Mezereon bark (Mezereum, U.S.P.) is obtained from Daphne Mezereum, Linn., D. Laureola, Linn., or D. Gnidium, Linn. (N.O. Thymelaceae). D. Mezereum and D. Laureola are indigenous to Britain, D. Gnidium to Southern Europe and Algeria. The commercial drug is chiefly derived from D. Mezereum and D. Gnidium. The bark is stripped from the entire plant, in the spring and dried; it is often made up into small rolls or bundles (D. Gnidium), but much is sold loose. It occurs in long, thin, flattened or quilled, very tough and flexible fibrous strips, about 0.5 to 2 centimetres wide, from which the papery cork easily separates. The cork of D. Mezereum is olive-brown or yellowish in colour, and bears scattered rounded scars of buds and leaves; inner surface whitish and silky. The bark of D. Gnidium may be distinguished by its dark purplish-brown colour; the scars resemble those of D. Mezereum. D. Laureola has a purplish-grey cork, and the scars are pointed-oval in shape, and crowded at intervals. The drug is odourless, or nearly so, but possesses a persistent, burning, acrid taste. It yields about 3 per cent. of ash.
Constituents.—The chief constituent of mezereon bark is a greenish-brown, amorphous, acrid resin (mezerein), which readily changes into a bitter, acid resin (mezereic acid). The crystalline bitter glucoside daphnin, fixed oil, and a substance resembling euphorbone have also been isolated, but none of these is acrid.
Action and Uses.—Mezereon bark is not much used internally. It was formerly employed in the treatment of syphilis and is still an ingredient of Liquor Sarsae Compositus Concentratus. Applied externally, it is stimulant and vesicant, the fresh bark especially so. In some parts of Europe, a small piece of the fresh bark is moistened with vinegar and applied to the skin to produce a blister. An ethereal extract of mezereon was formerly official in the B.P., and was used as an ingredient of compound mustard liniment, for its stimulating and vesicating properties.
Dose.—3 to 6 decigrams (5 to 10 grains).
- Extractum Mezerei Ethercum, B.P., 1885.—ETHEREAL EXTRACT OF MEZEREON.
- Mezereon bark, cut small, 1 pound; rectified spirit, 8 pints; ether (specific gravity, 0.735), 1 pint. Add 6 pints of the spirit to the drug and macerate for three days, with frequent agitation; then strain, press, and repeat the operation with the remainder of the spirit. Mix the strained liquids, filter, remove the greater part of the spirit by distillation, and evaporate the residue to a soft extract. Next macerate the extract with the ether for twenty-four hours, shaking frequently; then decant the ethereal solution, recover part of the ether by distillation, and evaporate the residue to the consistence of a soft extract.
- Fluidextractum Mezerei, U.S.P.—FLUIDEXTRACT OF MEZEREUM.
- Mezereum, in No. 30 powder, 100; alcohol (76 per cent.), sufficient to produce 100.
The British Pharmaceutical Codex, 1911, was published by direction of the Council of the Pharmaceutical Society of Great Britain.