WHAT ARE FIXED OILS AND FATS

FIXED OILS
These are the oils, which are obtained from various plants or animals. These are called fixed oils because they can not be distilled with out being decomposed. These are the esters of higher fatty acids such as oleic acid, palmitic acid, and stearic acid.

PROPERTIES: -
1. They are bland, non-irritant.
2. They leave a greasy mark on the paper.
3. They form soap with alkalis.
4. They are odorless and taste less.
5. Insoluble in water, soluble in organic solvent and in cold alcohol.
6. They are non-volatile.
7. Have usually few pharmacological actions.

WHAT ARE FATS: -
Fixed oils, which are solid at ordinary temperatures commonly, are called fats. Example is Lard. (Remington-P-388). Fats are natural esters of glycerol and fatty acids. All the three OH group of glycerol are esterified in fats therefore they are known as triglycerides. Fats used in pharmacy are Lard, Wool fat, Theobroma (cocoa butter).