Preparation. - The resin is dissolved out of the powdered root by exhausting with spirit, the greater part of which is recovered by distillation, and the remainder holding the resin in solution is poured into water slightly acidulated with hydrochloric acid, when the resin is precipitated as a fine powder, as it is insoluble in water. The resin itself consists to a great extent of a fatty and resinous acid, and subsides more quickly in acidulated than in pure water. It is afterwards washed and dried.

Characters and Solubility. - A pale greenish-brown amorphous powder, soluble in rectified spirit and in ammonia; precipitated from the former solution by water, from the latter by acids. Almost entirely soluble in pure ether.

Composition. - It consists chiefly of a fatty and resinous acid having little physiological action, and two active substances, podophyllotoxin and picropodophyllin, the former being much the more powerful.

Dose. - 1/8 to 1/2 grain.

B.P. Preparation.

Dose.

Tinctura Podophylli (1 gr. of resin in 1 fl. dr.) ...........................

15 min. to 1 fl. dr.

Physiological Action. - The resin is the part chiefly employed. It acts as a drastic purgative, increasing the secretions of the intestinal mucous membrane, and of the liver (p. 403). It acts on the bowels, when injected subcutaneously as well as when introduced into the intestinal canal. Like many other hepatic stimulants, it does not increase the secretion of bile so much when it acts as a purgative (p. 403).

Uses. - It is used in cases of biliousness associated with dark stools (Ringer). When the stools are pale, mercurial pill is usually employed. It is often employed in combination with other purgatives, such as colocynth, aloes, or rhubarb. It is useful in congestion of the liver, and of the portal circulation, in ague with congested liver, and in sick headache with biliousness. Its action is uncertain and it frequently causes griping.

Externally it acts as an irritant; if incautiously handled, it often produces conjunctivitis.