COPAI′BA

Syn. Copai′va , Copaiva balsam , Capiv′i , Balsam of capiv′i ; Copai′ba (Ph. L. E. & D.), L.; Baume de Copahu , Fr.; Cobaiva balsam , Ger. “The oleo-resin, of a brown colour, obtained by incision from the trunk of Copaifera multi juga.” (B. P.) Most of the balsam of commerce is obtained from Para and Maranhao. It is packed in casks containing from 1 to 1 1 ⁄ 2 cwt. each, or in large bottles, or in cylindrical tin boxes. Prop., Purific., . Copaiba, though usually called a ‘balsam,’ is not correctly so named, as it contains no benzoic or cinnamic acid. It is correctly described in the B. P. as an ‘oleo-resin.’ Considerable variation exists in the colour, odour, consistence, and transparency, as well as in the proportion of oil and resin yielded by different samples, scarcely any two of which exactly agree. The sp. gr. varies from ·950 to ·996. Brazilian copaiba is thin, clear, and pale; whilst the West Indian variety is thick, golden yellow, le transparent, and has a le agreeable and somewhat terebinth in ate smell. Some varieties are opaque, and continue so unle filtered. This is often a most troublesome operation. The opacity generally arises from the presence of water, which it retains with great tenacity. The following is the plan we have found to answer on the large scale:—Place the casks upon their ends in a warm situation, and leave them so for 10 days or a fortnight, or longer, if convenient. They may then be tapped a little above the bottom, when the contents of some of them will generally be found quite transparent, and may be drawn off and vatted, care being taken to avoid shaking up the bottom. The copaiva that remains foul must be filtered through one or more long Canton flannel bags, sunk in the bottom of a tin cistern, placed over a suitable receiver, in a similar way to that adopted for oils; a few pounds of coarsely powdered charcoal being mixed up with the first 5 or 6 gallons thrown in. This will rapidly fill up the pores of the bag, and make the balsam soon flow clear and pale. The “bottoms” of the casks, containing the water and impurities, may be poured into a large can or jar, and allowed to settle for a few days, when the copaiba may be poured off the top and filtered. A sudden change of temperature will frequently turn a transparent sample of this article opaque or milky; it is not, therefore, deemed fit to send out by the wholesale trade, unle it stands this test. To ascertain this point a common practice is to fill a small bottle with the copaiba, and to leave it out of doors all night in an exposed situation. Pur., Tests, . This substance is frequently adulterated; indeed, fully one half that sold for copaiba does not contain 10% of the genuine balsam. This is particularly the case with that sold in capsules, at low prices, in the shops. Pure balsam of copaiba may be recognised by the following characters:— 1. (Ph. E.) It is transparent; free of turpentine odour when heated; soluble in 2 parts of alcohol; and di olves one fourth of its weight of carbonate of magnesia with the aid of a gentle heat, and continues translucent. 2. (Cheval lier.) A drop of the balsam, placed on a piece of unsized paper, and heated until all the e ential oil is expelled, forms a semi-transparent, well-defined spot; but if the balsam has been adulterated with a fatty oil, it is surrounded by an oily areola. 3. (Planche.) 2 1 ⁄ 2 parts of balsam shaken with 1 part of solution of ammonia, sp. gr. ·965, forms a mixture which becomes clear and transparent in a few moments, and may be heated to 212° Fahr. without becoming opaque. 4. (Vigne.) Boiled with 50 times its weight of water for 1 hour, it should lose at least half its weight. 5. (Adder.) By agitating the suspected sample with a lye of caustic soda, and setting the mixture aside to repose, the balsam after a time rises to the surface, and the fatty oil present (if any) forms a soapy, thick ma below. 6. (‘Journ. de Pharm.,’ 1842.) Pure copaiba may be adulterated with 50 per cent. of a fat oil (nut, almond, or castor oil), without it ceasing to give a clear solution with 2 parts of alcohol; but it combines badly with magnesia and ammonia. Exce of alcohol, however, separates the oil in all cases. It was formerly considered that the best test for detecting the fat oils was pure alcohol, to which some caustic potash had been added. 7. (Dr Hager.) Copaiba which is adulterated with Gurgun balsam is not quite clear, and frequently exhibits prisms of gurginic acid under the microscope. The author states that the adulteration may be easily detected by mixing the suspected sample with four volumes of petroleum ether; the mixture at once becomes turbid, and gradually deposits a sediment, which, after half an hour’s settling, occupies the same volume as the copaiba operated upon. A mixture of pure copaiba with petroleum ether is clear at first, and either remains clear upon standing or it deposits after several hours a very slight sediment, which merely covers the bottom of the test tube like a thin film. Benzol may be used in place of petroleum ether. 