LIQUID CRYSTAL MAKE-UP REMOVER 33 Oil (TGO) • at 25øc 7 ,oo '-/.'--'"""" o,,.. o 0 2•) 4•) 6•) B•) 100 Water EOD-20 + Gly (a) I : 1.05 O/D:, Oil (TGO) 80 I::. I:': .. 30 Rinse-off./" •" "' .. • OLD2'. O/W •'..'.'..'-.'.': ,.,..'.. :.•.:-..: Water 40 60 x 40 60 EOD-20 + Gly 1 : 1.05 O/W-- O/D2 -• D2 D2/O (b) Figure 12. Changes in phase state of liquid crystal remover during rubbing and rinsing, which indicates the cleansing mechanism.

34 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS E 8000 4000 Phase transition o 50 lOO Shear rate (s -1) Figure 13. Rheological properties of liquid crystal remover before and after phase transition. without passing through the D 2 phase are relatively large, and therefore are subject to coalescence and tend to re-adhere to the skin as an oil film. Figure 14 shows the droplet diameter of emulsions formed while rinsing the LC re- mover, which contains different amounts of the oil component of the model impurities. The droplet diameter steeply increased when the amount of oil ratio exceeded 0.8 and as the systems became non-liquid crystal. From the above result, together with the result presented in Figure 10, a certain amount of LC remover is required for the efficient rinsing of the residues that contain the oil-based impurities. As described before, more than 1 g of LC remover results in a sufficient cleansing ability for the entire face. Physiological studies have been done after a three-week controlled-usage test of LC remover on human upper arms (N = 9). Skin surface conditions, the area size of corneocytes, and the skin surface texture were examined. In the case of the rinsing-off method, no remarkable changes in the size of corneocytes or in skin texture were determined. It is concluded that the LC remover has a strong cleansing ability, yet is mild on the skin without causing significant damage, as is believed to be seen in the wiping-off method. CONCLUSION A lameIlar liquid crystal containing a large amount of oil was formed by combination of a branched nonionic surfactant and a polyol. Using this liquid crystalline system as a make-up remover, oil-based cosmetics are easily dissolved and dispersed in it. Fur-