The damaging effect of hair brushing was studied. The cuticle scales of the hair shaft were lifted away and stripped off by brushing the hair under experimental and practical conditions. Daily brushing was concluded to one of the most damaging factors of hair grooming; mechanical factors such as brushing and combing were the direct cause of damage to the hair. The degree of damage from brushing and combing was in direct proportion to the force which the hair underwent during brushing and combing, The number of damaged hairs was declined to less than one-tenth by the application of a hair conditioner, and reducing the brushing force. Improved brushing procedure and a special type of hair brush also reduced the undesirable friction and resulted in decreasimg damage to the hair.

抄録全体を表示

Extract conditions of urocanic acid, a metabolic substance of histidine in the human epidermis, from the stratum corneum with water, and transepidermal of urocanic acid free stratum corneum were studied.
A new quantitative analytical method of urocanic acid by High Speed Liquid Chromatography was developed. Toyosoda LS-140 was employed as column packing. This method is more acurate and more rapid than conventional Thin Layer Chromatography. Extraction of urocanic acid from stratum corneum was perfomed by the cup method.
Urocanic acid was shawn to be rapidly eluted into water from stratum corneum and to be reproduced at a slow pace.
Consequently, stratum corneum once extracted with water was retained longer under urocanic acid deficient state than the control stratum corneum.

抄録全体を表示

Studies on the effect of surfactant location on O/W emulsifiction, revealed a useful correlation between the maximum amount of aqueous phase that could be solubilized in the oil phase containing the emulsifier and the average droplet size of the emulsion subsequently formed.
It is suggested that this correlation may be applied to develop a tool which can minimize the need for a trial-and-error process in selecting the best surfactant combination for a given emulsion formulation. The proposed method would have an advantage over Griffin's “required HLB” concept as, unlike required HLB values, solubilization measurements are relatively simple and the results are reproducible. Furthermore, this method should be more reliable since it takes into account the effects of other additives in the oil and aqueous phase.
The correlation between solubilization and emulsification is believed to be related to the basic emulsification mechanism.

抄録全体を表示

Water-in-oil emulsions stabilized by using the gels, which are viscous emulsior of W/O type forned between surfactants (D) and aqueous solution of amino acids (W), were studied. The gels cannot be obtained with any random combination of surfactants and amino acids; their tormation is possible only when the surfactant is a fluid which has lipophilic property and a specific orderly lamellar structure and the amino acids or their salts which are readily soluble in water.
By dispersing these gels into the oil phase and then adding the water phase, extremely stable w/o emulsions with wide ranges of water content were obtained. This type of emulsification was termed “gel-emulsification method” by the authors. When this new technology was applied to the preparation of cosmetics, products with outstanding characteristics were obtained.
The function of the amino acids in the emulsification was investigated by using physico-chemical methods such as X-ray analysis, NMR, heat of solution, electoron-microscopy and measurement of water content solubilized in the surfactant phase. It may be concluded that the amino acids are effective in forming tight surface atmosphere around water particles and in preventing coalescence of water particles by strong hydration effect of the amino acids, thus stabilizing the w/o emulsion.

抄録全体を表示