Extractum Nucis Vomicae (U. S. P.)—Extract of Nux Vomica.
Related entry: Nux Vomica (U. S. P.)—Nux Vomica
Preparation.—"Nux vomica, in No. 60 powder, one thousand grammes (1000 Gm.) [2 lbs. av., 3 ozs., 120 grs.]; acetic acid, fifty cubic centimeters (50 Cc.) [1 fl℥, 332♏]; alcohol, water, ether, sugar of milk, recently dried and in fine powder, each, a sufficient quantity. Mix alcohol and water in the proportion of seven hundred and fifty cubic centimeters (750 Cc.) [25 fl℥, 173♏] of alcohol to two hundred and fifty cubic centimeters (250 Cc.) [8 fl℥, 218♏] of water. Mix the powder with one thousand cubic centimeters (1000 Cc.) [33 fl℥, 391♏] of the mixture, to which the acetic acid had previously been added, and let it macerate, in a well-covered vessel, in a warm place, during 48 hours. Then pack it tightly in a cylindrical glass percolator; gradually pour menstruum upon it, and continue the percolation until the nux vomica is practically exhausted. Distill off the alcohol by means of a water-bath, transfer the remainder to a tared capsule, and evaporate it until it weighs about one hundred and fifty grammes (150 Gm.) [5 ozs. av., 127 grs.]. Transfer it to a bottle of the capacity of about five hundred cubic centimeters (500 Cc.) [16 fl℥, 435♏], and wash the capsule with about fifty cubic centimeters (50 Cc.) [1 fl℥, 332♏] of warm water, adding the washings to the bottle and mixing the contents thoroughly. When the liquid extract is cold, add to it 1/4 of its volume of ether, stopper the bottle, and bring the extract and ether into intimate contact by gently agitating and frequently inverting the bottle, avoiding violent shaking so as to prevent the formation of an emulsion. Pour off the ethereal layer as closely as possible, and repeat this treatment with ether several times, until a few drops of the ethereal layer no longer impart a permanent, greasy stain to filtering paper. Then transfer the contents of the bottle back to the tared capsule, using a sufficient quantity of warm water for washing. Recover the ether from the united ethereal washings, add to the oily residue about fifteen cubic centimeters (15 Cc.) [243♏] of boiling water, and then acetic acid, in drops, until the mixture has a permanent acid reaction. Then filter it through a moistened filter, and wash the filter with a little water. Add the filtrate to the extract in the capsule, evaporate until the residue weighs about two hundred grammes (200 Gm.) [7 ozs. av., 24 grs.], and allow it to become cold. Then determine its weight exactly, remove four grammes (4 Gm.) [62 grs.] of the mass, and assay this by the process given below, using the amounts of liquids there directed for two grammes (2 Gm.) [31 grs.] of dry extract. In another portion of five grammes (5 Gm.) [77 grs.] determine the amount of water by drying it, in a flat-bottomed capsule, at 100° C. (212° F.), until it ceases to lose weight. From the results thus obtained ascertain, by calculation, the amount of total alkaloids and of water contained in the remainder of the mass, add to this enough well-dried sugar of milk to bring the quantity of alkaloids in the final dry extract to 15 per cent, then evaporate the mass to complete dryness, reduce it to powder, and transfer it to small, well-stoppered bottles"—(U. S. P.).
ASSAY (U. S. P.)—"Extract of nux vomica, when assayed by the following process, should be found to contain 15 per cent of total alkaloids.
Assay of Extract of Nux Vomica.—"Extract of nux vomica, dried at 100° C. (212° F.), two grammes (2 Gm.), alcohol, ammonia water, water, chloroform, decinormal sulphuric acid (V.S.), centinormal potassium hydrate V.S., each, a sufficient quantity. Put 2 Gm. of the dried extract of nux vomica into a glass separator, add to it 20 Cc. of a previously prepared mixture of 2 volumes of alcohol, 1 volume of ammonia water (specific gravity 0.960), and 1 volume of water, and shake the well-stoppered separator until the extract is dissolved. Then add 20 Cc. of chloroform and agitate during 5 minutes. Allow the chloroform to separate, remove it as far as possible, pour into the separator a few cubic centimeters of chloroform, and, without shaking, draw this off through the stop-cock to wash the outlet tube. Repeat the extraction with 2 further portions of chloroform of 15 Cc. each, and wash the outlet tube each time as just directed. Collect all the chloroformic solutions in a wide beaker, expose the latter to a gentle heat, on a water-bath, until the chloroform and ammonia are completely dissipated, add to the residue 10 Cc. of decinormal sulphuric acid, measured with great care from a burette, stir gently, and then add 20 Cc. of hot water. When solution has taken place, add 2 Cc. of brazil wood T.S., and then carefully run in centinormal potassium hydrate V.S., until a permanent pinkish color is produced by the action of a slight excess of alkali upon the brazil wood indicator. Divide the number of cubic centimeters of centinormal potassium V.S. used by 10, subtract the number found from 10, (the 10 Cc. of decinormal acid used), multiply the remainder by 0.0364 and that product by 50 (or, multiply at once by 1.82), which will give the percentage of total alkaloids in the extract of nux vomica, it being assumed that strychnine and brucine are present in equal proportion, and the above factor being found by taking the mean of their respective molecular weights rounded off to whole numbers ([334+394]/2=364)"—(U. S. P.). A study of the foregoing formula for making the extract, shows that the use of ether is simply that of a fat remover. In our opinion, gasoline, or even benzin is its equal and is cheaper. Extract of nux vomica, as now made by the official process, has a light color, owing to the presence of much milk sugar.
Description, Medical Uses, and Dosage.—(See Nux Vomica). This is an intensely bitter, yellow-brown extract, of a somewhat variable percentage of strychnine, but usually about 6 per cent. Of total alkaloids the official demand is 15 per cent. It is used chiefly in pills. This extract contains the powerful properties of nux vomica, but necessarily varies in strength, as above stated, on account of the want of a uniform quantity of strychnine in the seeds. It may be employed in cases where the action of this agent is required. It is very useful in cases of obstinate constipation, and may be employed in the following combination: Take extract of butternut, 2 grains; resin of podophyllum, 1/16 grain; and extract of nux vomica, 1/4 of a grain; mix thoroughly together and form a pill, which is a dose, and may be repeated 2 or 3 times daily, or until the desired effect is produced. The dose of the above extract of nux vomica is from 1/4 to 2 grains, repeated 2 or 3 times a day, and carefully watching its effects. The small dose of the drug permits of a lower alkaloidal standard, and the interest of manufacturers should be considered whenever possible.
King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.