Extractum Colchici Cormi. U. S. (Br.) Extract of Colchicum Corm.
Ext. Colch. Corm. [Powdered Extract of Colchicum Corm.]
Related entries: Colchicum
"Extract of Colchicum Corm yields not less than 1.25 per cent. nor more than 1.55 per cent. of colchicine. One gramme of the Extract represents about four grammes of colchicum corm." U.S.
Extractum Colchici, Br.; Extractum Colchici Radicis, U. S., 1890; Extrait de Colchique acetique, Fr.; Zeitlosen Essigextrakt, G.
"Colchicum Corm, in No. 60 powder, one thousand grammes [or 35 ounces av., 120 grains]; Alcohol, Purified Petroleum Benzin, Starch, dried at 100° C. (212° F.), each, a sufficient quantity. Moisten the drug with sufficient alcohol, pack it in a cylindrical percolator and add enough 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 slowly, adding alcohol as required, until the percolate measures two thousand mils or until the drug is exhausted. Recover the alcohol from the percolate by distillation at as low a temperature as practicable until a residue measuring about one hundred and fifty mils [or 5 fluidounces, 35 minims] remains in the still. Transfer this residue to a flask, using a little warm alcohol to rinse the still, and add the rinsings 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; again add to the residue one hundred and fifty mils [or 5 fluidounces, 35 minims] of purified petroleum benzin, agitate and decant the benzin layer as before, repeat the washing with one hundred mils [or 3 fluidounces, 183 minims] of purified petroleum benzin and reject the benzin washings. Transfer the residue to a shallow evaporating dish, rinse the flask with a little warm alcohol, adding the rinsings to the residue in the dish, and evaporate it on a water bath to a thick extract. To this add fifty grammes [or 1 ounce av., 334 grains] of the dried starch, mix well, spread the mixture 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 alkaloid in the remainder of the powder and add to this enough of the dried starch to make the finished Extract contain 1.4 per cent. of colchicine. Mix the powders thoroughly, pass the Extract through a fine sieve, transfer it to small wide-mouthed bottles and stopper them tightly." U. S.
"Crush fresh Colchicum Corms, deprived of their coats; press out the juice; allow the feculence to subside, decant; heat the clear liquid to 100° C. (212° F.); strain through flannel, and evaporate at a temperature not exceeding 70° C. (158° F.) to a soft extract." Br.
The U. S. VIII extract was an acetic extract of the corm, but in the U. S. P. IX process the acetic acid was omitted. The British extract is made by evaporating the juice of fresh corms.
In Great Britain a preparation called preserved juice of colchicum is given in the dose of five minims (0.3 mil) or more. It is made by expressing the fresh corm, allowing the juice to stand for forty-eight hours that the starchy matter may subside, then adding one-fourth of its bulk of alcohol, allowing it again to stand for a short period, and ultimately filtering.
"Assay.—Proceed as directed under Colchici Semen, modifying the process there given by using 6 Gm. of the Extract of Colchicum Corm instead of 15 Gm. of colchicum seed. The final weight will be the amount of colchicine from two grammes of Extract of Colchicum Corm." U. S.
As the fresh colchicum corm is rarely to be had in this country, the U. S. Pharmacopoeia employs the dried corm; its process, if properly conducted, will afford a very efficient extract. In preparing this extract according to the British process, by expression from the recent corm, there will be experienced some inconveniences, which would seem to render the U. S. process under all circumstances preferable. (P. J., xiii, 62.) The acetic extract of colchicum made from fresh corms was abandoned by the Br. Ph., 1898, and by the U. S. P. IX, but the acetic acid menstruum is a good solvent for colchicine.
Dose, from one-fourth to one grain (0.016-0.065 Gm.).