"Myrobalans are the dried immature fruits of Terminalia Chebula, Retz., usually distinguished in commerce as Chebulic myrobalans." Br.
Five varieties of these East India fruits are distinguished by authors. The most important are as follows: (1) Myrobalani Chebula. This is the only variety which is official. It is produced by the Terminalia Chebula Retz (Buceras Chebula). This by some is believed to be identical with the T. Bellerica noted below. The fruit is roundish or ovate, varying in size from that of a hazel nut to that of a walnut. It consists of an exterior firm fleshy portion and an interior kernel which is light brown, inodorous and with a bitterish, astringent taste.
(2) Myrobalani Bellericae. This is obtained from the T. Bellerica Roxb. It closely resembles the previous variety but is of a more grayish brown color and is sometimes supplied with a short thick foot stalk which is lacking in the official form.
(3) Myrobalani citrinae vel flava. These are from a variety of the same tree which affords the chebula myrobalans, from which they differ only in being somewhat smaller, of a light brown or yellowish color, and of a taste rather more bitter. They were formerly sometimes sold in the shops of Philadelphia, under the name of white galls, to which, however, they bear no other resemblance than in taste.
(4) Myrobalani indices vel nigrae. These are thought to be the unripe fruit of T. Buceras (Bucida Buceras). They are ovate-oblong, from four to eight lines long and from two to three lines thick, of a blackish color, wrinkled longitudinally, and presenting, when broken, a thick brown mass, without kernel, but with a small cavity in the center. They are sourish and very astringent.
(5) Myrobalani emblicae. This variety is wholly different from the preceding, and derived from a plant having no affinity to the Terminaliae, of the fam. Combretaceae—namely, the Phyllanthus Emblica L. (fam. Euphorbiaceae).
Myrobalans are officially described in the Br. Pharm., 1914, as "irregularly ovoid or fusiform, from ten to thirty millimetres or more long and from five to fifteen millimetres wide; strongly shrivelled longitudinally, dark brown or nearly black; in transverse section dark, with a small central cavity; hard. No odor; taste very astringent." Br.
When the fruit is entire, it is blackish, spherical depressed, of the size of a cherry, presenting six obtuse ribs with as many deep furrows, and separating into six valves, and has a strongly astringent and acidulous taste. It is often in segments, as found in commerce. These fruits contain about 40 per cent. of tannin which is identical with gallotannic acid. They have occasionally been used for the commercial manufacture of tannin. The resulting product is less pure, however, than that from nut galls.
Uses.—Myrobalans were in high repute with the Arabians, and were long employed by European practitioners, as primarily laxative and secondarily astringent, in various complaints, particularly diarrhea and dysentery. Pierre Apery states that when roasted they are still used in Turkey with excellent results in intestinal catarrhs. (R. T., Dec., 1887.) Although the myrobalans are of various origin, they all probably depend for their physiological activity upon the presence of gallotannic acid. Procter states that they contain from 30 to 35 per cent. of gallotannic and ellagitannic acids.
The ointment is used as a local astringent.
The internal dose of myrobalans is one-half to one drachm (2.0-3.9 Gm.), given in the form of a powder.
Off. Prep.—Unguentum Myrobalani, Br.; Unguentum Myrobalani cum Opio, Br.