52 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS for a hand lotion incorporating acetoglycerides is given under the section headed "Lotions." (f) MEDICATED CREAMS AND OINTMENT BASES By virtue of the ease with which oil-in-water creams and lotions con- taining acetoglycerides are absorbed by the skin, such preparations are especially suitable for use as bases for ointments and medicated creams and lotions. The acetoglycerides are compatible with most of the active constituents of such preparations, and their use ensures close contact of the medicament with the tissues. (c) LOTIONS (a) EMU•.SIFIEr) LOTIONS Solid grades of acetoglycerides can be used in emulsified lotions, but liquid grades are normally preferred. Here the most important property is a high rate of absorption by the skin and the ability to yield not only lotions of desirable consistency, but also ones which will remain stable over long periods of storage and throughout marked temperature variations. In hand lotions and anti-sunburn lotions, the desirable emollient and softening effects which acetoglycerides have on the skin, coupled with the ability to yield continuous non-greasy films, are of considerable importance. The following formula for a hand lotion is typical of preparations of this type: Parts by weight i Acetoglyceride L/C ......... 10 Methyl Stearate ...... 3 Cosmetic paraffin oil ...... 5 Propylene glycol ......... 10 Polyethylene glycol monostearate ... 6 ! Sodium carboxymethylcellulose ... 0.5 [Water (softened or distilled) ... 64 Method Heat the constituents of part A to a temperature of about 75 ø C., and stir until evenly mixed. Stir together the constituents of part B at a similar temperature, and then add part A to part B with thorough stirring. Homogenise, cool, and incorporate the perfume. Allow to stand overnight, and stir again for about 20 minutes. (b) ALCOHOLIC LOTIONS The compatibility of acetoglycerides with a wide variety of materials, coupled with their excellent solvent power and absence of greasiness, has

CHEMISTRY OF ACETOGLYCERIDES AND THEIR USES IN COSMETICS 53 made them of considerable value in the formulation of alcoholic lotions, including deodorant preparations and anti-sunburn lotions. (D) 0 THER APPLICATIONS Although the applications listed above are those which have been investigated most thoroughly, acetoglycerides have interesting possibilities in other products which are still being evaluated. These are noted briefly below. (a) POWDER FOUNDATIONS Solid acetoglycerides may be used in the formulation of powder-cake preparations, and give greatly increased flexibility of the cake--thereby reducing the possibility of fracture. In liquid make-up preparations, the same considerations apply as for emulsified lotions: the liquid grades of acetoglycerides are normally preferred, and all types give non-greasy films--a point of considerable importance in this type of product. (b) SOAPS AND DETERGENTS Most of the acetoglycerides are useful in soap manufacture--where they have been proposed to improve milling, stamping and mould release. These features are also of interest in the preparation of detergent bars and, for these products, the superfatting properties of acetoglycerides are of added attraction. It has been suggested that the incorporation of acetoglycerides would not only give improved plasticity, but would also reduce the tendency of products of this type to soften when left in a moist atmosphere. (c) PHARMACEUTICAL PREPARATIONS Acetoglycerides are being used to good effect in pharmaceutical pre- parations. Apart from their use in creams and lotions, they are being used as waxes, where their standardised melting ranges are as important as their viscosity characteristics. CONCLUSIONS Whilst the claims made in some publications that acetoglycerides have revolutionised the science of cosmetics formulation would seem to be exaggerated, these products undoubtedly are proving to an ever increasing extent to be most valuable additions to the range of compounds at the disposal of the cosmetician and in many cases they have simplified the formulation of superior products.