Rubus is the dried bark of the rhizome of Rubus villosus, Anon, R. nigrobaccus, Bailey, or of R. cuneifolius, Pursh. (N.O. Rosaceae), species indigenous to the United States. The drug is official in the U.S.P. It occurs in elongated, tough, flexible quills, from 3 to 6 millimetres in diameter, or in similar bands, the bark 1 to 2 millimetres thick, dark brownish externally and yellow or pale brownish internally, with a tough, fibrous fracture, and splitting readily. The bark is odourless, hut has a strongly astringent and bitterish taste.
Constituents.—The chief constituent of rubus is tannin, which can be extracted readily by boiling water or diluted alcohol.
Action and Uses.—Rubus has an astringent action, and in the United States is a favourite domestic remedy for diarrhoea. It is administered usually in 1 to 2-ounce doses of a decoction prepared by boiling 1 of the drug with 30 of water until the liquid is reduced to 20, or as a fluidextract or syrup.
Dose.—1 to 2 grammes (15 to 30 grains).
- Fluidextractum Rubi, U.S.P.—FLUIDEXTRACT OF RUBUS. Syn.—Extractum Rubi Fluidum.
- Rubus, in No 40 powder, is exhausted with alcohol (49 per cent.), by macero-percolation, and the volume of the product adjusted so that 1 fluid part represents 1 part of the drug. Average dose.—1 mil (1.5 minims).
- Syrupus Rubi, U.S.P.—SYRUP OF RUBUS.
- Prepared by mixing 1 of fluidextract of rubus with 3 of syrup, U.S.P. Average dose.—4 mils (1 fluid drachm).