for 15 dayes and 30 days, and were plotted on the chromaticity diagram. 1. Chemical structure of a dyestuff has a dominant infuence on the fastness to sunlight. 2. The sort of acid od alkali is found to affect the sunlight fastness of dyestuff more than pH value of the solution. 3. Each perfume shows a different effect on the sun-light fastness of dyestuff. 4. Synergistic effect of perfume and acid or alkali is observed.
Emulsion stability is unguestionably a very important subject to cosmetic chemists and a quick and reliable determination of the stability without a prolonged testing period is very desirable from a practical view point. Toward such a goal, many workers have investigated and published various methods of stability measurement. Emulsion is a very complex system and its stability is dependent on various factors such as the surfactant type and quantity, viscosity, droplet size and electric charge etc. Since emulsion stability can not be determined by any individual factor alone, often two or three parameters of emulsion properties are measured and the stabiliy is inductively determined by comparing with the apparent change in the properties of emulsion which have been kept at an elevated tempmperature. By utilizing the light scattering property of emulsions, a method has been developed to allow determination of emulsion stability byspectal absorption. Up to a certain limit, the scattering of light from an emulsion increases with a decrease in the droplet size. moreover, the shorter the wave length of the light, the greater is the light scattering. By combining the above two observations, and bydetermining the absorption at two different wave lengths, it was possible to determine an absorptionratio which was found to be related to emulsion stability. This ratio was defined as emulsion stability index and the relation ships between this index and surfactant composition and concentration were investigated inthis report.
The sensory effects of cosmetic products on human skin are greatly divided into three; visual effects, tactile effects and olfactory effects. In order to measure visual effects on human skin, we developed a new skin color measuring apparatus applying a photo electric colorimeter. Firstly we checked the validity of this apparatus as a colorimeter and we evaluated that Luther condition was good and the data were accurate. Secondly we measured the colors by using foreheads and cheeks of about two hundred females aged from twenties to sixties in order to check the availability of the apparatus for skin meauring, and we could get the data that were agreed with the literatures. This apparatus can be available as a skin color measuring, though it has still some points for improvemet.
NMR spectroscopic methods are presented for the routine analysis of cosmetic raw materials. The methods for the characterization of (A) paraffin hydrocarbon, (B) higher alcohol and higher fatty acid, (C) polyethylene glycol, (D) nonionic surfactant (polyethylene oxide condensate), (E) other surfactant, and (F) silicone oil are described in detail. In particular, accurate results are obtained by forming trimethylsilyl derivatives in the determination of the average chain length of (B) and (D) together with the determination of the average moles of ethoxylation of (C) and (D). In addition to the above, the application of NMR to the determination of the water content of sorbitol solution and of the composition of resorcinol monoacetate are presented.
A Study was made on the possible assmilation of nonionic surfactants by various microorganisms. Microorganisms used in this study were isolated from cosmetic products. Among the 60 tested nonionic surfactants, those of pluronic type were not utilized by fungi, yeasts and bacteria. The reason for this can be attributed to the composition of the surfactants which is made up in combination between propylene glycol and ethylene glycol. However, other ester and ether-ester type nonionic surfactants were found to be utilized as a sole source of carbon by microorganisms. Especially, Psuedomonas aeruginosa (wild type No. 16) was noted to demonstrate a strong ability to assimilate most of the tested surfactants except those of pluronic type. In regard to the ability of assimilation, the microorganisms isolated from cosmetic products were generally superior to the type strains.
A new simple method for the determination of dyes (erythrosine, rhodamine B, tetrachloromofluorescein, deep maroon, eosine YS, permanent orange, lake red CBA) in lip sticks was studied. The lip stick was dissolved in a few milliliter of chloroform and filled up with ethanol (erythrosine, rhodamine B, eosine YS, tetrachlorotetrabromofluorescein), acidic ethanol (lake red CBA, deep maroon) or 1, 1, 2-trichloroethane (permanent orange). The coloring materials were separated by thin-layer chromatography. Ethanol, mixed solvents of petroleum ether: toluene: chloroform (1:2:3) or n-buthanol: ethanol: 0.5N acetic acid (6:2:3) were used for the chromatog raphy. After the thin-layer chromatographic separation, each spot on the thin-layer chromatogram was scanned dy a dual wave length densitometer under visible ray. The coefficients of variation of dual wave length densitometer were 0.85-1.74%. The recoveries of dyes added into lip stick were 90.9-102.4%.