TragacanthBotanical Name: Astragalus gummifer (LABILL.)
Family: N.O. Leguminosae
Synonyms: Gum Tragacanth. Syrian Tragacanth. Gum Dragon (known in commerce as Syrian Tragacanth).
Part Used: Gummy exudation.
Habitat: Asia Minor, Persia and Kurdistan.
Description: The plant is a small branching thorny shrub, the stem of which exudes a gum, vertical slits giving flat ribbon-shaped pieces and punctures giving tears; these have a horny appearance, are nearly colourless or faintly yellow, marked with numerous concentric ridges; the flakes break with a short fracture, are odourless and nearly tasteless; soaked in cold water, they swell and form a gelatinous mass 8 or 10 per cent only dissolving.
Constituents: The portion soluble in water contains chiefly polyarabinan-trigalaetangeddic acid; the insoluble part is called bassorin. Tragacanth also contains water, traces of starch, cellulose, and nitrogenous substances, yielding about 3 per cent ash.
Medicinal Action and Uses: Demulcent, but owing to its incomplete solubility is not often used internally. It is much used for the suspension of heavy, insoluble powders to impart consistence to lozenges, being superior to gum arabic, also in making emulsions, mucilago, etc. Mucilage of Tragacanth has been used as anapplication to burns; it is also employed by manufacturers for stiffening calico, crape, etc.
Mucilage, B.P. and U.S.P. Comp. Powder, B.P., 20 to 60 grains.
Adulterants: The Indian gum, the product of Coplospermum gossypium, also acacia, dextrin wheat and corn starch.