Extractum Pruni Virginianae Fluidum (U. S. P.)—Fluid Extract of Wild Cherry.
Related entry: Prunus Virginiana (U. S. P.)—Wild Cherry
Preparation.—"Wild cherry, in No. 20 Powder, one thousand grammes (1000 Gm.) [2 lbs. av., 3 ozs., 120 grs.]; glycerin, one hundred cubic centimeters (100 Cc.) [3 fl℥, 183♏]; alcohol, water, each a sufficient quantity to make one thousand cubic centimeters (1000 Cc.) [33 fl℥, 391♏]. Mix the glycerin with two hundred cubic centimeters (200 Cc.) [6 fl℥, 366♏] of water, and, having moistened the powder with the mixture, pack it firmly in a cylindrical glass percolator, and, having closely covered the percolator, macerate for 48 hours; then gradually add menstruum, made in the proportion of eight hundred and fifty cubic centimeters (850 Cc.) [28 fl℥, 356♏] of alcohol to one hundred and fifty cubic centimeters (150 Cc.) [5 fl℥, 35♏] of water, and allow the percolation to proceed until the wild cherry is exhausted. Reserve the first eight hundred cubic centimeters (800 Cc.) [27 fl℥, 25♏] the percolate, and evaporate the remainder, at a temperature not exceeding 50 C. (122° F.), to a soft extract; dissolve this in the reserved portion, and add enough menstruum to make the fluid extract measure one thousand cubic centimeters (1000 Cc.) [33 fl℥, 391♏]"—(U. S. P.).
Description, Medical Uses, and Dosage.—(See Prunus Virginiana). This preparation has been the subject of constant change of formula in each succeeding Pharmacopoeia. The present formula is thought to be an improvement upon all of its predecessors. However, barring its troublesome manipulation, the modified formula of Prof. W. Procter, Jr., has been considered by competent judges an excellent preparation. Procter's Process will be found below. This extract is a dark, wine-red, transparent liquid, not syrupy in consistence, and possessed of a bitter, hydrocyanic taste. If it be desired to make a preparation free from astringency, strips of isinglass, previously softened in water, may be added to the aqueous solution, which will remove the tannic acid.
This may be used wherever wild cherry bark is indicated. One fluid drachm of it represents 30 grains of the bark, 2 fluid ounces of the infusion, or a tablespoonful of the syrup. Four fluid ounces of this fluid extract may be added to 12 fluid ounces of simple syrup to form a syrup of wild cherry bark. Dose, 10 to 60 minims.
Procter's Formula.—FLUID EXTRACT OF WILD CHERRY. Take of wild cherry bark, 24 troy ounces; sweet almonds, 3 troy ounces; pure granulated sugar, 36 troy ounces; alcohol, 88 per cent, and water, each, a sufficient quantity. Macerate the powdered bark in 2 pints of alcohol for 8 hours, introduce it into a percolator and pour on alcohol till 5 pints have passed, observing to regulate the passage of the liquid by a cork or stop-cock. Introduce the tincture into a capsule (or distillatory apparatus, if the alcohol is to be regained), and evaporate it to a syrupy consistence; add ½ pint of water, and again evaporate till the alcohol is entirely removed. Beat the almonds, without blanching, into a smooth paste with a little of the water, and then add sufficient to make the emulsion measure 1 ½ pints, and pour it in a quart bottle previously containing the solution of the extract of the bark, cork it securely, and agitate occasionally for 24 hours, so as to give time for the decomposition of the amygdalin. The mixture is then to be quickly expressed and filtered into a bottle containing the sugar, marked to hold 3 pints. Water should be added to the dregs, and they again expressed till sufficient filtered liquid is obtained to make the fluid extract measure 3 pints (W. Procter, Jr.). A superior fluid extract of wild cherry, may be made by freely moistening the coarse powdered bark, 16 troy ounces, and sweet almonds, beaten to a paste with just enough water, 1 ½ troy ounces, with a mixture of equal parts of glycerin and water; cover and let them macerate for 4 days; pack uniformly in a percolator, and gradually add of the mixture of equal parts of glycerin and water, until 11 fluid ounces have been used altogether. Then gradually add alcohol until enough has passed to make the whole amount of fluid extract equal to 1 pint. It will be seen that this process is a modification of the formula of Prof. Procter, the advantage being that the manipulation is more simple. The dose of these extracts is that of the official preparation.