Tannic and Gallic Acids.

Preparations, and Doses.

Acidum Tannicum, Tannic Acid, Gallo-tannic Acid, Tannin ,—gr. j-xx.
Unguentum Acidi Tannici,—has 2 of T. to 8 of Benzoinated Lard.
Suppositoria Acidi Tannici,—have 1 of T. to 5 of Cacao-butter.
Glyceritum Acidi Tannici,—contains of Tannin to 4 of Glycerin.
Collodium Stypticum, Styptic Collodion,—has of Tannin 20, Alcohol 5, Ether 25, Collodion to make 100.
Acidum Gallicum, Gallic Acid ,—gr. x-xx; soluble in 100 of water.
Pyrogallol, Pyrogallic Acid,—a triatomic phenol, obtained chiefly by the dry distillation of Gallic Acid. Dose, gr. j-ij. Described under Carbolic Acid.

Difference between Tannic Acid and Gallic Acid. According to some authorities the difference is one of oxidation, Tannic Acid, when oxidized, being converted into Gallic Acid. According to others Tannic Acid is simply Gallic Acid Anhydride, and the difference is one of hydration. Tannic Acid is the most powerful of the two as an astringent. It coagulates albumen and gelatin, while Gallic Acid does not. It is, however, converted into Gallic Acid in the stomach before absorption.

Source and Extraction. Tannic Acid is obtained from the galls (Galla) of the Dyer's Oak (Quercus lusitanica), by treatment with Ether. Gallic Acid is obtained from the same galls, after exposure in a warm place for a month; or from Tannic Acid by the action of dilute Sulphuric Acid.

VEGETABLE ASTRINGENTS, nearly all contain some form of tannic or Gallic Acid, on which their physiological and therapeutical properties depend. The principal ones are the following-named, to wit,—

Galla, Nut gall.—The gall of Quercus lusitanica. Composition, Tannic Acid 15-75 per cent., Gallic Acid 5 per cent, Ellagic Acid, Pectin, Sugar, Starch.

Tinctura Gallae, ʒss-ij.
Unguentum Gallae, 10 per cent.

Quercus Alba, White-oak Bark. Contains Quercitannic Acid, Quercin, etc., but no Gallic Acid. No official preparations.

Castanea, Chestnut,—The leaves of Castanea vesca. Contains Tannin and Gallic Acids, salts, gum, etc.

Extractum Castaneae Fluidum, ʒss-ij.

Catechu,—An extract from the wood of Acacia catechu. Contains Catechutannic and Catechuic Acids. Dose, gr. j-xxx.

Tinctura Catechu Composita, ♏x-ʒj.
Trochisci Catechu, j-iij.

Geranium, Cranesbill,—The rhizome of Geranium maculatum. Contains Tannic and Gallic Acids, and possesses a rather pleasant taste.

Extractum Geranii Fluidum, ♏v-ʒj.

Granatum, Pomegranate,—The bark of the stem and root of Punica Granatum. Contains Punico-tannic Acid, also Tannic Acid, Mannite, and the liquid alkaloid Pelletierine, which is used as a taeniafuge, in 5 to 20 grain doses of the tannate. No official preparations.

*Extractum Granati Fluidum, ʒss-jss.
*Decoctum Granati, ℥iv-vj.

Haematoxylon, Logwood. Contains Tannic Acid, Haematoxylon, etc.

Extractum Haematoxyli, gr. v -xx.
*Decoctum Haematoxyli, ℥j-ij.

Hamamelis, Witch-hazel,—The leaves of Hamamelis virginica. Contains Tannic Acid, 8 per cent., a bitter principle, some volatile matters, etc.

Extractum Hamamelidis Fluidum, ♏ij-ʒj.
*Pond's Extract, a proprietary preparation, of uncertain composition, made by distilling the bark with very dilute alcohol.

Kino,—The juice of Pterocarpus Marsupium. Contains Kino-tannic Acid.

Tinctura Kino, ♏x-ʒij.
*Pulvis Kino Compositus, gr. v-xx.

Krameria, Rhatany,—The root of Krameria triandra, etc. Contains Rhatania-tannic Acid, Rhatanine, wax, gum, etc.

Tinctura Krameriae, ♏v-ʒj.
Extr. Krameriae Fluidum, ♏v-ʒss.
Trochisci Krameria, j-iij.
Syrupus Krameriae, ʒj-iv.

Rosa Centifolia, Pale Rose,—The petals of Rosa centifolia, the cabbage rose. Contains Tannic Acid, a volatile oil, etc.

Aqua Rosae, Rose Water, ʒj-ij.
Unguentum Aquae Rosae.

Rosa Gallica, Red Rose,—The petals of Rosa gallica. Contains Tannic and Gallic Acids, the volatile oil, Quercitrin, etc.

Extr. Rosae Fluidum, ♏v-ʒj.
Syrupus Rosae, ʒj-ij.
Confectio Rosae, Confection of Rose, gr. x-ʒj.
Mel Rosae, ʒj-ij.

Rubus, Black berry,—The bark of the root of Rubus villosus, and other varieties of Rubus. Contains Tannic Acid, 10 per cent., etc.

Extractum Rubi Fluidum, ♏x-ʒj.
Syrupus Rubi, ʒj-℥j.

*Alnus, Alder,—Bark of Alnus serrulata,—has Tannic Acid, oil, resin, etc.

