294 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS after ? days Figure 6. Change of water particles in gels w•th time at 25øC: (a) Sunsoft O-30B and 40 per cent aqueous solution of monosodium L_glutamate monohydrate system (b) Sunsoft O-3013 and water system *. '.:-:. , .- . '*- , ... ,.. . .... •.•.--.--., .,.• ..•,• .. .:,, •..,•..,• ,.,. .• S ..... • •:•. ß -½, -... " afte'r 7. days -. . .... .:. :,-. :.: .. .:. ::.. ' after 3t days

o • o o o o @ 37 ø 25 ø 0 ø Temp PH Glycine L-Arginine L-glutamic acid 5.0g/100g Wo,,, 5.0g/100gwo,,, 0.5g•100g Wo,c, o o o o o o PH' O O, O o o o o o o •7 ø 25 ø 0 ø Temp 37 ø 25 ø 0 ø Temp PH 1 1 o o @ o o o o o o o o o 37 ø 25 ø 0 ø Temp Evaluation' good-' O A, x Figure 7. Effect ofpH on stability of gels poor 0 I I I 1 2 3 Concentration (mol/• ) Figure 8. Heat of solution of surfactant to aqueous solution of amino acid or salt with various concentra- tions: (o) water, (a) L-serine, (e) Monosodium L-glutamate monohydrate