Mucilago Acaciae. U. S., Br. Mucilage of Acacia.
Related entries: Acacia
Mucilage of Gum Arabic; Mucilage of Gum Acacia; Mucilage de Gomme, Fr. Cod.; Mucilage arabique, Fr.; Mucilago Gummi Arabici, P. G.; Gummischleim, G.; Mucilagine di gomma arabica. It.; Mucilago de goma arabica, Sp.
"Acacia, in small fragments, three hundred and fifty grammes [or 12 ounces av., 151 grains]; Distilled Water, a sufficient quantity, to make one thousand grammes [or 35 ounces av., 120 grains]. Place the acacia in a tared bottle or flask having a capacity not exceeding one thousand mils [or 33 fluidounces, 6% fluidrachms], wash the drug with cold water, allow it to drain, and then add enough warm distilled water to make the mixture weigh one thousand grammes [or 35 ounces av., 120 grains]. Securely stopper the container, and agitate it from time to time until the acacia is dissolved. Strain the Mucilage and preserve it in small, well-filled bottles in a refrigerator or in a cool place. Mucilage of Acacia should be frequently made and must not be dispensed if it has become sour or moldy." U. S.
"Gum Acacia, 100 grammes; Distilled Water, 150 millilitres. Rapidly rinse the Gum Acacia with a little water; then dissolve it in the Distilled Water in a closed vessel and strain. The Mucilage should be recently prepared. In India and the Eastern Divisions of the Empire, Mucilage of Indian Gum may be employed in making the official preparations for which Mucilage of Gum Acacia is directed to be used (see 'Gummi Indicum')." Br.
The gum used for this purpose should be in small fragments or coarse powder, as it is more readily dissolved in this state than when finely pulverized. Straining is necessary to separate the foreign substances which are often mixed with gum arabic. This mucilage is semi-transparent, almost colorless, if prepared from good gum, viscid, tenacious, of a feeble, peculiar odor, and nearly tasteless. By straining a solution of gum through a layer of freshly precipitated alumina it can be almost entirely decolorized, particularly if the operation be repeated several times. By keeping, the mucilage becomes sour, and this happens even though it be enclosed in well-stoppered bottles; but, according to Guerin, the solution of pure gum undergoes no change in vacuo. Heat in its preparation is said to favor the production of acid, and hence cold has been substituted for boiling water in the present formulas. The U. S. P. VIII directed the addition of lime water in making this mucilage; this addition has proved advantageous by neutralizing the acidity generally found in acacia and it promotes stability, but the U. S. P. IX process deleted the lime water. According to R. Bother (A. J. P., xliv, 113), if glycerin-be employed in the proportion of one to eight of the mass, and the mixture of water and glycerin be added to the gum in a bottle and solution secured by agitation at intervals over several hours, the resulting mucilage does not spoil; the presence of glycerin is objectionable, however, for many of the uses of mucilage of acacia. E. D. Oesch (West. Drug., 1892, 38) adds about 6 per cent. of alcohol as a preservative. Keller preserves the mucilage by the addition of acetanilid (two grains in the fluid-ounce). (C. D., 1896, 378.) Archer & Co. have found (A. J. P., xlvi, 469) that if "Tolu water" be substituted for water the mucilage will keep for months. The Tolu water is made by rubbing two drachms of the tincture with magnesium carbonate and two pints of water, and filtering. Mucilage is employed chiefly in the making of pills, and in suspending insoluble substances in water. In prescribing it for mixtures, it should be recollected that it is a solution of definite strength, containing, according to the U. S. formula, half an ounce of the gum to each fluidounce of mucilage. The British mucilage is a little stronger. The adhesiveness of the mucilage is stated to be very much increased by the addition of one part of aluminum sulphate to one hundred and twenty-five parts of the mucilage, but this would not be permissible for a mucilage intended for medicinal purposes.