Gelatinum, Gelfoam, Puragel
Gelatin is a protein derivative obtained by evaporating an aqueous extract made from skins, tendons and bones of various domestic animals such as the cow Bos taurus Linn., the sheep, Ovis aries Linn., etc. of the family Bovidae.
Gelatin occurs as transparent sheets or flakes or coarse powders, which are nearly colourless or yellowish in colour, with no distinct odour or taste. Sheets are hard and brittle. It swells in cold water, but dissolves in hot water. It is also soluble in acetic acid and glycerin, but not in alcohol or ether and other organic solvents. It forms gel when cooled after boiling.
Gelatin consists chiefly of the protein gluten, which on hydrolysis gives a mixture of large number of amino acids. These include glycine, alanine, valine, leucine, cysteine, methionine, tyrosine, aspartic acid, arginine, lysine and histidine.
Gelatin is used in the preparation of capsule shells, pastes, suppositories, pastilles, pill-coatings, gelatin sponge, etc. It is also employed as a suspending agent, tablet binder and as stabilizer, thickener and texturizer in food preparations.