Extractum Aconiti. U. S. Extract of Aconite.
Ext. Aconit. [Powdered Extract of Aconite]
Related entries: Aconite
"Extract of Aconite yields not less than 1.8 per cent. nor more than 2.2 per cent. of the ether-soluble alkaloids of aconite and, if assayed biologically, the minimum lethal dose should not be greater than 0.00001 Gm. for each gramme of body weight of guinea-pig. One gramme of. the Extract represents about four grammes of aconite." U. S.
"Aconite, in No. 60 powder, one thousand grammes [or 35 ounces av., 120 grains]; Tartaric Acid, five grammes [or 77 grains]; Purified Petroleum Benzin, Starch, dried at 100° C. (212° F.), Alcohol, each, a sufficient quantity. Dissolve the tartaric acid in five hundred mils [or 16 fluidounces, 435 minims] of alcohol, moisten the drug with this solution and pack it in a cylindrical glass percolator; then add sufficient alcohol to saturate the powder and leave a stratum above it. When the liquid begins to drop from the percolator, close the lower orifice, and, having closely covered the percolator, macerate- for forty-eight hours. Then allow the percolation to proceed very slowly, adding alcohol as required. Reserve the first one thousand mils [or 33 fluidounces, 6 ½ fluidrachms] of percolate and continue the percolation, until the second percolate measures one thousand mils [or 33 fluidounces, 6 ½ fluidrachms] or until the drug is exhausted. Transfer this second percolate to a suitable apparatus and distil off the alcohol at as low a temperature as practicable, until a residue measuring about one hundred mils remains then add the reserved percolate and continue distillation until the residue in the still is of syrupy consistence. Transfer this syrupy residue to a flask, using a little warm alcohol to rinse the still, and adding the rinsing to the flask. When it has cooled, add two hundred and fifty mils [or 8 fluidounces, 218 minims] of purified petroleum benzin and shake the mixture thoroughly for several minutes. Allow the liquids to separate and decant the benzin layer as closely as possible; add again to the residue two hundred and fifty mils [or 8 fluidounces, 218 minims] of purified petroleum benzin, agitate and decant the benzin layer as before. Transfer the syrupy residue to a shallow evaporating dish, rinse the flask with twenty mils [or 325 minims] of warm alcohol, adding the rinsings to the residue in the dish, and then incorporate fifty grammes [or 1 ounce av., 334 grains] of the thoroughly dried starch. Evaporate the mixture by a very gentle heat on a water bath, frequently stirring, and, -when the mass has become thick, spread it on glass plates and continue the drying in an air bath at a temperature not exceeding 70° C. (158° F.) until thoroughly dry. Reduce the product to a fine powder and weigh it. Assay a portion of this product as directed below, and, from the alkaloidal content thus determined, ascertain by calculation the amount of alkaloids in the remainder of the powder and add to this enough of the dried starch to make the finished Extract contain 2 per cent. of the ether-soluble alkaloids of aconite. Mix the powders thoroughly, pass the Extract through a fine sieve, transfer it to small, wide-mouthed bottles and stopper them tightly.
"Assay.—Introduce 3 Gm. of Extract of Aconite into a 250 mil flask, add 10 Gm. of washed sand and mix thoroughly. Then add 150 mils of ether and 2 mils of ammonia water, shake the mixture vigorously every few minutes during a half hour, and when the dregs have settled decant 100 mils of the clear liquid, representing two grammes of the Extract. Proceed as directed under Belladonna Radix, modifying the process there given by using ether instead of chloroform for the final shaking out of the alkaloids.
"Each mil of tenth-normal sulphuric acid V.S. consumed corresponds to 64.539 milligrammes of the ether-soluble alkaloids of aconite." U. S.
For a biological method of assaying Extract of Aconite, see Aconitum.
This extract is an undesirable addition to the U. S. P. IX and requires the utmost care in its preparation, for notwithstanding the addition of both a chemical and biological assay it is often variable in strength as found in commerce.
Dose, one-eighth to one-fourth grain (0.008-0.015 Gm.).