This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
1. Bitter Orange-Peel. Aurantii Amari Cortex. U. S - Aurantii Cortex. Br.
2. Sweet Orange-Peel. Aurantii Dulcis Cortex. U.S.
This is the rind of the orange, of which there are two kinds, derived from different species or varieties of Citrus; the one, Citrus vulgaris, the bitter, or Seville Orange; the other, Citrus Auranlium, or common sweet orange. Both are natives of India and China, but cultivated generally in tropical latitudes.
Sensible and Chemical Properties. The rind consists of two parts, the outer, which is coloured, and the inner, white and spongy. In the former exclusively reside the virtues of the medicine; and sometimes it is only the outer coating that is kept in the shops.
The bitter orange-peel, which is imported into the United States, is generally, as found in the shops, in vertical slices, though sometimes in thin parings, as if cut off from the orange with a knife, like the paring of an apple. In the former, the white inner portion is retained, in the latter is wanting. The peel has an agreeable characteristic odour, and a bitter aromatic taste.
The sweet orange-peel is also in vertical slices, usually thinner than the other variety, with the same characteristic odour, and warm, aromatic taste, but without bitterness.
In both, there is a peculiar volatile oil, which resides in distinct cells in the rind, and may be obtained by pressure when the rind is fresh. In addition to this, there is, in the bitter orange-peel, a principle to which it owes its bitterness, but which has not been fully investigated. Water and alcohol extract all the virtues of the peel.
Kept in moist places, orange-peel is apt to spoil, in consequence of the attraction of the inner spongy portion for moisture. The parings keep better.
Bitter orange-peel has the virtues of the aromatics combined with those of the simple bitters; the sweet variety is simply aromatic. Both are mild, and the tonic powers of the bitter are feeble. They are used almost exclusively in connection with other medicines, to render them less disagreeable to the taste, and mere acceptable to the stomach. It is usually with tonics that they are associated, as with Peruvian bark, gentian, etc.; or with purgatives, as rhubarb. When with the former, the bitter variety should be preferred; when with the latter, the sweet.
Orange-peel is not altogether without danger if abused. I knew of a case in which death occurred, in an infant, from swallowing considerable quantities of the fresh rind. The child died with symptoms of obstruction of the bowels; and, on examination after death, the rind was found impacted in the intestines. But I am by no means certain that the oil contained in the rind may not have acted injuriously. In Buchner's Neues Repertorium (ii. 440-5) are given the results of numerous observations, by Dr. A. Imbert-Gourbeyre, of the effects of the oil of bitter orange, among which are mentioned headache, painful vision, busing in the ears, oppression of chest, loss of sleep, and phenomena similar to those of epileptic spasms. (Cent. Blatt, 15 Feb. 1854, s. 128).
The peel is rarely given in substance. The dose of the powder might be from ten grains to a drachm.
The infusion is generally preferred. When used as an adjuvant or corrective of other medicines, the peel is most commonly employed in this form; half an ounce of it, well bruised, being added to a pint of the liquid. When the other ingredients are prepared in decoction, the peel should not be added till the end of the boiling. The British Pharmacopoeia directs an Infusion (Infusum Aurantii, Br.), prepared with half an ounce of orange-peel, and an imperial half-pint or ten fluidounces of water. This may be used for the general purposes of the aromatics (see page 315), in wineglassful doses.
A Tincture (Tinctura Aurantii, Br.) is directed by the British Pharmacopoeia to be prepared from bitter orange-peel, and may be used to qualify the taste and action of various liquid preparations.
A Syrup (Syrupus Aurantii Corticis, U. S.; Syrupus Aurantii, Br.), prepared by the U. S. Pharmacopoeia from the sweet peel, by the British from a tincture of the bitter, is a very grateful addition to other medicines. The U. S. preparation is much to be preferred.
A Confection (Confectio Aurantii Corticis, U. S.) is prepared by separating the rind by a grater, and incorporating the coarse powder thus made with sugar. It is used chiefly as a vehicle for tonic and purgative medicines in powder.
An Aromatic Water (Aurantii Florum Aqua, U. S.; Aurantii Aqua, Br.), made by distilling water from the fresh flowers, is occasionally used as a perfume in the sick room.
Other products of the genus Citrus are occasionally used in medicine for their aromatic properties. Among these are the following.