*Coto Bark,—is the bark of an unknown Bolivian tree, and contains an acrid, bitter principle, named Cotoin, but no tannin. It is irritant to the skin and mucous membranes, but is highly recommended as an astringent in most forms of diarrhoea, especially that of phthisis, cholera, and typhoid fever. The tincture, in small doses (♏j-v), is used in diarrhoea of children. Paracoto Bark contains Paracotoin, and has similar properties. Dose, of fluid extract, ♏j-x or xv,—of Cotoin, gr. ½- ij, of Paracotoin, gr. iv- v.

*Diospyros, Persimmon,—Unripe fruit of Diospyros Virginiana,—has Tannin.

*Heuchera, Alum-root,—Root of Heuchera Americana,—has Tannic Acid.

*Mango, Bark of Mangifera Indica,—is supposed to act as an alterative astringent, within special tonic action on mucous membranes, and has been used in nasal catarrh, endometritis, vaginal leucorrhoea, diarrhoea and dysentery, to check profuse menstruation, and also the hemorrhage following on abortion. Dose, of the fl. extr., ♏x-ʒj. Mango fruit, or Mangosteen is the fruit of another Indian tree, the Garcinia mangostana. It is a powerful astringent, and is used for nasal and vaginal catarrhs, diarrhoeas, etc.

*Nymphaea, Water-lily,—Root of Nymphaea Odorata,—has both Tannic and Gallic Acids, etc.
*Decoctum Nymphaeae, ℥ss-j.

Pinus Canadensis, Canadian Pine,—properly the Abies Canadensis or Hemlock Spruce, of the U. S. and Canada,—is the basis of a preparation named the *Concentrated Extract of Pinus Canadensis,—an aqueous, non-irritant astringent, said to have a specific tonic action upon mucous membranes. This preparation received the endorsement of Dr. J. Marion Sims, and has been extensively employed, both locally and internally, as a topical application in uterine and vaginal catarrhs, and as a systemic remedy in catarrhal inflammation of the gastro-intestinal and broncho-pulmonary mucous membranes.

*Sarracenia Flava, Trumpet plant, Pitcher plant,—has been well employed in dyspepsia, various diarrhoeas, and chronic nasal catarrh, also as an astringent injection in gonorrhoea and leucorrhoea. Dose of the fluid extract, ♏x-℥j.

*Statice, Marsh Rosemary,—Root of Statice limonium,—has Tannic Acid.

*Yerba Reuma, Frankenia grandiflora,—this California plant is recommended as a highly efficient astringent in diseases of the mucous membranes, especially in chronic and nasal catarrh, gonorrhoea, leucorrhoea and dysentery, ʒij of the fluid extract to ℥iv of water. Dose, internally, ♏x-xx.

Physiological Action.

Tannic Acid is a more powerful astringent than Gallic Acid. It precipitates pepsin and coagulates albumen, impairs digestion, stops peristalsis, and causes constipation. It enters the blood as Gallic and Pyrogallic Acids, being converted into these by the organism. It is a crystalloidal body, but combines with colloids; and is a valuable antidote in poisoning by the alkaloids and Tartar Emetic, with which it forms nearly insoluble tannates. Its continued use disorders digestion, irritates the mucous membranes, and produces emaciation. Injected into the veins it causes deaths by the formation of emboli.
Gallic Acid is a much less powerful astringent, and does not coagulate either albumen or gelatin.
Haematoxylon is a mild astringent, of sweetish taste, producing blood red stools and urine. It does not constipate nor disorder the bowels, but has caused phlebitis.
Hamamelis seems to have special power in restraining venous hemorrhages, a property not wholly due to its Tannic Acid. In large doses it causes severe throbbing pain in the head.

Therapeutics. Tannic Acid is best used locally, and for astringent effect on the intestinal canal; Gallic Acid systemically, and for action on remote parts. In the following disorders they have proven specially efficient:—

Hemorrhoids, and hemorrhages from the lower bowel,—Tannic Acid locally and internally; or Hamamelis as an injection.
Hematemesis, not due to inflammation,—Tannic Acid, gr. x-xx in solution, taken in two or three divided doses.
Hematuria, and distant passive hemorrhages,—Hamamelis or Gallic Acid internally, are very efficient, and may usually be relied upon.
Epistaxis,—Hamamelis has long been employed successfully.
Albuminuria,—Gallic Acid, to restrain the waste of albumen.
Rectal Fissures and Ulcers,—Tannic Acid or its glycerite. Rhatany was a favorite remedy with Trousseau in these affections.
Catarrhs, and chronic local affections of the mucous membranes,—Glycerite of Tannin, or better still, Tannic Acid alone, by insufflation, or the white extract of Pinus Canadensis.
Gastric Catarrh, Pyrosis, etc.,—Tannic Acid or Kino, internally.
Endocervicitis, Leucorrhoea, etc.,—Tannic Acid with Iodoform.
Conjunctivitis,—powdered Tannin after the acute stage has passed. Also excellent in corneal ulcers and granular lids.
Dysentery and Diarrhoeas, acute and chronic,—Tannic Acid with Opium, or Catechu, internally,—Haematoxylon for diarrhoeas of children.
Whooping-cough,—Castanea in decoction, taken ad libitum.
Skin Diseases, as eczema, impetigo, intertrigo,—the Glycerite of Tannin.
Otorrhoea,—the Glycerite of Tannin is very serviceable in this affection.
Varicose Veins and Ulcers,—Hamamelis is satisfactorily employed.

A Compend of Materia Medica, Therapeutics, and Prescription Writing, 1902, by Sam'l O. L. Potter, M.D., M.R.C.P.L.