HAIR COLORING 47 the case of Ag-zeolite, we used seven kinds, which were 2.5, 5, 10, 15, and 20 wt% of silver in 0.4-nm pores and 2.5 wt% of silver in 0.7- and 1.3-nm pores. PLANT EXTRACT Hamamelis extract obtained from Maruzen-Seiyaku Co. Ltd. was used as the plant extract containing tannin. It was the extract with 1,3-butylene glycol. REAGENTS Other reagents used in this study were obtained from Nakarai Tesk, Kyoto, Japan. CONFIRMATION OF OXIDATIVE ABILITY OF METAL ZEOLITES PPDA was dissolved in Carmody buffer (Table I) at pH 9.6 in a concentration of 0.05%. 2.0 ml of PPDA solution, in which 0.02 g of metal-zeolite was suspended, was incubated at 25øC for ! min. After removing the zeolite by filtration, oxidation ability was judged with the naked eye in terms of the coloring of the tiltrate. HAIR COLORING Hair coloring was carried out in two steps. First the hair tresses were immersed in the solution containing plant extract. Then they were treated with PPDA solution in which Ag-zeolite was suspended. Both steps were carried out at 25øC. After coloring, the dyed tresses were rinsed under running tap water and air dried. PPDA was dissolved in a solution of about 1.5% ammonia and 5% isopropanol. COLOR EVALUATION OF HAll{ Color values and spectral reflectance data were obtained using the Spectrophotometric Color Meter CMC1200 (Murakami Color Research Laboratory). Three measurements were obtained per each tress and averaged. Results are expressed in the Hunter L, a, b color scale, where L is a measure of lightness and varies from 100 for perfect white to 0 for black. The coloring effect was evaluated with the L values only after coloring because of the color homogeneities in the gray hair tresses before coloring. Table I Carmody Buffer Composition Composition Conc. (M) A solution Boric acid 0.20 Citric acid 0.05 B solution Tri-sodium phosphate 0.10 The preparation of various pH solutions was carried out to add the appropriate amount of A solution to 50 ml B solution.

48 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II Sample for Mutagenicity Test System Sample Conventional dye Conventional dye q- Hamamelis extract Ag-zeolite dye q- Hamamelis extract PPDA q- H202 PPDA + H202 q- HE PPDA + Ag-zeo + HE Ag-zeo: Ag-zeolite containing 2.5 wt% silver. HE: Hamamelis extract. SHAMPOO STABILITY The colored tresses were stirred in a bath containing 5% of a commercial shampoo for 5 min, rinsed, and towel dried. This cycle was repeated seven times. Color measurements were taken before and after each cycle. The same area of the tress before and after treatment was measured using the special hair tress holder. The changes of color values were evaluated by the differences before and after measurement. OXIDATION REACTION OF PPDA BY SILVER IONS IN SOLUTION Carmody buffer was employed to control pH of the solvents. The preparation of the original solution containing silver ions was carried out by filtration of buffer-sus- pended Ag-zeolite after shaking. The concentration of silver ions in the buffer was determined with an Inductively Coupled Plasma Atomic Emission Spectrometer (Se- quentialplasma Spectrometer ICPS 100 II, Shimazu). The various silver concentration solutions were prepared by dilution of the original solution with buffer. The absorption spectra were measured at 25øC after mixing of the PPDA solution and silver ion solution in the spectrophotometer cell. The rate of the reaction at which PPDA was oxidized was defined as the slope that was obtained by the plot of the absorption of the solution at 450 nm vs time (min). ELUTION OF SILVER IONS FROM ZEOLITE Ag-zeolite containing 2.5 wt% silver was used. Ag-zeolite was suspended in 4 ml Carmody buffer and incubated at 25øC. The concentration of silver ions eluting into the solvent was determined with ICPS after removing the zeolite by filtration. MUTAGENICITY TEST This test was carried out using the Ames method with pre-incubation (6). We collected samples at three stages in the oxidation reaction, 0, 5, and 10 min after the start of Table III Oxidation Ability of Metal-Zeolite and Oxidation-Reduction Potential Oxidation-reduction Oxidation Metal ion potential (E ø/V) ability Ag (I) 0.799 O Fe (III) 0.771 X Cu (II) 0.153 X Zn (II) - 0.763 X