Podophylli Rhizoma, B.P., Podophyllum Rhizome.
Podophyllum rhizome (Podophyllum, U.S.P.), May Apple or Mandrake, is obtained from Podophyllum Peltatum, Linn. (N.O. Berberideae), a herb indigenous to the Eastern United States and Canada. The rhizome is collected late in the summer and dried with the roots attached. It is usually cut into pieces a few inches in length. The rhizome occurs in nearly cylindrical pieces, from 6 to 18 centimetres long, and 5 to 8 millimetres thick, Its surface is smooth, or slightly wrinkled longitudinally, and of a dark reddish-brown colour. The rhizome is enlarged at intervals of about 5 centimetres, and bears on the upper surface a concave scar, surrounded by circular leaf scars; at the same part, but on the under surface of the rhizome, are the lighter scars of the roots. Pieces of the rhizome break with a short fracture, the interior being white and starchy or yellowish and horny. The odour of the drug is characteristic, and its taste is bitter and acrid. On incineration, the drug yields about 3 per cent. of ash.
Constituents.—The chief constituents of podophyllum rhizome are a neutral crystalline substance named podophyllotoxin (0.2 to 1 per cent.) and an amorphous resin, podophylloresin, both of which are purgative. The drug also contains picropodophyllin, quercetin, and starch. Podophyllotoxin, C15H14O6, melts at 117°; alkalies convert it into the salt of an unstable, gelatinous acid, podophyllic acid; this readily loses water and furnishes crystalline picropodophyllin (melting-point, 227°), which is isomeric with podophyllotoxin, and probably the lactone of podophyllic acid. A concentrated alcoholic tincture poured into acidified water deposits the resinous mixture known as "podophyllin." Of this the drug yields from 2 to 6 per cent.
Action and Uses.—Podophyllum rhizome is used almost entirely in the form of podophyllum resin (see Podophylli Resina).
Dose.—2 to 6 decigrams (3 to 10 grains).
- Fluidextractum Podophylli, U.S.P.—FLUIDEXTRACT OF PODOPHYLLUM.
- Podophyllum rhizome, in No. 40 powder, 100; alcohol (76 per cent.), sufficient to produce 100. Average Dose.—3 decimils (0.3 milliliters) (8 minims).