Extractum Krameriae (U. S. P.)—Extract of Krameria.
SYNONYM: Extract of rhatany.
Preparation.—"Krameria, in No. 40 powder, one thousand grammes (1000 Gm.) [2 lbs. av., 3 ozs., 120 grs.]; water, a sufficient quantity. Moisten the powder with three hundred cubic centimeters (300 Cc.) [10 fl℥, 69♏] of water, pack it in a conical glass percolator, and gradually pour water upon it, until the infusion passes but slightly imbued with the astringency of the krameria. Heat the liquid to the boiling point, strain, and evaporate the strained liquid, by means of a water-bath, at a temperature not exceeding 70° C. (158° F.), to dryness"—(U. S. P.).
Description, Medical Uses, and Dosage.—Good extract of rhatany is of a dark-red color, somewhat glossy, non-hygroscopic, faintly odorous, powerfully astringent, and almost wholly dissolved by water. Its evaporation should be performed quickly (or else in vacuo), as the atmosphere speedily oxidizes its active principles, impairing them, and rendering them more or less insoluble. The bark of the root furnishes the greatest amount of extract, and that prepared with water is superior to that made with alcohol. For some purposes a soft extract is prepared by stopping the evaporation at the proper time. Much of the extract of rhatany found in commerce is of an inferior quality. It does not keep well, becoming brittle and hard by age, even in close containers. Extract of rhatany may be used whenever an astringent is required; in some cases it will be found preferable to any other agent of this class. The soft extract may be advantageously used as a local application to ulcers, hemorrhoids, and fissures of the anus. The dose is from 5 to 20 grains, 3 or 4 times a day.