temperature the drug ordinarily would crystallize out however once incorporated into the microemulsion it remains as a supersaturated solution the emulsion also contains lecithin as the emulsifier egg or soya lecithin is suitable lecithin itself is a solid but is also available commercially as a liquid by having been mixed with oil such as soybean oil these liquid lecithins are suitable and indeed are preferred attempts to accomplish the same liquefying effect by using some of our lower alkyl fatty ester have resulted in slightly cloudy emulsions but we think this is merely a matter of technique the continuous phase of the emulsion is a lower alkyl ester of a c 8 c 22 fatty acid such as ethyl palmitate or a triglyceride the alkyl is c 1 5 preferably c 1 3 monoesters are preferred because di or triesters such as soybean oil tend to be more oily in taste and texture although even this can be masked sweeteners such as saccharin aspartame depending on the temperature used in preparation sorbitol corn syrup etc and other taste maskers such as the oils of peppermint and sweet orange clove cherry syrup etc can be included in the formulation these agents can be added to any one or more of the components of the emulsion to insure their effectiveness throughout the whole emulsion the relative amount of the ingredients in the formulation will vary but is generally as follows with all percentages being volume percentages unless otherwise noted the continuous phase including any used as lecithin vehicle predominates relative to the internal phase and is usually 33 70 with the internal phase being 1 20 the actual lecithin i e excluding vehicle will be 20 60 preferably the continuous phase is 40 65 the.