Quillaiae Cortex, B.P. Quillaia Bark. Saponinum. Saponin.

Botanical name: 


Synonym.—Panama Bark.

Quillaia, or soap bark (Quillaja, U.S.P.), is obtained from Quillaja saponaria, Molina (N.O. Rosaceae), a large tree indigenous to Chili and Peru. The bark is removed in large pieces, freed from the outer portion, and dried. It occurs in large, flat sheets, about 4 millimetres thick. Its outer surface is longitudinally striated, and is of a pale brownish or yellowish-white colour, but reddish-brown where the outer portion has been imperfectly removed; the inner surface is smooth and white. The fracture is splintery, the fractured surface being laminated, and exhibiting small crystals of calcium oxalate when examined with a lens. A transverse section shows tangentially arranged bands of bast parenchyma, and groups of bast fibres traversed by radial medullary rays. The bark has no odour, but its taste is astringent and acrid. The yield of ash is from 8 to 14 per cent. The powder acts as a powerful sternutatory. A bark very closely resembling the one described, but thinner and less acrid, appears to be derived from a different species of Quillaja.

Constituents.—The chief constituents of the bark are two colourless, amorphous, toxic glucosides, quillajic acid and quillaja sapotoxin. These principles belong to the class of saponins (see Saponinum); they both impart to water the property of frothing, but the acrid taste and sternutatory effect are due to quillaja sapotoxin alone. The bark also contains sugar.

Action and Uses.—Quillaia has been recommended as an expectorant, and acts on the bronchiolar cells reflexly by irritating the stomach. As it contains so much more sapotoxin than senega it is a more powerful expectorant. Like most other expectorants, in large doses it is emetic; it is contra-indicated in inflammatory conditions of the stomach or intestines. Tincture of quillaia is used as an emulsifying agent, and the liquid extract may be used for washing the skin, especially of the scalp, before treatment.


Extractum Quillaiae Liquidum, B.P.C.—LIQUID EXTRACT OF QUILLAIA. 1 in 1.
This extract, diluted with water, may be used for washing the skin, and especially the scalp, before treatment.
Tinctura Quillaiae, B.P.—TINCTURE OF QUILLAIA.
Quillaia bark, in No. 20 powder, 5; alcohol (60 per cent.), sufficient to produce 100. Add 2.5 of the alcohol to the drug to moisten it, and complete the percolation process. Tincture of quillaia is rarely given internally, but has been recommended as an expectorant. Dose.—2 to 4 mils (½ to 1 fluid drachm).
Tinctura Quillajae, U.S.P.—TINCTURE OF QUILLAJA.
Quillaja in No. 20 powder, 20; alcohol (95 per cent.), 35; water, sufficient to produce 100. Prepared by boiling the quillaja with 80 of water for fifteen minutes, then straining while hot, washing the residue on the strainer with 20 of boiling water, evaporating the mixed liquids to 60, adding the alcohol to the cooled liquid, setting aside to clear, filtering, and passing sufficient water through the filter to produce 100.


Synonyms.—Quillaic Acid; Quillain.

Saponin is obtained chiefly from quillaia bark, and the commercial article is a mixture obtained by boiling the powdered bark with water until exhausted, evaporating the decoction thus obtained to dryness, and boiling the extract with alcohol under a reflux condenser. This solution deposits the "saponin" on cooling, and the process of boiling and cooling is repeated until the product is perfectly white. Saponin occurs as an amorphous, white powder, having a sweetish, afterwards bitter, acrid taste, accompanied by a burning sensation; its dust is intensely irritating and sternutatory. The solubility in water is increased by slight addition of alkali. An aqueous solution, even if so dilute as 1 in 1000 or less, froths like soap solution, the froth being very persistent, but dispersable by alcohol or ether. Saponin is a colloidal substance, has glucosidal properties, and is decomposed by the action of hot, diluted, mineral acids, dextrose and sapogenin resulting from the decomposition. Concentrated sulphuric acid dissolves it, the solution becoming yellow on standing, and then gradually red.

Soluble in water and in hot alcohol, with difficulty in cold alcohol, insoluble in ether, chloroform, benzene, or carbon bisulphide.

Constituents.—Commercial saponin contains quillaia-saponin, lactosin, a carbohydrate; quillaic acid, and sapotoxin, both of which are acrid and poisonous. Pure saponin is non-poisonous and non-sternutatory, and occurs in many plants, in several modifications, and in various parts of the plants.

Action and Uses.—Saponin is added to various liquids as a frothing agent, but is not given medicinally. It can be used to emulsify fixed oils, liquid tars, etc. (See under Emulsions.)

The British Pharmaceutical Codex, 1911, was published by direction of the Council of the Pharmaceutical Society of Great Britain.