358 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS EXPERIMENTAL Initially, two basic pressed powder formulations were investigated-a matte and a peadescent eyeshadow. Four master batches were prepared using a pony-type mixer. Two binder levels were chosen for each eyeshadow proto- type: 3 and 4% for the matte eyeshadow and 4 and 5% for the peadescent one. Table I shows an example of the matte eyeshadow. The peadescent pro- totype is presented in Table II. Table I Matte Eye Shadow Per Cent (w/w) Ingredients Sample 1 Sample 2 Alabama talc 141 • 15.0 15.0 Italian .talc 40.0 40.0 Metropolitan talc 4601 • 23.7 22.7 Kaolin 5.0 5.0 Zinc stearate 2.0 2.0 Methyl paraben, U.S.P. 0.1 0.1 Propyl paraben, U.S.P. 0.1 0.1 Germall 115 •0.1 0.1 Manganese violet 10.0 10.0 Cosmetic black oxide 1.0 1.0 Binder 3.0 4.0 100.0 100.0 Whittaker, Clark & Daniels, S. Plainfield, N.J. Sutton Laboratories, Roselie, N.J. The binder levels were determined by previous results obtained in these laboratories. After the master batches were prepared, each binder was incor- porated into a 100-g aliquot and mixed with a cake-mixer. All samples were micropulverized through a 0.027-in. herringbone screen. In the pearlescent variations the titanium-coated mica was mixed into the batches after pulveri- zation so as not to destroy the mica structure. Forty different binder variations xvere prepared for each of the four samples. The binding agents included hy- drocarbons, a cellulose gum, an inorganic colloidal silicate, a natural gum, a synthetic polymer, polyglycols, lanolin and derivatives, vegetable oils, emulsi- fiers, fatty alcohols and esters (Table III). This does not imply that similar materials from other sources or that materials not investigated would not work. All samples were pressed and evaluated in a standard round steel godet or pan having the following dimensions: diameter, 1.050 in. height, 0.150-0.155 in. It was found necessary to utilize two different laboratory presses in press-

CHEMICAL BINDERS AND PRESSED POWDERS 359 Table II Peadescent Eye Shadow Per Cent (w/w) Ingredients Sample 1 Sample 2 Alabama talc 141 • 9.7 8.7 Italian talc 115.0 115.0 Metropolitan talc 4601 ø 10.0 10.0 Kaolin 15.0 15.0 Zinc stearate 2.0 2.0 Methyl paraben, U.S.P. 0.1 0.1 Propyl paraben, U.S.P. 0.1 0.1 Germall 1115 * 0.1 0.1 Bismuth oxyehloride 30.0 30.0 Ultramarine blue 8.0 8.0 Cosmetic black oxide 1.0 1.0 Titanium-coated mica 115.0 Binder 4.0 '15.0 100.0 100.0 Whittaker, Clark & Daniels, S. Plainfield, N.I. Sutton Laboratories, Roselle, N.J. ing samples for the investigation. A modified Carver Laboratory Press* was used to compress the matte eye shadows and a Cavalla Presst to press the pearlescent samples. It was found that the Cavalla Press used hydraulically pressed the matte samples too hard for proper evaluation. The modified Carv- er Laboratory Press was used mechanically and set up with air pressure. This was effective for the matte eye shadow evaluations. Two specific pressures were used on each machine for pressing samples. Settings of 80 and 120 were used on the modified Carver Press, which were supposed to correspond to 1200 and 1800 psi, respectively. The Cavalla Press was set at 200 and 500. We were unable to correlate the pressure readings with the actual pressure ex- erted on the pans. Therefore, the findings of each press must be compared by itself. Experimentally, we were able to measure tablet hardness or consistency by taking penetrations with a Precision Penetrometer.* An average penetration of 3 tablets was recorded. Pay-off of all samples was compared by rubbing tablets with a foam appli- cator. A numerical rating system (1 to 3) was used to measure pay-off ( 1 = glazing, too hard, no pick-up 2 = slight glazing, moderately hard, slight pick-up 3 = no glazing, good pick-up). * F. S. Carver Inc., Div. Sterling Ind., Milwaukee, Wis. 153232. t A. Cavalla Inc., New York, N.Y. 10011. • Precision Scientific, Chicago, Ill.