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Dispersions of stearic acid in an aqueous phase containing polyhydric alcohol, stabilized by sodium and potassium soaps, so-called vanishing cream, have been studied by measuring their flow and creep properties. The stearic acid was a commercially available mixture of the long chain acids of C₁₄, C₁₆, C₁₈ and C₂₀; the polyhydric alcohol was a member of the series glycerin, propylene glycol, etc. All the systems examined showed complex flow properties, e.g., hysteresis loops and spur points in the flow experiments. The creep behavior of all the systems could be represented by a mechanical model composed of a Voigt unit and a Maxwell unit in series. The observed total compliance was markedly dependent on the formulation and the aging time of the systems. However, the retardation time did not change appreciably, indicating that there was no essential difference in the nature of the secondary bonds in the systems, which was break and reform during creep tests. These rheological properties may be explained by the presence of a network structure of the soap micelles in which fatty acid was solubilize partially, in the aqueous phase.

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Purity analysis of petrolatum in lanolin and paraffin in spermaceti was carried out, but satisfactory results was not obtained.
In a recent literature on this purity tests, Tamura et al, at Tokyo-to Laboratories for Medical Science, has reported a TLC method and another method was discribed in J. S. C. I.-1 that the impurities was separated and detected by TLC.
With these methods, a few experiments were performed.
As both methods was differented remarkably, in sample size of the application. The sample size was investigated with detail.
It was confirmed that sufficient sensitivity of detection and good separation with 5μl sample size was obtained.
In addition to, quantitative determination was made good precision by using TLCscanner CS-900. developed TLC directly also when petrolatum and paraffin was contained in samples.

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Antimicrobial activity of Imidazolidinyl urea (IU) is tested in M/10 phosphate buffer solutions against two strains; Escherichia coli and Pseudomonas aeruginosa. The influences of pH, gelatin and collagen hydrolysate on its activity are also tested respectively; the following results are obtained.
Antimicrobial activity of Imidazolidinyl urea (IU) has a tendency to be more effective in alkaline pH range.
Imidazolidinyl urea (IU) is slightly inactivated in the presence of gelatin.
But its activity is more effectively decreased in collagen hydrolysate solution, especially in the case of Pseudomonas aeruginosa. In this collagen hydrolysate solution, the growth of two microbes is less inhibited in alkaline pH range than in acid one.
Weak phototoxity of Imidazolidinyl urea (IU) against Escherichia coli is recognized by irradiation of 290-350nm ray.

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The dithizone method has been used for the determination of trace amounts of lead in raw materials and products for cosmetics. However, in order to determine lead in a safer manner, we studied the application of atomic absorption method such as direct, correction with D₂-lamp, and extraction to the routine work. As a result, it was found that this method can be effective for many kinds of these samples.

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[in Japanese]

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[in Japanese]

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