Cambogia - Gamboge. - A gum-resin obtained from Garcinia Morella. Imported from Siam.

Characters. - Cylindrical pieces, breaking easily with a smooth conchoidal glistening fracture; colour tawny, changing to yellow when it is rubbed with water; taste acrid.

Dose. - 1 to 4 gr.

Impurity. - Starch; detected by yielding a green colour with iodine.

Composition. - Gamboge contains about 73 per cent. of a resinous substance, gambogic acid, C20H13O4; 25 per cent. of gum; and about 2 per cent. of water. Gambogic acid is insoluble in water, gives the brilliant yellow colour to the gum-resin, and forms salts with bases. It is less active than the gum-resin.

Preparation.

Pilula Cambogiae Composita. - Gamboge, 1; Barbadoes Aloes, 1; Compound Powder of Cinnamon, 1; Hard Soap, 2; Syrup, q. s. Dose, 5 to 10 gr.

Action And Uses. 1. Immediate Local Action And Uses

Gamboge is an irritant to the stomach and bowels, causing vomiting in large doses, and in medicinal doses acting as a hydragogue cathartic not unlike colocynth, without being cholagogue. It is seldom prescribed alone, and not often as the compound pill. Such a remedy is indicated in dropsies, cerebral hyperaemia, and as an anthelmintic (not to children); but other substances have now almost completely displaced it.

2. Action In The Blood, Specific And Remote Local Action And Uses

Gambogic acid is chiefly thrown out in the liquid faeces; but part is absorbed, passes through the blood and tissues, and is excreted by the kidneys. These it stimulates, causing an increased flow of yellow-coloured urine. Its diuretic effect may add to its value in dropsy.