EVALUATION OF ANTIDANDRUFF PREPARATIONS 397 (14). Obviously, a subject should suffer from some degree of dandruff. For purposes of testing, the subjects should be divided into groups with mild, ,noderate, or severe dandruff. No subject is allowed to use any dandruff preparation for at least a 2-week period preceding the initial exa,nination. The difficulties of ,nisinterpretation of "nor,nal" and "abnormal" sealing can be avoided, to stone degree, by use of a sizeable panel so that purely randran effects ,nay be canceled out (14). The minimum number of subjects should be in the range of 45-50 for each product to be evaluated. The varied test emnplexities ,nake it highly desirable that a statistician be consulted at the clinical planning stages to ensure that the data are collected in a form suitable for statistical analysis. The progress of treatment versus controls is shown to great advantage by use of ternary or triangular plots (14). Greif (18) has described the use of computers to process the results of large studies. "Half-head" techniques are valuable, particularly for salon studies prior to clinical evaluations. These are done after toxicology tests attest to the safety of the products. In clinical evaluations, the scalp can be subdivided into sym- ,netrieally arranged areas (15, 19) and the scale esti,nated for each area. The values for particular sections can be added to yield a reasonable dandruff in- dex for the whole scalp. The use of visual grading can also be employed for assessing the effect of test products on scalp oiliness. A convenient method for loeahzing areas of the head is to use a fencing ,nask with holes cut in as many places as desired for examination (19). This ensures exa,nination of the same areas. CONCLUSION Dandruff represents an accelerated turnover of scalp cells. Methods are re- viewed to measure the reduced transit ti,nes of the eelIs through the epider- mal layer. Antimicrobial inhibition tests remain the major preelinieal screen. A guinea pig test model offers predictive promise. Glinieal trial techniques, necessary to judge the value of antidandruff preparations, are described. ( Received December 22, 1972) REFERENCES (1) Piewig, G., and Kligman, A.M., The effect of selenium sulfide on epidermal turnover of normal and dandruff scalps, J. Soc. Cosmet. Chem., 20, 765 (1969). (9.) McGinley, K. J., Marples, R. R., and Piewig, G., A method for visualizing and quan- titating the desquamating portion of the human stratum corneum, J. Invest. Derma- tol., 53, 107 (1969). (3) Laden, K., Comparative chemical study of dandruff flakes, skin scrapings and callus, J. Soc. Cosmet. Chem., 16, 491 (1965). (4) VanderWyk, R. W., and Roia, F. C., Jr., The relationship between dandruff and microbial flora of the human scalp, Ibid., 15, 761 (1964).

398 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS (5) (6) (7) (8) (9) (lO) (11) (12) (13) (14) (15) (16) (17) (18) (19) VanderWyk, R. W., and Hechemy, K. E., A comparison of the bacterial and yeast flora of the human scalp and their effect upon dandruff production, Ibid, 18, 629 (1967). Roia, F. C., Jr., and VanderWyk, R. W., Resident microbial flora of the human scalp and its relation to dandruff, Ibid., 20, 113 (1969). Sugden, J. K., Van Abbe, N. J., and Dixon, H., Chemotherapy of dandruff, Pharm. Acta Helv., 47, 51 (1972). Gosse, R. M., and VanderWyk, R. W., The relationship of a Nystatin-resistant strain of Pityrosporum ovale to dandruff, J. Soc. Cosmet. Chem., 20, 603 (1969). Brotherton, J., Relative effectiveness of different classes of fungitides against Pity- rosporum ovale, Brit. J. Dermatol., 80, 749 (1968). Tenenbaum, S., and Opdyke, D. L., Antimicrobial properties of antiseborrheic agents, Proc. Sci. Sect. Toilet Goods Ass., 47, 20 (1967). Troller, J. A., Model system for the investigation of dandruff, J. Soc. Cosmet. Chem., 22, 187 (1971). Finkelstein, P., and Laden, K., An objective method for evaluation of dandruff severity, Ibid., 19, 669 (1968). Botwinick, C. G., and Botwinick, I., Methods for evaluating anti-dandruff agents, Proc. Sci. Sect. Toilet Goods Ass., 47, 17 (1967). Van Abbe, N.J., and Dean, P.M., The clinical evaluation of anti-dandruff shampoos, J. Soc. Cosmet. Chem., 18, 439 (1967). Orentreich, N., Taylor, E. H., Berger, R. A., and Auerbach, R., Comparative study of two antidandruff preparations, J. Pharm. Sci., 58, 1279 (1969). Alexander, S., Do shampoos affect dandruff?, Brit. J. Dermatol., 79, 92 (1967). Spoor, H. J., Microbiological and clinical study of anti-dandruff agents, Proc. Sci. Sect. Toilet Goods Ass., Z3, 27 (1955). Greif, M., and Prokop, H. J., Use of electronic data processing in antidandruff clin- ical research, J Soc. Cosmet. Chem., 18, 785 (1967). Van Abbe, N.J., The investigation of dandruff, Ibid., 15, 609 (1964).