Foeniculi Fructus, B.P. Fennel Fruit.
Related entry: Oil of Fennel
Fennel fruit (Foeniculum, U.S.P.; Fennel) is the product of Foeniculum capillaceum, Gilib. (N.O. Umbelliferae), a plant indigenous to the countries bordering the Mediterranean, but cultivated for medicinal use in the South of France, Saxony, Russia, etc. The dried ripe fruit, collected from cultivated plants is alone official in the B.P. The U.S.P. describes the fruit as "nearly ripe." The chief commercial varieties are Saxon, Galician, and Russian; these varieties may be regarded as suitable for pharmaceutical use. The fruits are from 4 to 6 millimetres (Galician and Russian) or 8 to 10 millimetres (Saxon) in length, and about 3 millimetres in diameter, greenish or yellowish-brown in colour, oblong in shape and capped by a stylopod. They are glabrous, and each is composed of two mericarps united and attached to a pedicel. Each mericarp has five prominent primary ridges, and in transverse section exhibits six large oil glands (vittae) about 0.2 millimetre wide. The odour is aromatic; the taste, aromatic, sweet, and agreeable. The powder may be identified by the presence of large parenchymatous cells with spiral or reticulate thickening, and by the characteristic inner epidermis of the pericarp, which consists of groups of about six narrow elongated cells arranged with their long axes parallel to one another, but oblique to the long axes of other similar groups of cells; there are no hairs; the cells of the endosperm have rather thick walls and contain small cluster-crystals of calcium oxalate. The drug may yield about 8 per cent. of ash. The French sweet fennel yields only about 2 per cent. of oil, which is practically free from fenchone. French fennel resembles the Saxon in appearance, but has a decidedly sweet anise odour, due to a comparatively large proportion of anethol. Japanese fennel is small (3 to 4 millimetres in length) and has an odour intermediate between that of the French and Saxon varieties. These are less suitable for pharmaceutical use. Exhausted or partially exhausted fennel is deficient in oil, and therefore deficient in odour; it may often be distinguished by its darker colour.
Constituents.—The chief constituent of fennel fruit is from 4 to 5 per cent. of a volatile oil which contains anethol and fenchone.
Action and Uses.—Fennel fruit is aromatic and carminative; it is used in the form of powder with purgatives, as in Pulvis Glycyrrhizae Compositus, to allay their tendency to griping. Fennel water has properties similar to those of anise and dill water; mixed with sodium bicarbonate and syrup, these waters constitute the domestic "gripe water," used to correct the flatulence of infants. Volatile oil of fennel has these properties in concentration, and may be added to pills or given on sugar.
- Aqua Foeniculi, B.P.—FENNEL WATER.
- Fennel fruit, 10; water, 200. Add the fruit to the water and distil 100. Fennel water is used as an aromatic carminative, especially in the intestinal colic of children. Dose.—30 to 60 mils (1 to 2 fluid ounces).