Mucilago Tragacanthae. U. S., Br. Mucilage of Tragacanth.
Related entries: Tragacanth
Mucilage de Gomme Adragante, Fr. Cod., Mucilag adragant, Fr.; Traganthschleim, G.; Mucilagine di gomma adragante, It.
"Tragacanth, six grammes [or 93 grains]; Glycerin, eighteen grammes [or 278 grains]; Water, a sufficient quantity, to make one hundred grammes [or 3 ounces av., 231 grains]. Mix the glycerin with seventy-five mils [or 2 fluidounces, 257 minims] of water in a tared vessel, heat the mixture to boiling, remove the heat, add the tragacanth, and macerate during twenty-four hours, stirring occasionally. Then add enough water to make the mixture weigh one hundred grammes [or 3 ounces av., 231 grains], beat it until of a uniform consistence, and strain it forcibly through muslin." U. S.
"Tragacanth, in powder, 1.25 grammes; Alcohol (90 per cent.), 2.50 millilitres; Distilled Water, sufficient to produce 100.00 millilitres. Mix the Tragacanth with the Alcohol; add the Distilled Water as quickly as possible, and shake vigorously." Br.
A part only of tragacanth is soluble in water. The remainder swells up and forms a soft tenacious mass, which may be mechanically mixed with water, but does not form a proper solution. Hence trituration is necessary to complete the incorporation of the ingredients. This mucilage is thick and very viscid, but not permanent, as the water separates from the insoluble portion of the tragacanth on standing. It is chiefly used in making pills and troches. The addition of glycerin renders it more serviceable as an excipient. From its great tenacity, it may be advantageously employed for the suspension of heavy insoluble substances, such as the metallic oxides, in water. When kept long, it is apt to undergo decomposition, and to become offensive, but it will keep well if phenol be added. (A. J. P., 1864.) Lyon (P. J., 1901, 600) recommends the use of chloroform water as a preservative in making this mucilage; this is preferred in all cases if the mucilage is not to be used internally. The alcohol in the British process facilitates the quick production of the mucilage, and in addition acts as a preservative.