Tinctura Opii (U. S. P.)—Tincture of Opium.
SYNONYMS: Laudanum, Tinctura meconii, Tinctura thebaica.
Preparation.—"Powdered opium, one hundred grammes (100 Gm.) [3 ozs. av., 231 grs.]; precipitated calcium phosphate, fifty grammes (50 Gm.) [1 oz. av., 334 grs.]; water, four hundred cubic centimeters (400 Cc.) [13 fl℥, 252♏]; alcohol, four hundred cubic centimeters (400 Cc.) [13 fl℥, 252♏]; diluted alcohol, a sufficient quantity to make one thousand cubic centimeters (1000 Cc.) [33 fl℥, 391♏]. Rub the powders, in a mortar, with the water previously heated to the temperature of 90° C. (194° F.), until a smooth mixture is made, and macerate for 12 hours; then add the alcohol, mix thoroughly, and transfer the whole to a cylindrical percolator. Return to the percolator the first portion of the percolate, until it runs through clear, and, when the liquid ceases to drop, gradually pour on diluted alcohol, continuing the percolation slowly, until one thousand cubic centimeters (1000 Cc.) [33 fl℥, 391♏] of tincture are obtained"—(U. S. P.).
History and Description.—This tincture is universally known in this and other English-speaking countries as laudanum. It has been known throughout Europe as Laudanum Liquidum Simplex, in contradistinction to solid opium preparations, which were also called by the name laudanum, usually with some qualifying term, as Laudanum Antihystericum, etc. Tincture of opium has a deep red-brown color, and the characteristic odor and taste of opium. Lest concentration take place, through evaporation of its alcohol, it should be kept in securely-stoppered bottles. Each fluid drachm represents 5.7 grains of dry opium, or 1 grain of opium in about 10.5 minims of the tincture.
In preparing this tincture, it is essential that well-dried opium should be used, to insure a full-strength product, and it should be in a finely-powdered form. The admixture with calcium phosphate aids in its percolation, which could not otherwise be readily accomplished with diluted alcohol. The percolate passes slowly, and about 60 per cent of the opium constituents are obtained in solution by the use of the diluted alcohol. The Pharmacopoeia directs the drug to be macerated 12 hours previous to percolation. Twice that length of time, however, will better insure the complete disintegration of the opium. After completion of the percolation, water should abstract nothing from the dried residue, and only mere traces of alkaloids, or their compounds, should be abstracted by diluted acids.
VALUATION.—"If 100 Cc. of tincture of opium be assayed by the process immediately following, it should yield from 1.3 to 1.5 Gm. of crystallized morphine"—(U. S. P.).
ASSAY OF TINCTURE OF OPIUM.—"Tincture of opium, one hundred cubic centimeters (100 Cc.) [3 fl℥, 183♏] ammonia water, three and five-tenths cubic centimeters (3.5 Cc.) [57♏]; alcohol, ether, water, each, a sufficient quantity. Evaporate the tincture to about 20 Cc., add 40 Cc. of water, mix thoroughly, and set the liquid aside for an hour, occasionally stirring, and disintegrate the resinous flakes adhering to the capsule. Then filter, and wash the filter and residue with water, until all soluble matters are extracted, collecting the washings separately. Evaporate in a tared capsule, first, the washings to a small volume, then add the first filtrate, and evaporate the whole to a weight of 14 Gm. Rotate the concentrated solution about in the capsule until the rings of extract are redissolved, pour the liquid into a tared Erlenmeyer flask having a capacity of about 100 Cc., and rinse the capsule with a few drops of water at a time, until the entire solution weighs 20 Gm. Then add 10 Gm. (or 12.2 Cc.) of alcohol, shake well, add 25 Cc. of ether, and shake again. Now add the ammonia water from a graduated pipette or burette, stopper the flask with a sound cork, shake it thoroughly during 10 minutes, and then set it aside, in a moderately cool place, for at least 6 hours, or over night. Remove the stopper carefully, and, should any crystals adhere to it, brush them into the flask. Place in a small funnel 2 rapidly acting filters, of a diameter of 7 Cm., plainly folded, one within the other (the triple fold of the inner filter being laid against the single side of the outer filter), wet them well with ether, and decant the ethereal solution as completely as possible upon the inner filter. Add 10 Cc. of ether to the contents of the flask, rotate it, and again decant the ethereal layer upon the inner filter. Repeat this operation with another portion of 10 Cc. of ether. Then pour into the filter the liquid in the flask, in portions, in such a way as to transfer the greater portion of the crystals to the filter, and, when this has passed through, transfer the remaining crystals to the filter by washing the flask with several portions of water, using not more than about 10 Cc. in all. Allow the double filter to drain, then apply water to the crystals, drop by drop, until they are practically free from mother water, and afterward wash them, drop by drop from a pipette, with alcohol previously saturated with powdered morphine. When this has passed through, displace the remaining alcohol by ether, using about 10 Cc., or more, if necessary. Allow the filter to dry in a moderately warm place, at a temperature not exceeding 60° C. (140° F.), until its weight remains constant, then carefully transfer the crystals to a tared watch-glass and weigh them. The weight found represents the amount of crystallized morphine obtained from 100 Cc. of the tincture"—(U.S. P.).
Action, Medical Uses, and Dosage.—This tincture, occasionally termed Tinctura Thebaica, possesses the medicinal virtues of opium, and may be used in all cases where the drug is indicated, in doses of from 5 to 30 drops (see Opium).
Related Preparations.—TINCTURA OPII ACETATA. If diluted acetic acid be employed instead of water, it will form a much better tincture of opium, and one less liable to vary in strength (TINCTURA OPII ACETATA, or Acetated Tincture of Opium), and which may be given in the same doses as above. It is, however, seldom prescribed at the present day. The U. S. P. (1870) directed 2 troy ounces of dry-powdered opium to be macerated for 7 days in a mixture of 8 fluid ounces of alcohol and 12 fluid ounces of distilled vinegar; express and filter. Twenty fluid ounces are obtained. One grain of opium is contained in each 10 minims.
TINCTURA OPII MURIATICA.—In a mixture of hydrochloric acid, 1 fluid ounce, and water, 15 fluid ounces, macerate 1 ounce of powdered opium for 14 days, and filter. Then add sufficient water to make 1 pint of tincture. No alcohol is present. This is not quite half as strong as tincture of opium.
TINCTURA PAPAVERIS (N. F.), Tincture of poppy.—"Poppy capsules, freed from seeds, and in coarse powder, five hundred grammes (500 Gm.) [1 lb. av., 1 oz., 279 grs.]; glycerin, one hundred and twenty-five cubic centimeters (125 Cc.) [4 fl℥, 109♏]; alcohol, water, of each, a sufficient quantity to make one thousand cubic centimeters (1000 Cc.) [33 fl℥, 391♏]. Digest the poppy capsules with three thousand cubic centimeters (3000 Cc.) [101 fl℥, 212♏] of boiling water during 2 hours, then express and strain. Evaporate the strained liquid to five hundred cubic centimeters (500 Cc. [16 fl℥, 435♏], mix it with two hundred and fifty cubic centimeters (250 Cc.) [8 fl℥, 218♏] of alcohol, and set the mixture aside, well covered, until it is quite cold. Then filter, add the glycerin to the filtrate, and pass enough of a mixture of two (2) volumes of water and one (1) volume of alcohol through the filter, to make the product measure one thousand cubic centimeters (1000 Cc.) [33 fl℥, 391♏]. Each fluid drachm represents 30 grains of poppy (capsule) freed from seeds"—(Nat. Form.).