LINSEED OIL

Linseed oil is obtained from the dried ripe seeds of linum usitatissimum Linn. (Family Linaceae).the plants are cultivated in temperate regions around the world. In the preparation preparations of Linseed oil, the seeds are first crushed to break the seed coat, and then crushed seeds are subjected to hydraulic pressure and the fixed oil is removed by expression.
Description:
It occurs as a yellowish brown oil, with a faint characteristic odour and a bland unpleasant taste, gradually thickening on exposure to air it darkens in colours, acquires a pronounced odour and acrid taste, and a thin film of the oil dries to a hard, transparent varnish.
Constituents:
Linseed oil contains glycerides, the chief unsaturated fatty acids of which are linoleic (15%), isolinolenic (65%). The saturated fatty acid includes myristic (2%), stearic (2%) and palmitic acid (4%).
Physical and chemical characteristics:
Specific gravity: at 20, 0.924-934, refractive Index: at 40, 1.4725-1.4750. Acid value: not more than 5, Iodine Value: 170-200, Saponification Value: 187-195. Identification tests: place a drop of oil on a slide and leave to evaporate in air, oxidation of the unsaturated fatty acid produces a hard varnish on drying.
Action and uses:
Linseed oil is used internally as a laxative but due to its disagreeable taste it is rarely given internally. In veterinary medicine it is administered as a purgative for horses and cattle.