Manufacture of Emulsions by Shock Cooling
By MORTON W. SCOTT* A "shock cooling" technique was used in the preparation of five emulsion systems. The shock cooling was achieved by atomizing a heated blend of the emulsion phases in a laboratory model s ray dryer operating with chilled inlet air. The test reparations included an o/w gand lotion, an o/w baby lotion, a w/o cold cream krmulation, and an o/w cosmetic lotion containing suspended pigments and hydrophilic ointment U.S.P. The physical stability of the shock cooled products was equivalent to or improved over that of control materials processed by conventional slow cooling techniques. The results of this study suggest that the riaciple of shock cooling has value in large scale manufacture oPemulsions. MULSION SYSTEMS containing waxes, fats, and other low melting solids are widely used as dermatological vehicles and in the formulation of numerous cosmetic creams and lotions. The products generally are prepared by the fusion process. Briefly, this involves emulsifying the molten oil phase with the aqueous phase at elevated temperature (approximately 65 to 7 5 O ) , then slowly cooling the product to room Received June 3. 1963, from the Department of Pharmaceutical Technolog Warner-Lambert Research Institute, Warner-Lambert P ~k n a c e u t i c a l Co.. Morns Plains. N. J.