COMPUTER-ASSISTED PRODUCT DEVELOPMENT Table IV Typical Printout of Paint Formula 795 User ID Code: BILL Naxne of STD.: TEST STD. C Pigments/Coxnb., Field Size, & Sub. ID•p: 3 5 380 File Name and Pigment ID•pS: Test i 2 3 4 5 Standard % R's: 26 ß 235 ß 736 ß 235 ß 034 ß 434 ß 434 ß 534 ß 735 ß 638 ß 340 ß 340 ß 840 ß 640 ß 239 ß 939 ß 6 Formulas for Test Std. C Pigments Amount DEA DEF Cost Prim. Yellow 3.062 Oxide Red 6.289 Phthalo Blue 0.227 TiO2 90.422 Prim. Yellow 1.601 Oxide Red 3.652 Lamp Black Lt. 0.468 TiO• 94.2'80 Oxide Yellow 2.925 Oxide Red 5.446 Phthalo Blue 0.245 TiO• 91.385 Oxide Yellow 1.515 Oxide Red 3.113 Lamp Black Lt. 0.485 TiO,o 94.887 4.6 1.4 9.58 1.0 0.4 5.72 2.9 1.6 8.62 0.0 0.2 5.11 cal decision making steps. In addition, control of the test parameters and data reduction steps permit rapid analysis of physical and chemical data. Experience with this simple system should enable one to develop more intelligent planning and broader uses for this valuable tool. (Received January 9, 1973) REFERENCES (1) Faust, R. E., Research planning, Drug Cosmet. Indus., 111, No. 1, 42 (July 1972). (2) Walck, R. Organizing the small research project with PERT, Chem. Tech., 334-9 ( June 1972 ). (3) Critical Path Scheduling-Users Guide, Mark II, General Electric Co., Information Service Dept., 7735 Old Georgetown Rd., Bethesda, Md., 1968. (4) Gere, M. J., and Weaver, William Jr., Matrix Algebra For Engineers, D. Van Nos- trand Co., Inc., N.J., 1965. (5) Kaplow, R., and Posn, H., Online computer analysis and control of experiments, J. Appl. Phys., 40, 4948 (1969). (6) Numerical Analysis Routines-Users Guide, General Electric Co., Information Service Dept., 7735 Old Georgetown Rd., Bethesda, Md., 1968. (7) Applied Color Systems Users Guide, Princeton, N.J., 1972.

.I. Soc. Cosmet. Chem., 24, 797-814 (December 9, 1973) Effect of $urfactant Migration on the Stability of Emulsions T. J. LIN, Ph.D.,* H. KURIHARA, B.S.,* and H. OHTA, B.S.? Presented September I1-15, 1972, Seventh IFSCC Congress, Hamburg, Germany Synopsis-A new technique, which involves analyzing solutions from successively centri- fuged emulsions, was developed and applied to determine the SURFACTANT CONCEN- TRATIONS in the aqueous phase of O/W emulsions. By following the surfactant MIGRA- TION from one phase of the freshly prepared emulsion to the other phase, the effects of the migration on the DROPLET SIZE DISTRIBUTION and EMULSION STABILITY were investigated. It was found that, at a low mixing speed, the surfactant location had a significant in- fluence on the stability as well as the droplet size distribution of the newly formed O/W emulsions. In general, the emulsion prepared [½y initially placing the surfactant in the oil phase produced a more stable emulsion than a corresponding emulsion, with an identical composit/on, prepared by placing the surfactant in the aqueous phase. Microphotographic examinations suggested that the initial formation of a double emulsion was probably responsible for the difference. At a high mixing speed, this effect was not very pronounced. The data indicated that under intensive mixing, the time required from the moment of emulsification to the time when the average emulsion droplet size reached the minimum was approximately equal to, or slightly less than, the time required to reach surfactant equilibrium. Once the surfactant equilibrium was attained, further mixing of the emulsion did not improve the emulsion stability. INTRODUCTION Cosmetic chemists are often puzzled as to why the first batch of the emul- sion manufactured in the factory differs so much in physical characteristics or stability from those of the emulsion originally developed in the laboratory. If there is no weighing error or raw material variation, it is most likely due to the difference in manufacturing conditions. A plant's equipment is rarely identical to its laboratory equipment and the difference can easily influence one of the many physical factors which can affect the formation of the emulsion (1). *Shen Hsiang Tang Chemical Co., P.O. Box 150, Taichung, Taixvan. ? Takasago Perfumery Co., Ltd., Tokyo Central P.O. Box 1033, Tokyo, Japan. 797