Azadirachta. Azedarach, U. S. 1880. Pride of India. Pride of China. Ecorce d'Asedarach, Ecorce de Margousier, Fr. Zedrachrinde, G.—The U. S. P. formerly recognized the bark of the root of Melia Azedarach L. (Fam. Meliaceae), a beautiful tree, thirty or forty feet high, with a trunk fifteen or twenty inches in diameter. This species of Melia is a native of Syria, Persia, and the north of India, and is widely cultivated. It is abundant in our Southern States. North of Virginia it does not flourish. "The bark [root] is in curved pieces or quills of variable size and thickness; outer surface red-brown, with irregular, blackish, longitudinal ridges; inner surface whitish or brownish, longitudinally striate; fracture more or less fibrous; upon transverse section tangentially striate, with yellowish bast fibers; inodorous, sweetish, afterwards bitter and nauseous. If collected from old roots, the bark should be freed from the thick, rust-brown, nearly tasteless, corky layer." U. S., 1880. The bark of the trunk is "externally of a rusty-gray color, internally yellowish, and much foliated; coarsely fibrous; inodorous, bitter and slightly astringent, structure and thickness varying according to age." Br. Add. (For a description of the leaves and root bark, see Ph. Rev., 1896, p. 231.)
Oil of Azedarach is found of two kinds in Eastern Asia where it is used. One is employed for burning, the other medicinally. The latter oil, according to Lewkowitch (Oils, Fats, Waxes, vol. ii, p. 426), is known as Veepa Oil, Veppam Fat and Neem Oil, and has a specific gravity of 0.914, a saponification value of 196.9, and iodine value of 69.6, a Reichert-Meissel value of 1.1 and a butyro-refractometer reading of 52° at 25° C. (77° F.).
Azadirachta indica Br. Add. Neem Bark, Margosa Bark. Under this name was recognized the bark of the stem of Melia Azadirachta L., or Indian Lilac Tree.—This contains, according to Broughton (P. J., 1873, 992), a bitter amorphous resin, and a crystallizable principle, melting at 175° C. (347° F.). (See also Ph. Rev., 1896,231.) Cornish (Ind. Ann. Med. Sci., 4, 104) had previously announced the presence of a bitter alkaloid, to which he gave the name margosine.
The decoction of azedarach is affirmed to be cathartic and emetic, and in large doses narcotic; but in a number of experiments made by H. C. Wood with extracts from the dried bark and fruit, it was found impossible to poison frogs or rabbits. Robins eating of the sweetish fruit, of which they are very fond, are often rendered so far insensible as to be picked up under the tree; though they usually recover in a few hours. Children are said to eat the fruit without inconvenience, and possibly the robins simply choke themselves with the large berries. The bark is considered, in the Southern States, an efficient anthelmintic. The form of decoction is usually preferred. A quart of water is boiled with four ounces of the fresh bark to a pint, of which the dose for a child is a tablespoonful every two or three hours, until it affects the stomach or bowels. Another plan is to give a dose morning and evening for several successive days, and then to administer an active cathartic. The fresh bark and the fruit are said to be superior as vermifuges. The Br. Add. recognized an infusion (Infusum Azadirachtae Indicae, Br. Add.), eighty-eight grains in a pint of cold water, dose, one-half to one fluidounce (15-30 mils); also a tincture (Tinctura Azadirachtae Indicae, Br. Add.), two ounces in a pint of 45 per cent. alcohol, dose, one-half to one fluidrachm (1.8-3.75 mils).