374 JOURNAL OF COSMETIC SCIENCE treatment products to look for improvements in hair "strength" are difficult to do to gain statistically-significant data. This does not preclude however, the possibility that improving hair strength can occur at the follicle level where hair fiber structure and integrity is laid down for the first time. In this regard, viewing hair fiber health as a skin related issue is certainly a viable approach to enhancing the strength and beauty of the scalp hair as a whole. REFERENCES (1) J. A. Swift, Fundamentals of Human Hair Science. Butler H., Ed, (Micelle Press, Weymouth, England, 1997). (2) C.R. Robbins, Chemical and Physical Behavior of H11man Hair (Springer-Verlag, New York, 1994). (3) B. A. Bernard, The biology of hair follicle,]. Soc. Biol., 199, 343-348 (2005). (4) C. C. Zouboulis and K. Degitz, Androgen action on human skin-From basic research to clinical significance, Exp. Dermatol., 13, 5-10 (2004). (5) J.C. Harper, Antiandrogen therapy for skin and hair disease, Dermatol. Clin., 24, 137-143 (2006). (6) D. Stough, K. Stenn, R. Haber, W. M. Parsley, J.E. Vogel, D. A. Whiting, and K. Washenik, Psychological effect, pathophysiology and management of androgenetic alopecia in men, Mayo Clin. Proc. SO, 1316-1322 (2005). (7) M. Bienova, R. Kucerova, M. Fiuraskova, M. Hajduch, and Z. Kolar, Androgenetic alopecia and current methods of treatment, Acta Dermatovenerol. Alp. Panonica Adriat., 14, 5-8 (2005). (8) D. J. Hogan and M. Chamberlain, Male pattern baldness, South. Med.]., 93, 657-662 (2000). (9) C. Robbins, Hair breakage during combing. I. Pathways of breakage,]. Cosmet. Sci., 57, 233-243 (2006). (10) C. Robbins, Hair breakage during combing. II. Impact loading and hair breakage,]. Cosmet. Sci., 57, 245-257 (2006).

]. Cosmet. Sci., 58, 3 75-383 Quly/ August 2007) High throughput workflow for coacervate formation and characterization in shampoo systems T. H. KALANTAR, C. J. TUCKER, A. S. ZALUSKY, T. A. BOOMGAARD, B. E. WILSON, and M. LADIKA, The Dow Chemical Company, Core R&D, 1712 Building, Midland, MI 48674, S. L. JORDAN, W. K. LI, and X. ZHANG, Amerchol Corporation, A Subsidiary of The Dow Chemical Company, 171 River Road, Piscataway, NJ 08854, and C. G. GOH, Dow Chemical Pacific (Singapore), 16 Science Park Drive, Singapore. Synopsis Cationic cellulosic polymers find wide utility as benefit agents in shampoo. Deposition of these polymers onto hair has been shown to mend split-ends, improve appearance and wet combing, as well as provide controlled delivery of insoluble actives. The deposition is thought to be enhanced by the formation of a polymer/surfactant complex that phase-separates from the bulk solution upon dilution. A standard char- acterization method has been developed to characterize the coacervate formation upon dilution, but the test is time and material prohibitive. We have developed a semi-automated high throughput workflow to characterize the coacervate-forming behavior of different shampoo formulations. A procedure that allows testing of real use shampoo dilutions without first formulating a complete shampoo was identified. This procedure was adapted to a Tecan liquid handler by optimizing the parameters for liquid dispensing as well as for mixing. The high throughput workflow enabled preparation and testing of hundreds of formulations with different types and levels of cationic cellulosic polymers and surfactants, and for each formulation a haze diagram was constructed. Optimal formulations and their dilutions that give substantial coacervate formation (determined by haze measurements) were identified. Results from this high throughput workflow were shown to reproduce standard haze and bench-top turbidity measurements, and this workflow has the advantages of using less material and allowing more variables to be tested with significant time savings. BACKGROUND Coacervation is a critical phenomenon in shampoo applications (1). In shampoo formu- lations with polycationic polymers and anionic surfactants, different types of polymer/ surfactant aggregates can form depending on concentration of a formulation (2). In formulations with high concentration of surfactants (above the surfactant CMC), the anionic micelles shield electrostatically the cationic polymer and it is solubilized. Upon dilution (-10-fold) of the shampoo formulations, two types of complex polymer/ B. E. Wilson's current address is Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831. Address all correspondence to M. Ladika. 375