Extractum Gentianae. U. S., Br. Extract of Gentian.
Related entries: Gentian
Extrait de Gentiane, Fr. Cod.; Extractum Gentianae, P. G.; Enzianextrakt, G.; Estratto di genzian acquoso, It.; Extracto acuoso de genciana, Sp.
"Gentian, in No. 20 powder, one thousand grammes [or 35 ounces av., 120 grains]; Water, a sufficient quantity. Moisten the powder with sufficient water, and allow it to macerate for twenty-four hours; then pack it in a conical percolator, and gradually pour water upon it until the drug is exhausted. Reduce the liquid to two thousand mils [or 67 fluidounces, 301 minims] by boiling, strain it, and then evaporate it to a pilular consistence on a water bath." U. S.
"Infuse Gentian Root in ten times its weight of Distilled Water for two hours; boil for fifteen minutes; pour off; press; strain; evaporate the liquid to a soft extract." Br.
The plan of percolation with cold water is admirably adapted to the extraction of the active principles of gentian. By the use of cold water, starch and pectic acid are left behind, while any albumen that may be taken up is disposed of by the subsequent boiling and straining.
The extract, however, may be advantageously made by macerating the root in two parts of water for thirty-six hours, then expressing in a powerful press, again macerating with additional water, and in like manner expressing, and evaporating the united expressed liquors. Guibourt and Cadet de Vaux obtained by maceration in cold water an extract not only greater in amount, but also more transparent, more bitter, and possessing more of the color and odor of the root, than that prepared by decoction. Guibourt attributes this result to the circumstance that, as gentian contains little if any starch, it yields nothing to boiling which it will not also yield to cold water, while decoction favors the combination of a portion of the coloring matter with the lignin. But this opinion requires modification, now that it is understood that gentian contains pectic acid, which water will extract when boiling hot, but not when cold. Gentian, according to Brande, yields half its weight of extract by decoction.
As ordinarily procured, the extract of gentian has an agreeable odor, is very bitter, and of a dark brown color approaching to black, shining, and tenacious. It is frequently used as a tonic, in the form of pill, either alone or in connection with metallic preparations; but the practice of some pharmacists of using it indiscriminately as a pill excipient is deserving of severe censure.
Dose, from two to eight grains (0.12-0.5 Gm.).
Off. Prep.—Pilulae Antiperiodicae, N. F.; Pilulae Ferri, Quininae, Aloes, et Nucis Vomicae, N. F.