CHEMICAL BINDERS AND PRESSED POWDERS 361 Tablet creaminess and skin feel were compared by application with a foam applicator to the skin of the forearm. Creaminess was also ascertained by rubbing the tablet with the thumb. A rating system of 1 to 4 was used (1 -' poor, 2 --- fair, 3 = good, 4 = excellent). RESULTS Consistency Fatty alcohols were evaluated by testing hexadecyl alcohol and 2-octyl- dodecanol (saturated) and oleyl (unsaturated), respectively. Hexadecyl al- cohol produced a slightly harder tablet than oleyl alcohol when used as a binder 2-octyl dodecanol was about equal to oleyl alcohol. Fatty esters in general appeared to act similarly when used as binding agents. Isopropyl isostearate and isopropyl myristate consistently produced firmer tablets at lower percentages and pressures. Lanolin and derivatives as a group demonstrated interesting binding effects. Lanolin, liquid lanolin extract, and the two isop•:opyl esters evaluated showed marked superiority as binders for both the matte and pearleseent formulas. The results indicate that the lanolin alcohols ethoxylated, hydrocarbons ex- tract, and liquid lanolin on magnesium carbonate appear to be slightly inferior as binders for the pearleseent variation. Hydrocarbons behaved similarly on penetration. Findings were consistent for both formulation types. Vegetable oils, trigIyeerides, leeithin, and eastor oil demonstrated some ef- ficacy as binders. Peach kernel oil was the exception. Leeithin was not as ef- fective when used in the pearleseent formulation. The gum and polymer solutions, Veegum,©* with the exception of poly- vinyl pyrrolidone, did not behave as well as the aforementioned chemical groups. In production these materials are usually used in conjunction with oily materials for best results. Polyols behaved differently as a group. Polyalkylene glycol and propylene glycol were superior to glyeerine, ethoxylated glyeerine, and polyethylene glycol 1500. The last group evaluated consisted of emulsifiers. Of the nonionies, sorbitan monooleate showed marked superiority. Triethanolamine stearate (anionie) was not as effective when used to press the pearleseent prototype. Pay-off, Creaminess, and Skin Feel Pearlescent eyeshadows in general showed less tendency to glaze than the matte counterparts. Vegetable oil, derivatives, and castor oil showed the poor- * R. T. Vanderbilt Co., Inc., 30 Park Ave., New York, N.Y.

362 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS est pay-off and gave low scores as far as creaminess and skin feel. Vegetable oil triglycerides, however, showed good creaminess and skin feel. In both cases, lanolin derivatives gave markedly better results than anhy- drous and liquid lanolin by themselves. Fatty esters, as a group, produced one of the highest scores relative to creaminess and skin feel. Heavy mineral oil was far superior to light mineral oil or squalane in both pay-off and skin feel. Gums and polymers showed marked superiority in pay-off but only fair results in skin feel. As far as glycols, nonionics, and emulsifiers are concerned, there are wide variations in performance.* SUMMABY AND CONCLUSIONS The following effects on pressed powders were quantitated in this study: (a) consistency, (b) pay-off, (c) tablet creaminess and skin feel. As expected, tablet hardness varied directly with the percentage binder used at any given pressure. Secondly, this investigation demonstrated that certain chemical groups produce harder tablets regardless of the percentage of binder used or pressure exerted. Some binders were found more effective in pressing the pearlescent formulations. Within specific chemical groups sig- nificant differences were found. Glazing was usually related to the amount of binder used and pressure, al- though, in the matte formulation, slight glazing occurred with many samples. All things being equal, the pearlescent variations showed less tendency to glaze. Again, some chemical groups showed differences within themselves and between the two formula variations tested. Fatty esters, lanolin esters, and heavy mineral oil were superior when eval- uated for tablet creaminess and skin feel. Creaminess varied with the percent- age of binder used and pressure, only within the specific chemical groups, and primarily in the matte variation. In conclusion, it is hoped that the inferences drawn as a result of this inves- tigation will enlighten the cosmetic chemist concerned with the development and production of pressed powders and open the door for further studies in these areas. (Received December 12, 1972) REFEBENCES (1) Martin, J. R. L., Face Powders, in Sagarin, E., Cosmetics: Science and Technology, Interscience Publisher, New York, N.Y., 1057, pp. 9.45-0. (2) Schlossman, M. L., and Feldman, A. J., Trends in pressed powder technology, J. Soc. Cosmet. Chem., 22, 000-14 (1071). * TheseSdata are available from the authors.