Galbanum, B.P. Galbanum.
Galbanum is a gum-resin obtained from Ferula galbaniflua, Boissier and Buhse (N.O. Umbelliferae) and other species of Ferula. The drug is collected in Persia, and reaches the European market chiefly viâ Bombay. The method by which it is collected is not accurately known, but probably part exudes from the stem, while part is certainly obtained by cutting off the stem at the base, and collecting the gum-resin after it has been allowed to exude and harden, after which a slice of the root is removed and the operation repeated. The B.P. drug is the variety known as Levant galbanum, and is the kind generally met with in commerce. It occurs in separate tears, or small masses of agglutinated tears. The tears are usually small, 5 to 10 millimetres in diameter, and of a yellowish or orange-brown colour; the surface is often rough and dirty, and, though hard in cold weather, the tears soften between the fingers. Internally they are usually pale yellowish in colour and opaque, though sometimes translucent and bluish-green. The drug has an unpleasant bitter taste, and characteristic, somewhat aromatic, odour. It is distinguished from ammoniacum by being more readily softened as well as by its distinctive odour and by the presence in it of umbelliferone. Good galbanum yields about 10 per cent. of moisture, about 40 per cent. of substances insoluble in alcohol, and leaves about 7 per cent. of ash. Galbanum is often imported in lumps consisting of yellowish or bluish-green tears embedded in a brownish resinous mass; this variety is excluded by the B.P. description, but it has been asserted that it is preferable to the tears, inasmuch as it contains more volatile oil. The variety of galbanum known as Persian is now seldom seen on the market; it is softer than Levant, has a more terebinthinate odour, and contains fruits and fragments of stalks instead of slices of the root.
Constituents.—The gum-resin contains from 5 to 10 per cent. of volatile oil, about 60 per cent. of resin, and 20 per cent. of gum, together with moisture, mineral constituents, and impurities. Among the latter, circular slices of the root are regularly found in the galbanum of commerce. The volatile oil appears to vary in its characters according to the age, etc., of the drug from which it is obtained, that from Levant galbanum being laevorotatory, and that from Persian dextrorotatory. The resin consists of umbelliferone combined with galbaresinotannol, the drug yielding as much as 20 per cent. of umbelliferone; traces of this substance are also present uncombined. When boiled with solution of potassium hydroxide it yields umbellic (dioxycinnamic) acid.
Action and Uses.—Galbanum is employed as a stimulant expectorant in chronic bronchitis. It is used externally in the form of plaster (see Emplastrum Galbani) for inflammatory swellings. On account of its disagreeable taste and odour galbanum is administered in pill form, generally with asafetida as Pilula Galbani Composita, a combination which is especially useful in some hysterical conditions, and in chronic bronchitis, when accompanied by profuse expectoration.
Dose.—3 to 10 decigrams (5 to 15 grains).
- Emplastrum Galbani, B.P., 1885.—GALBANUM PLASTER.
- Galbanum, 9; ammoniacum, 9; yellow beeswax, 9; lead plaster, 72. Melt the galbanum and ammoniacum together; then add the beeswax and lead plaster, previously melted together, and mix. Galbanum plaster is a mild irritant and a favourite application to inflamed joints to reduce swelling.
- Pilula Galbani Composita, B.P.—COMPOUND PILL OF GALBANUM. Syn.—Compound Pill of Asafetida.
- Galbanum, 2; asafetida, 2; myrrh, 2; syrup of glucose, 1, or a sufficient quantity. Stir together on a water-bath until the mass is of uniform consistence. Dose.—4 to 8 grains.
- Tablettae Galbani Compositae), B.P.C.—COMPOUND GALBANUM TABLETS. Syn.—Compound Asafetida Tablets.
- Each tablet corresponds to 5 grains of the official pill mass and contains about 1 ½ grains each of galbanum, asafetida and myrrh. Dose.—1 or 2 tablets.