Kino, East Indian Kino, Malabar or Cochin Kino, consists of the dried juice obtained from the trunk of Pterocarpus Marsupium, Roxb. (N.O. Leguminosae), a tree growing in Southern India and Ceylon. It is also official in the U.S.P. The juice is contained in superposed, wide (50μ to 100μ) cells in the bast. Vertical incisions, with oblique lateral ones running into them, are made in the bark of the tree; the thick, reddish juice that exudes is collected and dried, and yields about half its weight of kino, which readily breaks up into small fragments. The juice is sometimes boiled before being evaporated. The drug occurs in small, angular, glistening, brittle fragments, which appear to be almost black in colour, but the edges, viewed by transmitted light, are seen to be dark red and transparent. The fragments break with a glassy fracture, and yield a brownish-red powder; the drug is, however, very free from dust. It has no odour, but an astringent taste, and tinges the saliva red, while adhering to the teeth when chewed. The term kino has been applied to a number of red astringent juices resembling the official Malabar or Cochin kino above described, but obtained from plants belonging to widely different natural orders. The following are the most important:—1. African kino, from Pterocarpus erinaceus, Lam.—2. Botany Bay kino (see Eucalypti Gummi and Kino Eucalypti). 3. Butea kino (see Buteae Gummi).
Partially soluble in water, more soluble (about 80 per cent.) in boiling water, and, when fresh, almost entirely soluble in alcohol.
Constituents.—The chief constituent of kino is kinotannic acid, of which it contains 70 to 80 per cent. It also contains kino red, a phlobaphene produced from kinotannic acid by oxidation, and small quantities of pyrocatechin (catechol), gallic acid, and gum. The presence of an oxydase causes oxidation of the kinotannic acid to proceed slowly in the drug, which gradually becomes duller in appearance. Oxidation also takes place in aqueous and alcoholic solutions, the phlobaphene produced causing the liquids to gelatinise. As the activity of the enzyme is destroyed by heat, a tincture of kino which has been boiled will not undergo gelatinisation, and the freshly collected kino might with advantage be subjected to the action of heat. The proportion of kinotannic acid present in the drug has been variously stated, but appears in good fresh samples assayed by the hide powder process to range from 70 to 82 per cent., moisture varying from 12.2 to 15.7, and ash from 1.0 to 2.3. Other investigators, working on the commercial drug, have obtained less, the difference being probably due partly to variation in the mode of assay and partly to the gradual production of oxidation products intermediate between the soluble tannic acid and insoluble phlobaphene.
Action and Uses.—Kino is a powerful astringent used either externally or internally. It has the general properties of substances containing a large proportion of tannic acid (see Acidum Tannicum), and has the advantage over the pure substance that it is not so readily absorbed, and exerts its astringent action in the intestine without upsetting the stomach, since the tannin is only slowly liberated in the alimentary canal. For inflamed throat, Trochisci Kino are employed. Powdered kino is used as an insufflation in epistaxis. The tincture is added to gargles (1 to 16); and, mixed with tincture of myrrh and diluted with water, it is used as an astringent wash for spongy gums. Internally, kino is administered as Pulvis Kino Compositus in obstinate diarrhoea and dysentery, the powder being given enclosed in a cachet or in a "Glutoid" capsule. The tincture may be prescribed with bismuth salts or chalk mixture in diarrhoea. Preparations of kino are incompatible with salts of iron and lead, lime water, mineral acids, alkalies, and gelatin.
Dose.—3 to 12 decigrams (5 to 20 grains).
- Pulvis Kino Compositus, B.P.—COMPOUND POWDER OF KINO.
- Kino, in powder, 75; opium, in powder, 5; cinnamon bark, in powder, 20. Mix the powders intimately. This preparation contains 5 per cent. of opium. It is employed as an astringent in diarrhoea. Dose.—3 to 12 decigrams (5 to 20 grains).
- Tinctura Kino, B.P.—TINCTURE OF KINO.
- Kino, 10; glycerin, 15; distilled water, 2.5; alcohol, sufficient to produce 100. Rub the kino to a smooth paste with a portion of the previously mixed glycerin and water, gradually add the remainder of the mixed liquids, add 50 of the alcohol, and allow to macerate for twelve hours, with frequent agitation; then filter through cotton wool, and pass sufficient alcohol through the filter to make up to the required volume. The tincture tends to gelatinise on keeping, owing to oxidation of the kinotannic acid in solution. The following formula has been suggested as yielding a product which does not gelatinise on keeping:—Add 10 of powdered kino to 50 of boiling water in a suitable vessel, and maintain the whole at 100° for half an hour, agitating frequently. Allow to cool, replace the water lost by evaporation, add 50 of alcohol, and set aside for twelve hours; then strain. Tincture of kino is a favourite remedy with bismuth or chalk mixture in diarrhoea. It is sometimes added to mouth washes for its astringency. Dose.—2 to 4 mils (½ to 1 fluid drachm).
- Tinctura Kino, U.S.P.—TINCTURE OF KINO, U.S.P.
- Kino, 5; purified talc, 1; glycerin, 15; alcohol (95 per cent.), a sufficient quantity; water, a sufficient quantity. Triturate the kino and talc with the glycerin and 20 of water, heat the mixture on a water-bath for about one hour, cool, replace the evaporated water, add 65 of the alcohol (95 per cent.), filter through cotton wool, and add sufficient alcohol (95 per cent.) to produce 100. Average Dose.—4 mils (1 fluid drachm).
- Trochisci Kino, B.P.C.—KINO LOZENGES.
- Each lozenge contains kino, 2 grains, with a sufficient quantity of fruit basis. Kino lozenges are used for their local astringent action.