8. (Muter.) Three to four grams of the sample are weighed into a clean, dry flask, and saponified on the water bath with 50 c. c. of alcohol, and a lump of caustic soda weighing not le than 5 grams. When all is di olved water is added, and the whole washed into a half-pint basin, so as to nearly fill it, and evaporated to 100 c. c. over a low gas flame. Dilute sulphuric acid is then added till the whole just becomes permanently turbid, and then solution of caustic soda is dropped in till it just clears again. By this means a solution is obtained with the least po ible exce of alkali, and with a good amount of sodium sulphate. The whole is now to be evaporated to perfect dryne on the water bath, stirring towards the end, so that the sulphate may mix with the soaps, and produce an easy pulverulent residue. The residue is moved from the basin into a small, wide-mouthed, stoppered bottle, treated with 70 c. c. of ether-alcohol, and well shaken up. As soon as it is fairly settled the fluid is filtered off through a quick filter, and this is repeated with two succe ive quantities of 70 c. c., making 210 c. c. in all of the solvent used. The residue in the bottle and in the filter now consists of sodium oleate and sulphate if the balsam be impure, and of the latter only if pure, with a little trace of the insoluble resin soap already referred to. The contents of the bottle and filter are then di olved in warm water, and after heating until all smell of ether is gone the whole is boiled freely acidulated with hydrochloric acid, and set to cool. If, when cold, nothing but a few specks of brown resin should rise to the surface, the balsam is pure; but if an oily layer be formed it is adulterated, and the smell of the separated oleic acid will at once determine whether it is actually castor oil or not. In the case of the presence of oil, 2 grams of pure and dry white wax are added, and the whole heated till the wax melts with the oleic acid. On cooling, a solid cake is formed, which is detached from the side of the beaker, and the fluid below pa ed through a filter. The cake is once more melted in boiling water, cooled, detached, dried by gentle pre ure between blotting paper, dried in a water-oven in a weighed platinum dish, and then weighed, and the weight of the wax used deducted. The beaker, filter, rod, ., used are, if at all dirty, dried, extracted with ether, and the residue left, after evaporation, weighed and added to the total. The calculation is then performed as follows:— (1.) To the weight in grams found add ·20 for lo of oleic acid in solvent, and then say as 95: 100:: total oleic acid. (2.) Calculate the per-centage from the quantity taken, and from this deduct 6 per cent. for po ible altered resin in the balsam. The error, owing to the correction, of course, increases with the amount of oil present; but it is stated to be always an error in the direction of under-estimation, which is the great point for public analysts. When working on 3 to 4 grains with an admixture of not over 25 per cent. the errors due to lo of oleic acid and insoluble resin soap are said to so nearly balance each other, that any correction is unnece ary, and the actual amount of oleic acid found may be taken as correct within a per cent. 9. (B. P.) According to the British Pharma copœia, copaiba should be soluble in an equal bulk of benzol. 10. (The evaporation test.) Mr Siebold says: “This is an excellent and exceedingly simple test, but is clumsily applied by many. Instead of boiling the balsam with water for many hours, a small quantity (about 1 to 1·5 gram) of the sample should be carefully heated in a watch-gla until all the oil is driven off, which is the case as soon as the residue has a umed a rich brown colour. A few minutes suffice for the experiment. “If the remaining resin is perfectly brittle and pulverisable there is no fatty matter present, for 1 per cent. of oil would diminish the brittlene of the resin, so that it cannot be reduced to a fine powder. One per cent. of oil is thus readily detected, and with larger quantities of the adulterant (3 to 5 per cent.) the resin feels quite sticky. “On heating the resin castor oil and linseed oil may be distinguished by the odour. By mixing the adulterated balsam with ten, twenty, forty, and fifty volumes of pure maranham balsam respectively, and testing each dilution in this manner, it is easy to find in which the oil has been reduced to below 1 per cent., and thus to ascertain whether the adulterant amounted to more than 10, 20, 30, 40, or 50 per cent., and this, I think, would be sufficiently near the mark for the purpose of public analysts.” Uses, . Balsam of copaiba is considered detersive vulnerary, diuretic, and astringent; and appears to po e a sort of specific power over diseases of the mucous membranes of the uri no-genital organs. It is hence a favourite remedy in gonorrhœa, as soon as the first inflammatory symptoms have subsided, antiphlogistic and soothing measures being previously adopted. Dose , 20 to 60 drops on sugar, floating on water, or made into an emulsion with yolk of egg or gum arabic, 3 or 4 times daily, if the stomach will bear it. The addition of a few drops of sweet spirits of nitre and laudanum have been recommended, to allay the nausea. By adding 1 dr. of oil of orange (ol. aurantii) to each oz. of the balsam, its flavour becomes far from disagreeable, and it sits well upon the stomach. Copaiba is also given in capsules and pills. See Capsules , Emulsion , Oil , Pills , . Obs. Numerous preparations of this article are sold under such names as ‘soluble copaiba,’ ‘specific solution,’ ‘salt of copaiba,’ .; none of these appear to po e equal activity and certainty of operation to the natural balsam. As the whole virtue of copaiba as a medicine depends on the e ential oil it contains, the value of any of these preparations may be estimated by the quantity of that article which is found in them. In the case of the first two articles above named the quantity is very small indeed, and in the last it is wholly deficient. The following forms are current in the trade for the reduction (adulteration) of balsam of capivi:— 1. Balsam of copaiba, 4 lbs.; castor oil, 3 lbs.; mix well. 2. Balsam, 7 lbs.; castor oil, 4 lbs; yellow resin, 2 lbs. 3. Equal parts of balsam of copaiba and Canada balsam. 4. To the last add Venice turpentine, 1 lb. 5. Balsams of Canada and copaiba and nut or castor oil, equal parts. 6. Copaiba, 7 lbs.; nut oil, 3 lbs.; yellow resin, 2 lbs.; Canada balsam, 1 lb. Used to fill the cheap capsules; and to sell in the lower parts of London and in the manufacturing districts. See also Copaiba, Factitious ( below ).