Cera Alba, B.P. White Beeswax. Cera Flava, B.P.
CERA ALBA, B.P.
Related entry: Honey
White beeswax (White Wax, U.S.P.) is the wax separated from the honeycomb of the hive bee, Apis mellifica, Linn. (Order Hymenoptera), bleached by exposing it in thin layers to the action of the air, sunlight, and moisture. The process may also be effected by the aid of chemicals, such as potassium bichromate and sulphuric acid, but wax so prepared is excluded by the B.P. description, although much of the white wax of commerce has been prepared in this way. It occurs in hard, nearly white, translucent masses, and may be tested in the same manner as yellow beeswax, Specific gravity, 0.958 to 0.970 (about 0.950 to 0.960 at 25°). Melting-point, 61° to 64°.
Use.—White beeswax is used in the preparation of emollient ointments, and occasionally to raise the melting-point of suppositories. The ointments so prepared, such as Unguentum Aquae Rosae and Unguentum Cetacei, are liable to become rancid.
- Cera Aseptica, B.P.C.—ASEPTIC WAX.
- White beeswax, 87.5; almond oil, 12.5; salicylic acid, 1. Used to arrest haemorrhage from cranial bones by smearing it over the bleeding surface; and for similar surgical purposes.
- Ceratum, U.S.P.—CERATE.
- White wax, 30; soft paraffin, white, 20; benzoated lard, 50.
- Liquor Cerae Aethereus, B.P.C.—ETHEREAL WAX SOLUTION. 1 in 4.
- Unguentum Durum Album, B.P.C.—HARD WHITE OINTMENT.
- White beeswax, 1; hydrous wool fat, 1.
CERA FLAVA, B.P.
Yellow beeswax (Yellow Wax, U.S.P.) is a secretion formed by the hive bee, Apis mellifica, Linn. (Order Hymenoptera), and used by the insect to form the walls of the cells of the honeycomb. After the extraction of the honey the wax is melted with water, separated, and strained. When obtained as described, beeswax is a yellowish or brownish-yellow solid, firm, and not unctuous to the touch, breaking with a dull, granular fracture, and having an agreeable honey-like odour. Specific gravity, 0.958 to 0.970 (about 0.951 to 0.960 at 25°). Melting-point, 61° to 64°. The official ranges of specific gravity (0.960 to 0.970) and melting-point (62.5° to 63.9°) are regarded as being rather too narrow. Beeswax should be readily and entirely soluble in hot oil of turpentine. It is officially stated that it should not yield more than 3 per cent. to cold alcohol, nor more than 50 per cent. to cold ether (specific gravity, 0.735), and nothing to water. The acid number should not exceed 17.9; the saponification number varies between 90 and 96, and the ester number between 69 and 76. The chief adulterants of beeswax are paraffin, stearic acid, tallow, carnauba wax, and possibly also starch, soap, and resin. Paraffin lowers the specific gravity and the saponification number of the wax; it may also be detected by heating with strong sulphuric acid, which chars the wax completely and leaves the paraffin unaltered, so that the latter may be dissolved out of the charred mass by ether. Stearic acid, tallow, and saponifiable fats and resins may be detected by boiling the wax with a saturated solution of sodium carbonate, filtering and acidifying with hydrochloric acid, when no precipitate should be produced. Colophony would also be soluble in cold alcohol, to which wax should yield not more than 3 per cent. Soap may be detected by the turbidity produced on acidifying the cooled and filtered decoction, and starch by the iodine test. Japan wax, obtained from the berries of various species of Rhus (N.O. Anacardiaceae) is a pale yellow solid, which can be kneaded between the fingers. Specific gravity, 0.975 to 0.993. It consists chiefly of palmitin and free palmitic acid. Carnauba wax, an exudation from the leaves of Copernicia cerifera, Mart. (N.O. Palmae), occurs in commerce as a whitish solid. Specific gravity, 0.990 to 0.999. It consists chiefly of myricyl cerotate, with small quantities of free cerotic acid and myricyl alcohol.
Constituents.—Beeswax contains about 80 per cent. of myricin or melissyl palmitate, C15H31COOC30H61, about 15 per cent. of cerotic acid, C26H56COOH, the aromatic body cerolein, and probably some melissyl stearate.
Use.—Yellow beeswax is used in pharmacy in the preparation of plasters, and of ointments in which its yellow colour is unobjectionable. Such ointments become rancid much less rapidly than when prepared with white beeswax. An emulsion prepared by mixing melted beeswax with an equal weight of powdered gum acacia in a warm mortar, and then adding water, is used as a demulcent for coughs.
Dose.—3 to 20 decigrams (5 to 30 grains).
- Unguentum Durum Flavum, B.P.C.—HARD YELLOW OINTMENT.
- Yellow beeswax, 1; wool fat, 1.