48 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS The thixotropic properties of acetoglyceride/wax blends allow the production of non-greasy lipsticks of good appearance and texture which are firm, but not brittle, over a wide temperature range, and which may be applied evenly and smoothly to the lips. Properly formulated lipsticks containing acetoglycerides will not only have a good initial appearance, but will not bloom on storage. They will neither fracture easily in cold conditions, nor will they buckle and become deformed under tropical conditions. A further property of acetoglycerides which is worthy of attention is that, although they are not themselves solvents for eosin dyes, they are compatible with the normal solvents used for this purpose. In the experience of the author, di-2-ethylhexyl sebacate has proved extremely efficient as an eosin solvent in lipsticks containing acetoglycerides. Below are given a number of formulae for lipsticks containing aceto- glycerides. If lipsticks made in accordance with these formula• are com- pared with similar products containing no acetoglycerides, the advantages of the former will be readily apparent. LIPSTICK FORMULAE Parts by weight 1 2 3 Acetoglyceride S/C ......... -- 8 Acetoglyceride S/C/1 ......... 20 20 10 Acetoglyceride L/C ......... 12 10 10 Lanolin ............... 6 6 7 Castor oil (first quality) ......... 22 24 26 Ozokerite ............... 5 8 9 Beeswax ............ -9 9 10 Carnauba wax ............ 3 4 4 Di-2-ethylhexyl sebacate ...... 5 5 5 Colour (lake colours and acid eosin) ... q.s. q.s. q.s. Perfume ............ q.s. q.s. q.s. Method Mix together the castor oil and Acetoglyceride L/C. Add sufficient of this mixture to the lake colours to form a stiff paste, and pass through a triple roll mill. Disperse the acid eosin in the di-2-ethylhexyl sebacate, add this dispersion to the blend of lake colours in oil, and pass again through the triple roll mill--this time with the nip finely adjusted. Heat together the waxes (including Acetoglyceride S/C and/or S/C/l) and remainder oi

CHEMISTRY OF ACETOGLYCERII)ES AND THEIR USES IN COSMETICS 49 the oil, and stir in the colour blend. When uniformly mixed, allow to cool and then mill again. The product may then be melted by warming to about 80 ø C., and finally poured into moulds. (B) CREAMS The properties of acetoglycerides render them of obvious importance in the preparation of all types of cosmetic creams. They can be used both in oil-in-water and water-in-oil emulsions, and may be readily emul- sifted--indeed, self-emulsifying grades are commercially available. The characteristics of acetoglycerides which contribute principally to their effectiveness in creams are their stability, and their effect on the micro-crystalline structure. If some of the oils and waxes normally used in creams are replaced by acetoglycerides, it is possible to obtain quite readily creams of such outstanding stability that their initial excellent appearance and texture is retained after long storage or exposure to varying temperatures. When properly formulated, such preparations not only maintain their even consistency in hot climates, but also have an unusually high freeze-thaw resistance. As would be expected, creams containing acetoglycerides are out- standing with respect to the ease with which they may be applied to the skin. They are readily absorbed and the skin is left supple, without any greasy feel being apparent. A particularly important application of acetoglycerides is in the formulation of creams containing medicaments, hormones, vitamins, or fruit iuices, which it is desired to bring into intimate contact with the skin. The following notes and formulae illustrate potential uses of aceto- glycerides in the preparation of various types of creams: GENERAL PURPOSE CREAMS Parts by weight Acetoglyceride S/C/4 ......... 10 Stearic acid ............ 3 Ozokerite ............... 4 Beeswax ............... 6 Petroleum jelly ............ 6 Cosmetic paraffin oil ......... 25 Water (softened or distilled) ...... 44 Preservative ............ 0.1 Perfume ............... q.s.