Oleum Adipis. Lard Oil.
Lard oil is a fixed oil obtained by subjecting lard to heavy pressure without the application of heat. It is official in the U.S.P. It occurs as a colourless. or pale yellow, oily liquid, having a peculiar odour and a bland taste. Specific gravity, 0.910 to 0.920 (0.905 to 0.915 at 25°). Exposed to a temperature somewhat below 10° it commences to deposit a white, granular fat, and becomes solid at 0°. Tested as described under Oleum Olivae it should be free from cotton seed oil. It is completely saponifiable with alcoholic solution of potassium hydroxide, the resulting soap being entirely soluble in water (absence of mineral oils). Saponification value, 195 to 197. Iodine value, 56 to 74.
Almost insoluble in alcohol; slightly soluble in boiling alcohol; easily soluble in ether, chloroform, benzene, or carbon bisulphide.
Constituents.—The oil contains varying proportions of stearin, and does not consist of pure olein; it is occasionally adulterated with liquid paraffin.
Uses.—Lard oil is not employed internally, but it is sometimes used in the manufacture of pharmaceutical preparations.